Optimization of Collimator Jaw Locations for the LHC

CERN Document Server

Kaltchev, D I; Servranckx, R V; Jeanneret, J B

1996-01-01

A highly effective collimation scheme is required in the LHC to limit heating of the vacuum chamber and superconducting magnets by protons either uncaptured at injection or scattered from the collision points. The proposed system would consist of one set of primary collimators followed by three sets of secondary collimators downstream to clean up protons scattered from the primaries. Each set of collimators would consist of four pairs of jaws - horizontal, vertical, and 45 o and 135 o skew. A study is reported of the optimization of the longitudinal positions of these jaws with the aim of minimizing the maximum betatron amplitudes of protons surviving the collimation system. This is performed using an analytical representation of the action of the jaws and is confirmed by tracking. Significant improvement can be obtained by omitting inactive jaws and adding skew jaws.

Self-aligning fixture used in lathe chuck jaw refacing

Science.gov (United States)

Linn, C. C.

1965-01-01

Self-aligning tool positions and rigidly holds lathe chuck jaws for refacing and truing of the clamping surface. The jaws clamp the fixture in the manner of clamping a workpiece. The fixture can be modified to accommodate four-jawed checks.

Monte Carlo-based simulation of dynamic jaws tomotherapy

Energy Technology Data Exchange (ETDEWEB)

Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S. [Department of Molecular Imaging, Radiotherapy and Oncology, Universite Catholique de Louvain, 54 Avenue Hippocrate, 1200 Brussels, Belgium and Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); TomoTherapy Inc., 1240 Deming Way, Madison, Wisconsin 53717 (United States); 21 Century Oncology., 1240 D' onofrio, Madison, Wisconsin 53719 (United States); TomoTherapy Inc., 1240 Deming Way, Madison, Wisconsin 53717 and Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Department of Radiotherapy and Oncology, Universite Catholique de Louvain, St-Luc University Hospital, 10 Avenue Hippocrate, 1200 Brussels (Belgium)

2011-09-15

Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is

Monte Carlo-based simulation of dynamic jaws tomotherapy

International Nuclear Information System (INIS)

Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S.

2011-01-01

Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is greater than 30% of the prescription dose (gamma analysis

Radiologic appearance of primary jaw lesions in children

Energy Technology Data Exchange (ETDEWEB)

Gupta, Malini; Kaste, Sue C. [Department of Diagnostic Imaging, St. Jude Children' s Research Hospital, Memphis, TN (United States); Hopkins, Kenneth P. [Department of Surgery, Division of Dentistry, St. Jude Children' s Research Hospital, Memphis, TN (United States)

2002-03-01

Background: The jaw (an unusual site of primary tumors in children and adolescents) has lesions often found incidentally by dentists on routine panoramic radiographs or during examination of a child who has swelling or tooth pain. Objective: This pictorial seeks to familiarize pediatric radiologists with the radiographic appearance of a variety of primary jaw lesions. Materials and methods: We retrospectively searched institutional records for cases of primary jaw lesions in children and adolescents. Jaw lesions were characterized as: I, well-circumscribed radiolucent lesions; II, lesions with mixed or variable appearance; III, poorly circumscribed radiolucent lesions; and IV, radiopaque lesions. Results: Although most oral and maxillofacial lesions in children are benign, a broad spectrum of tumors was identified; lesions may occur in patients with unrelated prior malignancy. Conclusion: Because radiologic studies may identify jaw lesions and direct further care, familiarity with the appearance of these entities is prudent. (orig.)

The relationships among jaw-muscle fiber architecture, jaw morphology, and feeding behavior in extant apes and modern humans.

Science.gov (United States)

Taylor, Andrea B; Vinyard, Christopher J

2013-05-01

The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function. While there have been numerous comparative studies of hominoid and hominin craniodental and mandibular morphology, little is known about hominoid jaw-muscle fiber architecture. We present novel data on masseter and temporalis internal muscle architecture for small- and large-bodied hominoids. Hominoid scaling patterns are evaluated and compared with representative New- (Cebus) and Old-World (Macaca) monkeys. Variation in hominoid jaw-muscle fiber architecture is related to both absolute size and allometry. PCSAs scale close to isometry relative to jaw length in anthropoids, but likely with positive allometry in hominoids. Thus, large-bodied apes may be capable of generating both absolutely and relatively greater muscle forces compared with smaller-bodied apes and monkeys. Compared with extant apes, modern humans exhibit a reduction in masseter PCSA relative to condyle-M1 length but retain relatively long fibers, suggesting humans may have sacrificed relative masseter muscle force during chewing without appreciably altering muscle excursion/contraction velocity. Lastly, craniometric estimates of PCSAs underestimate hominoid masseter and temporalis PCSAs by more than 50% in gorillas, and overestimate masseter PCSA by as much as 30% in humans. These findings underscore the difficulty of accurately estimating jaw-muscle fiber architecture from craniometric measures and suggest models of fossil hominin and hominoid bite forces will be improved by incorporating architectural data in estimating jaw-muscle forces. Copyright © 2013 Wiley Periodicals, Inc.

Jaw-Dropping: Functional Variation in the Digastric Muscle in Bats.

Science.gov (United States)

Curtis, Abigail A; Santana, Sharlene E

2018-02-01

Diet and feeding behavior in mammals is strongly linked to the morphology of their feeding apparatus. Cranio-muscular morphology determines how wide, forcefully, and quickly the jaw can be opened or closed, which limits the size and material properties of the foods that a mammal can eat. Most studies of feeding performance in mammals have focused on skull form and jaw muscles involved in generating bite force, but few explore how jaw abduction is related to feeding performance. In this study, we explored how the morphology of the digastric muscle, the primary jaw abducting muscle in mammals, and its jaw lever mechanics are related to diet in morphologically diverse noctilionoid bats. Results showed that insectivorous bats have strong digastric muscles associated with proportionally long jaws, which suggests these species can open their jaws quickly and powerfully during prey capture and chewing. Short snouted frugivorous bats exhibit traits that would enable them to open their jaws proportionally wider to accommodate the large fruits that they commonly feed on. Our results support the hypothesis that digastric muscle and jaw morphology are correlated with diet in bats, and that our results may also apply to other groups of mammals. Anat Rec, 301:279-290, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Corrective Jaw Surgery

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Full Text Available ... in face, mouth and jaw surgery.™ What We Do Who We Are News Videos Contact Find a Surgeon What We Do Anesthesia Anesthesia Oral and maxillofacial surgeons are extensively ...

Effects of Jaw Clenching and Jaw Alignment Mouthpiece Use on Force Production During Vertical Jump and Isometric Clean Pull.

Science.gov (United States)

Allen, Charles R; Fu, Yang-Chieh; Cazas-Moreno, Vanessa; Valliant, Melinda W; Gdovin, Jacob R; Williams, Charles C; Garner, John C

2018-01-01

Allen, CR, Fu, Y-C, Cazas-Moreno, V, Valliant, MW, Gdovin, JR, Williams, CC, and Garner, JC. Effects of jaw clenching and jaw alignment mouthpiece use on force production during vertical jump and isometric clean pull. J Strength Cond Res 32(1): 237-243, 2018-This study examined the effects of jaw clenching, a self-adapted, jaw-repositioning mouthpiece on force production during maximum countermovement vertical jump and maximum isometric midthigh clean pull assessments in an attempt to determine any ergogenic effect attributable to clenching, jaw-repositioning mouthpiece use, or the combination of both. Thirty-six male subjects performed vertical jump and isometric clean pull assessments from a force platform under various mouthpiece and clench conditions. A 3 × 2 (mouthpiece × clench) repeated-measures analysis of variance was conducted to analyze each of the following force production variables for both assessments: peak force, normalized peak force, and rate of force development. In addition, jump height was analyzed for the vertical jump. Results revealed improvements in peak force (F1,35 = 15.84, p ≤ 0.001, (Equation is included in full-text article.)= 0.31), normalized peak force (F1,35 = 16.28, p ≤ 0.001, (Equation is included in full-text article.)= 0.32), and rate of force development (F1,35 = 12.89, p = 0.001, (Equation is included in full-text article.)= 0.27) during the isometric clean pull assessment when participants maximally clenched their jaw, regardless of mouthpiece condition. There were no statistically significant differences in jump height, peak force, normalized peak force, or rate of force development during the vertical jump for any treatment condition. This study supports previous research demonstrating that the implementation of remote voluntary contractions such as jaw clenching can lead to concurrent activation potentiation and a resulting ergogenic effect during activities involving and requiring high-force production.

The virtual craniofacial patient: 3D jaw modeling and animation.

Science.gov (United States)

Enciso, Reyes; Memon, Ahmed; Fidaleo, Douglas A; Neumann, Ulrich; Mah, James

2003-01-01

In this paper, we present new developments in the area of 3D human jaw modeling and animation. CT (Computed Tomography) scans have traditionally been used to evaluate patients with dental implants, assess tumors, cysts, fractures and surgical procedures. More recently this data has been utilized to generate models. Researchers have reported semi-automatic techniques to segment and model the human jaw from CT images and manually segment the jaw from MRI images. Recently opto-electronic and ultrasonic-based systems (JMA from Zebris) have been developed to record mandibular position and movement. In this research project we introduce: (1) automatic patient-specific three-dimensional jaw modeling from CT data and (2) three-dimensional jaw motion simulation using jaw tracking data from the JMA system (Zebris).

Crocodile jaw sign

Directory of Open Access Journals (Sweden)

Brij Sharma

2016-01-01

Full Text Available This teaching image highlights the CT abdominal imaging finding of 'crocodile jaw sign' which should raise concern about the presence of an incomplete annular pancreas which causes partial encasement of the duodenum.

Corrective Jaw Surgery

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Full Text Available AAOMS - Oral and maxillofacial surgeons. The experts in face, mouth and jaw surgery.™ What We Do Who ... surgeons surgically treat the soft tissues of the face, mouth and gums to improve function, appearance and ...

Corrective Jaw Surgery

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Full Text Available ... Oral and maxillofacial surgeons. The experts in face, mouth and jaw surgery.™ What We Do Who We ... surgically treat the soft tissues of the face, mouth and gums to improve function, appearance and oral ...

Corrective Jaw Surgery

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Full Text Available ... It can also invite bacteria that lead to gum disease. Click here to find out more. Who We ... It can also invite bacteria that lead to gum disease. Click here to find out more. Corrective Jaw ...

Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape

Science.gov (United States)

Taylor, Andrea B.; Vinyard, Christopher J.

2009-01-01

Cebus apella is renowned for its dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between the tufted capuchin (C. apella; n = 12 ) and two “untufted” capuchins (C. capuchinus, n = 3; C. albifrons, n = 5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that C. apella exhibits architectural properties of their jaw muscles that facilitate relatively large forces, including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P0). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter, whole masseter, and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P0. As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in C. apella primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear

Specification of jaw identity by the Hand2 transcription factor

Science.gov (United States)

Funato, Noriko; Kokubo, Hiroki; Nakamura, Masataka; Yanagisawa, Hiromi; Saga, Yumiko

2016-01-01

Acquisition of the lower jaw (mandible) was evolutionarily important for jawed vertebrates. In humans, syndromic craniofacial malformations often accompany jaw anomalies. The basic helix-loop-helix transcription factor Hand2, which is conserved among jawed vertebrates, is expressed in the neural crest in the mandibular process but not in the maxillary process of the first branchial arch. Here, we provide evidence that Hand2 is sufficient for upper jaw (maxilla)-to-mandible transformation by regulating the expression of homeobox transcription factors in mice. Altered Hand2 expression in the neural crest transformed the maxillae into mandibles with duplicated Meckel’s cartilage, which resulted in an absence of the secondary palate. In Hand2-overexpressing mutants, non-Hox homeobox transcription factors were dysregulated. These results suggest that Hand2 regulates mandibular development through downstream genes of Hand2 and is therefore a major determinant of jaw identity. Hand2 may have influenced the evolutionary acquisition of the mandible and secondary palate. PMID:27329940

Jaw muscles in older overdenture patients.

Science.gov (United States)

Newton, James P; McManus, Frank C; Menhenick, Stephen

2004-03-01

To determine, using computer tomography (CT), whether the retention of a small number of teeth in the older adult used to support overdentures could affect the cross-sectional area (CSA) and X-ray density of two jaw closing muscles. Cross-sectional study of a group of older patients subdivided into dentate, edentulous and those wearing overdentures supported by two to five teeth. The sample consisted of 24 subjects aged 55-68 years. CSA and X-ray density of two jaw closing muscles, masseter and medial pterygoid were measured and evaluated using CT. There were no significant differences between left and right jaw muscles, but the CSA of the masseter muscles were significantly larger than the medial pterygoid muscles. The CSA of the masseter and medial pterygoid muscles was significantly smaller in edentulous subjects compared with dentate subjects but no significant difference was observed between subjects wearing overdentures and those with a natural dentition. No significant differences were observed with the X-ray density between different muscles or dental states. The retention of a small number of teeth in the older adult used to support overdentures appears to sustain the CSA of two jaw closing muscles and therefore could enhance these patients' masticatory ability compared with those who were edentulous.

Multiple myeloma of the jaw: A case report

Directory of Open Access Journals (Sweden)

Shubhasini A Raghavan

2014-01-01

Full Text Available Multiple myeloma is a systemic B-cell lymphoproliferative disease that causes osteolytic lesions in the vertebra, ribs, pelvic bone, skull and jaw. Rarely jaw lesions are seen as the first sign in multiple myeloma. This is a case report with follow up of a 57-year-old female patient, previously treated for osteoporosis, who presented with a swelling of the jaw. On radiographic examination, she was found to have osteolytic lesions in the mandible and skull bones. These conventional aids led to the diagnosis of multiple myeloma thereby proving that the osteoporotic lesions were a part of the spectrum of multiple myeloma. The patient underwent chemotherapy and is currently on follow-up. This case report emphasizes the importance of early diagnosis of multiple myeloma in the jaw using readily available technologies and illustrates the contribution that oral assessment can provide.

[Size of lower jaw as an early indicator of skeletal class III development].

Science.gov (United States)

Stojanović, Zdenka; Nikodijević, Angelina; Udovicić, Bozidar; Milić, Jasmina; Nikolić, Predrag

2008-08-01

Malocclusion of skeletal class III is a complex abnormality, with a characteristic sagital position of the lower jaw in front of the upper one. A higher level of prognatism of the lower jaw in relation to the upper one can be the consequence of its excessive length. The aim of this study was to find the differences in the length of the lower jaw in the children with skeletal class III and the children with normal sagital interjaw relation (skeletal class I) in the period of mixed dentition. After clinical and x-ray diagnostics, profile tele-x-rays of the head were analyzed in 60 examinees with mixed dentition, aged from 6 to 12 years. The examinees were divided into two groups: group 1--the children with skeletal class III and group 2--the children with skeletal class I. The length of the lower jaw, upper jaw and cranial base were measured. The proportional relations between the lengths measured within each group were established and the level of difference in the lengths measured and their proportions between the groups were estimated. No significant difference between the groups was found in the body length, ramus and the total length of the lower jaw. Proportional relation between the body length and the length of the lower jaw ramus and proportional relation between the forward cranial base and the lower jaw body were not significantly different. A significant difference was found in proportional relations of the total length of the lower jaw with the total lengths of cranial base and the upper jaw and proportional relation of the length of the lower and upper jaw body. Of all the analyzed parameters, the following were selected as the early indicators of the development of skeletal class III on the lower jaw: greater total length of the lower jaw, proportional to the total lengths of cranial base and theupper jaw, as well as greater length of the lower jaw body, proportional to the length of the upper jaw body.

Multidetector computed tomography of jaw lesions in children and adolescents

International Nuclear Information System (INIS)

Gadodia, A.; Seith, A.; Sharma, R.; Choudhury, A.R.; Bhutia, O.; Gupta, A.

2010-01-01

Full text: Jaw lesions in paediatric and adolescent population are uncommon and can arise in odontogenic or non-odontogenic tissues. With the advent of multidetector computed tomography (MDCT), algorithm for imaging jaw lesions has changed dramatically. This pictorial essay describes the imaging appearance of commonly encountered jaw lesions in children and adolescents with emphasis on MDCT findings

Evolutionary Trends in the Jaw Adductor Mechanics of Ornithischian Dinosaurs.

Science.gov (United States)

Nabavizadeh, Ali

2016-03-01

Jaw mechanics in ornithischian dinosaurs have been widely studied for well over a century. Most of these studies, however, use only one or few taxa within a given ornithischian clade as a model for feeding mechanics across the entire clade. In this study, mandibular mechanical advantages among 52 ornithischian genera spanning all subclades are calculated using 2D lever arm methods. These lever arm calculations estimate the effect of jaw shape and difference in adductor muscle line of action on relative bite forces along the jaw. Results show major instances of overlap between taxa in tooth positions at which there was highest mechanical advantage. A relatively low bite force is seen across the tooth row among thyreophorans (e.g., stegosaurs and ankylosaurs), with variation among taxa. A convergent transition occurs from a more evenly distributed bite force along the jaw in basal ornithopods and basal marginocephalians to a strong distal bite force in hadrosaurids and ceratopsids, respectively. Accordingly, adductor muscle vector angles show repeated trends from a mid-range caudodorsal orientation in basal ornithischians to a decrease in vector angles indicating more caudally oriented jaw movements in derived taxa (e.g., derived thyreophorans, basal ornithopods, lambeosaurines, pachycephalosaurs, and derived ceratopsids). Analyses of hypothetical jaw morphologies were also performed, indicating that both the coronoid process and lowered jaw joint increase moment arm length therefore increasing mechanical advantage of the jaw apparatus. Adaptive trends in craniomandibular anatomy show that ornithischians evolved more complex feeding apparatuses within different clades as well as morphological convergences between clades. © 2016 Wiley Periodicals, Inc.

Jaw morphology and ontogeny in five species of Ophryothrocha

DEFF Research Database (Denmark)

Macnaughton, Martin Oliver; Worsaae, Katrine; Eibye-Jacobsen, Danny

2010-01-01

Detailed scanning electron microscopy of jaws within the genus Ophryotrocha (Dorvilleidae, Annelida) was performed on 871 jaw parts. The investigations resulted in new understandings of the ontogeny and jaw morphology and have systematic implications for the family. Five species in the genus (Oph...

Radiologic study of osteomyelitis of the jaw

International Nuclear Information System (INIS)

Lee, Young Ho; Ahn, Hyung Kyu

1980-01-01

The author studied age and sex distribution, etiology, affected site and several radiographic features of osteomyelitis of the jaw. And radiologic classification of osteomyelitis was also done. The material consisted of 118 males and 96 females examined and/or treated under the diagnosis of osteomyelitis during past 11 years (1970-1980.6) in SNUDH. The obtained results were as followings. 1. The incidence is the highest in teen ages (22.9%) and the lowest in seventies. (2.8%). 2. 199 cases were found in lower jaw, and 15 cases in upper jaw. 30.8% of all cases were located at the posterior portion of mandibular body comprising alveolar region. 3. Radiographic examination of osteolytic lesion revealed that 21.5% of all patients had periapical and alveolar bone rarefaction combined with osteoporotic changes were present at the same time. 4. Sclerotic lesions were seen in 62.2% of all patients and 21.5% of sclerotic lesion were diffuse or homogenous type. 5. Based on the radiologic study, classification of the osteomyelitis of the jaw was made. Localized osteolytic type was the highest in incidence (38.8%) and localized sclerotic type was the lowest (7.0%).

Lip line changes in Class III facial asymmetry patients after orthodontic camouflage treatment, one-jaw surgery, and two-jaw surgery: A preliminary study.

Science.gov (United States)

Lee, Gung-Chol; Yoo, Jo-Kwang; Kim, Seong-Hun; Moon, Cheol-Hyun

2017-03-01

To evaluate the effects of orthodontic camouflage treatment (OCT), one-jaw surgery, and two-jaw surgery on the correction of lip line cant (LLC) and to examine factors affecting the correction of LLC in Class III craniofacial asymmetry patients. A sample of 30 Class III craniofacial asymmetry patients was divided into OCT (n = 10), one-jaw surgery (n = 10), and two-jaw surgery (n = 10) groups such that the pretreatment LLC was similar in each group. Pretreatment and posttreatment cone-beam computed tomography scans were used to measure dental and skeletal parameters and LLC. Pretreatment and posttreatment measurements were compared within groups and between groups. Pearson's correlation tests and multiple regression analyses were performed to investigate factors affecting the amount and rate of LLC correction. The average LLC correction was 1.00° in the one-jaw surgery group, and in the two-jaw surgery group, it was 1.71°. In the OCT group it was -0.04°, which differed statistically significantly from the LLC correction in the other two groups. The amount and rate of LLC correction could be explained by settling of skeletal discrepancies or LLC at pretreatment with goodness of fit percentages of approximately 82% and 41%, respectively. Orthognathic surgery resulted in significant correction of LLC in Class III craniofacial asymmetry patients, while OCT did not.

Jaw tremor as a physiological biomarker of bruxism.

Science.gov (United States)

Laine, C M; Yavuz, Ş U; D'Amico, J M; Gorassini, M A; Türker, K S; Farina, D

2015-09-01

To determine if sleep bruxism is associated with abnormal physiological tremor of the jaw during a visually-guided bite force control task. Healthy participants and patients with sleep bruxism were given visual feedback of their bite force and asked to trace triangular target trajectories (duration=20s, peak force bruxism have abnormal jaw tremor when engaged in a visually-guided bite force task. Measurement of jaw tremor may aid in the detection/evaluation of bruxism. In light of previous literature, our results also suggest that bruxism is marked by abnormal or mishandled peripheral feedback from the teeth. Copyright © 2015. Published by Elsevier Ireland Ltd.

Dentoskeletal Overjet Measurements of Iraqi Adult Sample with Different Skeletal Jaw Relationship

Directory of Open Access Journals (Sweden)

Shahbaa A Mohammed

2017-11-01

Full Text Available Background: Many attempts were done to develop a method that actually reflects the sagittal jaw discrepancies without depending on cranial landmarks or dental occlusion. This study aimed to use one of these methods (dentoskeletal overjet for assessing the sagittal jaw relationships of Iraqi adult sample with different skeletal jaw relationship. Materials and method: The sample consisted of 90 digital true lateral cephalometric radiographs of Iraqi individuals with no previous orthodontic treatment. Cephalometric analysis of skeletal sagittal jaw relationship -ANB angle, beta angle and Wits appraisal- will perform for everyone to divide the sample into three groups (skeletal class I, II, III for which the dentoskeletal overjet will be measured. All cephalometric measurements will be done using AutoCAD. Results: Descriptive statistics of all variables with different skeletal jaw relationship showed that mean values of dentoskeletal overjet were (1.15, 3.91 and –2.01 mm for skeletal class I, class II and class III jaw relationship respectively. Accurate reproducibility of dentoskeletal overjet in assessment of jaw skeletal relationship showed that the lowest value was for assessment of skeletal class III jaw relationship (73% and the value for assessment of both skeletal class I and class II was higher (93%. Conclusions: Dentoskeletal overjet could be utilized in accurate representation of skeletal jaw relationship.

SU-F-E-19: A Novel Method for TrueBeam Jaw Calibration

Energy Technology Data Exchange (ETDEWEB)

Corns, R; Zhao, Y; Huang, V [Fraser Valley Cancer Centre - BC Cancer Agency, Surrey, BC (United Kingdom)

2016-06-15

Purpose: A simple jaw calibration method is proposed for Varian TrueBeam using an EPID-Encoder combination that gives accurate fields sizes and a homogeneous junction dose. This benefits clinical applications such as mono-isocentric half-beam block breast cancer or head and neck cancer treatment with junction/field matching. Methods: We use EPID imager with pixel size 0.392 mm × 0.392 mm to determine the radiation jaw position as measured from radio-opaque markers aligned with the crosshair. We acquire two images with different symmetric field sizes and record each individual jaw encoder values. A linear relationship between each jaw’s position and its encoder value is established, from which we predict the encoder values that produce the jaw positions required by TrueBeam’s calibration procedure. During TrueBeam’s jaw calibration procedure, we move the jaw with the pendant to set the jaw into position using the predicted encoder value. The overall accuracy is under 0.1 mm. Results: Our in-house software analyses images and provides sub-pixel accuracy to determine field centre and radiation edges (50% dose of the profile). We verified the TrueBeam encoder provides a reliable linear relationship for each individual jaw position (R{sup 2}>0.9999) from which the encoder values necessary to set jaw calibration points (1 cm and 19 cm) are predicted. Junction matching dose inhomogeneities were improved from >±20% to <±6% using this new calibration protocol. However, one technical challenge exists for junction matching, if the collimator walkout is large. Conclusion: Our new TrueBeam jaw calibration method can systematically calibrate the jaws to crosshair within sub-pixel accuracy and provides both good junction doses and field sizes. This method does not compensate for a larger collimator walkout, but can be used as the underlying foundation for addressing the walkout issue.

Orthodontic treatment-induced temporal alteration of jaw-opening reflex excitability.

Science.gov (United States)

Sasaki, Au; Hasegawa, Naoya; Adachi, Kazunori; Sakagami, Hiroshi; Suda, Naoto

2017-10-01

The impairment of orofacial motor function during orthodontic treatment needs to be addressed, because most orthodontic patients experience pain and motor excitability would be affected by pain. In the present study, the temporal alteration of the jaw-opening reflex excitability was investigated to determine if orthodontic treatment affects orofacial motor function. The excitability of jaw-opening reflex evoked by electrical stimulation on the gingiva and recorded bilaterally in the anterior digastric muscles was evaluated at 1 (D1), 3 (D3), and 7 days (D7) after orthodontic force application to the teeth of right side; morphological features (e.g., osteoclast genesis and tooth movement) were also evaluated. To clarify the underlying mechanism of orthodontic treatment-induced alteration of orofacial motor excitability, analgesics were administrated for 1 day. At D1 and D3, orthodontic treatment significantly decreased the threshold for inducing the jaw-opening reflex but significantly increased the threshold at D7. Other parameters of the jaw-opening reflex were also evaluated (e.g., latency, duration and area under the curve of anterior digastric muscles activity), and only the latency of the D1 group was significantly different from that of the other groups. Temporal alteration of the jaw-opening reflex excitability was significantly correlated with changes in morphological features. Aspirin (300 mg·kg -1 ·day -1 ) significantly increased the threshold for inducing the jaw-opening reflex, whereas a lower dose (75-150 mg·kg -1 ·day -1 ) of aspirin or acetaminophen (300 mg·kg -1 ·day -1 ) failed to alter the jaw-opening reflex excitability. These results suggest that an increase of the jaw-opening reflex excitability can be induced acutely by orthodontic treatment, possibly through the cyclooxygenase activation. NEW & NOTEWORTHY It is well known that motor function is affected by pain, but the effect of orthodontic treatment-related pain on the trigeminal

Independently evolved upper jaw protrusion mechanisms show convergent hydrodynamic function in teleost fishes.

Science.gov (United States)

Staab, Katie Lynn; Holzman, Roi; Hernandez, L Patricia; Wainwright, Peter C

2012-05-01

A protrusible upper jaw has independently evolved multiple times within teleosts and has been implicated in the success of two groups in particular: Acanthomorpha and Cypriniformes. We use digital particle image velocimetry (DPIV) to compare suction feeding flow dynamics in a representative of each of these clades: goldfish and bluegill. Using DPIV, we contrast the spatial pattern of flow, the temporal relationship between flow and head kinematics, and the contribution of jaw protrusion to the forces exerted on prey. As expected, the spatial patterns of flow were similar in the two species. However, goldfish were slower to reach maximal kinematic excursions, and were more flexible in the relative timing of jaw protrusion, other jaw movements and suction flows. Goldfish were also able to sustain flow speeds for a prolonged period of time as compared with bluegill, in part because goldfish generate lower peak flow speeds. In both species, jaw protrusion increased the force exerted on the prey. However, slower jaw protrusion in goldfish resulted in less augmentation of suction forces. This difference in force exerted on prey corresponds with differences in trophic niches and feeding behavior of the two species. The bluegill uses powerful suction to capture insect larvae whereas the goldfish uses winnowing to sort through detritus and sediment. The kinethmoid of goldfish may permit jaw protrusion that is independent of lower jaw movement, which could explain the ability of goldfish to decouple suction flows (due to buccal expansion) from upper jaw protrusion. Nevertheless, our results show that jaw protrusion allows both species to augment the force exerted on prey, suggesting that this is a fundamental benefit of jaw protrusion to suction feeders.

Pain and Disability in the Jaw and Neck Region following Whiplash Trauma.

Science.gov (United States)

Häggman-Henrikson, B; Lampa, E; Marklund, S; Wänman, A

2016-09-01

The relationship between whiplash trauma and chronic orofacial pain is unclear, especially with regard to the time elapsed from trauma to development of orofacial pain. The aim was to analyze prevalence of jaw pain and disability, as well as the relationship between pain and disability in the jaw and neck regions in the early nonchronic stage after whiplash trauma. In this case-control study, 70 individuals (40 women, 30 men, mean age 35.5 y) who visited an emergency department with neck pain following a car accident were examined within 3 wk of trauma (group 1) and compared with 70 individuals (42 women, 28 men, mean age 33.8 y), who declined to attend a clinical examination but agreed to fill in questionnaires (group 2). The 2 case groups were compared with a matched control group of 70 individuals (42 women, 28 men, mean age 37.6 y) without a history of neck trauma. All participants completed questionnaires regarding jaw pain and dysfunction, rating pain intensity in jaw and neck regions on the Numerical Rating Scale, the Neck Disability Index, and Jaw Disability Checklist. Compared with controls, individuals with a recent whiplash trauma reported more jaw pain and dysfunction. Furthermore, there was a moderate positive correlation between jaw and neck pain ratings for group 1 (r = 0.61, P whiplash trauma report more jaw pain and disability compared with controls without a history of neck trauma. Furthermore, the correlation between jaw and neck pain intensity implies that intensity of neck pain in the acute stage after whiplash trauma might be a possible risk factor also for development of chronic orofacial pain. © International & American Associations for Dental Research 2016.

Eosinophilic Granuloma in Jaw Bone

African Journals Online (AJOL)

GB

CONCLUSION: EG should be considered as a differential diagnosis whenever there is a bony destructive lesion involving alveolar bone of the Jaws. Early diagnosis and surgical ... radiographic examination, these lesions should be biopsied.

Florid osseous dysplasia of the jaws

International Nuclear Information System (INIS)

Cho, Su Beom; Koh, Kwang Joon

1995-01-01

Few cases of florid osseous dysplasia has been described as a condition that characteristically affects the jaws. It usually manifests as multiple radiopaque masses distributed throughout the jaws. Confusion exists about the relationship of florid osseous dysplasia, gigantiform cementoma, chronic sclerosing osteomyelitis, sclerosing osteitis or multiple enostosis. Authors experienced a case of florid osseous dysplasia of the jaws in 52-year-old female on the basis of clinical, radiographic and histopathologic findings. The characteristic features are as follows: 1. In clinical examination, there was no clinical sign and symptoms except extrated area. And there was no facial asymmetry. 2. Radiograms show round or lobular dense radiopaque masses surrounded by radiolucent bands in lower molar teeth area bilaterally. And slight increased radiopacities in maxillary molar teeth area bilaterllay. There was no expansion or thinning of buccal and lingual cortical bones. There is no displacement or resorption of involved teeth. In right side of mandible, mandibular canal is displaced inferiorly due to mass. 3. Photomicrograms show densely mineralized sclerotic acellular masses with empty lacunae. Pattern is suggestive of cementum, although it could be considered sclerotic bone. In the periphery, lesion consisting of moderately cellular fibrous tissue in calcified products are deposited.

Surgical treatment of jaw osteonecrosis in "Krokodil" drug addicted patients.

Science.gov (United States)

Poghosyan, Yuri M; Hakobyan, Koryun A; Poghosyan, Anna Yu; Avetisyan, Eduard K

2014-12-01

Retrospective study of jaw osteonecrosis treatment in patients using the "Krokodil" drug from 2009 to 2013. On the territory of the former USSR countries there is widespread use of a self-produced drug called "Krokodil". Codeine containing analgesics ("Sedalgin", "Pentalgin" etc), red phosphorus (from match boxes) and other easily acquired chemical components are used for synthesis of this drug, which used intravenously. Jaw osteonecrosis develops as a complication in patients who use "Krokodil". The main feature of this disease is jawbone exposure in the oral cavity. Surgery is the main method for the treatment of jaw osteonecrosis in patients using "Krokodil". 40 "Krokodil" drug addict patients with jaw osteonecrosis were treated. Involvement of maxilla was found in 11 patients (27.5%), mandible in 21 (52.5%), both jaws in 8 (20%) patients. 35 Lesions were found in 29 mandibles and 21 lesions in 19 maxillas. Main factors of treatment success are: cessation of "Krokodil" use in the pre- (minimum 1 month) and postoperative period and osteonecrosis area resection of a minimum of 0.5 cm beyond the visible borders of osteonecrosis towards the healthy tissues. Surgery was not delayed until sequestrum formation. In the mandible marginal or segmental resection (with or without TMJ exarticulation) was performed. After surgery recurrence of disease was seen in 8 (23%) cases in the mandible, with no cases of recurrence in the maxilla. According to our experience in this case series, surgery is the main method for the treatment of jaw osteonecrosis in patients using "Krokodil". Cessation of drug use and jaw resection minimize the rate of recurrences in such patients. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Expression of Msx-1 is suppressed in bisphosphonate associated osteonecrosis related jaw tissue-etiopathology considerations respecting jaw developmental biology-related unique features.

Science.gov (United States)

Wehrhan, Falk; Hyckel, Peter; Ries, Jutta; Stockmann, Phillip; Nkenke, Emeka; Schlegel, Karl A; Neukam, Friedrich W; Amann, Kerstin

2010-10-13

Bone-destructive disease treatments include bisphosphonates and antibodies against the osteoclast differentiator, RANKL (aRANKL); however, osteonecrosis of the jaw (ONJ) is a frequent side-effect. Current models fail to explain the restriction of bisphosphonate (BP)-related and denosumab (anti-RANKL antibody)-related ONJ to jaws. Msx-1 is exclusively expressed in craniofacial structures and pivotal to cranial neural crest (CNC)-derived periodontal tissue remodeling. We hypothesised that Msx-1 expression might be impaired in bisphosphonate-related ONJ. The study aim was to elucidate Msx-1 and RANKL-associated signal transduction (BMP-2/4, RANKL) in ONJ-altered and healthy periodontal tissue. Twenty ONJ and twenty non-BP exposed periodontal samples were processed for RT-PCR and immunohistochemistry. An automated staining-based alkaline phosphatase-anti-alkaline phosphatase method was used to measure the stained cells:total cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed on ONJ-affected and healthy jaw periodontal samples (n = 20 each) to quantitatively compare Msx-1, BMP-2, RANKL, and GAPDH mRNA levels. Semi-quantitative assessment of the ratio of stained cells showed decreased Msx-1 and RANKL and increased BMP-2/4 (all p Msx-1 (p Msx-1 suppression in ONJ-adjacent periodontal tissue suggested a bisphosphonate-related impairment in cellular differentiation that occurred exclusively jaw remodelling. Further research on developmental biology-related unique features of jaw bone structures will help to elucidate pathologies restricted to maxillofacial tissue.

Jaw1/LRMP has a role in maintaining nuclear shape via interaction with SUN proteins.

Science.gov (United States)

Kozono, Takuma; Tadahira, Kazuko; Okumura, Wataru; Itai, Nao; Tamura-Nakano, Miwa; Dohi, Taeko; Tonozuka, Takashi; Nishikawa, Atsushi

2018-06-06

Jaw1/LRMP is characterized as a type II integral membrane protein that is localized to endoplasmic reticulum (ER), however, its physiological functions have been poorly understood. An alignment of amino acid sequence of Jaw1 with KASH proteins, outer nuclear membrane proteins, revealed that Jaw1 has a partial homology to the KASH domain. Here, we show that the function of Jaw1 is to maintain nuclear shape in mouse melanoma cell line. The siRNA-mediated knockdown of Jaw1 caused a severe defect in nuclear shape, and the defect was rescued by ectopic expression of siRNA-resistant Jaw1. Since co-immunoprecipitation assay indicates that Jaw1 interacts with SUN proteins that are inner nuclear proteins and microtubules, this study suggests that Jaw1 has a role in maintaining nuclear shape via interactions with SUN proteins and microtubules.

Masticatory jaw movement of Exaeretodon argentinus (Therapsida: Cynodontia inferred from its dental microwear.

Directory of Open Access Journals (Sweden)

Tai Kubo

Full Text Available Dental microwear of four postcanine teeth of Exaeretodon argentinus was analyzed using both two dimensional (2D and three dimensional (3D methods to infer their masticatory jaw movements. Results of both methods were congruent, showing that linear microwear features (scratches were well aligned and mostly directed to the antero-posterior direction in all four teeth examined. These findings support the palinal masticatory jaw movement, which was inferred in previous studies based on the observation of gross morphology of wear facets. In contrast, the lack of detection of lateral scratches confirmed the absence of the lateral jaw movement that was also proposed by a previous study. Considering previous microwear studies on cynodonts, palinal jaw movements observed in Exaeretodon evolved within cynognathian cynodonts from the fully orthal jaw movement of its basal member. Although there are currently only three studies of dental microwear of non-mammalian cynodonts including the present study, microwear analysis is a useful tool for the reconstruction of masticatory jaw movement and its future application to various cynodonts will shed light on the evolutionary process of jaw movement towards the mammalian condition in more detail.

Kinematic analysis of jaw function in children following traumatic brain injury.

Science.gov (United States)

Loh, E W L; Goozée, J V; Murdoch, B E

2005-07-01

To investigate jaw movements in children following traumatic brain injury (TBI) during speech using electromagnetic articulography (EMA). Jaw movements of two non-dysarthric children (aged 12.75 and 13.08 years) who had sustained a TBI were recorded using the AG-100 EMA system (Carstens Medizineletronik) during word-initial consonant productions. Mean quantitative kinematic parameters and coefficient of variation (variability) values were calculated and individually compared to the mean values obtained by a group of six control children (mean age 12.57 years, SD 1.52). The two children with TBI exhibited word-initial consonant jaw movement durations that were comparable to the control children, with sub-clinical reductions in speed being offset by reduced distances. Differences were observed between the two children in jaw kinematic variability, with one child exhibiting increased variability, while the other child demonstrated reduced or comparable variability compared to the control group. Possible sub-clinical impairments of jaw movement for speech were exhibited by two children who had sustained a TBI, providing insight into the consequences of TBI on speech motor control development.

Cytogenetics of jaw cysts - a pilot study.

Science.gov (United States)

Manor, Esther; Brennan, Peter A; Bodner, Lipa

2012-07-01

The pathogenesis of cysts that arise in the jaws is still not certain, and the underlying mechanisms of epithelial proliferation are not fully understood. Cysts of the jaw may involve a reactive, inflammatory, or neoplastic process. Cytogenetics, the study of the number and structure of chromosomes, has provided valuable information about the diagnosis, prognosis, and targeted treatment in many cancers, including oral squamous cell carcinoma. Cytogenetics can also provide information about the possible aetiology or neoplastic potential of a lesion, though to our knowledge no studies of this technique have been used for cysts in the jaws. In this pilot study we used cytogenetics in a series of 10 cysts (3 radicular, 4 dentigerous, 2 of the nasopalatine duct, and 1 dermoid). In all cases we found normal karyotypes. Further work and larger numbers are needed for a definitive study, but we can hypothesise from this pilot study that these cysts do not have cytogenetic aberrations and so have no neoplastic potential. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Fractures of the Jaw and Midface

Science.gov (United States)

... switch to the Professional version Home Injuries and Poisoning Facial Injuries Fractures of the Jaw and Midface Symptoms Diagnosis Treatment Treatment of mandible fractures Treatment of maxillary fractures ...

Early diagnosis of osteomyelitis occurred in the jaws

International Nuclear Information System (INIS)

Choi, Eun Sook; Na, Seung Mog; Lee, Un Gyeong; Koh, Kwang Joon

1994-01-01

Early diagnosis and treatment of osteomyelitis provide good prognosis and prevent severe complications. Therefore, it is important to early diagnose and treat before the bony changes are observed in conventional radiograms. Authors experienced three cases of early osteomyelitis, and scintigrams were useful to differentiate them from other diseases. The purpose of this report was to aid in the early diagnosis and treatment of osteomyelitis occurred in the jaws. The characteristic features were as follows: 1. In clinical examination, the patients complained mild pain and localized swelling in the jaws. 2. In radiographic findings, the conventional radiograms showed relatively mild bony change in the jaws. 3. The more severe periosteal reactions were observed in radiograms in children than in adult patient. 4. It showed marked increased uptake of radioisotopes in all scintigrams. 5. The three phase bone scanning were helpful to differentiate osteomyelitis from soft tissue diseases.

The ideal male jaw angle--An Internet survey.

Science.gov (United States)

Mommaerts, Maurice Y

2016-04-01

The ideal male jaw angle has not been established. With the advent of additive manufacturing, precise customized shaping is a reality. This study aimed to define the ideal masculine mandibular angle as an aid for 3-dimensional (3D) design. An Internet survey was conducted using black/white photographs of celebrities and non-celebrities. Preferences regarding gonial angle (profile and frontal views), intergonial width and vertical jaw angle position (face frontal view), and angle curvature and definition in oblique views were obtained using simplified, unbalanced Likert scales. Constructs were defined for planning 3D implant designs. The preferred jaw angle had these characteristics: 130° in face profile view, intergonial width similar to facial width, vertical position in frontal view at the oral commissure or at least not below the lower lip, jawline slope in the face frontal view nearly parallel to (with a maximum 15° downward deviation from) a line extending from the lateral canthus to the alare, ascending ramus slope 65°-75° to the Frankfort horizontal, and curvature in the oblique view visible from earlobe to chin and not pointy. Photogrammetric analysis of panel preferences lead to constructs with values useful for the design of 3D printed jaw angles. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

In the Jaws of Death

DEFF Research Database (Denmark)

Clasen, Mathias

The horror film Jaws (Spielberg, 1975) terrified millions of movie-goers and continues to resonate with audiences, despite its implausible premise and zoologically dubious depiction of a vengeful great white shark. An evolutionary approach explains why the film captured audiences’ imaginations an...

Electronic speckle-pattern interferometry (ESPI) applied to the study of mechanical behavior of human jaws

Science.gov (United States)

Roman, Juan F.; Moreno de las Cuevas, Vincente; Salgueiro, Jose R.; Suarez, David; Fernandez, Paula; Gallas, Mercedes; Blanchard, Alain

1996-01-01

The study of the mechanical behavior of the human jaw during chewing is helpful in several specific medical fields that cover the maxillo-facial area. In this work, electronic speckle pattern interferometry has been applied to study dead jaw bones under external stress which simulates the deformations induced during chewing. Fringes obtained after subtraction of two images of the jaw, the image of the relaxed jaw and that of the jaw under stress, give us information about the most stressed zones. The interferometric analysis proposed here is attractive as it can be done in real time with the jaw under progressive stress. Image processing can be applied for improving the quality of fringes. This research can be of help in orthognathic surgery, for example in diagnosis and treatment of fractured jaws, in oral surgery, and in orthodontics because it would help us to know the stress dispersion when we insert an osseointegrated implant or place an orthodontic appliance, respectively. Studying fragments of human jaw some results about its elasticity and flexibility were obtained.

Development of 4D jaw movement visualization system for dental diagnosis support

Science.gov (United States)

Aoki, Yoshimitsu; Terajima, Masahiko; Nakasima, Akihiko

2004-10-01

A person with an asymmetric morphology of maxillofacial skeleton reportedly possesses an asymmetric jaw function and the risk to express temporomandibular disorder is high. A comprehensive analysis from the point of view of both the morphology and the function such as maxillofacial or temporomandibular joint morphology, dental occlusion, and features of mandibular movement pathways is essential. In this study, the 4D jaw movement visualization system was developed to visually understand the characteristic jaw movement, 3D maxillofacial skeleton structure, and the alignment of the upper and lower teeth of a patient. For this purpose, the 3D reconstructed images of the cranial and mandibular bones, obtained by computed tomography, were measured using a non-contact 3D measuring device, and the obtained morphological images of teeth model were integrated and activated on the 6 DOF jaw movement data. This system was experimentally applied and visualized in a jaw deformity patient and its usability as a clinical diagnostic support system was verified.

[Osteonecrosis of the jaws and bisphosphonates].

Science.gov (United States)

Junod, A F; Carrel, J-P; Richter, M; Vogt-Ferrier, N

2005-11-02

Widely prescribed, bisphosphonates inhibit bone resorption. They are not metabolised and have long half-lives. Two cases of osteonecrosis of the jaws have recently been attributed to bisphosphonates at the University Hospital of Geneva. The recent literature reveals more than a hundred similar cases throughout the world. Bone exposure appears spontaneously or after dental care. Treatment of the osteonecrosis is controversial and cure very difficult. This pathology is usually seen in patients on chemotherapy, steroids and i.v. bisphosphonates, but is sometimes seen with low-dose p.o. bisphosphonates. In view of the strong association between bisphosphonate therapy and osteonecrosis of the jaw, specialists have recommended dental and oral evaluation during bisphosphonate therapy as well as for several years after drug discontinuation.

Comparative jaw muscle anatomy in kangaroos, wallabies, and rat-kangaroos (marsupialia: macropodoidea).

Science.gov (United States)

Warburton, Natalie Marina

2009-06-01

The jaw muscles were studied in seven genera of macropodoid marsupials with diets ranging from mainly fungi in Potorous to grass in Macropus. Relative size, attachments, and lamination within the jaw adductor muscles varied between macropodoid species. Among macropodine species, the jaw adductor muscle proportions vary with feeding type. The relative mass of the masseter is roughly consistent, but grazers and mixed-feeders (Macropus and Lagostrophus) had relatively larger medial pterygoids and smaller temporalis muscles than the browsers (Dendrolagus, Dorcopsulus, and Setonix). Grazing macropods show similar jaw muscle proportions to "ungulate-grinding" type placental mammals. The internal architecture of the jaw muscles also varies between grazing and browsing macropods, most significantly, the anatomy of the medial pterygoid muscle. Potoroines have distinctly different jaw muscle proportions to macropodines. The masseter muscle group, in particular, the superficial masseter is enlarged, while the temporalis group is relatively reduced. Lagostrophus fasciatus is anatomically distinct from other macropods with respect to its masticatory muscle anatomy, including enlarged superficial medial pterygoid and deep temporalis muscles, an anteriorly inflected masseteric process, and the shape of the mandibular condyle. The enlarged triangular pterygoid process of the sphenoid bone, in particular, is distinctive of Lagsotrophus. (c) 2009 Wiley-Liss, Inc.

Influence of maximum bite force on jaw movement during gummy jelly mastication.

Science.gov (United States)

Kuninori, T; Tomonari, H; Uehara, S; Kitashima, F; Yagi, T; Miyawaki, S

2014-05-01

It is known that maximum bite force has various influences on chewing function; however, there have not been studies in which the relationships between maximum bite force and masticatory jaw movement have been clarified. The aim of this study was to investigate the effect of maximum bite force on masticatory jaw movement in subjects with normal occlusion. Thirty young adults (22 men and 8 women; mean age, 22.6 years) with good occlusion were divided into two groups based on whether they had a relatively high or low maximum bite force according to the median. The maximum bite force was determined according to the Dental Prescale System using pressure-sensitive sheets. Jaw movement during mastication of hard gummy jelly (each 5.5 g) on the preferred chewing side was recorded using a six degrees of freedom jaw movement recording system. The motion of the lower incisal point of the mandible was computed, and the mean values of 10 cycles (cycles 2-11) were calculated. A masticatory performance test was conducted using gummy jelly. Subjects with a lower maximum bite force showed increased maximum lateral amplitude, closing distance, width and closing angle; wider masticatory jaw movement; and significantly lower masticatory performance. However, no differences in the maximum vertical or maximum anteroposterior amplitudes were observed between the groups. Although other factors, such as individual morphology, may influence masticatory jaw movement, our results suggest that subjects with a lower maximum bite force show increased lateral jaw motion during mastication. © 2014 John Wiley & Sons Ltd.

Jaw Dislocation as an Unusual Complication of Upper Endoscopy

Directory of Open Access Journals (Sweden)

Evan S. Dellon

2016-05-01

Full Text Available This case report presents an unusual complication of upper endoscopy, resulting in jaw dislocation. Temporomandibular joint dislocation is commonly reported in association with anesthesia and intubation, but it is not widely recognized as a complication of gastrointestinal endoscopy. This report also reviews the current literature regarding this complication and discusses the potential causes of dislocation, differential diagnoses for jaw pain following endoscopy, and recommendations for prevention.

Patterns of variation across primates in jaw-muscle electromyography during mastication.

Science.gov (United States)

Vinyard, Christopher J; Wall, Christine E; Williams, Susan H; Hylander, William L

2008-08-01

Biologists that study mammals continue to discuss the evolution of and functional variation in jaw-muscle activity during chewing. A major barrier to addressing these issues is collecting sufficient in vivo data to adequately capture neuromuscular variation in a clade. We combine data on jaw-muscle electromyography (EMG) collected during mastication from 14 species of primates and one of treeshrews to assess patterns of neuromuscular variation in primates. All data were collected and analyzed using the same methods. We examine the variance components for EMG parameters using a nested ANOVA design across successive hierarchical factors from chewing cycle through species for eight locations in the masseter and temporalis muscles. Variation in jaw-muscle EMGs was not distributed equally across hierarchical levels. The timing of peak EMG activity showed the largest variance components among chewing cycles. Relative levels of recruitment of jaw muscles showed the largest variance components among chewing sequences and cycles. We attribute variation among chewing cycles to (1) changes in food properties throughout the chewing sequence, (2) variation in bite location, and (3) the multiple ways jaw muscles can produce submaximal bite forces. We hypothesize that variation among chewing sequences is primarily related to variation in properties of food. The significant proportion of variation in EMGs potentially linked to food properties suggests that experimental biologists must pay close attention to foods given to research subjects in laboratory-based studies of feeding. The jaw muscles exhibit markedly different variance components among species suggesting that primate jaw muscles have evolved as distinct functional units. The balancing-side deep masseter (BDM) exhibits the most variation among species. This observation supports previous hypotheses linking variation in the timing and activation of the BDM to symphyseal fusion in anthropoid primates and in strepsirrhines

An examination of the degrees of freedom of human jaw motion in speech and mastication.

Science.gov (United States)

Ostry, D J; Vatikiotis-Bateson, E; Gribble, P L

1997-12-01

The kinematics of human jaw movements were assessed in terms of the three orientation angles and three positions that characterize the motion of the jaw as a rigid body. The analysis focused on the identification of the jaw's independent movement dimensions, and was based on an examination of jaw motion paths that were plotted in various combinations of linear and angular coordinate frames. Overall, both behaviors were characterized by independent motion in four degrees of freedom. In general, when jaw movements were plotted to show orientation in the sagittal plane as a function of horizontal position, relatively straight paths were observed. In speech, the slopes and intercepts of these paths varied depending on the phonetic material. The vertical position of the jaw was observed to shift up or down so as to displace the overall form of the sagittal plane motion path of the jaw. Yaw movements were small but independent of pitch, and vertical and horizontal position. In mastication, the slope and intercept of the relationship between pitch and horizontal position were affected by the type of food and its size. However, the range of variation was less than that observed in speech. When vertical jaw position was plotted as a function of horizontal position, the basic form of the path of the jaw was maintained but could be shifted vertically. In general, larger bolus diameters were associated with lower jaw positions throughout the movement. The timing of pitch and yaw motion differed. The most common pattern involved changes in pitch angle during jaw opening followed by a phase predominated by lateral motion (yaw). Thus, in both behaviors there was evidence of independent motion in pitch, yaw, horizontal position, and vertical position. This is consistent with the idea that motions in these degrees of freedom are independently controlled.

Effect of different head-neck-jaw postures on cervicocephalic kinesthetic sense.

Science.gov (United States)

Zafar, H; Alghadir, A H; Iqbal, Z A

2017-12-01

To investigate the effect of different induced head-neck-jaw postures on head-neck relocation error among healthy subjects. 30 healthy adult male subjects participated in this study. Cervicocephalic kinesthetic sense was measured while standing, habitual sitting, habitual sitting with clenched jaw and habitual sitting with forward head posture during right rotation, left rotation, flexion and extension using kinesthetic sensibility test. Head-neck relocation error was least while standing, followed by habitual sitting, habitual sitting with forward head posture and habitual sitting with jaw clenched. However, there was no significant difference in error between different tested postures during all the movements. To the best of our knowledge, this is the first study to see the effect of different induced head-neck-jaw postures on head-neck position sense among healthy subjects. Assuming a posture for a short duration of time doesn't affect head-neck relocation error in normal healthy subjects.

Expression of Msx-1 is suppressed in bisphosphonate associated osteonecrosis related jaw tissue-etiopathology considerations respecting jaw developmental biology-related unique features

Directory of Open Access Journals (Sweden)

Schlegel Karl A

2010-10-01

Full Text Available Abstract Background Bone-destructive disease treatments include bisphosphonates and antibodies against the osteoclast differentiator, RANKL (aRANKL; however, osteonecrosis of the jaw (ONJ is a frequent side-effect. Current models fail to explain the restriction of bisphosphonate (BP-related and denosumab (anti-RANKL antibody-related ONJ to jaws. Msx-1 is exclusively expressed in craniofacial structures and pivotal to cranial neural crest (CNC-derived periodontal tissue remodeling. We hypothesised that Msx-1 expression might be impaired in bisphosphonate-related ONJ. The study aim was to elucidate Msx-1 and RANKL-associated signal transduction (BMP-2/4, RANKL in ONJ-altered and healthy periodontal tissue. Methods Twenty ONJ and twenty non-BP exposed periodontal samples were processed for RT-PCR and immunohistochemistry. An automated staining-based alkaline phosphatase-anti-alkaline phosphatase method was used to measure the stained cells:total cell-number ratio (labelling index, Bonferroni adjustment. Real-time RT-PCR was performed on ONJ-affected and healthy jaw periodontal samples (n = 20 each to quantitatively compare Msx-1, BMP-2, RANKL, and GAPDH mRNA levels. Results Semi-quantitative assessment of the ratio of stained cells showed decreased Msx-1 and RANKL and increased BMP-2/4 (all p Conclusions These results explain the sclerotic and osteopetrotic changes of periodontal tissue following BP application and substantiate clinical findings of BP-related impaired remodeling specific to periodontal tissue. RANKL suppression substantiated the clinical finding of impaired bone remodelling in BP- and aRANKL-induced ONJ-affected bone structures. Msx-1 suppression in ONJ-adjacent periodontal tissue suggested a bisphosphonate-related impairment in cellular differentiation that occurred exclusively jaw remodelling. Further research on developmental biology-related unique features of jaw bone structures will help to elucidate pathologies restricted to

The oral microbial community of gingivitis and lumpy jaw in captive macropods.

Science.gov (United States)

Antiabong, John F; Boardman, Wayne; Moore, Robert B; Brown, Melissa H; Ball, Andrew S

2013-12-01

Gingivitis and lumpy jaw are diseases of polymicrobial aetiology. Although Fusobacterium necrophorum has been associated with these diseases in macropods, little is known about other organisms associated with these diseases in this animal species. PCR-DGGE analysis revealed the potential pathogens associated with gingivitis and lumpy jaw in macropods. PCR-DGGE profile comparison between the healthy and disease groups indicated a shift in the oral bacterial community structures with similarity coefficients of 48% and 35% for gingivitis and lumpy jaw respectively. Moreover, gingivitis was associated with increase in bacterial diversity (Shannon index = 2.87; PL curve = 45%) while lumpy jaw resulted in a decline in bacterial diversity (Shannon index = 2.47; PL curve = 74%). This study suggest that the establishment of gingivitis and lumpy jaw diseases follows the ecological plaque hypothesis. This forms the basis for an expanded investigation in an epidemiological scale and suggests the need for the appropriate choice of antimicrobial agent(s) and for the effective management and control of polymicrobial diseases. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of nonexposed and exposed bisphosphonate-induced osteonecrosis of the jaws

DEFF Research Database (Denmark)

Schiodt, Morten; Reibel, Jesper; Oturai, Peter

2014-01-01

Nonexposed osteonecrosis of the jaws (NE-ONJ) does not fit into the current definition of osteonecrosis, which requires exposed bone. A modification of the classification of bisphosphonate-induced osteonecrosis of the jaws (ONJ) is proposed. This study aimed to test proposed criteria for NE...

The influence of jaw's curvature on the results of the Brazilian disc test

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Ch.F. Markides

2016-04-01

Full Text Available The general contact problem of a disc squeezed between jaws of arbitrary curvature is considered employing Muskhelishvili's complex potentials. Taking advantage of the general solution introduced, the closed-form expressions for the stresses along strategic loci (loaded rim, loaded diameter, disc's center are obtained, in terms of the ratio ρ of the disc's to the jaw's curvature. Then, the effect of ρ (as well as that of the relative stiffness of the disc's and jaw's materials dictating the contact arc on the stress distribution along these loci is explored. It is concluded that, for both smooth contact (zero friction and contact with friction, the role of the jaw's curvature is significant not only along the disc-jaw contact arc (as it could be expected, but also all along the loaded diameter. On the other hand, it is indicated that the stress field at the disc's center is more or less insensitive to the jaw's curvature assuming that ρ lies within the range (0, 0.67 or in other words within the limits defined by the two standardized suggestions, i.e. that of American Society for Testing and Materials (ASTM (plane loading platens with ρ = 0 and that of International Society for Rock Mechanics (ISRM (curved jaws with ρ = 0.67. The upper limit of this range is a kind of compromise between the need to make the stress field at the disc's center independent of the boundary conditions while keeping at the same time the contact angle large enough to reduce the stress concentration and the risk for premature fracture initiation far from the disc's center. For jaws with radius of curvature exceeded by that suggested by ISRM, the stress field at the disc's center is significantly influenced. Especially for jaws with radius approaching that of the disc, the stress field at the disc's center is dramatically distorted rendering Hondros' formula inapplicable and the test results erroneous.

Dislocation of jaws

International Nuclear Information System (INIS)

Katzberg, R.W.; Hayakawa, K.; Anderson, Q.N.; Manzione, J.V.; Helms, C.A.; Tallents, R.

1984-01-01

Pluri-directional tomographic and arthrotomographic findings are described in six patients with dislocation of the jaw severe enough to require medical assistance. A grooved defect along the posterior aspect of the condylar head was noted in two of the six patients. The arthrotomographic findings that were obtained in one patient that was dislocated at the time of the arthrogram did not suggest a meniscocondyle incoordination as a mechanism. However, arthrotomographic findings in the six reported cases suggest that significant intra-articular soft tissue damage may result. (orig.)

REHABILITATION OF SEVERELY ATROPHIED UPPER JAW WITH INTRAOSSAL DENTAL IMPLANTS - clinical case

OpenAIRE

Ivan Chenchev; Radka Cholakova; Cvetan Cvetanov; Ir. Mitarcheva

2010-01-01

Objective: The purpose of this presentation is to show the difficulty in prosthetization of a clinical case with a pronounced atrophy of the upper jaw and the various types and nature of restrictions imposed by the requirements of the patient. Methods: The clinical analysis, surgical protocol and prosthetic solution are presented in the treatment of 72 year-old woman with a pronounced atrophy of the upper jaw. OPG, standard CT of the upper jaw was used in the planning and a special surgical t...

Dental CT: imaging technique, anatomy, and pathologic conditions of the jaws

International Nuclear Information System (INIS)

Gahleitner, Andre; Watzek, G.; Imhof, H.

2003-01-01

In addition to conventional imaging methods, dental CT has become an established method for anatomic imaging of the jaws prior to dental implant placement. More recently, this high-resolution imaging technique has gained importance in diagnosing dental-associated diseases of the mandible and maxilla. Since most radiologists have had little experience in these areas, many of the CT findings remain undescribed. The objective of this review article is to present the technique of dental CT, to illustrate the typical appearance of jaw anatomy and dental-related diseases of the jaws with dental CT, and to show where it can serve as an addition to conventional imaging methods in dental radiology. (orig.)

Dental CT: imaging technique, anatomy, and pathologic conditions of the jaws

Energy Technology Data Exchange (ETDEWEB)

Gahleitner, Andre [Department of Radiology/Osteology, Medical School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria); Department of Oral Surgery, Dental School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria); Watzek, G. [Department of Oral Surgery, Dental School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria); Imhof, H. [Department of Radiology/Osteology, Medical School, University of Vienna, Waehringer Strasse 25a, 1090 Vienna (Austria)

2003-02-01

In addition to conventional imaging methods, dental CT has become an established method for anatomic imaging of the jaws prior to dental implant placement. More recently, this high-resolution imaging technique has gained importance in diagnosing dental-associated diseases of the mandible and maxilla. Since most radiologists have had little experience in these areas, many of the CT findings remain undescribed. The objective of this review article is to present the technique of dental CT, to illustrate the typical appearance of jaw anatomy and dental-related diseases of the jaws with dental CT, and to show where it can serve as an addition to conventional imaging methods in dental radiology. (orig.)

Epidemiology of ameloblastomas of the jaws; A report from the Netherlands

NARCIS (Netherlands)

Oomens, Marjolijn A. E. M.; van der Waal, Isaac

2014-01-01

Objectives: To provide epidemiological data of ameloblastomas of the jaws in the Netherlands over a 25-year time period (1985-2010) and to compare these data with data from other parts of the world. Material and Methods: The data of all patients diagnosed with a primary ameloblastoma of the jaws in

[Jaw osteosarcomas].

Science.gov (United States)

Steve, M; Ernenwein, D; Chaine, A; Bertolus, C; Goudot, P; Ruhin-Poncet, B

2011-11-01

Osteosarcoma (OS) is the most frequent bone malignant tumor. It is usually found on long bones, 5 to 10% are located on jaws, accounting for 0.5 to 1% of all facial tumors. There is little published data which concerns only few patients. Our aim was to study retrospectively cases of facial bone OS in adults, and to compare our results with published data to suggest an optimal management scheme. Thirty-three patients were managed for an OS, from January 1997 to January 2007. Fourteen patients with a maxillary and mandibular OS, treated in first-intention in our unit, were included. The following data were analyzed: age; personal history; circumstance of discovery; clinical, functional, and physical signs; loco-regional extension and metastasis radiological investigation. The histological slides were systematically reviewed. The protocol, therapeutic outcome, and follow-up were studied. The mean age at diagnosis was 43. Swelling was the most frequent functional sign. The mean delay before management was 3.4 months. The most frequent radiological presentation was a lytic and hyperdense image. The diagnosis was suggested after CT scan in 57.1% of cases. The biopsy was correlated to the anatomopathological analysis in 78.6% of cases. The most common treatment was surgical exeresis completed by chemotherapy. The 5-year survival rate was 50%. Jaw OS are specific because of their localization and specific bone ultrastructure. Their management remains controversial: should they be managed like limb OS or treated more specifically? Neoadjuvant chemotherapy, even if it delays exeresis for 3 months, seems to stop the growth or reduce the tumor. An early anatomopathological analysis of the surgical piece determines adjuvant therapy. The negative prognostic factors are: maxillary localization because of limited exeresis margins, tumoral size, and osteoblastic sub-type. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

SU-E-T-471: Small Field Jaw/MLC Reference Data

International Nuclear Information System (INIS)

Kerns, J; Alvarez, P; Followill, D; Lowenstein, J; Molineu, A; Summers, P; Kry, S

2014-01-01

Purpose: In recent years the need for small field data of MLCs has increased due to the use of intensity-modulated radiation (IMRT), but moreover the use of stereotactic body radiation (SBRT) has increased, which uses not simply small field sizes, but small jaw and field sizes together. Having reference data for these small fields that is reliable would be invaluable to the physics community. Our study has gathered these values and the data distributions from the Radiological Physics Center's (RPC) site visits between 1990 and the present. Methods: For all measurements, the RPC used a 25 × 25 × 25cm water phantom placed at 100cm SSD. All measurements were made with an Exradin A16 cylindrical ion chamber at an effective depth of 10 cm. A total of 42 Varian machine measurements were used to compose the data for a 6 MV beam and 5 TrueBeam 6 MV flattening filter free (FFF) beams were used for FFF data. Results: Jaw/MLC fields were measured for both 6 MV and 6 MF FFF beams with the jaws and MLCs both at the following field sizes: 6×6, 4×4, 3×3, and 2×2cm. Measurements were normalized to the 10×10 field readings (defined by the jaws and MLC). Spread in the data was minimal and demonstrates a high level of accuracy of acquired data. Conclusion: Small field Jaw/MLC reference data for Varian 6MV and 6 MV FFF beams has been analyzed and presented here, composed of the aggregation of numerous RPC site visits. Obtaining reliable small field data remains difficult, however the RPC has collected high fidelity small field Jaw/MLC data. The data are presented as a reference along with their distributions, in such a way that the physicist can act based upon their own desired agreement with the reference data

Leaf transmission reduction using moving jaws for dynamic MLC IMRT

International Nuclear Information System (INIS)

Schmidhalter, D.; Fix, M. K.; Niederer, P.; Mini, R.; Manser, P.

2007-01-01

The aim of this work is to investigate to what extent it is possible to use the secondary collimator jaws to reduce the transmitted radiation through the multileaf collimator (MLC) during an intensity modulated radiation therapy (IMRT). A method is developed and introduced where the jaws follow the open window of the MLC dynamically (dJAW method). With the aid of three academic cases (Closed MLC, Sliding-gap, and Chair) and two clinical cases (prostate and head and neck) the feasibility of the dJAW method and the influence of this method on the applied dose distributions are investigated. For this purpose the treatment planning system Eclipse and the Research-Toolbox were used as well as measurements within a solid water phantom were performed. The transmitted radiation through the closed MLC leads to an inhomogeneous dose distribution. In this case, the measured dose within a plane perpendicular to the central axis differs up to 40% (referring to the maximum dose within this plane) for 6 and 15 MV. The calculated dose with Eclipse is clearly more homogeneous. For the Sliding-gap case this difference is still up to 9%. Among other things, these differences depend on the depth of the measurement within the solid water phantom and on the application method. In the Chair case, the dose in regions where no dose is desired is locally reduced by up to 50% using the dJAW method instead of the conventional method. The dose inside the chair-shaped region decreased up to 4% if the same number of monitor units (MU) as for the conventional method was applied. The undesired dose in the volume body minus the planning target volume in the clinical cases prostate and head and neck decreased up to 1.8% and 1.5%, while the number of the applied MU increased up to 3.1% and 2.8%, respectively. The new dJAW method has the potential to enhance the optimization of the conventional IMRT to a further step

Hyperparathyroidism-jaw tumour syndrome detected by aggressive generalized osteitis fibrosa cystica.

Science.gov (United States)

Guerrouani, Alae; Rzin, Abdelkader; El Khatib, Karim

2013-01-01

Severe hyperparathyroidism can affect bone metabolism and be in the origine of multiple brown tumours (generalized osteitis fibrosa cystica). When associated with fibro-ossifying tumours of the jaw, it realizes a rare genetic syndrome referred as Hyperparathyroidism-jaw tumour HPT-JT. We report the case of a patient we treated for HPT-JT, and literature review.

Directional selection has shaped the oral jaws of Lake Malawi cichlid fishes.

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Albertson, R Craig; Streelman, J Todd; Kocher, Thomas D

2003-04-29

East African cichlid fishes represent one of the most striking examples of rapid and convergent evolutionary radiation among vertebrates. Models of ecological speciation would suggest that functional divergence in feeding morphology has contributed to the origin and maintenance of cichlid species diversity. However, definitive evidence for the action of natural selection has been missing. Here we use quantitative genetics to identify regions of the cichlid genome responsible for functionally important shape differences in the oral jaw apparatus. The consistent direction of effects for individual quantitative trait loci suggest that cichlid jaws and teeth evolved in response to strong, divergent selection. Moreover, several chromosomal regions contain a disproportionate number of quantitative trait loci, indicating a prominent role for pleiotropy or genetic linkage in the divergence of this character complex. Of particular interest are genomic intervals with concerted effects on both the length and height of the lower jaw. Coordinated changes in this area of the oral jaw apparatus are predicted to have direct consequences for the speed and strength of jaw movement. Taken together, our results imply that the rapid and replicative nature of cichlid trophic evolution is the result of directional selection on chromosomal packages that encode functionally linked aspects of the craniofacial skeleton.

Local anaesthesia in the upper jaw

NARCIS (Netherlands)

Baart, J.A.; Baart, J.A.; Brand, H.S.

2017-01-01

The sensory innervation of the upper jaw arises from the second trunk of the trigeminal nerve, the maxillary nerve. This main branch of the trigeminal nerve leaves the neurocranium via the foramen rotundum, reaches the pterygopalatine fossa and runs straight through the infraorbital nerve, branching

Radiographic features of large cystic lesions of the jaws in children

International Nuclear Information System (INIS)

Bodner, Lipa; Woldenberg, Yitzhak; Bar-Ziv, Jacob

2003-01-01

The surgical approach to cystic lesions of the jaws is either marsupialisation or enucleation. The treatment of choice is dependent on the size of the lesion, the bony integrity of the cyst and its proximity to anatomical structures.Objectives. To assess large (>2.0 cm) cystic lesions of the jaws using plain film radiography (PFR), CT, multiplanar reconstruction program (MPR) and three-dimensional CT (3D-CT).Patients and methods. Twelve children aged 7-14 years.Results. The classic radiological feature was a unilocular radiolucent area surrounded by a well-defined radio-opaque margin adjacent to the root of a non-viable tooth or associated with the crown of an unerupted tooth. Malposition of teeth and root resorption were more common in dentigerous cysts. The features seen on CT were clear and more precise than those seen on PFR. MPR, by the three-dimensional visualisation of the jaw (axial, panoramic, and bucco-lingual), provided useful information for determining the outline of the cyst and its proximity to adjacent anatomical structures, such as teeth, nerves or maxillary sinus. 3-D CT further and more clearly demonstrated discontinuity in the buccal or palatal/lingual cortices of the jaw bone. PFR was very accurate in determining root resorption.Conclusions. CT with MPR and, ideally, 3-D CT should be used for the comprehensive diagnostic work-up and meticulous surgical management of large cystic lesions of the jaws in children. (orig.)

Analyzing surface EMG signals to determine relationship between jaw imbalance and arm strength loss

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Truong Quang Dang Khoa

2012-08-01

Full Text Available Abstract Background This study investigated the relationship between dental occlusion and arm strength; in particular, the imbalance in the jaw can cause loss in arm strength phenomenon. One of the goals of this study was to record the maximum forces that the subjects can resist against the pull-down force on their hands while biting a spacer of adjustable height on the right or left side of the jaw. Then EMG measurement was used to determine the EMG-Force relationship of the jaw, neck and arms muscles. This gave us useful insights on the arms strength loss due to the biomechanical effects of the imbalance in the jaw mechanism. Methods In this study to determine the effects of the imbalance in the jaw to the strength of the arms, we conducted experiments with a pool of 20 healthy subjects of both genders. The subjects were asked to resist a pull down force applied on the contralateral arm while biting on a firm spacer using one side of the jaw. Four different muscles – masseter muscles, deltoid muscles, bicep muscles and trapezoid muscles – were involved. Integrated EMG (iEMG and Higuchi fractal dimension (HFD were used to analyze the EMG signals. Results The results showed that (1 Imbalance in the jaw causes loss of arm strength contra-laterally; (2 The loss is approximately a linear function of the height of the spacers. Moreover, the iEMG showed the intensity of muscle activities decreased when the degrees of jaw imbalance increased (spacer thickness increased. In addition, the tendency of Higuchi fractal dimension decreased for all muscles. Conclusions This finding indicates that muscle fatigue and the decrease in muscle contraction level leads to the loss of arm strength.

Extensive jaw mobility in suckermouth armored catfishes (Loricariidae): a morphological and kinematic analysis of substrate scraping mode of feeding.

Science.gov (United States)

Adriaens, Dominique; Geerinckx, Tom; Vlassenbroeck, Jelle; Van Hoorebeke, Luc; Herrel, Anthony

2009-01-01

Loricariidae, or suckermouth armored catfishes, possess upper and lower jaws that are ventrally oriented and that bear teeth that touch the substrate from which algae and other food items are scraped. The ventral orientation and the highly specialized morphology of the jaws, characterized by protrusible upper jaws and left-right decoupled lower jaws, are observed in Pterygoplichthys disjunctivus, the species investigated here. Kinematic data of the scraping feeding movements, obtained by external high-speed and x-ray recordings, are used to quantify jaw movement, especially to test for upper jaw mobility and versatility during substrate scraping. Our results show that the mobility of the jaws is indeed high compared with what is standard for catfishes. The upper jaw's ability to perform a substantial degree of rostrocaudal movement is quite unique for catfishes. The ventromedially oriented lower jaws, with the teeth and the coronoid process at opposite sides, display an extensive mobility: they rotate around the suspensorial articulation and around their longitudinal axis, resulting in an extended scraping movement and thereby covering a large surface area. The lower jaws also show a left-right asymmetry in their movements during scraping. Thus, our results suggest that the extreme morphological specializations of the jaws in loricariid catfishes are linked to an increased mobility and functional versatility, allowing these animals to efficiently scrape algae from substrates with irregular surfaces.

Regulation of eye and jaw colouration in three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Franco-Belussi, L; De Oliveira, C; Sköld, H N

2018-03-25

Fish can change their skin and eye colour for background matching and signalling. Males of Gasterosteus aculeatus develop ornamental blue eyes and a red jaw during the reproductive season, colours that are further enhanced during courtship. Here, the effects of different hormones on physiological colour changes in the eyes and jaws of male and female G. aculeatus were investigated in vitro. In an in vivo experiment, G. aculeatus were injected with a receptor blocker of a pivotal hormone (noradrenaline) that controls colour change. In males, noradrenaline had aggregating effects on melanophore and erythrophore pigments resulting in blue eyes and a pale jaw, whereas melanocyte-concentrating hormone (MCH) and melatonin resulted in a pale jaw only. When noradrenalin was combined with melanocyte stimulating hormone (MSH) or prolactin, the jaw became red, while the eyes remained blue. In vivo injection of yohimbine, an alpha-2 adrenoreceptor blocker, resulted in dispersion of melanophore pigment in the eyes and inhibited the blue colouration. Altogether, the data suggest that noradrenalin has a pivotal role in the short-term enhancement of the ornamental colouration of male G. aculeatus, potentially together with MSH or prolactin. This study also found a sex difference in the response to MCH, prolactin and melatonin, which may result from different appearance strategies in males, versus the more cryptic females. © 2018 The Fisheries Society of the British Isles.

Bisphosphonates and osteonecrosis of the jaw.

Science.gov (United States)

Shannon, Jodi; Shannon, John; Modelevsky, Steven; Grippo, Anne A

2011-12-01

Bisphosphonates are used worldwide as a successful treatment for people with osteoporosis, which is the major underlying cause of fractures in postmenopausal women and older adults. These agents are successful at increasing bone mass and bone trabecular thickness, decreasing the risk of fracture, and decreasing bone pain, enabling individuals to have better quality of life. Bisphosphonates are also used to treat multiple myeloma, bone metastasis, and Paget's disease; however, bisphosphonate treatment may result in negative side effects, including osteonecrosis of the jaw (ONJ). ONJ involves necrotic, exposed bone in the jaw, pain, possible secondary infection, swelling, painful lesions, and various dysesthesias, although less-severe cases may be asymptomatic. First-generation bisphosphonates, which do not contain nitrogen, are metabolized into a nonfunctional, cytotoxic analogue of adenosine triphosphate and cause osteoclast death by starvation. Second-generation bisphosphonates are nitrogen-containing agents; these inhibit osteoclast vesicular trafficking, membrane ruffling, morphology, and cytoskeletal arrangement by inhibiting farnesyl diphosphate synthase in the mevalonate pathway. Physicians treating older adults with osteoporosis and cancer should work together with dental practitioners, pharmacists, and other clinicians to inform individuals receiving bisphosphonates of their possible side effects and to suggest precautionary steps that may minimize the risk of osteonecrosis, particularly of the jaw. These include practicing good oral hygiene; scheduling regular dental examinations and cleanings; and cautioning people who are scheduling treatment for periodontal disease, oral and maxillofacial therapy, endodontics, implant placement, restorative dentistry, and prosthodontics. Recommendations for management of people with ONJ include an oral rinse, such as chlorhexidine, and antibiotics. © 2011, Copyright the Authors Journal compilation © 2011, The American

New look at the anatomy of the jaws by dental CT imaging

International Nuclear Information System (INIS)

Nikolov, V.

2006-01-01

Full text: We represent a part of a retrospective study of CT findings of the jaws and teeth's by Dental CT. For preoperative planning in dental implantology, 215 jaws of 169 patients was investigated. There have been established the reasons for the lost of teeth's, the exact anatomical situation, the height and the vestibular-lingual thickness of the alveolar crest, the thickness of the cortical bone, the presence and volume of the bone defects, the bone mineral density in the implantation zone. A try has been made to create a mathematic model for calculating the risk of failed osseointegration. The investigating of jaws and teeth by Dental CT made it possible to find and localize excessive vascular canals in the frontal parts of the mandible, which is important to prevent complications in operative insertion of implants. There is a high percentage of patients with a great vestibular cortical resorption in the incisive and premolar region of both jaws. The existence of such similar situation in younger patients without periodontal disease

Central xanthoma of the jaw in association with Noonan syndrome.

Science.gov (United States)

Olson, Nicholas J; Addante, Rocco R; de Abreu, Francine B; Memoli, Vincent A

2018-05-01

Xanthomas are histiocytic lesions of the skin, soft tissue and bone and are generally considered to be reactive in nature. When they arise in the bones of the jaw, they are referred to as central xanthomas. New evidence supports the hypothesis that central xanthomas are a separate and distinct entity from their extragnathic counterparts. Noonan syndrome (NS) is an autosomal dominant disorder that has been associated with giant cell lesions which also commonly occur in the jaw. We present a case of a 15year-old-male with NS who presented with a radiolucent lesion of the mandible that on excision, was found to be a central xanthoma. Although giant cell lesions have been well described in NS, xanthomas of the jaw have not been reported. We will also discuss the entities that must be excluded prior to making a diagnosis of central xanthoma, as this can affect both treatment and follow up. Copyright © 2018. Published by Elsevier Inc.

Computer tomography valorization of the vascular lingual channels in the jaw

International Nuclear Information System (INIS)

Costantino, Sebastian; Capiel, Carlos h; Bouzas, Carlos; Vuotto, Miguel; Ferrari, Daniela; Bazzano, Sebastian

2006-01-01

Purpose: To determine the frequency, location and position of vascular lingual channels of jaw by dental CT and classifying them based on its location. Material and methods: Dental CT of 100 consecutive patients were reevaluated as previous evaluation to the positioning of dental implants. They are classified by linking their location on the jaw with the number of tooth present or absent in that area. Results: All patients had at least one lingual vascular channel in the jaw; 36 patients presented two channels, eight patients presented three and a patient presented four. The more frequent location was between the sectors of the pieces 31 and 41. Sixteen patients showed two channels (superior and inferior) in that location. The second location by frequency was between pieces 32 and 33 (nine patients). The average distance between the lingual surface of the alveolar rim and the vascular channels was of 16 mm. Conclusion: the dental CT is an excellent method for the identification of the vascular lingual channels by its multiplanar capacity and appropriate image resolution. The characterization and classification of these conduits by a method of easy reading for the radiologists and the dentists assure a correct pre surgical valuation avoiding hemorrhages during the jaw perforation in the positioning of dental implants. (author) [es

Failure analysis of vise jaw holders for hacksaw machine

Directory of Open Access Journals (Sweden)

Essam Ali Al-Bahkali

2018-01-01

Full Text Available Failure analysis in mechanical components has been investigated in many studies in the last few years. Failure analysis and prevention are important functions in all engineering disciplines. Materials engineers are often the lead role in the analysis of failures, where a component or product fails in service or if a failure occurs during manufacturing or production processing. In any case, one must determine the cause of the failure to prevent future occurrences and/or to improve the performance of the device, component or structure. For example, the vise jaw holders of hacksaws can break due to accidental heavy loads or machine misuse. The parts that break are the stationary and movable vise jaw holders and the connecter power screw between the holders. To investigate the failure of these components, a three-dimensional finite element model for stress analysis was performed. First, the analysis identified the broken components of the hacksaw machine. In addition, the type of materials of the broken parts was identified, a CAD model was built, and the hacksaw mechanism was analyzed to determine the accurate applied loads on the broken parts. After analyzing the model using Abaqus CAE software, the results showed that the location of the high stresses was identical with the high-stress locations in the original, broken parts. Furthermore, the power screw was subjected to a high load, which deformed the power screw. Also, the stationary vise jaw holder was broken by impact because it was not touched by the power screw until the movable vise jaw holder broke. A conclusion is drawn from the failure analysis and a way to improve the design of the broken parts is suggested.

Bisphosphonate-associated osteonecrosis of the jaws

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Pankaj Agarwal

2012-01-01

Full Text Available Bisphosphonates constitute a group of drugs capable of modulating bone turnover and reduce its remodeling when an excessive resorption occurs. This is why they are indicated in a large group of bone diseases like postmenopausal osteoporosis or osteolysis associated with breast cancer or multiple myeloma. Over the last few years and due to their extensive use, many cases of complications associated with their use have been published. Among the most important possible adverse effects are the oral ones, with the appearance of ulcerations and, especially, osteonecrosis of the jaws associated with this therapy. In this paper, we have analyzed the general characteristics of these drugs and their mechanisms of action as well as the described adverse effects, especially oral and maxillofacial, have been made special reference, regarding the prevention of osteonecrosis of the jaws, heightened by cases described in the medical and odontological literature. The preventive protocol backs up the fundamental role of the odontologist in the effective prevention of this process before, during and after the treatment.

Osteosarcoma: a comparison of jaw versus nonjaw localizations and review of the literature

NARCIS (Netherlands)

van den Berg, H.; Schreuder, W.H.; de Lange, J.

2013-01-01

Purpose. It is assumed that osteosarcomas of the jaws mainly occur at older ages, whereas the most prominent sites, that is, the long bones, are more affected at ages <20. Jaw-localized tumors are less malignant and have lower metastatic spread rates. Patients and Methods. This study analyses the

Osteosarcoma: A Comparison of Jaw versus Nonjaw Localizations and Review of the Literature

NARCIS (Netherlands)

van den Berg, H.; Schreuder, W. H.; de Lange, J.

2013-01-01

Purpose. It is assumed that osteosarcomas of the jaws mainly occur at older ages, whereas the most prominent sites, that is, the long bones, are more affected at ages <20. Jaw-localized tumors are less malignant and have lower metastatic spread rates. Patients and Methods. This study analyses the

Beam feasibility study of a collimator with in-jaw beam position monitors

Science.gov (United States)

Wollmann, Daniel; Nosych, Andriy A.; Valentino, Gianluca; Aberle, Oliver; Aßmann, Ralph W.; Bertarelli, Alessandro; Boccard, Christian; Bruce, Roderik; Burkart, Florian; Calvo, Eva; Cauchi, Marija; Dallocchio, Alessandro; Deboy, Daniel; Gasior, Marek; Jones, Rhodri; Kain, Verena; Lari, Luisella; Redaelli, Stefano; Rossi, Adriana

2014-12-01

At present, the beam-based alignment of the LHC collimators is performed by touching the beam halo with both jaws of each collimator. This method requires dedicated fills at low intensities that are done infrequently and makes this procedure time consuming. This limits the operational flexibility, in particular in the case of changes of optics and orbit configuration in the experimental regions. The performance of the LHC collimation system relies on the machine reproducibility and regular loss maps to validate the settings of the collimator jaws. To overcome these limitations and to allow a continuous monitoring of the beam position at the collimators, a design with jaw-integrated Beam Position Monitors (BPMs) was proposed and successfully tested with a prototype (mock-up) collimator in the CERN SPS. Extensive beam experiments allowed to determine the achievable accuracy of the jaw alignment for single and multi-turn operation. In this paper, the results of these experiments are discussed. The non-linear response of the BPMs is compared to the predictions from electromagnetic simulations. Finally, the measured alignment accuracy is compared to the one achieved with the present collimators in the LHC.

Non-radiation related osteonecrosis of the jaws in dogs: 14 cases (1996 - 2014

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Santiago ePeralta

2015-05-01

Full Text Available Osteonecrosis of the jaws is an entity of major clinical impact characterized by chronically exposed necrotic mandibular or maxillary bone. Its clinicopathological characteristics and possible inciting or risk factors are well described in humans but only anecdotally reported in dogs. Treatment modalities and outcome vary depending on the inciting factors involved and the extent and severity of the lesions. The objectives of this study were to retrospectively describe the clinicopathological features of non-radiation related osteonecrosis of the jaws in a series of 14 dogs, identify possible inciting or risk factors, and report on the surgical treatment and outcome. For all patients, the medical records were used to collect information regarding signalment, clinical signs, characteristics of the oral, jaw and dental lesions, diagnostic imaging findings, histopathological and microbiological analysis, treatment performed and outcome. The data collected showed that non-radiation related osteonecrosis of the jaws appears to be an infrequent clinical entity but of significant impact in dogs; that a history of systemic antibiotics and dental disease is common among affected dogs; that previous dental extractions are commonly associated with ONJ sites; that using a systematic diagnostic approach is essential for diagnosis; and that thorough surgical débridement combined with a course of oral antibiotics was effective in the described dogs affected by advanced non-radiation related osteonecrosis of the jaws.

Jaw muscle fiber type distribution in Hawaiian gobioid stream fishes: histochemical correlations with feeding ecology and behavior.

Science.gov (United States)

Maie, Takashi; Meister, Andrew B; Leonard, Gerald L; Schrank, Gordon D; Blob, Richard W; Schoenfuss, Heiko L

2011-12-01

Differences in fiber type distribution in the axial muscles of Hawaiian gobioid stream fishes have previously been linked to differences in locomotor performance, behavior, and diet across species. Using ATPase assays, we examined fiber types of the jaw opening sternohyoideus muscle across five species, as well as fiber types of three jaw closing muscles (adductor mandibulae A1, A2, and A3). The jaw muscles of some species of Hawaiian stream gobies contained substantial red fiber components. Some jaw muscles always had greater proportions of white muscle fibers than other jaw muscles, independent of species. In addition, comparing across species, the dietary generalists (Awaous guamensis and Stenogobius hawaiiensis) had a lower proportion of white muscle fibers in all jaw muscles than the dietary specialists (Lentipes concolor, Sicyopterus stimpsoni, and Eleotris sandwicensis). Among Hawaiian stream gobies, generalist diets may favor a wider range of muscle performance, provided by a mix of white and red muscle fibers, than is typical of dietary specialists, which may have a higher proportion of fast-twitch white fibers in jaw muscles to help meet the demands of rapid predatory strikes or feeding in fast-flowing habitats. Copyright © 2011 Elsevier GmbH. All rights reserved.

Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

Energy Technology Data Exchange (ETDEWEB)

Motazavi, Hamed; Bharvand, Maryam [Dept. of Oral Medicine, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2016-09-15

This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as 'jaw lesion', 'jaw disease', 'impacted tooth', and 'unerupted tooth'. More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs.

Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

International Nuclear Information System (INIS)

Motazavi, Hamed; Bharvand, Maryam

2016-01-01

This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as 'jaw lesion', 'jaw disease', 'impacted tooth', and 'unerupted tooth'. More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs

A comparison of cephalometric analyses for assessing sagittal jaw relationship

International Nuclear Information System (INIS)

Erum, G.; Fida, M.

2008-01-01

To compare the seven methods of cephalometric analysis for assessing sagittal jaw relationship and to determine the level of agreement between them. Seven methods, describing anteroposterior jaw relationships (A-B plane, ANB, Wits, AXB, AF-BF, FABA and Beta angle) were measured on the lateral cephalographs of 85 patients. Correlation analysis, using Cramer's V-test, was performed to determine the possible agreement between the pair of analyses. The mean age of the sample, comprising 35 males and 50 females was 15 years and 3 months. Statistically significant relationships were found among seven sagittal parameters with p-value <0.001. Very strong correlation was found between AXB and AF-BF distance (r=0.924); and weak correlation between ANB and Beta angle (r=0.377). Wits appraisal showed the greatest coefficient of variability. Despite varying strengths of association, statistically significant correlations were found among seven methods for assessing sagittal jaw relationship. FABA and A-B plane may be used to predict the skeletal class in addition to the established ANB angle. (author)

JAW CYSTS AND GUIDED BONE REGENERATION (a late complication after enucleation

Directory of Open Access Journals (Sweden)

Hristina Lalabonova

2013-10-01

Full Text Available Maxillary jaw bone possesses a high regenerative capacity. Yet sometimes the defects enucleation of jaw cysts leaves may regenerate only partially or not at all. For this reason some researchers advise treatment of the residual cavities after cystectomy using bone regeneration stimulation methods. We report a case of an atypical complication after enucleation of a maxillary cyst manifesting itself eight years after the initial treatment. The symptoms the patient reported were at first periodic sweating on the left sides of face and head. This was followed by a piercing pain in the left palpebral fissure radiating to the middle of the palate and felt in the left cheekbone, left eye and left supraorbital ridge. The patient has a history of maxillary cysts recurring three times and of three operations she had 20, 12 and 8 years previously. The multiple recurrences of the cysts after their enucleation indicates poor regenerative capacity of the body which resulted in the formation of cicatricial tissue. It is most probably this tissue that was responsible for the disruption of the nerve conduction capacity which can account for the reported symptoms. We filled the cavity with bone graft material which boosted the bone structure regeneration. Although maxillary jaws possess high regenerative capacity we advise the use of guided bone regeneration in cases of large bone defects that usually occur after enucleation of jaw cysts.

Investigation of Pitch and Jaw Width to Decrease Delivery Time of Helical Tomotherapy Treatments for Head and Neck Cancer

International Nuclear Information System (INIS)

Moldovan, Monica; Fontenot, Jonas D.; Gibbons, John P.; Lee, Tae Kyu; Rosen, Isaac I.; Fields, Robert S.; Hogstrom, Kenneth R.

2011-01-01

Helical tomotherapy plans using a combination of pitch and jaw width settings were developed for 3 patients previously treated for head and neck cancer. Three jaw widths (5, 2.5, and 1 cm) and 4 pitches (0.86, 0.43, 0.287, and 0.215) were used with a (maximum) modulation factor setting of 4. Twelve plans were generated for each patient using an identical optimization procedure (e.g., number of iterations, objective weights, and penalties, etc.), based on recommendations from TomoTherapy (Madison, WI). The plans were compared using isodose plots, dose volume histograms, dose homogeneity indexes, conformity indexes, radiobiological models, and treatment times. Smaller pitches and jaw widths showed better target dose homogeneity and sparing of normal tissue, as expected. However, the treatment time increased inversely proportional to the jaw width, resulting in delivery times of 24 ± 1.9 min for the 1-cm jaw width. Although treatment plans produced with the 2.5-cm jaw were dosimetrically superior to plans produced with the 5-cm jaw, subsequent calculations of tumor control probabilities and normal tissue complication probabilities suggest that these differences may not be radiobiologically meaningful. Because treatment plans produced with the 5-cm jaw can be delivered in approximately half the time of plans produced with the 2.5-cm jaw (5.1 ± 0.6 min vs. 9.5 ± 1.1 min), use of the 5-cm jaw in routine treatment planning may be a viable approach to decreasing treatment delivery times from helical tomotherapy units.

Differences in loading of the temporomandibular joint during opening and closing of the jaw

NARCIS (Netherlands)

Tuijt, M.; Koolstra, J.H.; Lobbezoo, F.; Naeije, M.

2010-01-01

Kinematics of the human masticatory system during opening and closing of the jaw have been reported widely. Evidence has been provided that the opening and closing movement of the jaw differ from one another. However, different approaches of movement registration yield divergent expectations with

On The Evolution of Human Jaws and Teeth: A Review

Directory of Open Access Journals (Sweden)

Serhat Yalcin

2011-06-01

Full Text Available The jaws and teeth of Homo sapiens have evolved, from the last common ancestor of chimpanzee and men to their current form. Many factors such as the foods eaten and the processing of foods by fire and tools have effected this evolution course. The evolution of the masticatory complex is related to other anatomical features such as brain size and bipedal posture, and leads to important proceedings like the formation of speech and language. In this review, the evolution of human jaws and teeth and its impact on the general course of human evolution is discussed.

Electromagnetic Simulations of an Embedded BPM in Collimator Jaws

CERN Document Server

Boccard, C; Nosych, A

2011-01-01

Next gen­er­a­tion of the LHC col­li­ma­tors will be equipped with but­ton beam po­si­tion mon­i­tors (BPMs) em­bed­ded into the col­li­ma­tor jaws. Such a so­lu­tion will im­prove the ac­cu­ra­cy of the jaw align­ment with respect to the beam and re­duce the beam time nec­es­sary for the collima­tor setup. This paper de­scribes re­sults of elec­tro­mag­net­ic simu­la­tions of the jaw BPMs per­formed with the CST Par­ti­cle Stu­dio suite, aimed at char­ac­ter­i­sa­tion of the BPMs as well as the simulation soft­ware it­self. The re­sults are com­pared to the mea­sure­ments ob­tained with beam on a pro­to­type sys­tem in­stalled in the CERN SPS.

Influence of botulinum toxin on rabbit jaw muscle activity and anatomy.

Science.gov (United States)

Korfage, J A M; Wang, Jeffrey; Lie, S H J T J; Langenbach, Geerling E J

2012-05-01

Muscles can adapt their fiber properties to accommodate to new conditions. We investigated the extent to which a decrease in muscle activation can cause an adaptation of fiber properties in synergistic and antagonistic jaw muscles. Three months after the injection of botulinum toxin type A in one masseter (anterior or posterior) muscle changes in fiber type composition and fiber cross-sectional areas in jaw muscles were studied at the microscopic level. The injected masseter showed a steep increase in myosin type IIX fibers, whereas fast fibers decreased by about 50% in size. Depending on the injection site, both synergistic and antagonistic muscles showed a significant increase in the size of their fast IIA fibers, sometimes combined with an increased number of IIX fibers. Silencing the activity in the masseter not only causes changes in the fibers of the injected muscle but also leads to changes in other jaw muscles. Copyright © 2012 Wiley Periodicals, Inc.

A morphological study of the masseter muscle using magnetic resonance imaging in patients with jaw deformities. Cases demonstrating mandibular deviation

International Nuclear Information System (INIS)

Higashi, Katsuhiko; Goto, Tazuko K.; Kanda, Shigenobu; Shiratsuchi, Yuji; Nakashima, Akihiko; Horinouchi, Yasufumi

2006-01-01

Numerous studies on the cross-sectional area of masticatory muscles, which are correlated to the facial shape, have been reported for normal subjects in previous articles. However to date, there have been no such studies on masseter muscles at jaw-closing and jaw-opening in patients with jaw deformities involving mandibular deviation. The MRI data sets of the masseter muscles at jaw-closing and jaw-opening in 14 female patients with mandibular deviation, who demonstrated a more than 3-mm deviation in the median line in the lower first incisors in comparison to the upper ones, were utilized. The cross-sectional areas from the origin to the insertion at jaw-closing and jaw-opening which were reconstructed perpendicular to the three-dimensional long axis of each masseter muscle, each maximum cross-sectional area (MCSA) and the ratio of the change in MCSA after jaw-opening were analyzed. As a result, a significant difference was observed between the MCSA at jaw-closing and jaw-opening on the same side. However, no difference in MCSA was seen between the deviated and non-deviated side of the mandible. The line chart patterns of the masseter muscles from the origin to the insertion could be classified into four types. Our results suggest that it is important to analyze cross-sectional areas of the masseter muscles in each subject while considering the three-dimensional axis of each muscle. (author)

The relationship between jaw-opening force and the cross-sectional area of the suprahyoid muscles in healthy elderly.

Science.gov (United States)

Kajisa, E; Tohara, H; Nakane, A; Wakasugi, Y; Hara, K; Yamaguchi, K; Yoshimi, K; Minakuchi, S

2018-03-01

We conducted a clinical cross-sectional study to examine the relationship between jaw-opening force and the cross-sectional area of the suprahyoid muscles and whole skeletal muscle mass. Subjects were healthy 39 males and 51 females without dysphagia and sarcopenia, aged 65 years and older. Jaw-opening force was measured three times using a jaw-opening sthenometer; the maximum of these three was taken as the measurement value. The cross-sectional area of the geniohyoid and anterior belly of the digastric muscles were evaluated using ultrasonography. The skeletal muscle mass index, gait speed and grip strength were evaluated according to the diagnostic criteria of the Asian Working Group for Sarcopenia. For each sex, a multiple regression analysis determined the factors that affect jaw-opening force. Jaw-opening force was associated with the cross-sectional area of the geniohyoid muscle in males (regression coefficient [β] = 0.441, 95% confidence interval [CI] = 14.28-56.09) and females (β = 0.28, 95% CI = 3.10-54.57). Furthermore, in females only, jaw-opening force was associated with the skeletal muscle mass index (β = 0.40, 95% CI = 3.67-17.81). In contrast, jaw-opening force was not associated with the cross-sectional area of the anterior belly of the digastric muscle in either sex. In healthy elderly males and females, jaw-opening force was positively associated with the cross-sectional area of the geniohyoid muscle. However, the jaw-opening force was positively associated with the skeletal muscle mass index only in females. © 2017 John Wiley & Sons Ltd.

Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

International Nuclear Information System (INIS)

Jensen, Michael D.; Hrinivich, W. Thomas; Jung, Jongho A.; Holdsworth, David W.; Drangova, Maria; Chen, Jeff; Wong, Eugene

2013-01-01

Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm 2 were measured using EBT2 film in the center of a 70 × 70 × 22 mm 3 solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm 3 . A calibrated Farmer ion chamber in a 70 × 70 × 20 mm 3 solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm 2 . Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to 0.8 mm.Conclusions: A

Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

Energy Technology Data Exchange (ETDEWEB)

Jensen, Michael D. [Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Hrinivich, W. Thomas; Jung, Jongho A. [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Holdsworth, David W. [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Surgery, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Drangova, Maria [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8, Canada and Department of Medical Biophysics, The University of Western Ontario 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Chen, Jeff [Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Oncology, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Wong, Eugene [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Oncology, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada)

2013-08-15

Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm{sup 2} were measured using EBT2 film in the center of a 70 × 70 × 22 mm{sup 3} solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm{sup 3}. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm{sup 3} solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm{sup 2}. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to

Analysis of feeding function and jaw stability in bedridden elderly.

Science.gov (United States)

Tamura, Fumiyo; Mizukami, Miki; Ayano, Rika; Mukai, Yoshiharu

2002-01-01

The purpose of this study was to analyze the relationship between jaw stability and the feeding function of 53 bedridden elderly dysphagic patients. Investigations included a questionnaire on daily life activities and meals, oral examinations, functional tests for feeding ability, and assessments of feeding function during the meal. The results of intraoral examination of this patient population for jaw stability revealed that 34.0% of individuals had posterior support for occlusion regardless of whether they had natural teeth or dentures. Thus, the number classified as having mandibular stability (ST) was 18 and that with no mandibular stability (NST) was 35. In a Repetitive Saliva Swallowing Test (RSST), 83.3% of the NST group and 40.0% of the ST group were unable to swallow more than 3 times within 30 seconds. In a water swallowing test, 91.4% of the NST of group was unable to swallow 15 mL of water by a single swallow, while 40.0% of ST group was capable. The results suggest that jaw stabilization by occlusion with the posterior teeth or dental prosthetics is important to feeding function, particularly swallowing.

Evolution of Muscle Activity Patterns Driving Motions of the Jaw and Hyoid during Chewing in Gnathostomes

Science.gov (United States)

Konow, Nicolai; Herrel, Anthony; Ross, Callum F.; Williams, Susan H.; German, Rebecca Z.; Sanford, Christopher P. J.; Gintof, Chris

2011-01-01

Although chewing has been suggested to be a basal gnathostome trait retained in most major vertebrate lineages, it has not been studied broadly and comparatively across vertebrates. To redress this imbalance, we recorded EMG from muscles powering anteroposterior movement of the hyoid, and dorsoventral movement of the mandibular jaw during chewing. We compared muscle activity patterns (MAP) during chewing in jawed vertebrate taxa belonging to unrelated groups of basal bony fishes and artiodactyl mammals. Our aim was to outline the evolution of coordination in MAP. Comparisons of activity in muscles of the jaw and hyoid that power chewing in closely related artiodactyls using cross-correlation analyses identified reorganizations of jaw and hyoid MAP between herbivores and omnivores. EMG data from basal bony fishes revealed a tighter coordination of jaw and hyoid MAP during chewing than seen in artiodactyls. Across this broad phylogenetic range, there have been major structural reorganizations, including a reduction of the bony hyoid suspension, which is robust in fishes, to the acquisition in a mammalian ancestor of a muscle sling suspending the hyoid. These changes appear to be reflected in a shift in chewing MAP that occurred in an unidentified anamniote stem-lineage. This shift matches observations that, when compared with fishes, the pattern of hyoid motion in tetrapods is reversed and also time-shifted relative to the pattern of jaw movement. PMID:21705368

A case of early detection of bisphosphonate-related osteonecrosis of the jaw

OpenAIRE

Mori, Miyu; Koide, Tetsuro; Matsui, Yuriyo; Matsuda, Toru

2015-01-01

Osteonecrosis of the jaws is an adverse reaction associated with the use of bisphosphonates. Although the diagnosis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is based on symptomatology, it is often detected late because the patients become symptomatic only after osteonecrosis is well established. We describe a case of early oral BRONJ detected by magnetic resonance imaging (MRI) accidentally. Head MRI revealed low signal of T1-weight images in left mandibula. Patient had been...

Radiographic features of central giant cell granuloma of the jaws in children

International Nuclear Information System (INIS)

Bodner, L.; Bar-Ziv, J.

1996-01-01

The radiographic features of ten pediatric cases of central giant cell granuloma of the jaws were studied, using plain film radiography (PFR), computed tomography (CT), and a dental CT software program (DS). The radiologic features varied from ill-defined destructive lesions to a well-defined, multilocular appearance. Teeth or root displacement was found as the most consistent feature. Root resorption was rare. The features seen on CT were clearer than those seen on PFR. DS, by its visualization of the jaw in three plans - axial, panoramic, and buccolingual - provided useful information for determining the topography of the lesion in its structure (uni- or multilocular) and proximity to adjacent anatomic structures, such as teeth, nerves, or maxillary sinus. CT and, ideally, CT with DS should be used for diagnosis and surgical management of central giant cell granuloma of the jaws in children. (orig.). With 3 figs., 1 tab

Radiographic features of central giant cell granuloma of the jaws in children

Energy Technology Data Exchange (ETDEWEB)

Bodner, L. [Department of Oral and Maxillofacial Surgery, Soroka Medical Center, P. O. Box 151, Beer-Sheva 84101 (Israel); Bar-Ziv, J. [Department of Radiology, Hebrew University and Hadassah School of Medicine, Jerusalem (Israel)

1996-02-01

The radiographic features of ten pediatric cases of central giant cell granuloma of the jaws were studied, using plain film radiography (PFR), computed tomography (CT), and a dental CT software program (DS). The radiologic features varied from ill-defined destructive lesions to a well-defined, multilocular appearance. Teeth or root displacement was found as the most consistent feature. Root resorption was rare. The features seen on CT were clearer than those seen on PFR. DS, by its visualization of the jaw in three plans - axial, panoramic, and buccolingual - provided useful information for determining the topography of the lesion in its structure (uni- or multilocular) and proximity to adjacent anatomic structures, such as teeth, nerves, or maxillary sinus. CT and, ideally, CT with DS should be used for diagnosis and surgical management of central giant cell granuloma of the jaws in children. (orig.). With 3 figs., 1 tab.

REHABILITATION OF SEVERELY ATROPHIED UPPER JAW WITH INTRAOSSAL DENTAL IMPLANTS - clinical case

Directory of Open Access Journals (Sweden)

Ivan Chenchev

2010-07-01

Full Text Available Objective: The purpose of this presentation is to show the difficulty in prosthetization of a clinical case with a pronounced atrophy of the upper jaw and the various types and nature of restrictions imposed by the requirements of the patient. Methods: The clinical analysis, surgical protocol and prosthetic solution are presented in the treatment of 72 year-old woman with a pronounced atrophy of the upper jaw. OPG, standard CT of the upper jaw was used in the planning and a special surgical template was fabricated, helping us to find intraoperatively the exact locations of implants. The preliminary analysis of the number, height and diameter of intraossal implants helped us to find the exact prosthetic solution in this clinical case. The preparation of the implant bed was done by conical osteotomy in order to expand and condense the existing bone, which allowed us to use endoossal implants with a possible maximum size in a very limited maxillary volume and the reluctance of the patient to use other methods and surgical techniques. Conical threaded and self-tapping intraossal implants were used, placed according to a classic two-stage methodology with a flap and a long-term functional loading after a period of four months.Results and Conclusion: The applied surgical and prosthetic solution allowed us to achieve a good functional and aesthetic rehabilitation in this case of severe atrophy of the upper jaw, following a number of restrictions imposed on us by the reluctance of the patient to use other surgical solutions. This shows that in the case of severe atrophy of the upper jaw, a good clinical result can be achieved. For this reason, the use of CT,a well-planned surgical template, sufficient preparation ,the maximum use of available bone volume and the choice of a good prosthetic solution is very important.

New insights into dinosaur jaw muscle anatomy.

Science.gov (United States)

Holliday, Casey M

2009-09-01

Jaw muscles are key components of the head and critical to testing hypotheses of soft-tissue homology, skull function, and evolution. Dinosaurs evolved an extraordinary diversity of cranial forms adapted to a variety of feeding behaviors. However, disparate evolutionary transformations in head shape and function among dinosaurs and their living relatives, birds and crocodylians, impair straightforward reconstructions of muscles, and other important cephalic soft tissues. This study presents the osteological correlates and inferred soft tissue anatomy of the jaw muscles and relevant neurovasculature in the temporal region of the dinosaur head. Hypotheses of jaw muscle homology were tested across a broad range archosaur and sauropsid taxa to more accurately infer muscle attachments in the adductor chambers of non-avian dinosaurs. Many dinosaurs likely possessed m. levator pterygoideus, a trait shared with lepidosaurs but not extant archosaurs. Several major clades of dinosaurs (e.g., Ornithopoda, Ceratopsidae, Sauropoda) eliminated the epipterygoid, thus impacting interpretations of m. pseudotemporalis profundus. M. pseudotemporalis superficialis most likely attached to the caudoventral surface of the laterosphenoid, a trait shared with extant archosaurs. Although mm. adductor mandibulae externus profundus and medialis likely attached to the caudal half of the dorsotemporal fossa and coronoid process, clear osteological correlates separating the individual bellies are rare. Most dinosaur clades possess osteological correlates indicative of a pterygoideus ventralis muscle that attaches to the lateral surface of the mandible, although the muscle may have extended as far as the jugal in some taxa (e.g., hadrosaurs, tyrannosaurs). The cranial and mandibular attachments of mm adductor mandibulae externus superficialis and adductor mandibulae posterior were consistent across all taxa studied. These new data greatly increase the interpretive resolution of head anatomy in

Radiolucent rim as a possible diagnostic aid for differentiating jaw lesions

Science.gov (United States)

Mortazavi, Hamed; Rahmani, Somayeh; Jafari, Soudeh; Parvaei, Parvin

2015-01-01

In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as "jaw disease," "jaw lesions," "radiolucent rim," "radiolucent border," and "radiolucent halo." More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs. PMID:26730374

Comparative studies of jaw morphology and ontogeny in two species of asexually reproducing Dorvilleidae (Annelida)

DEFF Research Database (Denmark)

Macnaughton, Martin Oliver; Eibye-Jacobsen, Danny; Worsaae, Katrine

2011-01-01

found in closely related species (Macnaughton et al. 2009). Details of dentition and numbers of maxillary plates as well as the ontogenetic growth patterns of the jaws were found to provide significant information of systematic value. Based on detailed studies of jaw ontogeny and morphology, Dorvillea...

Emission computer tomographic orthopan display of the jaws - method and normal values

International Nuclear Information System (INIS)

Bockisch, A.; Koenig, R.; Biersack, H.J.; Wahl, G.

1990-01-01

A tomoscintigraphic method is described to create orthopan-like projections of the jaws from SPECT bone scans using cylinder projection. On the basis of this projection a numerical analysis of the dental regions is performed in the same computer code. For each dental region the activity relative to the contralateral region and relative to the average activity of the corresponding jaw is calculated. Using this method, a set of normal activity relations has been established by investigation of 24 patients. (orig.) [de

Osteonecrosis of the jaw after dental implant placement. A case report

Directory of Open Access Journals (Sweden)

J.L. Calvo-Guirado

2014-03-01

Full Text Available Background: In the past few years, the occurrence of an oral lesion, called osteonecrosis of the jaw, has increasingly been reported in patients undergoing treatment with systemic bisphosphonates (BPs; however, few papers dealing with oral biphosphonates related osteonecrosis of the jaws (BRONJ can be found in the literature. The purpose of the present case was to report an occurrence of BRONJ after implant insertion. Case report: Ten years ago, eight dental implants were inserted in the jaw of a 65-year-old female. After 5 years of treatment with alendronic acid, a breakdown of the oral mucosa covering the implants occurred with a purulent discharge in the left side of the jaw; periapical radiolucency was present around both distal implants. An en-block resection of the alveolar bone including the two implants was performed. Thirthy-five hyperbaric sessions were taken and no signs of recurrence of the lesion were observed after a follow-up of 20 months. Before the new implant insertion, the patient had suspended the treatment with alendronic acid for 6 months. At the interface of one of the implants, a gap was observed between bone and implant. This bone was non vital, and many osteocyte lacunae were empty. Moreover, this bone appeared to be partially demineralized. Conclusion: There is certainly a temporal association between oral BPs use and development of BRONJ, but a correlation does not necessarily mean causation. In patients undergoing oraltreatment, clinicians must be aware of the increased risk of implant failure.

The clinical value of X-ray images of the teeth and jaws

International Nuclear Information System (INIS)

Brocklebank, Laetitia

2003-01-01

X-ray images of the teeth and jaws are required for a variety of diagnostic purposes to supplement a clinical examination, and are invaluable for providing pictorial information about the structures that cannot be examined with direct vision. They can be acquired using traditional film systems which produce analogue images, or using a variety of alternative image receptors which result in a digital image. Irrespective of the method of image acquisition they are utilised by the dental surgeon in order to benefit their patients' management. Numerous disease processes can affect the teeth and jaws, in addition to a range of developmental abnormalities. These can be classified according to a radiological sieve, which also includes artefactual and iatrogenic features. The key components of the classification are: developmental, inflammatory, traumatic, cystic, neoplastic, osteodystrophies and systemic disorders. This paper will utilise examples of radiographic images of patients to illustrate components of this classification which are unique to the teeth and jaws

Jaw dysfunction is associated with neck disability and muscle tenderness in subjects with and without chronic temporomandibular disorders.

Science.gov (United States)

Silveira, A; Gadotti, I C; Armijo-Olivo, S; Biasotto-Gonzalez, D A; Magee, D

2015-01-01

Tender points in the neck are common in patients with temporomandibular disorders (TMD). However, the correlation among neck disability, jaw dysfunction, and muscle tenderness in subjects with TMD still needs further investigation. This study investigated the correlation among neck disability, jaw dysfunction, and muscle tenderness in subjects with and without chronic TMD. Participants. Forty females between 19 and 49 years old were included in this study. There were 20 healthy controls and 20 subjects who had chronic TMD and neck disability. Subjects completed the neck disability index and the limitations of daily functions in TMD questionnaires. Tenderness of the masticatory and cervical muscles was measured using an algometer. The correlation between jaw disability and neck disability was significantly high (r = 0.915, P cervical muscles with jaw dysfunction and neck disability showed fair to moderate correlations (r = 0.32-0.65). High levels of muscle tenderness in upper trapezius and temporalis muscles correlated with high levels of jaw and neck dysfunction. Moreover, high levels of neck disability correlated with high levels of jaw disability. These findings emphasize the importance of considering the neck and its structures when evaluating and treating patients with TMD.

The earliest herbivorous marine reptile and its remarkable jaw apparatus.

Science.gov (United States)

Chun, Li; Rieppel, Olivier; Long, Cheng; Fraser, Nicholas C

2016-05-01

Newly discovered fossils of the Middle Triassic reptile Atopodentatus unicus call for a radical reassessment of its feeding behavior. The skull displays a pronounced hammerhead shape that was hitherto unknown. The long, straight anterior edges of both upper and lower jaws were lined with batteries of chisel-shaped teeth, whereas the remaining parts of the jaw rami supported densely packed needle-shaped teeth forming a mesh. The evidence indicates a novel feeding mechanism wherein the chisel-shaped teeth were used to scrape algae off the substrate, and the plant matter that was loosened was filtered from the water column through the more posteriorly positioned tooth mesh. This is the oldest record of herbivory within marine reptiles.

Toolmarks made by lathe chuck jaws.

Science.gov (United States)

Finkelstein, Nir; Aronson, Ayal; Tsach, Tsadok

2017-06-01

This paper presents a forensic method to evidentially tie a workpiece with a specific lathe. Examining using this method can prove or exclude a connection between the two. The importance of this method is mostly due to the growing trend among lawbreakers of manufacturing improvised firearm parts using machining processes. This method is based on comparing jaw impressions made by the chuck on a workpiece. Copyright © 2017 Elsevier B.V. All rights reserved.

Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA

Energy Technology Data Exchange (ETDEWEB)

Han, Eun Young, E-mail: eyhan@uams.edu [Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR (United States); Kim, Dong-Wook [Department of Radiation Oncology, Kyung Hee University Hospital, Seoul (Korea, Republic of); Zhang, Xin; Penagaricano, Jose; Liang, Xiaoying; Hardee, Matthew; Morrill, Steve; Ratanatharathorn, Vaneerat [Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR (United States)

2015-10-01

It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently, the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy.

Brain activity associated with memory and cognitive function during jaw-tapping movement in healthy subjects using functional magnetic resonance imaging.

Science.gov (United States)

Cho, Seung-Yeon; Shin, Ae-Sook; Na, Byung-Jo; Jahng, Geon-Ho; Park, Seong-Uk; Jung, Woo-Sang; Moon, Sang-Kwan; Park, Jung-Mi

2013-06-01

To determine whether jaw-tapping movement, a classically described as an indication of personal well-being and mental health, stimulates the memory and the cognitive regions of the brain and is associated with improved brain performance. Twelve healthy right-handed female subjects completed the study. Each patient performed a jaw-tapping task and an n-back task during functional magnetic resonance imaging (fMRI). The subjects were trained to carry out the jaw-tapping movement at home twice a day for 4 weeks. The fMRI was repeated when they returned. During the first and second jaw-tapping session, both sides of precentral gyrus and the right middle frontal gyrus (BA 6) were activated. And during the second session of the jaw-tapping task, parts of frontal lobe and temporal lobe related to memory function were more activated. In addition, the total percent task accuracy in n-back task significantly increased after 4 weeks of jawtapping movement. After jaw-tapping training for 4 weeks, brain areas related to memory showed significantly increased blood oxygen level dependent signals. Jaw-tapping movement might be a useful exercise for stimulating the memory and cognitive regions of the brain.

surgical management of aggressive synchronous jaw central giant ...

African Journals Online (AJOL)

2012-08-08

Aug 8, 2012 ... Central giant cell granuloma ( CGCG) appears to be a lesion that is unique to the jaws. It is difficult to ... have been noted, particularly in the long bones. Though rare ... examination and biochemical and radiographic investigations are ... A photomicrograph depicting histopathologic features consistent with ...

Sella size and jaw bases - Is there a correlation???

Directory of Open Access Journals (Sweden)

Neha

2016-01-01

Full Text Available Introduction: Sella turcica is an important cephalometric structure and attempts have been made in the past to correlate its dimensions to the malocclusion. However, no study has so far compared the size of sella to the jaw bases that determine the type of malocclusion. The present study was undertaken to find out any such correlation if it exists. Materials and Methods: Lateral cephalograms of 110 adults consisting of 40 Class I, 40 Class II, and 30 Class III patients were assessed for the measurement of sella length, width, height, and area. The maxillary length, mandibular ramus height, and body length were also measured. The sella dimensions were compared among three malocclusion types by one-way ANOVA. Pearson correlation was calculated between the jaw size and sella dimensions. Furthermore, the ratio of jaw base lengths and sella area were calculated. Results and Conclusion: Mean sella length, width and area were found to be greatest in Class III, followed by Class I and least in Class II though the results were not statistically significant. 3 out of 4 measured dimensions of sella, correlated significantly with mandibular ramus and body length each. However, only one dimension of sella showed significant correlation with maxilla. The mandibular ramus and body length show a nearly constant ratio to sella area (0.83–0.85, 0.64–0.65, respectively in all the three malocclusions. Thus, mandible has a definite and better correlation to the size of sella turcica.

Ameloblastomatous Change in Radicular Cyst of The Jaw in a Nigerian Population.

Science.gov (United States)

Omoregie, F O; Sede, M A; Ojo, A M

2015-06-01

To determine the incidence, age, gender, jaw-sites and subtypes of radicular cyst, and to determine the incidence of ameloblastomatous change in radicular cyst in a Nigerian population. A 10-year retrospective analysis of all diagnosed orofacial lesions in the Department of Oral Pathology and Medicine, University of Benin Teaching Hospital, Benin City, Nigeria. From the 785 diagnosed orofacial lesions within the study period; there were 54 (6.9%) cases of radicular cysts of the jaws. The peak age group was the 3(rd) decade (n=23, 42.6%) with a mean age of 31 ± 1.7 years. There were 29 (53.7%) males and 25 (46.3%) females, giving a ratio of 1.2:1. The mandible was the commonest jaw-site (n=32, 59.3%). There were 12 (22.2%) cases of periapical cyst which were significantly associated with anterior maxillary site (n=8, 14.8%) [p=0.001]. Seven (13.0%) cases of cystic ameloblastoma were diagnosed among the radicular cysts, with a predilection of the lesions for 3(rd) and 4(th) decades of life (n=6, 11.1%), and posterior mandible (n=5, 9.3%). This study showed a low incidence of radicular cyst of the jaw among orofacial lesions and a relatively higher incidence of ameloblastomatous change in radicular cyst compared to previous reports. Immuno-histochemical examination is recommended to differentiate radicular cyst with ameloblastomatous-like change from cystic ameloblastoma arising from radicular cyst.

Dental diseases and radionuclide imaging of the jaws.

Science.gov (United States)

Arias, Jose A; Pardo, Carlos; Olmos, Antonio; Cuadrado, Maria L; Ruibal, Alvaro

2004-03-01

The aim of this study was to compare the results of radionuclide bone scans of the jaws with data obtained at the nuclear medicine department from a brief and feasible dental history, taking special account of cases with a positive scan and no recent dental events. Ninety-eight patients undergoing radionuclide bone scan as part of their diagnosis in non-dental, oncological and non-oncological diseases were imaged with 99mTc-labelled oxidronate. Superior and inferior halves of the mandible and maxilla (392 quadrants) were regarded as normal or having an abnormally high uptake. A recent (1 year) dental history was also obtained through a brief questionnaire and data were referred to each quadrant of the jaws. The association between the bone scan and dental disease was assessed by means of the chi-squared test. The overall results of scintigraphy and history coincided in 66 patients (46 with abnormal and 20 with normal findings; P = 0.002). Twenty-five patients had a positive scintigram without any known dental disorder. Results of scintigraphy and history coincided in 254 quadrants (78 with abnormal and 176 with normal findings; P < 0.001). Eighty-three quadrants had hot spots in the scintigram without any known dental lesion. It can be concluded that abnormal jaw scintigrams are frequent in patients without known dental disease, and this may indicate silent osteoblastic activity. These observations should be reported to the dentist for several reasons. First, they may reveal asymptomatic dental lesions. Second, the use of oral prostheses and implants is increasing and they require the support of healthy alveolar bone.

Some additional Notes on external Features and on the jaw muscles of Orthragoriscus mola (L.)

NARCIS (Netherlands)

Roon, van J.M.

1942-01-01

In 1939 J. M. van Roon and J. J. ter Pelkwijk published some data on two specimens of Orthragoriscus mola (L.) stranded on the Dutch coast. Measurements of bones and muscles of the jaw were given on account of the functional treatise concerning the mechanism of the jaw of Orthragoriscus given by Van

Oroantral fistula from bisphosphonate induced osteonecrosis of the jaw

Directory of Open Access Journals (Sweden)

Henry Sharp

2010-07-01

Full Text Available Bisphosphonates like alendronic acid, disodium etidronate, and risedronate are effective for preventing postmenopausal and corticosteroid induced osteoporosis. They are also useful in the treatment of Paget’s disease, hypercalcaemia of malignancy and in bony metastases. However osteonecrosis of the jaw has been reported following intravenous bisphosphonate use and rarely in those taking them orally.Increasingly, oroantral fistulae have been shown to occur as sequelae of bisphosphonate-induced osteonecrosis of the jaw and this case report highlights a patient that presented to our ENT department and required sinus surgery in collaboration with maxillofacial surgeons.This case report aims to raise awareness among ENT surgeons to these patients on bisphosphonates that could present to them with sinus disease from oroantral fistulae. There is an on-going audit in the maxillofacial community on this emerging trend.

Postural stability and the influence of concurrent muscle activation--Beneficial effects of jaw and fist clenching.

Science.gov (United States)

Ringhof, Steffen; Leibold, Timo; Hellmann, Daniel; Stein, Thorsten

2015-10-01

Recent studies reported on the potential benefits of submaximum clenching of the jaw on human postural control in upright unperturbed stance. However, it remained unclear whether these effects might also be observed among active controls. The purpose of the present study, therefore, was to comparatively examine the influence of concurrent muscle activation in terms of submaximum clenching of the jaw and submaximum clenching of the fists on postural stability. Posturographic analyses were conducted with 17 healthy young adults on firm and foam surfaces while either clenching the jaw (JAW) or clenching the fists (FIST), whereas habitual standing served as the control condition (CON). Both submaximum tasks were performed at 25% maximum voluntary contraction, assessed, and visualized in real time by means of electromyography. Statistical analyses revealed that center of pressure (COP) displacements were significantly reduced during JAW and FIST, but with no differences between both concurrent clenching activities. Further, a significant increase in COP displacements was observed for the foam as compared to the firm condition. The results showed that concurrent muscle activation significantly improved postural stability compared with habitual standing, and thus emphasize the beneficial effects of jaw and fist clenching for static postural control. It is suggested that concurrent activities contribute to the facilitation of human motor excitability, finally increasing the neural drive to the distal muscles. Future studies should evaluate whether elderly or patients with compromised postural control might benefit from these physiological responses, e.g., in the form of a reduced risk of falling. Copyright © 2015 Elsevier B.V. All rights reserved.

The evolution of jaw protrusion mechanics is tightly coupled to bentho-pelagic divergence in damselfishes (Pomacentridae).

Science.gov (United States)

Cooper, W James; Carter, Casey B; Conith, Andrew J; Rice, Aaron N; Westneat, Mark W

2017-02-15

Most species-rich lineages of aquatic organisms have undergone divergence between forms that feed from the substrate (benthic feeding) and forms that feed from the water column (pelagic feeding). Changes in trophic niche are frequently accompanied by changes in skull mechanics, and multiple fish lineages have evolved highly specialized biomechanical configurations that allow them to protrude their upper jaws toward the prey during feeding. Damselfishes (family Pomacentridae) are an example of a species-rich lineage with multiple trophic morphologies and feeding ecologies. We sought to determine whether bentho-pelagic divergence in the damselfishes is tightly coupled to changes in jaw protrusion ability. Using high-speed video recordings and kinematic analysis, we examined feeding performance in 10 species that include three examples of convergence on herbivory, three examples of convergence on omnivory and two examples of convergence on planktivory. We also utilized morphometrics to characterize the feeding morphology of an additional 40 species that represent all 29 damselfish genera. Comparative phylogenetic analyses were then used to examine the evolution of trophic morphology and biomechanical performance. We find that pelagic-feeding damselfishes (planktivores) are strongly differentiated from extensively benthic-feeding species (omnivores and herbivores) by their jaw protrusion ability, upper jaw morphology and the functional integration of upper jaw protrusion with lower jaw abduction. Most aspects of cranial form and function that separate these two ecological groups have evolved in correlation with each other and the evolution of the functional morphology of feeding in damselfishes has involved repeated convergence in form, function and ecology. © 2017. Published by The Company of Biologists Ltd.

APPLICATION OF 3D MODELING IN 3D PRINTING FOR THE LOWER JAW RECONSTRUCTION

Directory of Open Access Journals (Sweden)

Yu. Yu. Dikov

2015-01-01

Full Text Available Aim of study: improvement of functional and aesthetic results of microsurgery reconstructions of the lower jaw due to the use of the methodology of 3D modeling and 3D printing. Application of this methodology has been demonstrated on the example of treatment of 4 patients with locally distributed tumors of the mouth cavity, who underwent excision of the tumor with simultaneous reconstruction of the lower jaw with revascularized fibular graft.Before, one patient has already undergo segmental resection of the lower jaw with the defect replacement with the avascular ileac graft and a reconstruction plate. Then, a relapse of the disease and lysis of the graft has developed with him. Modeling of the graft according to the shape of the lower jaw was performed by making osteotomies of the bone part of the graft using three-dimensional virtual models created by computed tomography data. Then these 3D models were printed with a 3D printer of plastic with the scale of 1:1 with the fused deposition modeling (FDM technology and were used during the surgery in the course of modeling of the graft. Sterilizing of the plastic model was performed in the formalin chamber.This methodology allowed more specific reconstruction of the resected fragment of the lower jaw and get better functional and aesthetic results and prepare patients to further dental rehabilitation. Advantages of this methodology are the possibility of simultaneous performance of stages of reconstruction and resection and shortening of the time of surgery.

Convergent evolution of jaws between spinosaurid dinosaurs and pike conger eels

Directory of Open Access Journals (Sweden)

Romain Vullo

2016-12-01

Full Text Available Spinosaurs represent a group of peculiar theropod dinosaurs that have often been described as “crocodile-mimic”, predominantly fish-eating predators, and recently claimed to have been semi-aquatic animals. Here we report a suite of craniodental characters unexpectedly shared by spinosaurs and pike conger eels. Pike conger eels are predatory, mainly piscivorous bottom-dwelling anguilliform fishes that inhabit marine and brackish environments. These two groups of dinosaurs and fishes show a mediolaterally compressed, elongated rostrum, a terminal “rosette” bearing enlarged teeth in both upper and lower jaws, and a notch posterior to the premaxillary “rosette” characterized by the presence of reduced teeth. The morphological convergence observed in the jaws of these two distantly related groups of vertebrates may result from similar feeding behaviours. This typical jaw morphology likely represents an effective biomechanical adaptation for biting and grabbing elusive prey items in low-light aquatic environments. Associated with this specialized snout morphology, numerous integumentary mechanoreceptors involved in prey detection are present in both spinosaurs and pike congers. Our new observations provide an additional convincing argument regarding the decades-long and widely debated lifestyle of spinosaurs.

Radiolucent rim as a possible diagnostic aid for differentiating jaw lesions

Energy Technology Data Exchange (ETDEWEB)

Mortazavi, Hamed; Baharvand, Maryam; Rarahmani, Somayeh; Jafati, Soudeh; Parvaei, Parvin [Oral Medicine, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2015-12-15

In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as 'jaw disease,' 'jaw lesions,' 'radiolucent rim,' 'radiolucent border,' and 'radiolucent halo.' More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs.

Radiolucent rim as a possible diagnostic aid for differentiating jaw lesions

International Nuclear Information System (INIS)

Mortazavi, Hamed; Baharvand, Maryam; Rarahmani, Somayeh; Jafati, Soudeh; Parvaei, Parvin

2015-01-01

In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as 'jaw disease,' 'jaw lesions,' 'radiolucent rim,' 'radiolucent border,' and 'radiolucent halo.' More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs

Cell based bone tissue engineering in jaw defects

NARCIS (Netherlands)

Meijer, Gert J.; de Bruijn, Joost Dick; Koole, Ron; van Blitterswijk, Clemens

2008-01-01

In 6 patients the potency of bone tissue engineering to reconstruct jaw defects was tested. After a bone marrow aspirate was taken, stem cells were cultured, expanded and grown for 7 days on a bone substitute in an osteogenic culture medium to allow formation of a layer of extracellular bone matrix.

Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement.

Science.gov (United States)

Yunus, Barunawaty

2011-06-01

This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement

Energy Technology Data Exchange (ETDEWEB)

Yunus, Barunawaty [Faculty of Dentistry, Hasanuddin University, Makassar (Malaysia)

2011-06-15

This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement

International Nuclear Information System (INIS)

Yunus, Barunawaty

2011-01-01

This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

Hyperparathyroidism-jaw Tumor Syndrome: An Overlooked Cause of Severe Hypercalcemia.

Science.gov (United States)

Mathews, Joseph Wolfgang; Winchester, Rhonda; Alsaygh, Nebras; Bartlett, Anne M; Luttrell, Louis

2016-09-01

Ossifying fibromas of the maxillofacial bones are an uncommon form of benign neoplasm usually treated by surgical excision. Up to 30% of patients with hyperparathyroidism-jaw tumor syndrome, a rare form of multiple endocrine neoplasia resulting from autosomal dominant inactivating mutation of the Hrpt2 tumor suppressor gene, initially present with ossifying fibromas. Coincident hypercalcemia because of the presence of parathyroid adenoma is common in these patients, of whom 15% may have or may develop parathyroid carcinoma. The authors present a case of severe postsurgical hypercalcemia after removal of a large maxillary ossifying fibroma in a patient with previously unrecognized hyperparathyroidism-jaw tumor AU3 syndrome. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Modulation of jaw muscle spindle afferent activity following intramuscular injections with hypertonic saline.

Science.gov (United States)

Ro, J Y; Capra, N F

2001-05-01

Transient noxious chemical stimulation of small diameter muscle afferents modulates jaw movement-related responses of caudal brainstem neurons. While it is likely that the effect is mediated from the spindle afferents in the mesencephalic nucleus (Vmes) via the caudally projecting Probst's tract, the mechanisms of pain induced modulations of jaw muscle spindle afferents is not known. In the present study, we tested the hypothesis that jaw muscle nociceptors gain access to muscle spindle afferents in the same muscle via central mechanisms and alter their sensitivity. Thirty-five neurons recorded from the Vmes were characterized as muscle spindle afferents based on their responses to passive jaw movements, muscle palpation, and electrical stimulation of the masseter nerve. Each cell was tested by injecting a small volume (250 microl) of either 5% hypertonic and/or isotonic saline into the receptor-bearing muscle. Twenty-nine units were tested with 5% hypertonic saline, of which 79% (23/29) showed significant modulation of mean firing rates (MFRs) during one or more phases of ramp-and-hold movements. Among the muscle spindle primary-like units (n = 12), MFRs of 4 units were facilitated, five reduced, two showed mixed responses and one unchanged. In secondary-like units (n = 17), MFRs of 9 were facilitated, three reduced and five unchanged. Thirteen units were tested with isotonic saline, of which 77% showed no significant changes of MFRs. Further analysis revealed that the hypertonic saline not only affected the overall output of muscle spindle afferents, but also increased the variability of firing and altered the relationship between afferent signal and muscle length. These results demonstrated that activation of muscle nociceptors significantly affects proprioceptive properties of jaw muscle spindles via central neural mechanisms. The changes can have deleterious effects on oral motor function as well as kinesthetic sensibility.

Jaw cyst-Basal cell nevus-Bifid rib syndrome: A case report

Directory of Open Access Journals (Sweden)

Rai S

2007-09-01

Full Text Available Jaw cyst-Basal cell nevus-Bifid rib syndrome or Gorlin-Goltz syndrome involves multiple organ system. The most common findings include multiple odontogenic keratocysts in the jaws and basal cell nevus on the skin that have an early age onset. These multiple odontogenic keratocysts warrant aggressive treatment at the earliest because of the damage and possible complications associated with them. Recurrence in these lesions is the most characteristic feature that has to be taken in consideration while explaining the prognosis to the patient. A case report of a child affected with Gorlin-Goltz syndrome diagnosed, treated and followed at this hospital is presented here.

Prevention of functional disorders of temple-lower-jaw joints in the orthopedic treatment of patients with terminal defects of teeth row

Directory of Open Access Journals (Sweden)

Tokmakova E.V.

2011-03-01

Full Text Available The study of temple-lower-jaw joints was provided in 40 patients with defects of teeth row, complicated with distal displacement of lower jaw. It was functional disorders of temple-lower-jaw joint and identified the possibility of their prevention

Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA.

Science.gov (United States)

Han, Eun Young; Kim, Dong-Wook; Zhang, Xin; Penagaricano, Jose; Liang, Xiaoying; Hardee, Matthew; Morrill, Steve; Ratanatharathorn, Vaneerat

2015-01-01

It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently, the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy. Copyright © 2015 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation

Directory of Open Access Journals (Sweden)

Salzburger Walter

2011-04-01

Full Text Available Abstract Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp. in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among

Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation.

Science.gov (United States)

Muschick, Moritz; Barluenga, Marta; Salzburger, Walter; Meyer, Axel

2011-04-30

Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp.) in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated--among other traits--between Midas Cichlid species, its plasticity

Processing system of jaws tomograms for pathology identification and surgical guide modeling

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Putrik, M. B., E-mail: pmb-88@mail.ru; Ivanov, V. Yu. [Ural Federal University named after the first President of Russia B.N. Yeltsin, Yekaterinburg (Russian Federation); Lavrentyeva, Yu. E. [Private dental clinic «Uraldent», Yekaterinburg (Russian Federation)

2015-11-17

The aim of the study is to create an image processing system, which allows dentists to find pathological resorption and to build surgical guide surface automatically. X-rays images of jaws from cone beam tomography or spiral computed tomography are the initial data for processing. One patient’s examination always includes up to 600 images (or tomograms), that’s why the development of processing system for fast automation search of pathologies is necessary. X-rays images can be useful not for only illness diagnostic but for treatment planning too. We have studied the case of dental implantation – for successful surgical manipulations surgical guides are used. We have created a processing system that automatically builds jaw and teeth boundaries on the x-ray image. After this step, obtained teeth boundaries used for surgical guide surface modeling and jaw boundaries limit the area for further pathologies search. Criterion for the presence of pathological resorption zones inside the limited area is based on statistical investigation. After described actions, it is possible to manufacture surgical guide using 3D printer and apply it in surgical operation.

Processing system of jaws tomograms for pathology identification and surgical guide modeling

International Nuclear Information System (INIS)

Putrik, M. B.; Ivanov, V. Yu.; Lavrentyeva, Yu. E.

2015-01-01

The aim of the study is to create an image processing system, which allows dentists to find pathological resorption and to build surgical guide surface automatically. X-rays images of jaws from cone beam tomography or spiral computed tomography are the initial data for processing. One patient’s examination always includes up to 600 images (or tomograms), that’s why the development of processing system for fast automation search of pathologies is necessary. X-rays images can be useful not for only illness diagnostic but for treatment planning too. We have studied the case of dental implantation – for successful surgical manipulations surgical guides are used. We have created a processing system that automatically builds jaw and teeth boundaries on the x-ray image. After this step, obtained teeth boundaries used for surgical guide surface modeling and jaw boundaries limit the area for further pathologies search. Criterion for the presence of pathological resorption zones inside the limited area is based on statistical investigation. After described actions, it is possible to manufacture surgical guide using 3D printer and apply it in surgical operation

Imaging of jaw with dental CT software program: Normal Anatomy

International Nuclear Information System (INIS)

Kim, Myong Gon; Seo, Kwang Hee; Jung, Hak Young; Sung, Nak Kwan; Chung, Duk Soo; Kim, Ok Dong; Lee, Young Hwan

1994-01-01

Dental CT software program can provide reformatted cross-sectional and panoramic images that cannot be obtained with conventional axial and direct coronal CT scan. The purpose of this study is to describe the method of the technique and to identify the precise anatomy of jaw. We evaluated 13 mandibles and 7 maxillae of 15 subjects without bony disease who were being considered for endosseous dental implants. Reformatted images obtained by the use of bone algorithm performed on GE HiSpeed Advantage CT scanner were retrospectively reviewed for detailed anatomy of jaw. Anatomy related to neurovascular bundle(mandibular foramen, inferior alveolar canal, mental foramen, canal for incisive artery, nutrient canal, lingual foramen and mylohyoid groove), muscular insertion(mylohyoid line, superior and inferior genial tubercle and digastric fossa) and other anatomy(submandibular fossa, sublingual fossa, contour of alveolar process, oblique line, retromolar fossa, temporal crest and retromolar triangle) were well delineated in mandible. In maxilla, anatomy related to neurovascular bundle(greater palatine foramen and groove, nasopalatine canal and incisive foramen) and other anatomy(alveolar process, maxillary sinus and nasal fossa) were also well delineated. Reformatted images using dental CT software program provided excellent delineation of the jaw anatomy. Therefore, dental CT software program can play an important role in the preoperative assessment of mandible and maxilla for dental implants and other surgical conditions

Jaw Dysfunction Related to Pterygoid and Masseter Muscle Dosimetry After Radiation Therapy in Children and Young Adults With Head-and-Neck Sarcomas

International Nuclear Information System (INIS)

Krasin, Matthew J.; Wiese, Kristin M.; Spunt, Sheri L.; Hua, Chia-ho; Daw, Najat; Navid, Fariba; Davidoff, Andrew M.; McGregor, Lisa; Merchant, Thomas E.; Kun, Larry E.; McCrarey, Lola

2012-01-01

Purpose: To investigate the relationship between jaw function, patient and treatment variables, and radiation dosimetry of the mandibular muscles and joints in children and young adults receiving radiation for soft-tissue and bone sarcomas. Methods and Materials: Twenty-four pediatric and young adult patients with head-and-neck sarcomas were treated on an institutional review board−approved prospective study of focal radiation therapy for local tumor control. Serial jaw depression measurements were related to radiation dosimetry delivered to the medial and lateral pterygoid muscles, masseter muscles, and temporomandibular joints to generate mathematical models of jaw function. Results: Baseline jaw depression was only influenced by the degree of surgical resection. In the first 12 weeks from initiation of radiation, surgical procedures greater than a biopsy, administration of cyclophosphamide containing chemotherapy regimes, and large gross tumor volumes adversely affected jaw depression. Increasing dose to the pterygoid and masseter muscles above 40 Gy predicted loss of jaw function over the full course of follow-up. Conclusions: Clinical and treatment factors are related to initial and subsequent jaw dysfunction. Understanding these complex interactions and the affect of specific radiation doses may help reduce the risk for jaw dysfunction in future children and young adults undergoing radiation therapy for the management of soft-tissue and bone sarcomas.

Jaw Dysfunction Related to Pterygoid and Masseter Muscle Dosimetry After Radiation Therapy in Children and Young Adults With Head-and-Neck Sarcomas

Energy Technology Data Exchange (ETDEWEB)

Krasin, Matthew J., E-mail: matthew.krasin@stjude.org [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Wiese, Kristin M. [Department of Rehabilitation Services, St. Jude Children' s Research Hospital, Memphis, TN (United States); Spunt, Sheri L. [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Hua, Chia-ho [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Daw, Najat [Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Navid, Fariba [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Davidoff, Andrew M. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Surgery, University of Tennessee College of Medicine, Memphis, TN (United States); McGregor, Lisa [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee College of Medicine, Memphis, TN (United States); Merchant, Thomas E.; Kun, Larry E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); McCrarey, Lola [Department of Rehabilitation Services, St. Jude Children' s Research Hospital, Memphis, TN (United States); and others

2012-01-01

Purpose: To investigate the relationship between jaw function, patient and treatment variables, and radiation dosimetry of the mandibular muscles and joints in children and young adults receiving radiation for soft-tissue and bone sarcomas. Methods and Materials: Twenty-four pediatric and young adult patients with head-and-neck sarcomas were treated on an institutional review board-approved prospective study of focal radiation therapy for local tumor control. Serial jaw depression measurements were related to radiation dosimetry delivered to the medial and lateral pterygoid muscles, masseter muscles, and temporomandibular joints to generate mathematical models of jaw function. Results: Baseline jaw depression was only influenced by the degree of surgical resection. In the first 12 weeks from initiation of radiation, surgical procedures greater than a biopsy, administration of cyclophosphamide containing chemotherapy regimes, and large gross tumor volumes adversely affected jaw depression. Increasing dose to the pterygoid and masseter muscles above 40 Gy predicted loss of jaw function over the full course of follow-up. Conclusions: Clinical and treatment factors are related to initial and subsequent jaw dysfunction. Understanding these complex interactions and the affect of specific radiation doses may help reduce the risk for jaw dysfunction in future children and young adults undergoing radiation therapy for the management of soft-tissue and bone sarcomas.

Modulation of human exteroceptive jaw reflexes during simulated mastication

NARCIS (Netherlands)

Lobbezoo, F.; Sowman, P.F.; Türker, K.S.

2009-01-01

Objective: To investigate changes in synaptic input from lower lip afferents to human jaw muscle motoneurons during simulated mastication. Methods: The lower lip of 14 subjects was stimulated electrically under static and dynamic conditions. In the static condition, subjects bit at mid-open position

Manajemen Pelayanan Mahasiswa Difabel di PLD UIN Sunan Kalijaga Berbasis Komputer Job Access with Speech (JAWS

Directory of Open Access Journals (Sweden)

Kuzaemah

2017-05-01

Full Text Available This research attempt to meganalisis how management of computer service JAWS for student of blind at PLD UIN Sunan Kalijaga Yogyakarta. This research is a field research using qualitative approach. Data collection is done through observation, interview, and documentation. The results of this study indicate that JAWS Computer Service Management in PLD UIN Sunan Kalijaga Yogyakarta includes several management functions, the first, the planning of the PLD chairman determines the schedule of activities. Second, the organizing of the PLD chair divides the duties of each position. Third, the implementation of all PLD members who have been tasked by the leader perform their duties respectively. Fourth, supervision of all activities in the PLD is always monitored and held a regular meeting to find out the problems faced so that can be solved together. Benefits of the existence of JAWS computer service is to increase knowledge of technology for blind students and train the independence of blind students in doing lecture tasks that blessed with typing as well as paper assignments, thesis and so on. The factors supporting the implementation of JAWS computer service that is the spirit of learning blind students and the help of PLD volunteers. For the inhibiting factor is the number of JAWS computers are very limited so they have to take turns in using it

Msx-1 is suppressed in bisphosphonate-exposed jaw bone analysis of bone turnover-related cell signalling after bisphosphonate treatment.

Science.gov (United States)

Wehrhan, F; Hyckel, P; Amann, K; Ries, J; Stockmann, P; Schlegel, Ka; Neukam, Fw; Nkenke, E

2011-05-01

Bone-destructive disease treatments include bisphosphonates and antibodies against receptor activator for nuclear factor κB ligand (aRANKL). Osteonecrosis of the jaw (ONJ) is a side-effect. Aetiopathology models failed to explain their restriction to the jaw. The osteoproliferative transcription factor Msx-1 is expressed constitutively only in mature jaw bone. Msx-1 expression might be impaired in bisphosphonate-related ONJ. This study compared the expression of Msx-1, Bone Morphogenetic Protein (BMP)-2 and RANKL, in ONJ-affected and healthy jaw bone. An automated immunohistochemistry-based alkaline phosphatase-anti-alkaline phosphatase method was used on ONJ-affected and healthy jaw bone samples (n = 20 each): cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed to quantitatively compare Msx-1, BMP-2, RANKL and GAPDH mRNA levels. Labelling indices were significantly lower for Msx-1 (P Msx-1, 22-fold lower (P Msx-1, RANKL suppression and BMP-2 induction were consistent with the bisphosphonate-associated osteopetrosis and impaired bone remodelling in BP- and aRANKL-induced ONJ. Msx-1 suppression suggested a possible explanation of the exclusivity of ONJ in jaw bone. Functional analyses of Msx-1- RANKL interaction during bone remodelling should be performed in the future. © 2011 John Wiley & Sons A/S.

Diagnostic sensitivity and specificity in a retrospective clinical, radiographic and histopathological study of 166 cystic jaw lesions

DEFF Research Database (Denmark)

Therkildsen, N. M.; Andersen, Kristian; Blomlôf, J.

2014-01-01

, but a low diagnostic sensitivity in relation to the keratocystic odontogenic tumour (KCOT) was revealed. The radicular cyst, dentigerous cyst and KCOT were the most frequently observed cystic jaw lesions. Conclusion In general, a high diagnostic specificity for all cystic jaw lesions was observed. A low...

Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles.

Science.gov (United States)

Capra, N F; Ro, J Y

2000-05-01

The aim of the present study was to investigate the effects of intramuscular injection with hypertonic saline, a well-established experimental model for muscle pain, on central processing of proprioceptive input from jaw muscle spindle afferents. Fifty-seven cells were recorded from the medial edge of the subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation from 11 adult cats. These cells were characterized as central units receiving jaw muscle spindle input based on their responses to electrical stimulation of the masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were successfully tested with 5% hypertonic saline, were categorized as either dynamic-static (DS) (n=25) or static (S) (n=20) neurons based on their responses to different speeds and amplitudes of jaw movement. Seventy-six percent of the cells tested with an ipsilateral injection of hypertonic saline showed a significant modulation of mean firing rates (MFRs) during opening and/or holding phases. The most remarkable saline-induced change was a significant reduction of MFR during the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS units (11/16 modulated) also showed significant changes in MFRs limited to the hold phase. However, in the DS neurons, the MFRs increased in seven units and decreased in four units. Finally, five DS neurons showed significant changes of MFRs during both opening and holding phases. Injections of isotonic saline into the ipsilateral masseter muscle had little effect, but hypertonic saline injections made into the contralateral masseter muscle produced similar results to ipsilateral injections with hypertonic saline. These results unequivocally demonstrate that intramuscular injection with an algesic substance, sufficient to produce muscle pain, produces significant changes in the proprioceptive properties of the jaw movement-related neurons. Potential mechanisms involved in saline-induced changes in the

Jaw lever analysis of Hawaiian gobioid stream fishes: a simulation study of morphological diversity and functional performance.

Science.gov (United States)

Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

2009-08-01

Differences in feeding behavior and performance among the five native Hawaiian gobioid stream fishes (Sicyopterus stimpsoni, Lentipes concolor, Awaous guamensis, Stenogobius hawaiiensis, and Eleotris sandwicensis) have been proposed based on the skeletal anatomy of their jaws and dietary specialization. However, performance of the feeding apparatus likely depends on the proportions and configurations of the jaw muscles and the arrangement of the jaw skeleton. We used a published mathematical model of muscle function to evaluate potential differences in jaw closing performance and their correlations with morphology among these species. For example, high output force calculated for the adductor mandibulae muscles (A2 and A3) of both A. guamensis and E. sandwicensis matched expectations based on the morphology of these species because these muscles are larger than in the other species. In contrast, Stenogobius hawaiiensis exhibited an alternative morphological strategy for achieving high relative output forces of both A2 and A3, in which the placement and configuration of the muscles conveyed high mechanical advantage despite only moderate cross-sectional areas. These differing anatomical pathways to similar functional performance suggest a pattern of many-to-one mapping of morphology to performance. In addition, a functional differentiation between A2 and A3 was evident for all species, in which A2 was better suited for producing forceful jaw closing and A3 for rapid jaw closing. Thus, the diversity of feeding performance of Hawaiian stream gobies seems to reflect a maintenance of functional breadth through the retention of some primitive traits in combination with novel functional capacities in several species. (c) 2009 Wiley-Liss, Inc.

Evaluation of jaw and neck muscle activities while chewing using EMG-EMG transfer function and EMG-EMG coherence function analyses in healthy subjects.

Science.gov (United States)

Ishii, Tomohiro; Narita, Noriyuki; Endo, Hiroshi

2016-06-01

This study aims to quantitatively clarify the physiological features in rhythmically coordinated jaw and neck muscle EMG activities while chewing gum using EMG-EMG transfer function and EMG-EMG coherence function analyses in 20 healthy subjects. The chewing side masseter muscle EMG signal was used as the reference signal, while the other jaw (non-chewing side masseter muscle, bilateral anterior temporal muscles, and bilateral anterior digastric muscles) and neck muscle (bilateral sternocleidomastoid muscles) EMG signals were used as the examined signals in EMG-EMG transfer function and EMG-EMG coherence function analyses. Chewing-related jaw and neck muscle activities were aggregated in the first peak of the power spectrum in rhythmic chewing. The gain in the peak frequency represented the power relationships between jaw and neck muscle activities during rhythmic chewing. The phase in the peak frequency represented the temporal relationships between the jaw and neck muscle activities, while the non-chewing side neck muscle presented a broad range of distributions across jaw closing and opening phases. Coherence in the peak frequency represented the synergistic features in bilateral jaw closing muscles and chewing side neck muscle activities. The coherence and phase in non-chewing side neck muscle activities exhibited a significant negative correlation. From above, the bilateral coordination between the jaw and neck muscle activities is estimated while chewing when the non-chewing side neck muscle is synchronously activated with the jaw closing muscles, while the unilateral coordination is estimated when the non-chewing side neck muscle is irregularly activated in the jaw opening phase. Thus, the occurrence of bilateral or unilateral coordinated features in the jaw and neck muscle activities may correspond to the phase characteristics in the non-chewing side neck muscle activities during rhythmical chewing. Considering these novel findings in healthy subjects, EMG

The effect of food bolus location on jaw movement smoothness and masticatory efficiency.

Science.gov (United States)

Molenaar, W N B; Gezelle Meerburg, P J; Luraschi, J; Whittle, T; Schimmel, M; Lobbezoo, F; Peck, C C; Murray, G M; Minami, I

2012-09-01

Masticatory efficiency in individuals with extensive tooth loss has been widely discussed. However, little is known about jaw movement smoothness during chewing and the effect of differences in food bolus location on movement smoothness and masticatory efficiency. The aim of this study was to determine whether experimental differences in food bolus location (anterior versus posterior) had an effect on masticatory efficiency and jaw movement smoothness. Jaw movement smoothness was evaluated by measuring jerk-cost (calculated from acceleration) with an accelerometer that was attached to the skin of the mentum of 10 asymptomatic subjects, and acceleration was recorded during chewing on two-colour chewing gum, which was used to assessed masticatory efficiency. Chewing was performed under two conditions: posterior chewing (chewing on molars and premolars only) and anterior chewing (chewing on canine and first premolar teeth only). Jerk-cost and masticatory efficiency (calculated as the ratio of unmixed azure colour to the total area of gum, the unmixed fraction) were compared between anterior and posterior chewing with the Wilcoxon signed rank test (two-tailed). Subjects chewed significantly less efficiently during anterior chewing than during posterior chewing (P = 0·0051). There was no significant difference in jerk-cost between anterior and posterior conditions in the opening phase (P = 0·25), or closing phase (P = 0·42). This is the first characterisation of the effect of food bolus location on jaw movement smoothness at the same time as recording masticatory efficiency. The data suggest that anterior chewing decreases masticatory efficiency, but does not influence jerk-cost. © 2012 Blackwell Publishing Ltd.

Central Giant Cell Granuloma of the Jaws: Correlation between Vascularity and Biologic Behavior

Directory of Open Access Journals (Sweden)

Saede Atarbashi Moghadam

2017-03-01

Full Text Available Introduction: Giant cell lesions of the bone comprise a group of jaw bone pathologies. Different pathogeneses such as reactive, vascular or neoplastic have been proposed for these lesions. In addition, differentiating between aggressive and nonaggressive central giant cell granuloma (CGCG of the jaws based on histopathologic features is still impossible and due to different treatment protocols for the two groups, correct diagnosis is necessary. The purpose of this study was to compare the expression of CD34 between aggressive and nonaggressive CGCGs of the jaws. Methods & Materials: This retrospective study was carried out on 16 paraffin blocks in each aggressive and nonaggressive CGCGs group. The expression of CD34 was evaluated with immunohistochemical technique. Afterwards, t-test was used for quantitative evaluation and comparison of CD34 expression among the two groups. Eventually, statistical analysis was performed using Spss20 software. Significance was assigned at p < 0.05. Results: In the present study, the average age of patients in aggressive and nonaggressive groups was 20.93±8.08 and 26.18±16.97, respectively. In both groups, female predilection was observed. Mandible was the most common site of involvement in the aggressive group and the distribution of nonaggressive lesions was equal between both jaws. Although the expression of CD34 in the aggressive group was higher than the nonaggressive group, no statistically significant difference was seen (p=0.15. Conclusion: According to the results of the current study, it appears that CD34 protein cannot be used for identifying the clinical behavior of CGCGs.

SU-E-T-346: Effect of Jaw Position On Dose to Critical Structures in 3-D Conformal Radiotherapy Treatment of Pancreatic Cancer

Energy Technology Data Exchange (ETDEWEB)

Paudel, N; Han, E; Liang, X; Morrill, S; Zhang, X; Hardee, M; Penagaricano, J; Ratanatharathorn, V [Vaneerat, University of Arkansas for Medical Sciences, Little Rock, AR (United States)

2015-06-15

Purpose: Three-dimensional conformal therapy remains a valid and widely used modality for pancreatic radiotherapy treatment. It usually meets dose constraints on critical structures. However, careful positioning of collimation jaws can reduce dose to the critical structures. Here we investigate the dosimetric effect of jaw position in MLC-based 3-D conformal treatment planning on critical structures. Methods: We retrospectively selected seven pancreatic cancer patients treated with 3-D conformal radiotherapy. We started with treatment plans (Varian Truebeam LINAC, Eclipse TPS, AAA, 18MV) having both x and y jaws aligned with the farthest extent of the block outline (8mm around PTV). Then we subsequently moved either both x-jaws or all x and y jaws outwards upto 3 cm in 1 cm increments and investigated their effect on average and maximum dose to neighboring critical structures keeping the same coverage to treatment volume. Results: Lateral displacement of both x-jaws by 1cm each increased kidney and spleen mean dose by as much as 1.7% and 1.3% respectively and superior inferior displacement increased liver, right kidney, stomach and spleen dose by as much as 2.1%, 2%, 5.2% and 1.6% respectively. Displacement of all x and y-jaws away by 1cm increased the mean dose to liver, right kidney, left kidney, bowels, cord, stomach and spleen by as much as 4.9%, 5.9%, 2.1%, 2.8%, 7.4%, 10.4% and 4.2% respectively. Percentage increase in mean dose due to 2 and 3cm jaw displacement increased almost linearly with the displaced distance. Changes in maximum dose were much smaller (mostly negligible) than the changes in mean dose. Conclusion: Collimation jaw position affects dose mostly to critical structures adjacent to it. Though treatment plans with MLCs conforming the block margin usually meet dose constraints to critical structures, keeping jaws all the way in, to the edge of the block reduces dose to the critical structures during radiation treatment.

Assessment of the Survival of Dental Implants in Irradiated Jaws ...

African Journals Online (AJOL)

frequency of dental implant placement in irradiated jaws from. 2002 to 2008 in India. Table 2 ..... Linsen SS, Martini M, Stark H. Long-term results of endosteal implants following radical oral ... Oral Health 2015:5;1-6. 21. Visch LL, van Waas MA ...

Root canal therapy for the prevention of osteonecrosis of the jaws: an evidence-based clinical update.

Science.gov (United States)

Kyrgidis, Athanassios; Arora, Amit; Lyroudia, Kleoniki; Antoniades, Konstantinos

2010-12-01

Osteonecrosis of the jaws is an adverse effect of bone preservation treatment. There is a sufficient body of evidence to associate osteonecrosis of the jaws development with dental extractions and trauma caused from ill-fitting dentures. In this review, we critically appraise available evidence about the clinical efficacy of root canal therapy in patients receiving bisphosphonates.We review a series of theories to explain why endodontic treatment is a safe clinical intervention to prevent osteonecrosis of the jaws in patients receiving bisphosphonates. Root canal therapy could postpone or even eradicate the need for dental extractions of carious teeth in patients on bisphosphonates who may develop osteonecrosis of the jaws. Patients receiving bisphosphonates should be offered the full range of preventive care to reduce their risk to both dental caries and periodontal disease, so that the need for both endodontic therapy and dental extractions will be reduced. Implementing such a strategy would require both practitioner and patient education through the combined efforts of medical and dental societies. Such an approach is justified, as the risk of compromising the oral health of patients on bisphosphonates undertaking endodontic treatment is negligible compared with the benefit from avoiding dental extractions.

Modern trends in the conservative management of lower jaw radio-necrosis following radiotherapy for tongue cancer

International Nuclear Information System (INIS)

Dapkova, L.

1997-01-01

This is a report on radio-necrosis of the lower jaw developing after radiation treatment for tongue cancer. Brief literature data concerning lower jaw osteoradionecrosis are presented, including incidence rate, dependence on the type of irradiation and doses applied and overall therapeutic approach to the lesion. An original scheme for complex conservative management, consistent with the specific pathogenetic patterns of post-irradiation necrosis, promoting active osteogenesis is proposed. It includes: antibiotics (4 quinolines, metronidazole, lincomycin, cephalosporin, nystatin), local antiseptic drugs (gargle with camomile, sol. tripaflavini 2 per cent, borax-glycerin, sterile 10 per cent solution of sodium chloride and the like), Miacalcic (calcitonin), vitamin D2, calcium-phospho C, parenteral nutrition, vitamins, retabolil, analgesics (general and local). The scheme, used in three patients with lower jaw radio-necrosis developing after radiotherapy for lingual cancer, yields very good results - pain relief, disappearance of trismus, with nutrition and sleep returning to normal. After demarcation of the necrotic tissue, sequestrectomy is done with ensuing complete epithelization. Lower jaw integrity is preserved without any functional and cosmetic defects. The duration of treatment is 8, 4 and 2 months, respectively (author)

Multiple jaw cysts not associated with basal cell nevus syndrome

International Nuclear Information System (INIS)

Yoon, Suk Ja; Kang, Byung Cheol

2003-01-01

We present two cases of multiple jaw cysts not associated with basal cell nevus syndrome. Case 1 : a nine year-old boy visited CNU Hospital for orthodontic treatment and his radiographs showed cystic lesions surrounding the crowns of teeth 13 and 17 respectively, which were diagnosed as dentigerous cysts. Subsequently, two more cysts were found on his follow-up radiographs in 12 and 15 months. The two cysts were determined to be odontogenic keratocysts. The boy had no skeletal abnormalities and no skin lesions associated with basal cell nevus syndrome. Case 2: a fifty-eight year old man had three impacted third molars with pericoronal radiolucencies, which were diagnosed as dentigerous cysts. He had no additional abnormalities associated with basal cell nevus syndrome. Multiple jaw cysts can occur at any age, and periodic radiographic surveillance may be needed for any cases of impacted tooth.

Effect of Repeated Food Morsel Splitting on Jaw Muscle Control

DEFF Research Database (Denmark)

A, Kumar; Svensson, Krister G; Baad-Hansen, Lene

2014-01-01

Mastication is a complex motor task often initiated by splitting of the food morsel between the anterior teeth. Training of complex motor tasks has consistently been shown to trigger neuroplastic changes in corticomotor control and optimization of muscle function. It is not known if training...... and repeated food morsel splitting lead to changes in jaw muscle function. Objective: To investigate if repeated splitting of food morsels in participants with natural dentition changes the force and jaw muscle electromyographic (EMG) activity. Methods: Twenty healthy volunteers (mean age = 26.2 ± 3.9 years......) participated in a single one-hour session divided into six series. Each series consisted of ten trials of a standardized behavioral task (total of 60 trials). The behavioral task was to hold and split a food morsel (8 mm, 180 mg placebo tablet) placed on a bite force transducer with the anterior teeth...

Multiple jaw cysts not associated with basal cell nevus syndrome

Energy Technology Data Exchange (ETDEWEB)

Yoon, Suk Ja; Kang, Byung Cheol [Chonnam National University College of Medicine, Kwangju (Korea, Republic of)

2003-09-15

We present two cases of multiple jaw cysts not associated with basal cell nevus syndrome. Case 1 : a nine year-old boy visited CNU Hospital for orthodontic treatment and his radiographs showed cystic lesions surrounding the crowns of teeth 13 and 17 respectively, which were diagnosed as dentigerous cysts. Subsequently, two more cysts were found on his follow-up radiographs in 12 and 15 months. The two cysts were determined to be odontogenic keratocysts. The boy had no skeletal abnormalities and no skin lesions associated with basal cell nevus syndrome. Case 2: a fifty-eight year old man had three impacted third molars with pericoronal radiolucencies, which were diagnosed as dentigerous cysts. He had no additional abnormalities associated with basal cell nevus syndrome. Multiple jaw cysts can occur at any age, and periodic radiographic surveillance may be needed for any cases of impacted tooth.

Determination of capacity of single-toggle jaw crusher, taking into account parameters of kinematics of its working mechanism

Science.gov (United States)

Golikov, N. S.; Timofeev, I. P.

2018-05-01

Efficiency increase of jaw crushers makes the foundation of rational kinematics and stiffening of the elements of the machine possible. Foundation of rational kinematics includes establishment of connection between operation mode parameters of the crusher and its technical characteristics. The main purpose of this research is just to establish such a connection. Therefore this article shows analytical procedure of getting connection between operation mode parameters of the crusher and its capacity. Theoretical, empirical and semi-empirical methods of capacity determination of a single-toggle jaw crusher are given, taking into account physico-mechanical properties of crushed material and kinematics of the working mechanism. When developing a mathematical model, the method of closed vector polygons by V. A. Zinoviev was used. The expressions obtained in the article give an opportunity to solve important scientific and technical problems, connected with finding the rational kinematics of the jaw crusher mechanism, carrying out a comparative assessment of different crushers and giving the recommendations about updating the available jaw crushers.

[Florid cemento-osseous dysplasia of the jaws].

Science.gov (United States)

Benazzou, S; Boulaadas, M; El Ayoubi, A; Nazih, N; Essakalli, L; Kzadri, M

2011-06-01

Florid cemento-osseous dysplasia is a benign and rare tumor of the jaws. It is more commonly seen in middle-aged black women. Most cases are asymptomatic and are found during routine radiographic examination. We report two complicated cases of florid cemento-osseous dysplasia, one with facial deformity and the other with chronic osteitis. The diagnosis of florid cemento-osseous dysplasia is based on clinical and radiological features. The lesions are commonly bilateral and symmetrical. Copyright © 2011. Published by Elsevier Masson SAS.

Pattern and polarity in the development and evolution of the gnathostome jaw: both conservation and heterotopy in the branchial arches of the shark, Scyliorhinus canicula.

Science.gov (United States)

Compagnucci, Claudia; Debiais-Thibaud, Melanie; Coolen, Marion; Fish, Jennifer; Griffin, John N; Bertocchini, Federica; Minoux, Maryline; Rijli, Filippo M; Borday-Birraux, Véronique; Casane, Didier; Mazan, Sylvie; Depew, Michael J

2013-05-15

The acquisition of jaws constitutes a landmark event in vertebrate evolution, one that in large part potentiated their success and diversification. Jaw development and patterning involves an intricate spatiotemporal series of reciprocal inductive and responsive interactions between the cephalic epithelia and the cranial neural crest (CNC) and cephalic mesodermal mesenchyme. The coordinated regulation of these interactions is critical for both the ontogenetic registration of the jaws and the evolutionary elaboration of variable jaw morphologies and designs. Current models of jaw development and evolution have been built on molecular and cellular evidence gathered mostly in amniotes such as mice, chicks and humans, and augmented by a much smaller body of work on the zebrafish. These have been partnered by essential work attempting to understand the origins of jaws that has focused on the jawless lamprey. Chondrichthyans (cartilaginous fish) are the most distant group to amniotes within extant gnathostomes, and comprise the crucial clade uniting amniotes and agnathans; yet despite their critical phylogenetic position, evidence of the molecular and cellular underpinnings of jaw development in chondrichthyans is still lacking. Recent advances in genome and molecular developmental biology of the lesser spotted dogfish shark, Scyliorhinus canicula, make it ideal for the molecular study of chondrichthyan jaw development. Here, following the 'Hinge and Caps' model of jaw development, we have investigated evidence of heterotopic (relative changes in position) and heterochronic (relative changes in timing) shifts in gene expression, relative to amniotes, in the jaw primordia of S. canicula embryos. We demonstrate the presence of clear proximo-distal polarity in gene expression patterns in the shark embryo, thus establishing a baseline molecular baüplan for branchial arch-derived jaw development and further validating the utility of the 'Hinge and Caps' model in comparative

The biological basis of treating jaw discrepancies: An interplay of mechanical forces and skeletal configuration.

Science.gov (United States)

Karamesinis, Konstantinos; Basdra, Efthimia K

2018-05-01

Jaw discrepancies and malrelations affect a large proportion of the general population and their treatment is of utmost significance for individuals' health and quality of life. The aim of their therapy is the modification of aberrant jaw development mainly by targeting the growth potential of the mandibular condyle through its cartilage, and the architectural shape of alveolar bone through a suture type of structure, the periodontal ligament. This targeted treatment is achieved via external mechanical force application by using a wide variety of intraoral and extraoral appliances. Condylar cartilage and sutures exhibit a remarkable plasticity due to the mechano-responsiveness of the chondrocytes and the multipotent mesenchymal cells of the sutures. The tissues respond biologically and adapt to mechanical force application by a variety of signaling pathways and a final interplay between the proliferative activity and the differentiation status of the cells involved. These targeted therapeutic functional alterations within temporo-mandibular joint ultimately result in the enhancement or restriction of mandibular growth, while within the periodontal ligament lead to bone remodeling and change of its architectural structure. Depending on the form of the malrelation presented, the above treatment approaches, in conjunction or separately, lead to the total correction of jaw discrepancies and the achievement of facial harmony and function. Overall, the treatment of craniofacial and jaw anomalies can be seen as an interplay of mechanical forces and adaptations occurring within temporo-mandibular joint and alveolar bone. The aim of the present review is to present up-to-date knowledge on the mechano-biology behind jaw growth modification and alveolar bone remodeling. Furthermore, future molecular targeted therapeutic strategies are discussed aiming at the improvement of mechanically-driven chondrogenesis and osteogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Solitary Intra-Osseous Myofibroma of the Jaw: A Case Report and Review of Literature

Directory of Open Access Journals (Sweden)

Anita Dhupar

2017-10-01

Full Text Available Myofibroma is a rare benign spindle cell neoplasm in children that usually affects both soft tissue and bone in the head and neck region. Approximately one third of these cases are seen within jaw bones as solitary lesions. Solitary intra-osseous myofibroma of the jaw bone shares its clinical, radiographic and histological features with other spindle cell tumors. The rarity of this lesion can make diagnosis difficult for clinicians and pathologists. We report a case of a solitary intra-osseous myofibroma in the mandible of a nine-year-old child.

"Converting a bi-jaw surgery to a single-jaw surgery:" Posterior maxillary dentoalveolar intrusion with microimplants to avoid the need of a maxillary surgery in the surgical management of skeletal Class III vertical malocclusion

Directory of Open Access Journals (Sweden)

Abhisek Ghosh

2016-01-01

Full Text Available The management of a vertical skeletal Class III malocclusion with mandibular prognathism revolves around the protocol of bi-jaw surgery (maxillary LeFort I impaction and mandibular bilateral sagittal split osteotomy with setback. The maxillary surgery not only provides increased stability to the ultimate surgical outcome but also increases the amount by which the mandibular set back can be done, therefore aiding in greater profile improvement. With the need of maxillary surgery almost inevitable in treating such situations, the complexity and the increased discomfort associated with such surgery can never be ignored. Is it at all possible to convert a bi-jaw surgery into a single-jaw surgery with the aid of microimplants? With increasing number of patients being treated with microimplants for anterior openbite and gummy smiles, our idea was to incorporate this novel protocol in treating Class III vertical situations and therefore avoid the need of a maxillary surgery in treating such a situation, together with achieving optimum treatment outcome.

Jaws calibration method to get a homogeneous distribution of dose in the junction of hemi fields

International Nuclear Information System (INIS)

Cenizo de Castro, E.; Garcia Pareja, S.; Moreno Saiz, C.; Hernandez Rodriguez, R.; Bodineau Gil, C.; Martin-Viera Cueto, J. A.

2011-01-01

Hemi fields treatments are widely used in radiotherapy. Because the tolerance established for the positioning of each jaw is 1 mm, may be cases of overlap or separation of up to 2 mm. This implies heterogeneity of doses up to 40% in the joint area. This paper presents an accurate method of calibration of the jaws so as to obtain homogeneous dose distributions when using this type of treatment. (Author)

A fixed-jaw method to protect critical organs during intensity-modulated radiotherapy

International Nuclear Information System (INIS)

Chen, Jiayun; Chen, Xinyuan; Huang, Manni; Dai, Jianrong

2014-01-01

Intensity-modulated radiotherapy (IMRT) plays an important role in cancer radiotherapy. For some patients being treated with IMRT, the extremely low tolerances of critical organs (such as lens, ovaries, and testicles) cannot be met during treatment planning. The aim of this article is to introduce a new planning method to overcome that problem. In current planning practice, jaw positions are automatically set to cover all target volumes by the planning system (e.g., Pinnacle 3 system). Because of such settings, critical organs may be fully blocked by the multileaf collimator (MLC), but they still sit in the field that is shaped by collimator jaws. These critical organs receive doses from the transmission and leakage of MLC leaves. We manually fixed jaw positions to block them to further reduce such doses. This method has been used for different treatment sites in our clinic, and it was thoroughly evaluated in patients with radical hysterectomy plus ovarian transposition after surgery. For each patient, 2 treatment plans were designed with the same optimization parameters: the original plan with automatically chosen jaw positions (called O-plan) and the plan with fixed-jaw positions (named F-plan). In the F-plan, the jaws were manually fixed to block the ovaries. For target coverage, the mean conformity index (CI) of the F-plan (1.28 ± 0.02) was remarkably lower than that of the O-plan (1.53 ± 0.09) (p < 0.05). The F-plan and the O-plan performed similarly in target dose homogeneity. Meanwhile, for the critical organ sparing, the mean dose of both ovaries were much lower in the F-plan than that in the O-plan (p < 0.05). The V 20 , V 30 , and V 40 of bladder were also lower in the F-plan (93.57 ± 1.98, 73.99 ± 5.76, and 42.33 ± 3.7, respectively) than those in the O-plan (97.98 ± 1.11, 85.07 ± 4.04, and 49.71 ± 3.63, respectively) (p < 0.05). The maximum dose to the spinal cord planning organ at risk (OAR) volume (PRV) in the O-plan (3940.24 ± 102.8) was

[Acupuncture combined with magnetic therapy for treatment of temple-jaw joint dysfunction].

Science.gov (United States)

Wang, Xiao-Hui; Zhang, Wen

2009-04-01

To compare clinical therapeutic effects of acupuncture combined with magnetic therapy and simple magnetic therapy on temple-jaw joint dysfunction. Eighty-two cases were randomly divided into an observation group (n = 52) and a control group (n = 30). The observation group was treated with acupuncture at Xiaguan (ST 7), Jiache (ST 6), Hegu (LI 4), etc. and AL-2 low frequency electromagnetic comprehensive treatment instrument; the control group was treated with AL-2 low frequency electromagnetic comprehensive treatment instrument. The cured and markedly effective rate of 90.4% in the observation group was significantly better than 66.7% in the control group (P magnetic therapy is significantly better than that of the simple magnetic therapy on temple-jaw joint dysfunction.

Bisphosphonate-associated Osteonecrosis of the jaws and endodontic treatment: two case reports.

Science.gov (United States)

Goodell, Gary

2006-01-01

Bisphosphonates are commonly used in the management of bone diseases, such as osteoporosis and Paget's disease, and to prevent bone complications and treat malignant hypercalcemia in certain types of cancer. Although this class of drugs has clear evidence of medical efficacy, there are an, increasing number of reports of bisphosphonate-associated osteonecrosis of the jaws that have substantial implications for the patient and for the treating dentist. This article reviews proposed possible mechanisms of bisphosphonate-associated osteonecrosis of the jaws and describes two case reports where non-surgical and surgical root canal treatment were precipitating factors. Recommendations for prevention and treatment of the disease follow. Thorough history-taking and timely consultation with the patient's oral surgeon and oncologist are emphasized.

[The clinical and X-ray classification of osteonecrosis of the low jaw].

Science.gov (United States)

Medvedev, Iu A; Basin, E M; Sokolina, I A

2013-01-01

To elaborate a clinical and X-ray classification of osteonecrosis of the low jaw in people with desomorphine or pervitin addiction. Ninety-two patients with drug addiction who had undergone orthopantomography, direct frontal X-ray of the skull, and multislice computed tomography, followed by multiplanar and three-dimensional imaging reconstruction were examined. One hundred thirty four X-ray films and 74 computed tomographic images were analyzed. The authors proposed a clinical and X-ray classification of osteonecrosis of the low jaw in people with desomorphine or pervitin addiction and elaborated recommendations for surgical interventions on the basis of the developed classification. The developed clinical and X-ray classification and recommendations for surgical interventions may be used to treat osteonecroses of various etiology.

Osteonecrosis of the jaw: a rare and devastating side effect of bisphosphonates.

LENUS (Irish Health Repository)

Ryan, P

2009-12-01

Evidence has emerged that bisphosphonate use in cancer patients is associated with osteonecrosis of the jaw. This form of osteonecrosis has been termed bisphosphonate induced osteonecrosis of the jaw (BIONJ). BIONJ is commonly precipitated by a tooth extraction in patients treated with long term, potent, high dose intravenous bisphosphonates for the management of myeloma, breast or prostate cancer. The overall prevalence of BIONJ is about 5% in patients with these malignancies. Current evidence shows that the risk of BIONJ in non-cancerous patients, such as those with osteoporosis, is very low and appears to be comparable with that of the general population. Prescribing physicians need to encourage cancer patients to see their dentists before the initiation of bisphosphonate treatment, and regularly thereafter.

Raman Spectroscopic Analyses of Jaw Periosteal Cell Mineralization

Directory of Open Access Journals (Sweden)

Eva Brauchle

2017-01-01

Full Text Available To achieve safer patient treatments, serum-free cell culture conditions have to be established for cell therapies. In previous studies, we demonstrated that serum-free culture favored the proliferation of MSCA-1+ osteoprogenitors derived from the jaw periosteum. In this study, the in vitro formation of bone-specific matrix by MSCA-1+ jaw periosteal cells (JPCs, 3 donors was assessed and compared under serum-free and serum-containing media conditions using the marker-free Raman spectroscopy. Based on a standard fluorescence assay, JPCs from one patient were not able to mineralize under serum-containing culture conditions, whereas the other cells showed similar mineralization levels under both conditions. Raman spectra from mineralizing MSCA-1+ JPCs revealed higher levels of hydroxyapatite formation and higher mineral to matrix ratios under serum-free culture conditions. Higher carbonate to phosphate ratios and higher crystallinity in JPCs cultured under serum-containing conditions indicated immature bone formation. Due to reduced collagen production under serum-free conditions, we obtained significant differences in collagen maturity and proline to hydroxyproline ratios compared to serum-free conditions. We conclude that Raman spectroscopy is a useful tool for the assessment and noninvasive monitoring of in vitro mineralization of osteoprogenitor cells. Further studies should extend this knowledge and improve JPC mineralization by optimizing culture conditions.

Measurements on the movement of the lower jaw in speech

NARCIS (Netherlands)

Nooteboom, S.G.; Slis, I.H.

1970-01-01

This report concerns some preliminary measurements on the movement of the lower jaw in speech. Such measurements may be interesting for several reasons. One of these is that they more easily than measurements on the movements of other articulators may give some insight into the effect of stress,

Assessment of the survival of dental implants in irradiated jaws ...

African Journals Online (AJOL)

Background: In patients undergoing head and neck surgery for various pathologic conditions, implants are one of the best restorative options and are increasing widely used. Therefore, we evaluated the success of dental implants in the irradiated jaws of patients following treatment of oral cancer oral cancer treated patients ...

Time to onset of bisphosphonate-related osteonecrosis of the jaws

DEFF Research Database (Denmark)

Fung, Ppl; Bedogni, G; Bedogni, A

2017-01-01

OBJECTIVES: Osteonecrosis of the jaw (ONJ) is a potentially severe adverse effect of bisphosphonates (BP). Although the risk of ONJ increases with increasing duration of BP treatment, there are currently no reliable estimates of the ONJ time to onset (TTO). The objective of this study was to esti...

Orofacial pain, jaw function, and temporomandibular disorders in adult women with a history of juvenile chronic arthritis or persistent juvenile chronic arthritis

DEFF Research Database (Denmark)

Bakke, M.; Zak, M.; Jensen, B.L.

2001-01-01

Orofacial pain, jaw function, temporomandibular disorders, adult women persistent juvenil chronic arthritis......Orofacial pain, jaw function, temporomandibular disorders, adult women persistent juvenil chronic arthritis...

Selection of osteoprogenitors from the jaw periosteum by a specific animal-free culture medium.

Directory of Open Access Journals (Sweden)

Dorothea Alexander

Full Text Available The goal of our research work is to establish mesenchymal osteoprogenitors derived from human jaw periosteum for tissue engineering applications in oral and maxillofacial surgery. For future autologous and/or allogeneic transplantations, some issues must be addressed. On the one hand, animal-free culture conditions have yet to be established. On the other hand, attempts should be undertaken to shorten the in vitro culturing process efficiently. The aim of the present study is to compare and analyze the phenotype of osteoprogenitors from the jaw periosteum under normal FCS-containing and animal-free culture conditions. Therefore, we analyzed the proliferation rates of MesenCult-XF medium (MC- in comparison to DMEM-cultured JPCs. Whereas jaw periosteal cells (JPCs show relatively slow proliferation rates and a fibroblastoid shape under DMEM culture conditions, MC-cultured JPCs diminished their cell size significantly and proliferated rapidly. By live-monitoring measurements of adhesion and proliferation, we made an interesting observation: whereas the proliferation of the MSCA-1(+ subpopulation and the unseparated cell fraction were favored by the animal-free culture medium, the proliferation of the MSCA-1(- subpopulation seemed to be repressed under these conditions. The alkaline phosphatase expression pattern showed similar results under both culture conditions. Comparison of the mineralization capacity revealed an earlier formation of calcium-phosphate precipitates under MC culture conditions; however, the mineralization capacity of the DMEM-cultured cells seemed to be higher. We conclude that the tested animal-free medium is suitable for the in vitro expansion and even for the specific selection of osteoprogenitor cells derived from the jaw periosteum.

A description on pharyngeal jaw apparatus and diets of halfbeak fish Zenarchopterus buffonis (Valenciennes 1847) in Malaysian waters

Science.gov (United States)

Abidin, Diana Atiqah Zainal; Hashim, Marina; Das, Simon K.; Ghaffar, Mazlan Abd.

2015-09-01

Information on the feeding mechanism and diet of halfbeak fish species in harsh estuarine environment ecosystem is still lacking. The present study investigates the fine structure of pharyngeal jaw apparatus and diets of halfbeak fish Zenarchopterus buffonis. A total of 84 halfbeak fish samples have been collected from the coastal water of Peninsular Malaysia using fishing rod. Scanning electron microscopy was used to examine the micrographs of fine microstructure of the pharyngeal teeth. The fundamental anatomy of pharyngeal jaw apparatus displayed that the upper pharyngeal jaw (third pharyngobranchials) displays larger size of hook-like or tricuspid teeth which was analogous to tricuspid morphology. The lower pharyngeal jaw (fifth ceratobranchial) bears mainly conical teeth and appears triangular shape with two, short projections. The estimated TROPH values (1 - 3.2±0.55) denoted that halfbeak fish were omnivores in nature. The findings of this study was found to be useful as a baseline information for a better representation of the trophic flows associated with large medium and small surface water fishes.

A description on pharyngeal jaw apparatus and diets of halfbeak fish Zenarchopterus buffonis (Valenciennes 1847) in Malaysian waters

International Nuclear Information System (INIS)

Abidin, Diana Atiqah Zainal; Hashim, Marina; Ghaffar, Mazlan Abd.; Das, Simon K.

2015-01-01

Information on the feeding mechanism and diet of halfbeak fish species in harsh estuarine environment ecosystem is still lacking. The present study investigates the fine structure of pharyngeal jaw apparatus and diets of halfbeak fish Zenarchopterus buffonis. A total of 84 halfbeak fish samples have been collected from the coastal water of Peninsular Malaysia using fishing rod. Scanning electron microscopy was used to examine the micrographs of fine microstructure of the pharyngeal teeth. The fundamental anatomy of pharyngeal jaw apparatus displayed that the upper pharyngeal jaw (third pharyngobranchials) displays larger size of hook-like or tricuspid teeth which was analogous to tricuspid morphology. The lower pharyngeal jaw (fifth ceratobranchial) bears mainly conical teeth and appears triangular shape with two, short projections. The estimated TROPH values (1 − 3.2±0.55) denoted that halfbeak fish were omnivores in nature. The findings of this study was found to be useful as a baseline information for a better representation of the trophic flows associated with large medium and small surface water fishes

A description on pharyngeal jaw apparatus and diets of halfbeak fish Zenarchopterus buffonis (Valenciennes 1847) in Malaysian waters

Energy Technology Data Exchange (ETDEWEB)

Abidin, Diana Atiqah Zainal, E-mail: diana.atiqah@gmail.com; Hashim, Marina; Ghaffar, Mazlan Abd., E-mail: magfish05@yahoo.com [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Das, Simon K. [Marine Ecosystem Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi (Malaysia)

2015-09-25

Information on the feeding mechanism and diet of halfbeak fish species in harsh estuarine environment ecosystem is still lacking. The present study investigates the fine structure of pharyngeal jaw apparatus and diets of halfbeak fish Zenarchopterus buffonis. A total of 84 halfbeak fish samples have been collected from the coastal water of Peninsular Malaysia using fishing rod. Scanning electron microscopy was used to examine the micrographs of fine microstructure of the pharyngeal teeth. The fundamental anatomy of pharyngeal jaw apparatus displayed that the upper pharyngeal jaw (third pharyngobranchials) displays larger size of hook-like or tricuspid teeth which was analogous to tricuspid morphology. The lower pharyngeal jaw (fifth ceratobranchial) bears mainly conical teeth and appears triangular shape with two, short projections. The estimated TROPH values (1 − 3.2±0.55) denoted that halfbeak fish were omnivores in nature. The findings of this study was found to be useful as a baseline information for a better representation of the trophic flows associated with large medium and small surface water fishes.

An unusual case of osteonecrosis of the jaw associated with dengue fever and periodontitis.

Science.gov (United States)

Indurkar, M S; Sethi, R

2016-03-01

Osteonecrosis is a disorder rarely occurring in the jaw. Dengue fever is a common mosquito-borne disease prevalent in many countries including India. The following report presents an interesting case of maxillary osteonecrosis in a middle aged male with a history of dengue infection. We also diagnosed symptoms of chronic periodontitis, which may have potentiated the necrosis. This case report will describe a novel clinical presentation and management of osteonecrosis of the jaw (ONJ) of unknown origin and a possible pathogenesis explaining the association of ONJ with dengue fever and periodontitis. © 2015 Australian Dental Association.

Jaw Osteomyelitis as a Complication of Sickle Cell Anaemia in Three Omani Patients; Case reports and literature review

Directory of Open Access Journals (Sweden)

Hilal Al-Ismaili

2017-03-01

Full Text Available Sickle cell anaemia (SCA is a common haemoglobinopathy among people from the Middle East, the Afro-Caribbean region, the Mediterranean and East India. While osteomyelitis of the long bones is a welldocumented complication of SCA, there are few documented cases of SCA patients presenting with jaw osteomyelitis. We report three SCA patients with chronic jaw osteomyelitis who presented to the Department of Oral Health, Sultan Qaboos University Hospital, Muscat, Oman, between 2009 and 2013. Two of the patients had osteomyelitis of the mandible and the third had osteomyelitis of the maxilla. In addition, a brief review of the literature is presented focusing on the clinical presentation, diagnosis and management of jaw osteomyelitis among patients with SCA.

Unicystic Jaw Lesions: A Radiographic Guideline

Directory of Open Access Journals (Sweden)

Giju George

2010-01-01

Full Text Available The unilocular radiolucencies remain the topic of much interest for the clinicians and histhopathologists for decades. Adequate use of diagnostic aids and careful observation will clinically help the dentist to arrive at a proper diagnosis and renders quality treatment to patients. Despite of the development of various cross-sectional imaging modalities, the radiograph still remains as the first and most important investigation. Jaw bone lesions, especially unilocular ones, are difficult to diagnose radiologically because of their similar radiographic appearance. It is, thus, very important for the clinician to have a sound knowledge of various radiographic features of the tooth and its supporting structures.

Effect of stimulus parameters and contraction level on inhibitory responses in human jaw-closing muscles: Implications for contingent stimulation

DEFF Research Database (Denmark)

Jadidi, F; Wang, K; Arendt-Nielsen, Lars

2009-01-01

  Objective: Examine the effect of stimulus duration as well as stimulus intensity and level of muscle contraction on the inhibitory responses in human jaw-closing muscles. Design: The inhibitory jaw-reflexes, ES1 and ES2, were recorded in the surface electromyogram (EMG) of masseter and temporal...

Self-Controlling Rig for Jaw Crusher Assembly

OpenAIRE

Saurabh Jadhav; Anup Pawar

2017-01-01

The aim of the work is to develop a method for easy assembly of the bearing in the housing by standardized way. The assembly of bearing should take place on the atomized set up. Based on this method a assembly setup was constructed which enables to assembly of the shaft with bearing of different models of jaw crusher. First tests were done with manual alignment and it shows that with proper alignment shaft assembly is very easy operation and also safe. Results of those tests show that the dev...

The jaw is a second-class lever in Pedetes capensis (Rodentia: Pedetidae

Directory of Open Access Journals (Sweden)

Philip G. Cox

2017-08-01

Full Text Available The mammalian jaw is often modelled as a third-class lever for the purposes of biomechanical analyses, owing to the position of the resultant muscle force between the jaw joint and the teeth. However, it has been proposed that in some rodents the jaws operate as a second-class lever during distal molar bites, owing to the rostral position of the masticatory musculature. In particular, the infraorbital portion of the zygomatico-mandibularis (IOZM has been suggested to be of major importance in converting the masticatory system from a third-class to a second-class lever. The presence of the IOZM is diagnostic of the hystricomorph rodents, and is particularly well-developed in Pedetes capensis, the South African springhare. In this study, finite element analysis (FEA was used to assess the lever mechanics of the springhare masticatory system, and to determine the function of the IOZM. An FE model of the skull of P. capensis was constructed and loaded with all masticatory muscles, and then solved for biting at each tooth in turn. Further load cases were created in which each masticatory muscle was removed in turn. The analyses showed that the mechanical advantage of the springhare jaws was above one at all molar bites and very close to one during the premolar bite. Removing the IOZM or masseter caused a drop in mechanical advantage at all bites, but affected strain patterns and cranial deformation very little. Removing the ZM had only a small effect on mechanical advantage, but produced a substantial reduction in strain and deformation across the skull. It was concluded that the masticatory system of P. capensis acts as a second class lever during bites along almost the entire cheek tooth row. The IOZM is clearly a major contributor to this effect, but the masseter also has a part to play. The benefit of the IOZM is that it adds force without substantially contributing to strain or deformation of the skull. This may help explain why the

Digital assessment of preliminary impression accuracy for edentulous jaws: Comparisons of 3-dimensional surfaces between study and working casts.

Science.gov (United States)

Matsuda, Takashi; Goto, Takaharu; Kurahashi, Kosuke; Kashiwabara, Toshiya; Watanabe, Megumi; Tomotake, Yoritoki; Nagao, Kan; Ichikawa, Tetsuo

2016-07-01

The aim of this study was to compare 3-dimensional surfaces of study and working casts for edentulous jaws and to evaluate the accuracy of preliminary impressions with a view to the future application of digital dentistry for edentulous jaws. Forty edentulous volunteers were serially recruited. Nine dentists took preliminary and final impressions in a routine clinical work-up. The study and working casts were digitized using a dental 3-dimensional scanner. The two surface images were superimposed through a least-square algorithm using imaging software and compared qualitatively. Furthermore, the surface of each jaw was divided into 6 sections, and the difference between the 2 images was quantitatively evaluated. Overall inspection showed that the difference around residual ridges was small and that around borders were large. The mean differences in the upper and lower jaws were 0.26mm and 0.45mm, respectively. The maximum values of the differences showed that the upward change mainly occurred in the anterior residual ridge, and the downward change mainly in the posterior border seal, and the labial and buccal vestibules, whereas every border of final impression was shortened in the lower jaw. The accuracy in all areas except the border, which forms the foundation, was estimated to be less than 0.25mm. Using digital technology, we here showed the overall and sectional accuracy of the preliminary impression for edentulous jaws. In our clinic, preliminary impressions have been made using an alginate material while ensuring that the requisite impression area was covered. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Fibrous dysplasia of the jaws associated with secondary hyperparathyroidism: a case report

International Nuclear Information System (INIS)

Whi, Jung Hyun; Kim, Young Joo; Chun, Kyung Ah; Kim, Ki Tae; Chang, Eun Deok; Kim, Young Ok; Lee, Won

2007-01-01

There have been few reports on fibrous dyplasia associated with secondary hyperparathyroidism. We report a case of a hemodialysis patient with secondary hyperparathyroidism concomitant with fibrous dysplasia of the jaws causing an abnormal deformity

Fetal jaw movement affects Ihh signaling in mandibular condylar cartilage development: the possible role of Ihh as mechanotransduction mediator.

Science.gov (United States)

Jahan, Esrat; Matsumoto, Akihiro; Rafiq, Ashiq Mahmood; Hashimoto, Ryuju; Inoue, Takayuki; Udagawa, Jun; Sekine, Joji; Otani, Hiroki

2014-10-01

Jaw movement is an important mechanical factor for prenatal development of the condylar cartilage of mandible. Fetal jaw movement restriction has been shown to cause deformity of the mandibular condyle. We hypothesized that this treatment affects the expression of mechanosensitive molecules, namely Indian hedgehog (Ihh) and Parathyroid hormone related protein (PTHrP) in the condyle. We restrained jaw movement by suturing the jaw of E15.5 mouse embryos and allowed them to develop until E18.5 using exo utero system, and analyzed them by immunohistochemistry and in situ hybridization methods. Morphological, histomorphometric and immunohistochemical study showed that the mandibular condylar cartilage was reduced and deformed, the volume and total cell numbers in the condylar cartilage were also reduced, and number and/or distribution of 5-bromo-2'-deoxyuridine-positive cells, Ihh-positive cells in the mesenchymal and pre-hypertrophic zones were significantly and correspondingly decreased in the sutured group. Using in situ hybridization, reduced expression of Ihh, PTHrP and their related receptors were observed in condylar cartilage of the sutured embryos. Our results revealed that the altered mechanical stress induced by prenatal jaw movement restriction decreased proliferating cells, the amount of cartilage, and altered expression of the Ihh and PTHrP, suggesting that Ihh act as mechanotransduction mediators in the development of mandibular condylar cartilage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of botulinum toxin on rabbit jaw muscle activity and anatomy

NARCIS (Netherlands)

Korfage, J.A.M.; Wang, J.; Lie, S.H.J.T.J.; Langenbach, G.E.J.

2012-01-01

Introduction: Muscles can adapt their fiber properties to accommodate to new conditions. We investigated the extent to which a decrease in muscle activation can cause an adaptation of fiber properties in synergistic and antagonistic jaw muscles. Methods: Three months after the injection of botulinum

A feasibility study of using conventional jaws to deliver complex IMRT plans for head and neck cancer

International Nuclear Information System (INIS)

Mu, G; Xia, P

2009-01-01

Previous studies have demonstrated that simple intensity-modulated radiotherapy (IMRT) plans can be produced with a series of rectangular segments formed by conventional jaws. This study investigates whether complex IMRT plans for head and neck cancer can be delivered with the conventional jaws efficiently. Six nasopharyngeal cancer patients, previously treated with multi-leaf collimator (MLC)-IMRT plans, were re-planned using conventional jaw delivery options. All IMRT plans were subject to the plan acceptance criteria of the RTOG-0225 protocol. For a selected patient, the maximum number of segments varied from five to nine per beam, and was tested for both jaws-only IMRT (JO-IMRT) plans and MLC-IMRT plans. Subsequently, JO-IMRT plans and MLC-IMRT on the same treatment planning system were attempted for all patients with identical beams. The dose distribution, dose volume histograms (DVH), the conformal index (COIN), the uniformity index and delivery efficiency were compared between the MLC-IMRT and JO-IMRT plans. All JO-IMRT plans met the RTOG-0225 criteria for tumor coverage and sensitive structures sparing. The corresponding MLC-IMRT and JO-IMRT plans show comparable conformality and uniformity, with average COINs of the planning gross tumor volume(pGTV) 37.7% ± 18.7% versus 37.9% ± 18.1%, and the average uniformity index 82.8% ± 2.5% versus 83.6% ± 3.1%, respectively. The average monitor unit for JO-IMRT plans was about twice that of MLC-IMRT plans. In conclusion, conventional jaws can be used solely to deliver complex IMRT plans for patients with nasopharyngeal cancer yet still within a practical delivery time.

SU-E-T-394: The Use of Jaw Tracking in Intensity Modulated and Volumetric Modulated Arc Radiotherapy for Spine Stereotactic Radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Chin, K; Wen, N; Huang, Y; Kim, J; Zhao, B; Siddiqui, S; Chetty, I; Ryu, S [Henry Ford Health System, Detroit, MI (United States)

2014-06-01

Purpose: To evaluate the potential advantages of jaw tracking for intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in spine radiosurgery. Methods: VMAT and IMRT plans were retrospectively generated for ten patients. Six plans for each patient were created in the Eclipse treatment planning system for a Varian Truebeam equipped with a Millennium 120 MLC. Plans were created to study IMRT and VMAT plans with and without jaw tracking, as well as IMRT plans of different flattening filter free (FFF) energies. Plans were prescribed to the 90% isodose line to 16 or 18 Gy in one fraction to cover 95% of the target. Planning target volume (PTV) coverage, conformity index (CI), dose to spinal cord, distance to fall off from the 90% to 50% isodose line (DTF), as well as delivery time were evaluated. Ion chamber and film measurements were performed to verify calculated and measured dose distributions. Results: Jaw tracking decreased the spinal cord dose for both IMRT and VMAT plans, but a larger decrease was seen with the IMRT plans (p=0.004 vs p=0.04). The average D10% for the spinal cord was least for the 6MV FFF IMRT plan with jaw tracking and was greatest for the 10MV FFF plan without jaw tracking. Treatment times between IMRT and VMAT plans with or without jaw tracking were not significantly different. Measured plans showed greater than 98.5% agreement for planar dose gamma analysis (3%/2 mm) and less than 2.5% for point dose analysis compared to calculated plans. Conclusion: Jaw tracking can be used to help decrease spinal cord dose without any change in treatment delivery or calculation accuracy. Lower dose to the spinal cord was achieved using 6 MV beams compared to 10 MV beams, though 10 MV may be justified in some cases to decrease skin dose.

SU-E-T-394: The Use of Jaw Tracking in Intensity Modulated and Volumetric Modulated Arc Radiotherapy for Spine Stereotactic Radiosurgery

International Nuclear Information System (INIS)

Chin, K; Wen, N; Huang, Y; Kim, J; Zhao, B; Siddiqui, S; Chetty, I; Ryu, S

2014-01-01

Purpose: To evaluate the potential advantages of jaw tracking for intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in spine radiosurgery. Methods: VMAT and IMRT plans were retrospectively generated for ten patients. Six plans for each patient were created in the Eclipse treatment planning system for a Varian Truebeam equipped with a Millennium 120 MLC. Plans were created to study IMRT and VMAT plans with and without jaw tracking, as well as IMRT plans of different flattening filter free (FFF) energies. Plans were prescribed to the 90% isodose line to 16 or 18 Gy in one fraction to cover 95% of the target. Planning target volume (PTV) coverage, conformity index (CI), dose to spinal cord, distance to fall off from the 90% to 50% isodose line (DTF), as well as delivery time were evaluated. Ion chamber and film measurements were performed to verify calculated and measured dose distributions. Results: Jaw tracking decreased the spinal cord dose for both IMRT and VMAT plans, but a larger decrease was seen with the IMRT plans (p=0.004 vs p=0.04). The average D10% for the spinal cord was least for the 6MV FFF IMRT plan with jaw tracking and was greatest for the 10MV FFF plan without jaw tracking. Treatment times between IMRT and VMAT plans with or without jaw tracking were not significantly different. Measured plans showed greater than 98.5% agreement for planar dose gamma analysis (3%/2 mm) and less than 2.5% for point dose analysis compared to calculated plans. Conclusion: Jaw tracking can be used to help decrease spinal cord dose without any change in treatment delivery or calculation accuracy. Lower dose to the spinal cord was achieved using 6 MV beams compared to 10 MV beams, though 10 MV may be justified in some cases to decrease skin dose

Bisphosphonates-induced osteonecrosis of the jaw: pharmacology and clinical procedures.

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Candice Belchior Duplat

2012-01-01

Full Text Available Osteonecrosis of the jaw is a consequent condition of a variety of local and systemic factors that compromises the bone blood flow. Bisphosphonates are a class of compounds widely used for the treatment of disorders of bone metabolism, such as bone metastasis and osteoporosis. Bisphosphonates-induced osteonecrosis of the jaw is a new complication, published for the first time at 2003, and can be defined as an unexpected necrosis development on the oral cavity in patients who received bisphosphonates and were not being treated with head and neck radiotherapy. Radiographies show radiolucent zones or sclerotic bone and, in some cases, show areas with delayed or absent bone remodeling after extraction, remain the socket cavity. The treatment can be done in accordance with the condition stage, since management of 0,12% chlorhexidine and antibiotics until laser utilization, hyperbaric oxygen, surgical debridement and resection. It is important to promote more communication between physicians and dentists to guarantee dental attention during the bisphosphonate administration, establishing oral health and preventing complications, such as osteonecrosis induced by this medication.

BISPHOSPHONATES-INDUCED OSTEONECROSIS OF THE JAW: PHARMACOLOGY AND CLINICAL PROCEDURES.

Directory of Open Access Journals (Sweden)

Candice Belchior Duplat

2012-08-01

Full Text Available Osteonecrosis of the jaw is a consequent condition of a variety of local and systemic factors that compromises the bone blood flow. Bisphosphonates are a class of compounds widely used for the treatment of disorders of bone metabolism, such as bone metastasis and osteoporosis. Bisphosphonates-induced osteonecrosis of the jaw is a new complication, published for the first time at 2003, and can be defined as an unexpected necrosis development on the oral cavity in patients who received bisphosphonates and were not being treated with head and neck radiotherapy. Radiographies show radiolucent zones or sclerotic bone and, in some cases, show areas with delayed or absent bone remodeling after extraction, remain the socket cavity. The treatment can be done in accordance with the condition stage, since management of 0,12% chlorhexidine and antibiotics until laser utilization, hyperbaric oxygen, surgical debridement and resection. It is important to promote more communication between physicians and dentists to guarantee dental attention during the bisphosphonate administration, establishing oral health and preventing complications, such as osteonecrosis induced by this medication.

Analysis of the Single Toggle Jaw Crusher Force Transmission Characteristics

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Moses Frank Oduori

2016-01-01

Full Text Available This paper sets out to perform a static force analysis of the single toggle jaw crusher mechanism and to obtain the force transmission characteristics of the mechanism. In order to obtain force transmission metrics that are characteristic of the structure of the mechanism, such influences as friction, dead weight, and inertia are considered to be extraneous and neglected. Equations are obtained by considering the balance of forces at the moving joints and appropriately relating these to the input torque and the output torque. A mechanical advantage, the corresponding transmitted torque, and the variations thereof, during the cycle of motion of the mechanism, are obtained. The mechanical advantage that characterizes the mechanism is calculated as the mean value over the active crushing stroke of the mechanism. The force transmission characteristics can be used as criteria for the comparison of different jaw crusher mechanism designs in order to select the most suitable design for a given application. The equations obtained can also be used in estimating the forces sustained by the components of the mechanism.

Kinematics and Mechanics analysis of trap-jaw ant Odontomachus monticola

Science.gov (United States)

Hao, Wenteng; Yao, Guang; Zhang, Xiangyu; Zhang, Deyuan

2018-03-01

Trap-jaw ants of the genus Odontomachus exhibit spectacularly rapid predatory and fugitive strikes. In order to reveal the extraordinary impact resistance of the apical teeth material, we analyzed the kinematics and mechanics of the closing mandibles. Odontomachus monticola is an Odontomachus species and extensive in China. We video-recorded jaw-strikes to measure the closing velocity and acceleration. The experimental results showed that O. monticola’s mandibles closed at a highest velocity of 35.42 m/s and a highest acceleration of 750,000 m/s2 within an average duration of 0.16 ms. In addition, in order to measure the strike force, we developed an extraordinary measuring method with poly (vinylidene fluoride) (PVDF) piezoelectric film. First, the dynamic calibration of the PVDF piezoelectric film was conducted, then the calibrated piezoelectric film was struck by O. monticola. Finally, the mandible strike force was calculated according to the calibration result and the output signal. The measurements results demonstrated that the strike force ranges from 102.2 N to 235.2 N, which is impressive contrast with O. monticola’s body weight.

Microbiota associated with chronic osteomyelitis of the jaws

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Elerson Gaetti-Jardim Júnior

2010-12-01

Full Text Available Chronic osteomyelitis of maxilla and mandible is rare in industrialized countries and its occurrence in developing countries is associated with trauma and surgery, and its microbial etiology has not been studied thoroughly. The aim of this investigation was to evaluate the microbiota associated with osteomyelitis of mandible or maxilla from some Brazilian patients. After clinical and radiographic evaluation, samples of bone sequestra, purulent secretion, and biopsies of granulomatous tissues from twenty-two patients with chronic osteomyelitis of mandible and maxilla were cultivated and submitted for pathogen detection by using a PCR method. Each patient harbored a single lesion. Bacterial isolation was performed on fastidious anaerobe agar supplemented with hemin, menadione and horse blood for anaerobes; and on tryptic soy agar supplemented with yeast extract and horse blood for facultative bacteria and aerobes. Plates were incubated in anaerobiosis and aerobiosis, at 37ºC for 14 and 3 days, respectively. Bacteria were cultivated from twelve patient samples; and genera Actinomyces, Fusobacterium, Parvimonas, and Staphylococcus were the most frequent. By PCR, bacterial DNA was detected from sixteen patient samples. The results suggest that cases of chronic osteomyelitis of the jaws are usually mixed anaerobic infections, reinforcing the concept that osteomyelitis of the jaws are mainly related to microorganisms from the oral environment, and periapical and periodontal infections may act as predisposing factors.

Developmental finite element analysis of cichlid pharyngeal jaws: Quantifying the generation of a key innovation

Science.gov (United States)

Müller, Gerd B.

2018-01-01

Advances in imaging and modeling facilitate the calculation of biomechanical forces in biological specimens. These factors play a significant role during ontogenetic development of cichlid pharyngeal jaws, a key innovation responsible for one of the most prolific species diversifications in recent times. MicroCT imaging of radiopaque-stained vertebrate embryos were used to accurately capture the spatial relationships of the pharyngeal jaw apparatus in two cichlid species (Haplochromis elegans and Amatitlania nigrofasciata) for the purpose of creating a time series of developmental stages using finite element models, which can be used to assess the effects of biomechanical forces present in a system at multiple points of its ontogeny. Changes in muscle vector orientations, bite forces, force on the neurocranium where cartilage originates, and stress on upper pharyngeal jaws are analyzed in a comparative context. In addition, microCT scanning revealed the presence of previously unreported cement glands in A. nigrofasciata. The data obtained provide an underrepresented dimension of information on physical forces present in developmental processes and assist in interpreting the role of developmental dynamics in evolution. PMID:29320528

Developmental finite element analysis of cichlid pharyngeal jaws: Quantifying the generation of a key innovation.

Directory of Open Access Journals (Sweden)

Tim Peterson

Full Text Available Advances in imaging and modeling facilitate the calculation of biomechanical forces in biological specimens. These factors play a significant role during ontogenetic development of cichlid pharyngeal jaws, a key innovation responsible for one of the most prolific species diversifications in recent times. MicroCT imaging of radiopaque-stained vertebrate embryos were used to accurately capture the spatial relationships of the pharyngeal jaw apparatus in two cichlid species (Haplochromis elegans and Amatitlania nigrofasciata for the purpose of creating a time series of developmental stages using finite element models, which can be used to assess the effects of biomechanical forces present in a system at multiple points of its ontogeny. Changes in muscle vector orientations, bite forces, force on the neurocranium where cartilage originates, and stress on upper pharyngeal jaws are analyzed in a comparative context. In addition, microCT scanning revealed the presence of previously unreported cement glands in A. nigrofasciata. The data obtained provide an underrepresented dimension of information on physical forces present in developmental processes and assist in interpreting the role of developmental dynamics in evolution.

A case of brain abscess caused by radioosteomyelitis of the jaw

International Nuclear Information System (INIS)

Saruwatari, Tomoko; Koga, Makoto; Yoh, Junko; Sakaino, Hidenori; Koga, Chihiro; Kusukawa, Jingo

2008-01-01

We report a rare case of a brain abscess secondary to radioosteomyelitis of the jaw. A 61-year-old man who had received irradiation to a tumor of the tonsil in 1991 had been conservatively treated for radioosteomyelitis of the mandible at our hospital at regular intervals. Then he felt narrowing of the visual field with a serious headache and was immediately admitted to our hospital in September 2006. On the next day, convulsive seizures occurred. Brain CT scanning was immediately performed and demonstrated a low density area in the right occipital lobe. The patient was given a diagnosis of brain abscess. A craniotomy followed by aspiration with drainage was performed by a neurosurgeon. After the operation, the narrowing of visual field improved immediately, and both CT and MRI revealed disappearance of the low density area. Hematogenous infection due to radioosteomyelitis of the jaw was strongly suspected to have caused the brain abscess. After discharge from our hospital, no further symptoms have occurred. (author)

Giant cell lesion of the jaw as a presenting feature of Noonan syndrome.

Science.gov (United States)

Sinnott, Bridget P; Patel, Maya

2018-05-30

This is a case of a 20-year-old woman who presented with a left jaw mass which was resected and found to be a giant cell granuloma of the mandible. Her history and physical examination were suggestive for Noonan syndrome which was confirmed with genetic testing and the finding of a PTPN11 gene mutation which has rarely been associated with giant cell lesions of the jaw. Given her particular genetic mutation and the presence of a giant cell lesion, we present a case of Noonan-like/multiple giant cell lesion syndrome. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Complex Sensory Corpuscles in the Upper Jaw of Horsfield’s Tortoise (Testudo horsfieldii

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Marcela Buchtová

2009-01-01

Full Text Available The sensory corpuscles of Testudo horsfieldii in the skin of the upper lip and face were studied with light and electron microscopy. The sensory corpuscles were situated under epidermis; in the corium and also between the upper jaw bone tissues in the rostral part of oral cavity. The skin sensory corpuscles with a ramified inner core were grouped in clusters. Within the corpuscle there were several simple inner cores embedded within a common superficial capsule. The complex corpuscles have a novel structure in comparison to what has been described for sensory nerve endings in turtle. The complex sensory corpuscles probably function as mechanoreceptors important for monitoring the movement of the keratinized ridges and the most rostral part of the upper jaw, the rhamphotheci.

Effects of over-the-counter jaw-repositioning mouth guards on dynamic balance, flexibility, agility, strength, and power in college-aged male athletes.

Science.gov (United States)

Golem, Devon L; Arent, Shawn M

2015-02-01

Improvements in muscular power and anaerobic performance have resulted from the use of jaw-repositioning mouth guards designed with advanced dental techniques. The high cost of such techniques has dissuaded the widespread use. Recently, more affordable, over-the-counter (OTC) jaw-repositioning mouth guards have become available. The primary objective of this study was to examine the effects of 2 OTC jaw-repositioning mouth guards on muscular power and strength performance in college-aged male athletes. It was hypothesized that similar to previous observations with advanced dentistry-designed mouth guards, OTC jaw-repositioning mouth guards would impart positive effects on muscular power but not have any effect on muscular strength. Secondary objectives of this study included the examination of the effects of 2 OTC jaw-repositioning mouth guards on other variables related to athletic performance. Male collegiate athletes (N = 20) participated in 4 separate testing sessions that consisted of assessment of muscular power, dynamic balance, flexibility, agility, and muscular strength. The 4 conditions, 1 per testing session, were assigned in a randomized order and consisted of a no-mouth guard control (CON), a placebo mouth guard, a self-adapted jaw-repositioning mouth guard (SA), and a custom-fitted jaw-repositioning mouth guard (CF). No significant differences were observed between conditions in muscular power (p = 0.78), dynamic balance (p = 0.99), agility (p = 0.22), or muscular strength (p = 0.47). The CF had significantly lower hip flexion than the CON (p = 0.014) and had significantly greater lumbar spine lateral flexion compared with the SA condition (p = 0.054). However, these flexibility differences lack practical relevance as the effect sizes remain very small (ES = -0.27 and -0.14, respectively). In conclusion, the jaw-repositioning technique used in the design of these OTC mouth guards did not affect performance. It is important to note that negative

Choice of biomaterials—Do soft occlusal splints influence jaw-muscle activity during sleep? A preliminary report

Science.gov (United States)

Arima, Taro; Takeuchi, Tamiyo; Tomonaga, Akio; Yachida, Wataru; Ohata, Noboru; Svensson, Peter

2012-12-01

AimThe choice of biomaterials for occlusal splints may significantly influence biological outcome. In dentistry, hard acrylic occlusal splints (OS) have been shown to have a temporary and inhibitory effect on jaw-muscle activity, such as tooth clenching and grinding during sleep, i.e., sleep bruxism (SB). Traditionally, this inhibitory effect has been explained by changes in the intraoral condition rather than the specific effects of changes in occlusion. The aim of this preliminary study was to investigate the effect of another type of occlusal surface, such as a soft-material OS in addition to a hard-type OS in terms of changes in jaw-muscle activity during sleep. Materials and methodsSeven healthy subjects (mean ± SD, six men and one woman: 28.9 ± 2.7 year old), participated in this study. A soft-material OS (ethylene vinyl acetate copolymer) was fabricated for each subject and the subjects used the OS for five continuous nights. The EMG activity during sleep was compared to baseline (no OS). Furthermore, the EMG activity during the use of a hard-type OS (Michigan-type OS, acrylic resin), and hard-type OS combined with contingent electrical stimulation (CES) was compared to baseline values. Each session was separated by at least two weeks (washout). Jaw-muscle activity during sleep was recorded with single-channel ambulatory devices (GrindCare, MedoTech, Herlev, Denmark) in all sessions for five nights. ResultsJaw-muscle activity during sleep was 46.6 ± 29.8 EMG events/hour at baseline and significantly decreased during the hard-type OS (17.4 ± 10.5, P = 0.007) and the hard-type OS + CES (10.8 ± 7.1, P = 0.002), but not soft-material OS (36.3 ± 24.5, P = 0.055). Interestingly, the soft-material OS (coefficient of variance = 98.6 ± 35.3%) was associated with greater night-to-night variations than baseline (39.0 ± 11.8%) and the hard-type OS + CES (53.3 ± 13.7%, P < 0.013). ConclusionThe present pilot study in small sample showed that a soft

Brown tumor of the jaw after pregnancy and lactation in a MEN1 patient

Directory of Open Access Journals (Sweden)

Anna Casteràs

2016-11-01

Full Text Available Skeletal manifestations of primary hyperparathyroidism (pHPT include brown tumors (BT, which are osteoclastic focal lesions often localized in the jaws. Brown tumors are a rare manifestation of pHTP in Europe and USA; however, they are frequent in developing countries, probably related to vitamin D deficiency and longer duration and severity of disease. In the majority of cases, the removal of the parathyroid adenoma is enough for the bone to remineralize, but other cases require surgery. Hyperparathyroidism in MEN1 develops early, and is multiglandular and the timing of surgery remains questionable. To our knowledge, there are no reports of BT in MEN 1 patients. We present a 29-year-old woman with MEN 1 who developed a brown tumor of the jaw 24 months after getting pregnant, while breastfeeding. Serum corrected calcium remained under 2.7 during gestation, and at that point reached a maximum of 2.82 mmol/L. Concomitant PTH was 196 pg/mL, vitamin D 13.7 ng/mL and alkaline phosphatase 150 IU/L. Bone mineral density showed osteopenia on spine and femoral neck (both T-scores = −1.6. Total parathyroidectomy was performed within two weeks, with a failed glandular graft autotransplantation, leading to permanent hypoparathyroidism. Two months after removal of parathyroid glands, the jaw tumor did not shrink; thus, finally it was successfully excised. We hypothesize that higher vitamin D and mineral requirements during maternity may have triggered an accelerated bone resorption followed by appearance of the jaw BT. We suggest to treat pHPT before planning a pregnancy in MEN1 women or otherwise supplement with vitamin D, although this approach may precipitate severe hypercalcemia.

Myoelectric manifestations of jaw elevator muscle fatigue and recovery in healthy and TMD subjects.

Science.gov (United States)

Castroflorio, T; Falla, D; Tartaglia, G M; Sforza, C; Deregibus, A

2012-09-01

The effects of muscle pain and fatigue on the control of jaw elevator muscles are not well known. Furthermore, the myoelectric manifestations of fatigue and recovery from fatigue in the masticatory muscles are not reported in literature. The main aims of this study were (i) to evaluate the possible use of surface electromyography (sEMG) as an objective measure of fatigue of the jaw elevator muscles, (ii) to compare the myoelectric manifestations of fatigue in the temporalis anterior and masseter muscles bilaterally, (iii) to assess recovery of the investigated muscles after an endurance test and (iv) to compare fatigue and recovery of the jaw elevator muscles in healthy subjects and patients with muscle-related temporomandibular disorders (TMD). The study was performed on twenty healthy volunteers and eighteen patients with muscle-related TMD. An intra-oral compressive-force sensor was used to measure the voluntary contraction forces close to the intercuspal position and to provide visual feedback of submaximal forces to the subject. Surface EMG signals were recorded with linear electrode arrays during isometric contractions at 20%, 40%, 60% and 80% of the maximum voluntary contraction force, during an endurance test and during the recovery phase. The results showed that (i) the slope of the mean power spectral frequency (MNF) and the initial average rectified value (ARV) could be used to monitor fatigue of the jaw elevators, (ii) the temporalis anterior and masseter muscle show the same myoelectric manifestations of fatigue and recovery and (iii) the initial values of MNF and ARV were lower in patients with muscle-related TMD. The assessment of myoelectric manifestations of fatigue in the masticatory muscles may assist in the clinical assessment of TMDs. © 2012 Blackwell Publishing Ltd.

Finite Element Analysis of the Cingulata Jaw: An Ecomorphological Approach to Armadillo's Diets.

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Sílvia Serrano-Fochs

Full Text Available Finite element analyses (FEA were applied to assess the lower jaw biomechanics of cingulate xenarthrans: 14 species of armadillos as well as one Pleistocene pampathere (11 extant taxa and the extinct forms Vassallia, Eutatus and Macroeuphractus. The principal goal of this work is to comparatively assess the biomechanical capabilities of the mandible based on FEA and to relate the obtained stress patterns with diet preferences and variability, in extant and extinct species through an ecomorphology approach. The results of FEA showed that omnivorous species have stronger mandibles than insectivorous species. Moreover, this latter group of species showed high variability, including some similar biomechanical features of the insectivorous Tolypeutes matacus and Chlamyphorus truncatus to those of omnivorous species, in agreement with reported diets that include items other than insects. It remains unclear the reasons behind the stronger than expected lower jaw of Dasypus kappleri. On the other hand, the very strong mandible of the fossil taxon Vassallia maxima agrees well with the proposed herbivorous diet. Moreover, Eutatus seguini yielded a stress pattern similar to Vassalia in the posterior part of the lower jaw, but resembling that of the stoutly built Macroeuphractus outesi in the anterior part. The results highlight the need for more detailed studies on the natural history of extant armadillos. FEA proved a powerful tool for biomechanical studies in a comparative framework.

Small vertical changes in jaw relation affect motor unit recruitment in the masseter.

Science.gov (United States)

Terebesi, S; Giannakopoulos, N N; Brüstle, F; Hellmann, D; Türp, J C; Schindler, H J

2016-04-01

Strategies for recruitment of masseter muscle motor units (MUs), provoked by constant bite force, for different vertical jaw relations have not previously been investigated. The objective of this study was to analyse the effect of small changes in vertical jaw relation on MU recruitment behaviour in different regions of the masseter during feedback-controlled submaximum biting tasks. Twenty healthy subjects (mean age: 24·6 ± 2·4 years) were involved in the investigation. Intra-muscular electromyographic (EMG) activity of the right masseter was recorded in different regions of the muscle. MUs were identified by the use of decomposition software, and root-mean-square (RMS) values were calculated for each experimental condition. Six hundred and eleven decomposed MUs with significantly (P recruitment behaviour were organised into localised MU task groups. MUs with different task specificity in seven examined tasks were observed. The RMS EMG values obtained from the different recording sites were also significantly (P recruitment was significantly (P recruited MUs and the RMS EMG values decreased significantly (P recruitment behaviour in discrete subvolumes of the masseter in response to small changes in vertical jaw relations. These fine-motor skills might be responsible for its excellent functional adaptability and might also explain the successful management of temporomandibular disorder patients by somatic intervention, in particular by the use of oral splints. © 2015 John Wiley & Sons Ltd.

Open-mouth jaw locking in cats: a literature review and use of computed tomography in three cases.

Science.gov (United States)

Nutt, Anna E; Anderson, Thomas; Gracis, Margherita; Doran, Ivan; Warren-Smith, Chris; Langley-Hobbs, Sorrel J

2017-11-01

Case series summary This report summarises and reviews the published cases of open-mouth jaw locking in cats and describes three further cases. Case 1 was a 5-year-old, 5.3 kg male neutered domestic shorthair cat. CT identified changes consistent with temporomandibular joint (TMJ) dysplasia with osseous degenerative changes, and the cat subsequently underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. Case 2 was a 10-year-old, 6.0 kg male neutered Exotic Shorthair. Aside from a fracture of the left maxillary canine tooth crown and absence of the left maxillary fourth premolar tooth, no abnormalities were found on CT scan. The cat also underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. The third case was a 1-year-old, 4.0 kg male neutered Persian cat. Changes on CT were consistent with bilateral TMJ dysplasia, and the cat underwent staged bilateral partial zygomectomy with bilateral partial coronoidectomy. There was no recurrence of open-mouth jaw locking in any of the cases on long-term follow-up. Relevance and novel information Open-mouth jaw locking has been reported in cats of a wide range of ages, from 1-10 years of age. Cats with all skull types (brachycephalic, mesaticephalic and dolichocephalic) may be affected, but brachycephalic breeds seem to be over-represented. A CT scan with the jaw locked in place is recommended for diagnosis and surgical planning purposes; two of the cases reported here document the first cases of TMJ dysplasia in cats to be definitively diagnosed using CT. Trauma and symphyseal or TMJ laxity may also predispose to development of the condition. Partial coronoidectomy and partial zygomatic arch resection performed alone or in combination are generally successful at preventing recurrence. Bilateral partial zygomectomy with bilateral partial coronoidectomy has not previously been reported as a surgical treatment, and is recommended when open-mouth jaw locking occurs bilaterally.

Extracting DNA from 'jaws': High yield and quality from archived tiger shark (Galeocerdo cuvier) skeletal material

DEFF Research Database (Denmark)

Eg Nielsen, Einar; Morgan, J. A T; Maher, S. L.

2017-01-01

of tiger sharks (Galeocerdo cuvier). Protocols were compared for DNA yield and quality using a qPCR approach. For jaw swarf, all methods provided relatively high DNA yield and quality, while large differences in yield between protocols were observed for vertebrae. Similar results were obtained from samples...... observed, likely reflecting different preparation and storage methods for the trophies. Trial sequencing of DNA capture genomic libraries using 20 000 baits revealed that a significant proportion of captured sequences were derived from tiger sharks. This study demonstrates that archived shark jaws...

[Clinical experience in osteoplastic material Allomatrix-implant and fibrin rich platelets use in surgical treatment of jaw radicular cysts].

Science.gov (United States)

Kuz'minykh, I A

2009-01-01

Bones forming optimizators applying in surgical dentistry is an important element of jaw destructive processes successful treatment. Today use of osteoplastic materials on the collagen basis is widely spread. One of this challenge solution is FRP and Allomatrix-implant material applying to jaws during surgery operations. We described clinical investigation phase: the estimation of postoperative and remote results of treatment was carried out.

Central giant cell granuloma of the jaws: clinical and radiological evaluation of 22 cases

International Nuclear Information System (INIS)

Sun, Zhi-Jun; Cai, Yu; Zhao, Yi-Fang; Zwahlen, Roger A.; Zheng, Yun-Fei; Wang, Shi-Ping

2009-01-01

The objective was to investigate the clinical and radiological characteristics of central giant cell granulomas (CGCGs) of the jaws. A retrospective analysis of a 20-year database was performed regarding both clinical and radiological features of 22 patients affected with CGCGs of the jaws. Fourteen women and 8 men were included with the age range of 7-81 years (mean 31.7 years). Among the 22 lesions, 16 were located in the mandible and 6 in the maxilla. Painless swelling was the most common clinical feature in 18 of all cases. Limited mouth opening was noted in 2 patients where the lesions involved the condyle. Radiographically, 13 lesions were homogeneously osteolytic and 9 lesions were trabeculated. Fifteen lesions were unilocular and 14 lesions presented with well-defined but not sclerotic margins. CT images in 5 patients clearly showed the trabeculation within the lesions. The follow-up ranged from 1.5 to 11 years with a mean period of 5 years. Three out of 9 aggressive and 1 out of 13 nonaggressive lesions developed recurrence. Diagnosis of CGCGs of the jaws depends on both correct interpretation of clinical, radiographic and pathological data. Differentiation between aggressive and nonaggressive CGCGs should be considered to improve individual treatment planning. (orig.)

Central giant cell granuloma of the jaws: clinical and radiological evaluation of 22 cases

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhi-Jun; Cai, Yu; Zhao, Yi-Fang [School and Hospital of Stomatology, Wuhan University, Key Laboratory for Oral Biomedical Engineering of Ministry of Education, Wuhan, Hubei (China); Wuhan University, Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan, Hubei (China); Zwahlen, Roger A. [University of Hong Kong, Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry (China); Zheng, Yun-Fei [School and Hospital of Stomatology, Wuhan University, Key Laboratory for Oral Biomedical Engineering of Ministry of Education, Wuhan, Hubei (China); Wang, Shi-Ping [Wuhan University, Department of Oral and Maxillofacial Radiology, School and Hospital of Stomatology, Wuhan (China)

2009-09-15

The objective was to investigate the clinical and radiological characteristics of central giant cell granulomas (CGCGs) of the jaws. A retrospective analysis of a 20-year database was performed regarding both clinical and radiological features of 22 patients affected with CGCGs of the jaws. Fourteen women and 8 men were included with the age range of 7-81 years (mean 31.7 years). Among the 22 lesions, 16 were located in the mandible and 6 in the maxilla. Painless swelling was the most common clinical feature in 18 of all cases. Limited mouth opening was noted in 2 patients where the lesions involved the condyle. Radiographically, 13 lesions were homogeneously osteolytic and 9 lesions were trabeculated. Fifteen lesions were unilocular and 14 lesions presented with well-defined but not sclerotic margins. CT images in 5 patients clearly showed the trabeculation within the lesions. The follow-up ranged from 1.5 to 11 years with a mean period of 5 years. Three out of 9 aggressive and 1 out of 13 nonaggressive lesions developed recurrence. Diagnosis of CGCGs of the jaws depends on both correct interpretation of clinical, radiographic and pathological data. Differentiation between aggressive and nonaggressive CGCGs should be considered to improve individual treatment planning. (orig.)

Imaging of the jaw cysts with a dental CT software program : distinction of odontogenic keratocysts from other cysts

International Nuclear Information System (INIS)

Lee, Jung Man; Shin, Sang Hoon; Lee, Won Hoon; Oh, Kyu Hyen; Jung, Hak Young; Lee, Young Hwan; Sung, Nak Kwan; Jung, Duck Soo; Kim, Ok Dong

1997-01-01

To evaluate the usefulness of a dental CT software program in the assessment of jaw cysts and in the differentiation of odontogenic keratocysts and other cysts. Seventeen patients with proven jaw cysts(8 maxillae and 9 mandibles) were evaluated with a dental CT sofware program for location, locularity, the presence or absence of marginal scallping, and height to length ratio. For the delineation of involvement or displace-ment of neurovascular bundles, cortical erosion, perforation or expansion, and tooth root resorption by the jaw cysts, images from this program were compared to conventional images. Seventeen lesions icomprised 15 odontogenic cysts (five odontogenic keratocysts, five radicular, three residual and two dentigerous cysts) and two non-odontogenic cysts (one nasopalatine duct cyst and one postoperative maxillary cyst). Images of jaw cysts obtained with the dental CT software program delineated much more clearly than conventional images the status of neurovascular bundle and cortical bone, but there was no clear difference between the two modalities in delineating tooth root erosion. Dental CT findings of five mandibular odontogenic keratocysts were scalloped margin in all, mandibular ramus involvement in four, height to length ratio below 60% in four ,and multilocularity in two. The findings of the other 12 cysts (eight maxillae and four mandibles) were unilocularity in all, smooth inner margin in ten, height to length ratio below 60% in only two, and ramus involvement in none. A dental CT software program is an improved imaging modality for assessing jaw cysts;and findings which tend to indicate odontogenic keratocysts are marginal scalloping, mandibular ramus involvement, prominent spread along the marrow space and multilocularity

High-resolution computed tomography of the toothed jaw compared with histologic microsections

International Nuclear Information System (INIS)

Klein, H.M.; Fuhrmann, R.; Diedrich, P.; Guenther, R.W.

1993-01-01

Human bone segments of the toothed jaw were scanned using high-resolution CT with axial and coronal contiguous 1 and 2 mm slices. The bone segments were sliced analogous to the performed CT image positions. Contact films and micro-sections were made from the cuttings. Length and width of the teeth, the thickness of the alveolar bone and the distance between bone and dental surface were measured. Comparison of the CT measurements with contact films and histological specimen yielded best results for axial slices with 1 mm slice thickness (mean error 0.3-0.5 mm). Coronary oriented slices showed an error of 0.3-1.6 mm. 3D-reformatting can improve spatial orientation for axially produced image series. For CT imaging of the toothed jaw concerning the dento-alveolar structures, contiguous axial scanning with 1 mm slice thickness appears to be the concept of choice. (orig.) [de

A novel method for single sample multi-axial nanoindentation of hydrated heterogeneous tissues based on testing great white shark jaws.

Science.gov (United States)

Ferrara, Toni L; Boughton, Philip; Slavich, Eve; Wroe, Stephen

2013-01-01

Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the great white shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of great white shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable

A novel method for single sample multi-axial nanoindentation of hydrated heterogeneous tissues based on testing great white shark jaws.

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Toni L Ferrara

Full Text Available Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard and non-mineralized (soft layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the great white shark (Carcharodon carcharias. A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of great white shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method

Renal osteodystrophy with facial hyperostosis and 'rubber jaw' in an adult dog.

Science.gov (United States)

Kyle, M G; Davis, G B; Thompson, K G

1985-07-01

A nine-year-old male Sheltie dog was presented with bilaterally symmetrical maxilliary swelling, loose teeth and flexible mandibles. The condition was progressive over a period of two months. Biochemical and histopathological examinations supported a diagnosis of renal osteodystrophy with facial hyperostosis and 'rubber jaw'.

Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry.

Science.gov (United States)

Esfahanizadeh, Nasrin; Davaie, Sotoudeh; Rokn, A R; Daneshparvar, Hamid Reza; Bayat, Noushin; Khondi, Nasrin; Ajvadi, Sara; Ghandi, Mostafa

2013-07-01

The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA) was carried out to determine bone mineral density (BMD) of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson's correlation coefficient. The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001). There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005). There was a negative correlation (P < 0.01) between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones.

Morphology of the jaw, suspensorial, and opercle musculature of Beloniformes and related species (Teleostei: Acanthopterygii), with a special reference to the m. adductor mandibulae complex.

Science.gov (United States)

Werneburg, Ingmar

2015-01-01

The taxon Beloniformes represents a heterogeneous group of teleost fishes that show an extraordinary diversity of jaw morphology. I present new anatomical descriptions of the jaw musculature in six selected beloniforms and four closely related species. A reduction of the external jaw adductor (A1) and a changed morphology of the intramandibular musculature were found in many Beloniformes. This might be correlated with the progressively reduced mobility of the upper and lower jaw bones. The needlefishes and sauries, which are characterised by extremely elongated and stiffened jaws, show several derived characters, which in combination enable the capture of fish at high velocity. The ricefishes are characterised by several derived and many plesiomorphic characters that make broad scale comparisons difficult. Soft tissue characters are highly diverse among hemiramphids and flying fishes reflecting the uncertainty about their phylogenetic position and interrelationship. The morphological findings presented herein may help to interpret future phylogenetic analyses using cranial musculature in Beloniformes.

Morphology of the jaw, suspensorial, and opercle musculature of Beloniformes and related species (Teleostei: Acanthopterygii, with a special reference to the m. adductor mandibulae complex

Directory of Open Access Journals (Sweden)

Ingmar Werneburg

2015-02-01

Full Text Available The taxon Beloniformes represents a heterogeneous group of teleost fishes that show an extraordinary diversity of jaw morphology. I present new anatomical descriptions of the jaw musculature in six selected beloniforms and four closely related species. A reduction of the external jaw adductor (A1 and a changed morphology of the intramandibular musculature were found in many Beloniformes. This might be correlated with the progressively reduced mobility of the upper and lower jaw bones. The needlefishes and sauries, which are characterised by extremely elongated and stiffened jaws, show several derived characters, which in combination enable the capture of fish at high velocity. The ricefishes are characterised by several derived and many plesiomorphic characters that make broad scale comparisons difficult. Soft tissue characters are highly diverse among hemiramphids and flying fishes reflecting the uncertainty about their phylogenetic position and interrelationship. The morphological findings presented herein may help to interpret future phylogenetic analyses using cranial musculature in Beloniformes.

The relevance of clinical and radiographic features of jaw lesions: A prospective study

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Juliane Piragine ARAUJO

Full Text Available Abstract The study was carried out in a Brazilian population and the aim was to describe the prevalence and the clinic-radiographical features of jaw lesions. In addition, a comparison between the main diagnosis hypothesis and final diagnosis was accessed. A prospective study which evaluated all patients with jaw lesions diagnosed in an Oral Diagnosis Center, between August 2013 and October 2014. A total of 450 patients were observed for the first time, and 130 had some type of jaw lesion. The mean age of the patients was 35.2 years ± 17.86. Among these, 71 were women (54.62% and 87 were Caucasian (66.92%. The mandible was affected more frequently (71.43% than the maxilla (28.57%. Swelling and pain were the most frequent clinical signs and symptoms and were observed in 60 (42.85% and 38 (27.14% cases, respectively. The panoramic x-ray was the main radiographic exam utilized (88.57%. Radiolucent lesions accounted for 89 cases (63.57% and the unilocular form was present in 114 cases (81.43%. A total of 93 cases had histopathological analyses and the periapical cyst was the most frequent lesion. In the other 47 lesions, the diagnosis was conducted by clinical and radiographic management. Bone lesions were frequent, being noted on first visit in approximately 30% of patients; in 1/3 of the cases, the diagnoses were completed with a combination of clinical and radiographic exams.

Relationships among nocturnal jaw muscle activities, decreased esophageal pH, and sleep positions.

Science.gov (United States)

Miyawaki, Shouichi; Tanimoto, Yuko; Araki, Yoshiko; Katayama, Akira; Imai, Mikako; Takano-Yamamoto, Teruko

2004-11-01

The purpose of this study was to examine the relationships among nocturnal jaw muscle activities, decreased esophageal pH, and sleep positions. Twelve adult volunteers, including 4 bruxism patients, participated in this study. Portable pH monitoring, electromyography of the temporal muscle, and audio-video recordings were conducted during the night in the subjects' homes. Rhythmic masticatory muscle activity (RMMA) episodes were observed most frequently, with single short-burst episodes the second most frequent. The frequencies of RMMA, single short-burst, and clenching episodes were significantly higher during decreased esophageal pH episodes than those during other times. Both the electromyography and the decreased esophageal pH episodes were most frequently observed in the supine position. These results suggest that most jaw muscle activities, ie, RMMA, single short-burst, and clenching episodes, occur in relation to gastroesophageal reflux mainly in the supine position.

Myxoma of the Jaw Bones: Analysis of 27 Cases | Ajike | Nigerian ...

African Journals Online (AJOL)

Twenty-seven patients with histologically confirmed cases of odontogenic myxoma of the jaws were managed in a 10-year period. They represent 8.5% of all odontogenic tumours seen during the period. There was a female preponderance with the female to male ratio of 2.4:1. The age range was 11-70 years with majority ...

Medication-Related Osteonecrosis of the Jaws (MRONJ: Etiological Update

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Gianluca Tenore

2014-12-01

Full Text Available Osteonecrosis of the jaws (ONJ is an uncommon but severe bone disease, can be related to various medicaments (MRONJ including bisphosphonates (BRONJ, antiangiogenic and antiresorptive medicaments such as Denosumab (DRONJ, human monoclonal antibody to the receptor activator of nuclear factor-kB ligand. The rise in number in the latest years can be explained with many patients treated with all these drugs, assumed for osteometabolic (i.e osteoporosis, osteogenesis imperfecta or neoplastic diseases (multiple myeloma, metastatic breast, prostate and renal cancer. The onset mechanism of MRONJ is not entirely understood, probably different mechanisms are involved, such as inhibition of the osteoclasts differentiation and function, decrease of the angiogenesis and inflammation/infection of the jaw bones. Some pathogenetic mechanisms are different according to the drugs, for example the cases of the RANK-ligand inhibitor related ONJ may occur without considering the period of medication intake; also the risk of ONJ manifestation after bisphosphonates (BF is not significantly diminished after interrupting the drug therapy, because BF bind to the bone matrix for many years. Drugs currently implicated in osteonecrosis pathology are various, therefore the term ONJ was currently replaced by MRONJ; it is necessary that the anamnestic phase and management of the patients to be more detailed and correct, not only to prevent osteonecrosis but also to plan all necessary treatments before start of the drug therapy.

FUSIMOTOR EFFECTS OF MIDBRAIN STIMULATION ON JAW MUSCLE-SPINDLES OF THE ANESTHETIZED CAT

NARCIS (Netherlands)

TAYLOR, A; JUCH, PJW

The effects of electrical stimulation within the midbrain on fusimotor output to the jaw elevator muscles were studied in anaesthetized cats. Muscle spindle afferents recorded in the mesencephalic trigeminal nucleus were categorised as primary or secondary by their responses to succinylcholine

Survival, Function, and Complications of Oral Implants Placed in Bone Flaps in Jaw Rehabilitation: A Systematic Review.

Science.gov (United States)

Zhang, Lei; Ding, Qian; Liu, Cunrui; Sun, Yannan; Xie, Qiufei; Zhou, Yongsheng

2016-01-01

This systematic review attempted to determine the survival rate of implants placed in bone flaps in jaw rehabilitation and the functional gains and the most common complications related to these implants. An electronic search was undertaken of PubMed, EMBASE, and CNKI records from 1990 through July 2014. Two independent examiners read the titles and abstracts of the results to identify studies that met the inclusion criteria. Subsequently, the reference lists of the selected publications were hand searched. Descriptive statistics were used to report all data related to the survival rate of implants placed in bone flaps in jaw rehabilitation, the functional gains, and complications. A total of 20 studies were included for systematic review without repetition. The mean follow-up time after implant placement ranged from 1.75 to 9.5 years. Within the limitations of available studies, the survival rate of implants placed in bone flaps in jaw rehabilitation ranged from 82.4% to 100%. Of the 20 included studies, 15 reported a survival rate higher than 90%. The cumulative survival rate was 93.2%, with the longest follow-up time being 12.9 years. The most common complications related to these implants were peri-implant bone resorption or peri-implant inflammation, and peri-implant soft tissue proliferation. The main factors associated with the survival rate of implants in bone flaps were reported as time of implant placement and radiotherapy. Despite some persistent soft tissue problems and implant loss, most patients reached a satisfactory functional and esthetic outcome, as evaluated by clinical examination and subjectively by the patients at interview. Implant-supported dental prosthetic rehabilitation in reconstructed jaws improved the quality of life in terms of speech, nutrition, oral competence, and facial appearance. Placement of implants in bone flaps in jaw rehabilitation was demonstrated to be a reliable technique with a high survival rate. Multicentered

Bone and Soft Tissue Changes after Two-Jaw Surgery in Cleft Patients

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Yung Sang Yun

2015-07-01

Full Text Available BackgroundOrthognathic surgery is required in 25% to 35% of patients with a cleft lip and palate, for whom functional recovery and aesthetic improvement after surgery are important. The aim of this study was to examine maxillary and mandibular changes, along with concomitant soft tissue changes, in cleft patients who underwent LeFort I osteotomy and sagittal split ramus osteotomy (two-jaw surgery.MethodsTwenty-eight cleft patients who underwent two-jaw surgery between August 2008 and November 2013 were included. Cephalometric analysis was conducted before and after surgery. Preoperative and postoperative measurements of the bone and soft tissue were compared.ResultsThe mean horizontal advancement of the maxilla (point A was 6.12 mm, while that of the mandible (point B was -5.19 mm. The mean point A-nasion-point B angle was -4.1° before surgery, and increased to 2.5° after surgery. The mean nasolabial angle was 72.7° before surgery, and increased to 88.7° after surgery. The mean minimal distance between Rickett's E-line and the upper lip was 6.52 mm before surgery and 1.81 mm after surgery. The ratio of soft tissue change to bone change was 0.55 between point A and point A' and 0.93 between point B and point B'.ConclusionsPatients with cleft lip and palate who underwent two-jaw surgery showed optimal soft tissue changes. The position of the soft tissue (point A' was shifted by a distance equal to 55% of the change in the maxillary bone. Therefore, bone surgery without soft tissue correction can achieve good aesthetic results.

Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry

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Nasrin Esfahanizadeh

2013-01-01

Full Text Available Background: The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. Materials and Methods: A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA was carried out to determine bone mineral density (BMD of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson′s correlation coefficient. Results: The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001. There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005. There was a negative correlation (P < 0.01 between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. Conclusion: The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones.

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

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Ning Gan

Full Text Available Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95μm and precision was (55.26±11.21μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78μm and precision was (59.52±11.29μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p0.05, but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016. A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r = 0.485, p = 0.002 for full dentitions. It was feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Wider dental arch contributed to lower precision of an intraoral

Contrast-enhanced multidetector computerized tomography for odontogenic cysts and cystic-appearing tumors of the jaws: is it useful?

Science.gov (United States)

Kakimoto, Naoya; Chindasombatjaroen, Jira; Tomita, Seiki; Shimamoto, Hiroaki; Uchiyama, Yuka; Hasegawa, Yoko; Kishino, Mitsunobu; Murakami, Shumei; Furukawa, Souhei

2013-01-01

The purpose of this study was to investigate the usefulness of computerized tomography (CT), particularly contrast-enhanced CT, in differentiation of jaw cysts and cystic-appearing tumors. We retrospectively analyzed contrast-enhanced CT images of 90 patients with odontogenic jaw cysts or cystic-appearing tumors. The lesion size and CT values were measured and the short axis to long axis (S/L) ratio, contrast enhancement (CE) ratio, and standard deviation ratio were calculated. The lesion size and the S/L ratio of keratocystic odontogenic tumors were significantly different from those of radicular cysts and follicular cysts. There were no significant differences in the CE ratio among the lesions. Multidetector CT provided diagnostic information about the size of odontogenic cysts and cystic-appearing tumors of the jaws that was related to the lesion type, but showed no relation between CE ratio and the type of these lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

Actinomyces israelii in osteoradionecrosis of the jaws. Histopathologic and immunocytochemical study of five cases

International Nuclear Information System (INIS)

Happonen, R.P.; Viander, M.; Pelliniemi, L.; Aitasalo, K.

1983-01-01

Five surgically treated patients with osteoradionecrosis of the jaws are presented. The clinical history of the disease varied from 3 to 17 years. In three cases the progression of the disease was enhanced by surgical procedures performed in the irradiated area causing exfoliation of the premaxillary area in one case and spontaneous mandibular fracture in two cases. Actinomyces israelii was demonstrated in tissue sections of all five cases by using FITC-labeled specific antiserum and additionally with peroxidase-antiperoxidase method in one case. Candida was found in histologic sections of three cases. Radiation damage in the oral soft tissues and jawbones makes the atmosphere favorable for anaerobic microorganisms. The present results indicate that the role of A. israelii in the pathogenesis of osteoradionecrosis of the jaws has not been fully appreciated

[Permanent constrictions of the jaws (author's transl)].

Science.gov (United States)

Dupuis, A; Michaud, J

1981-01-01

Permanent constrictions of the jaws are of various types depending on the site of the lesion: temporomaxillary ankylosis, extra-articular constrictions of bone, skin, muscle, or mucosal origin, and those arising from tumors. The commonest cause is injury, those due to infection being currently less frequently observed, which cannot be said for those of tumoral origin. The consequences are difficulty in taking foud and poor buccodental hygiene, while temporomaxillary ankylosis in children provokes mandibular growth disturbances. Surgical treatment is aimed at removing the constriction. Total resection of the ankylosed block is essential to avoid recurrences, while reeducation of buccal opening must be started early and continued for long periods in all cases.

Multiple fibromyxomas of the jaws: A case report

Energy Technology Data Exchange (ETDEWEB)

Zayet, Mohamed Khalifa; Eiid, Salma Belal [Dept. of Oral Radiology, Faculty of Oral and Dental Medicine, Cairo University, Cairo (Egypt)

2014-09-15

Fibromyxoma of the jaw is a rare benign mesenchymal odontogenic tumor with locally aggressive behavior. In the present report, a 13-year-old female patient presented to our university hospital with delayed eruption of some of her teeth. A panoramic radiograph taken at the initial examination revealed four pericoronal radiolucencies related to the four third molars. Thereafter, a magnetic resonance imaging (MRI) examination was performed. After the surgical removal of these molars, the microscopic examination diagnosed the four lesions as fibromyxomas. Here, we have discussed the clinical, panoramic radiography, MRI, and histopathological findings of the case.

Benign Tumors and Tumor-like Lesions of the Oral Cavity and Jaws ...

African Journals Online (AJOL)

2016-06-15

Jun 15, 2016 ... Purpose: The purpose was to examine the prevalence, gender, age and site(s) of odontogenic and nonodontogenic benign tumors, and tumor‑like lesions occurring in the oral cavity and jaws in a Turkish population, particularly, in the Eastern Turkey, and to compare findings of this study with other reports.

The effect of food bolus location on jaw movement smoothness and masticatory efficiency

NARCIS (Netherlands)

Molenaar, W.N.B.; Gezelle Meerburg, P.J.; Luraschi, J.; Whittle, T.; Schimmel, M.; Lobbezoo, F.; Peck, C.C.; Murray, G.M.; Minami, I.

2012-01-01

Masticatory efficiency in individuals with extensive tooth loss has been widely discussed. However, little is known about jaw movement smoothness during chewing and the effect of differences in food bolus location on movement smoothness and masticatory efficiency. The aim of this study was to

Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding

Science.gov (United States)

Williams, Vincent S.; Barrett, Paul M.; Purnell, Mark A.

2009-01-01

Understanding the feeding mechanisms and diet of nonavian dinosaurs is fundamental to understanding the paleobiology of these taxa and their role in Mesozoic terrestrial ecosystems. Various methods, including biomechanical analysis and 3D computer modeling, have been used to generate detailed functional hypotheses, but in the absence of either direct observations of dinosaur feeding behavior, or close living functional analogues, testing these hypotheses is problematic. Microscopic scratches that form on teeth in vivo during feeding are known to record the relative motion of the tooth rows to each other during feeding and to capture evidence of tooth–food interactions. Analysis of this dental microwear provides a powerful tool for testing hypotheses of jaw mechanics, diet, and trophic niche; yet, quantitative analysis of microwear in dinosaurs has not been attempted. Here, we show that analysis of tooth microwear orientation provides direct evidence for the relative motions of jaws during feeding in hadrosaurid ornithopods, the dominant terrestrial herbivores of the Late Cretaceous. Statistical testing demonstrates that Edmontosaurus teeth preserve 4 distinct sets of scratches in different orientations. In terms of jaw mechanics, these data indicate an isognathic, near-vertical posterodorsal power stroke during feeding; near-vertical jaw opening; and propalinal movements in near anterior and near posterior directions. Our analysis supports the presence of a pleurokinetic hinge, and the straightness and parallelism of scratches indicate a tightly controlled occlusion. The dominance of scratched microwear fabrics suggests that Edmontosaurus was a grazer rather than a browser. PMID:19564603

Hybrid fixation in the bilateral sagittal split osteotomy for lower jaw advancement

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Felipe Ladeira Pereira

2010-02-01

Full Text Available Miniplate and screw fixation has been widely used in bilateral sagittal split osteotomy, but some issues remain unclear concerning its lack of rigidity when compared to Spiessl's bicortical technique. This paper demonstrates the hybrid fixation technique in a case report. A 34-year-old female patient underwent a double jaw surgery with counter-clockwise rotation of the mandible fixed using the hybrid fixation technique. The patient evolved well in the postoperative period and is still under follow up after 14 months, reporting satisfaction with the results and no significant deviation from the treatment plan up to now. No damage to tooth roots was done, maxillomandibular range of motion was within normality and regression of the inferior alveolar nerve paresthesia was observed bilaterally. The hybrid mandibular fixation is clearly visible in the panoramic and cephalometric control radiographs. It seems that the hybrid fixation can sum the advantages of both monocortical and bicortical techniques in lower jaw advancement, increasing fixation stability without significant damage to the mandibular articulation and the inferior alveolar nerve. A statistical investigation seems necessary to prove its efficacy.

Osteonecrosis of the jaw: effect of bisphosphonate type, local concentration, and acidic milieu on the pathomechanism.

Science.gov (United States)

Otto, Sven; Pautke, Christoph; Opelz, Christine; Westphal, Ines; Drosse, Inga; Schwager, Joanna; Bauss, Frieder; Ehrenfeld, Michael; Schieker, Matthias

2010-11-01

Osteonecrosis of the jaw has been reported in patients receiving high doses of intravenous nitrogen-containing bisphosphonates (N-BPs) because of malignant disease. The exact pathomechanisms have been elusive and questions of paramount importance remain unanswered. Recent studies have indicated toxic effects of bisphosphonates on different cell types, apart from osteoclast inhibition. Multipotent stem cells play an important role in the processes of wound healing and bone regeneration, which seem to be especially impaired in the jaws of patients receiving high doses of N-BPs. Therefore, the aim of the present study was to investigate the effects of different bisphosphonate derivatives and dose levels combined with varying pH levels on the mesenchymal stem cells in vitro. The effect of 2 N-BPs (zoledronate and ibandronate) and 1 non-N-BP (clodronate) on immortalized mesenchymal stem cells was tested at different concentrations, reflecting 1, 3, and 6 months and 1, 3, 5, and 10 years of exposure to standard oncology doses of the 2 N-BPs and equimolar concentrations of clodronate at different pH values (7.4, 7.0, 6.7, and 6.3). Cell viability and activity were analyzed using a WST assay. Cell motility was investigated using scratch wound assays and visualized using time-lapse microscopy. Both types of bisphosphonates revealed remarkable differences. Zoledronate and ibandronate showed a dose- and pH-dependent cellular toxicity. Increasing concentrations of both N-BPs and an acidic milieu led to a significant decrease in cell viability and activity (P key role in the pathogenesis of osteonecrosis of the jaw in patients receiving high doses of N-BPs for malignant diseases. Also the potency of N-BPs might be different, suggesting a greater risk of osteonecrosis of the jaw with zoledronate. Copyright © 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Jaw osteonecrosis related to bisphosphonate therapy: a severe secondary disorder.

Science.gov (United States)

Dannemann, C; Grätz, K W; Riener, M O; Zwahlen, R A

2007-04-01

Bisphosphonate-related osteonecrosis of the jaws (BON), first described in 2003, is gaining importance due to the increasing indication spectrum of bisphosphonate therapy [S. Takeyama, M. Ito, H. Shinoda, A novel bisphosphonate, TRK-530, for periodontitis, Bone 38 (2006) 31-31; M. Tagil, A. W-Dahl, J. Astrand, D. Little, S. Toksvig-Larsen, Decreasing the catabolic response by a single bisphosphonate infusion shortens the healing time in hemicallotasis operations, Bone 38 (2006) 84-85; E. Rodriguez, M.C. Duran, L.M. Rodriguez, R. Ros, M.R. Aleman, M. Rodriguez-Gaspar, A.M. Lopez, E. Garcia-Valdecasas, F. Santolaria, Intravenous (IV) bisphosphonates for osteopenic cancer survivor women: an alternative treatment, Bone 38 (2006) 72-73; D.G. Little, K. Ward, P. Kiely, M.C. Bellemore, J. Briody, C.T. Cowell, Bisphosphonate rescue in distraction osteogenesis: a case series, Bone 38 (2006) 80-80; R. Marx, Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: a growing epidemic, J. Oral Maxillofac. Surg. 61 (2003) 1115-1118]. BON patients suffering from varying bony defects and symptoms are extremely restricted in their quality of life. Due to a limited knowledge of the aetiology of BON efficient evidence-based treatment strategies are lacking. Until now 23 patients with bisphosphonate-related osteonecrosis have been admitted to the Department of Cranio-Maxillofacial Surgery of the University of Zurich. A complete history has been recorded. All patients underwent clinical and radiographic examination. CT scans and MRI have been performed in selected cases. All patients had in common that, before signs of BON were observed, a local traumatic incidence had occurred. All patients showed signs of infection which could be remarkably reduced by antibacterial treatment. Furthermore, the period of bisphosphonate treatment was found to be one of the significant factors causing bisphosphonate-related osteonecrosis of the jaws. The aetiology of BON

Do patients with chronic unilateral orofacial pain due to a temporomandibular disorder show increased attending to somatosensory input at the painful side of the jaw?

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Van Damme, Stefaan; Vanden Bulcke, Charlotte; Van Den Berghe, Linda; Poppe, Louise; Crombez, Geert

2018-01-01

Patients with chronic orofacial pain due to temporomandibular disorders (TMD) display alterations in somatosensory processing at the jaw, such as amplified perception of tactile stimuli, but the underlying mechanisms remain unclear. This study investigated one possible explanation, namely hypervigilance, and tested if TMD patients with unilateral pain showed increased attending to somatosensory input at the painful side of the jaw. TMD patients with chronic unilateral orofacial pain ( n  = 20) and matched healthy volunteers ( n  = 20) performed a temporal order judgment (TOJ) task indicated which one of two tactile stimuli, presented on each side of the jaw, they had perceived first. TOJ methodology allows examining spatial bias in somatosensory processing speed. Furthermore, after each block of trials, the participants rated the perceived intensity of tactile stimuli separately for both sides of the jaw. Finally, questionnaires assessing pain catastrophizing, fear-avoidance beliefs, and pain vigilance, were completed. TMD patients tended to perceive tactile stimuli at the painful jaw side as occurring earlier in time than stimuli at the non-painful side but this effect did not reach conventional levels of significance ( p  = .07). In the control group, tactile stimuli were perceived as occurring simultaneously. Secondary analyses indicated that the magnitude of spatial bias in the TMD group is positively associated with the extent of fear-avoidance beliefs. Overall, intensity ratings of tactile stimuli were significantly higher in the TMD group than in the control group, but there was no significant difference between the painful and non-painful jaw side in the TMD patients. The hypothesis that TMD patients with chronic unilateral orofacial pain preferentially attend to somatosensory information at the painful side of the jaw was not statistically supported, although lack of power could not be ruled out as a reason for this. The findings are discussed within

Bisphosphonate-related osteonecrosis of the jaw: specificities

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Siri Paulo

2014-09-01

Full Text Available Bisphosphonate-related osteonecrosis of the jaws (BRONJ is a severe complication that has recently emerged in patients treated with intravenous bisphosphonates for malignant diseases. This complication usually presents after a minor local trauma during a dental treatment. Several etiopathogenic mechanisms of this pathological condition have been proposed, but no model can explain all morphological changes observed at the macroscopic and microscopic level. BRONJ is likely to be related to direct toxicity in the bone and soft tissue cells, due to nitrogen-containing bisphosphonates. This review elucidates the clinical indications and mechanism of action of bisphosphonates, reports some clinical diagnostic criteria for BRONJ, describe the histopathological criteria for BRONJ diagnosis, the potential triggering pathways and the available treatment strategies.

Assessment of the Survival of Dental Implants in Irradiated Jaws Following Treatment of Oral Cancer: A Retrospective Study

Science.gov (United States)

Rana, Meenakshi Chauhan; Solanki, Swati; Pujari, Sudarshan C; Shaw, Eisha; Sharma, Swati; Anand, Abhishek; Singh, Harkanwal Preet

2016-01-01

Background: In patients undergoing head and neck surgery for various pathologic conditions, implants are one of the best restorative options and are increasing widely used. Therefore, we evaluated the success of dental implants in the irradiated jaws of patients following treatment of oral cancer oral cancer treated patients. Materials and Methods: Data of oral cancer treated patients was collected retrospectively from 2002 to 2008. We took 46 oral cancer treated patients in which implants were placed in irradiated jaws for rehabilitation. Results: It was found that out of 162 dental implants placed, 52 failed. Furthermore, there was no variation in the implant survival rate in between both the jaws. Radiation dose of <50 Gy units also showed significantly increased amount of implant survival rate. Conclusions: Implant survival is multifactorial and depends upon a number of factors like level of radiation exposure in that area, time gap between last radiation doses etc., Further research is required in this field to improve the esthetics and quality of life of cancer treated patients. PMID:27843270

Assessment of the survival of dental implants in irradiated jaws following treatment of oral cancer: A retrospective study

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Meenakshi Chauhan Rana

2016-01-01

Full Text Available Background: In patients undergoing head and neck surgery for various pathologic conditions, implants are one of the best restorative options and are increasing widely used. Therefore, we evaluated the success of dental implants in the irradiated jaws of patients following treatment of oral cancer oral cancer treated patients. Materials and Methods: Data of oral cancer treated patients was collected retrospectively from 2002 to 2008. We took 46 oral cancer treated patients in which implants were placed in irradiated jaws for rehabilitation. Results: It was found that out of 162 dental implants placed, 52 failed. Furthermore, there was no variation in the implant survival rate in between both the jaws. Radiation dose of <50 Gy units also showed significantly increased amount of implant survival rate. Conclusions: Implant survival is multifactorial and depends upon a number of factors like level of radiation exposure in that area, time gap between last radiation doses etc., Further research is required in this field to improve the esthetics and quality of life of cancer treated patients.

Endodontic therapy as a method in sanation of disturbed occlusion polytraumatized upper and lower jaw of a cat

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Prokić Branislav

2014-01-01

Full Text Available Concomitant injuries of bone and soft tissues of the upper and lower jaws are classified as multiple trauma symptoms associated with early complications, such as shock, disordered breathing, bleeding, pain, deformity and facial asymmetry, abnormal jaw movement, crepitation, palsy-paralysis of traumatized soft tissue regions and languages. The goal of this work is to present polytraumatised rehabilitation of upper and lower jaws by the system of endodontic treatment of upper canines in cats. Primary approach to stabilization polytraumatised cats is highlighted, also as procedures to be undertaken in animal in shock, injury of the maxilla and mandible, and the order of diagnostic procedures. Mandibular prognation and incorrect occlusion with consequent demage of mandibular gingiva with maxilla kaninus are complications wich were resolved in our case with endodontic treatment of upper canines of the cat. This paper presents a detailed approach to the reduction of dental caninus maxilla and establishing proper bite in the molar region of the maxila and mandible. [Projekat Ministarstva nauke Republike Srbije, br. III 45006

SU-F-E-20: A Mathematical Model of Linac Jaw Calibration Integrated with Collimator Walkout

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Zhao, Y; Corns, R; Huang, V [Fraser Valley Cancer Centre - BC Cancer Agency, Surrey, BC (United Kingdom)

2016-06-15

Purpose: Accurate jaw calibration is possible, but it does not necessarily achieve good junctions because of collimator rotation walkout. We developed a mathematical model seeking to pick an origin for calibration that minimizes the collimator walkout effect. Methods: We use radioopaque markers aligned with crosshair on the EPID to determine the collimator walkout at collimator angles 0°, 90° and 270°. We can accurately calibrate jaws to any arbitrary origin near the radiation field centre. While the absolute position of an origin moves with the collimator walkout, its relative location to the crosshair is an invariant. We studied two approaches to select an optimal origin. One approach seeks to bring all three origin locations (0°–90°–270°) as close as possible by minimizing the perimeter of the triangle formed by these points. The other approach focuses on the gap for 0°–90° junctions. Results: Our perimeter cost function has two variables and non-linear behaviour. Generally, it does not have zero-perimeter-length solution which leads to perfect jaw matches. The zero solution can only be achieved, if the collimator rotates about a single fixed axis. In the second approach, we can always get perfect 0°–0° and 0°–90° junctions, because we ignore the 0°–270° situation. For our TrueBeams, both techniques for selecting an origin improved junction dose inhomogeneities to less than ±6%. Conclusion: Our model considers the general jaw matching with collimator rotations and proposes two potential solutions. One solution optimizes the junction gaps by considering all three collimator angles while the other only considers 0°–90°. The first solution will not give perfect matching, but can be clinically acceptable with minimized collimator walkout effect, while the second can have perfect junctions at the expense of the 0°–270° junctions. Different clinics might choose between these two methods basing on their clinical practices.

SU-F-E-20: A Mathematical Model of Linac Jaw Calibration Integrated with Collimator Walkout

International Nuclear Information System (INIS)

Zhao, Y; Corns, R; Huang, V

2016-01-01

Purpose: Accurate jaw calibration is possible, but it does not necessarily achieve good junctions because of collimator rotation walkout. We developed a mathematical model seeking to pick an origin for calibration that minimizes the collimator walkout effect. Methods: We use radioopaque markers aligned with crosshair on the EPID to determine the collimator walkout at collimator angles 0°, 90° and 270°. We can accurately calibrate jaws to any arbitrary origin near the radiation field centre. While the absolute position of an origin moves with the collimator walkout, its relative location to the crosshair is an invariant. We studied two approaches to select an optimal origin. One approach seeks to bring all three origin locations (0°–90°–270°) as close as possible by minimizing the perimeter of the triangle formed by these points. The other approach focuses on the gap for 0°–90° junctions. Results: Our perimeter cost function has two variables and non-linear behaviour. Generally, it does not have zero-perimeter-length solution which leads to perfect jaw matches. The zero solution can only be achieved, if the collimator rotates about a single fixed axis. In the second approach, we can always get perfect 0°–0° and 0°–90° junctions, because we ignore the 0°–270° situation. For our TrueBeams, both techniques for selecting an origin improved junction dose inhomogeneities to less than ±6%. Conclusion: Our model considers the general jaw matching with collimator rotations and proposes two potential solutions. One solution optimizes the junction gaps by considering all three collimator angles while the other only considers 0°–90°. The first solution will not give perfect matching, but can be clinically acceptable with minimized collimator walkout effect, while the second can have perfect junctions at the expense of the 0°–270° junctions. Different clinics might choose between these two methods basing on their clinical practices.

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

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Gan, Ning; Xiong, Yaoyang; Jiao, Ting

2016-01-01

Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (pimpressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues

Science.gov (United States)

Gan, Ning; Xiong, Yaoyang; Jiao, Ting

2016-01-01

Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (pimpressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r

Convergent evolution of hemoglobin switching in jawed and jawless vertebrates.

Science.gov (United States)

Rohlfing, Kim; Stuhlmann, Friederike; Docker, Margaret F; Burmester, Thorsten

2016-02-01

During development, humans and other jawed vertebrates (Gnathostomata) express distinct hemoglobin genes, resulting in different hemoglobin tetramers. Embryonic and fetal hemoglobin have higher oxygen affinities than the adult hemoglobin, sustaining the oxygen demand of the developing organism. Little is known about the expression of hemoglobins during development of jawless vertebrates (Agnatha). We identified three hemoglobin switches in the life cycle of the sea lamprey. Three hemoglobin genes are specifically expressed in the embryo, four genes in the filter feeding larva (ammocoete), and nine genes correspond to the adult hemoglobin chains. During the development from the parasitic to the reproductive adult, the composition of hemoglobin changes again, with a massive increase of chain aHb1. A single hemoglobin chain is expressed constitutively in all stages. We further showed the differential expression of other globin genes: Myoglobin 1 is most highly expressed in the reproductive adult, myoglobin 2 expression peaks in the larva. Globin X1 is restricted to the embryo; globin X2 was only found in the reproductive adult. Cytoglobin is expressed at low levels throughout the life cycle. Because the hemoglobins of jawed and jawless vertebrates evolved independently from a common globin ancestor, hemoglobin switching must also have evolved convergently in these taxa. Notably, the ontogeny of sea lamprey hemoglobins essentially recapitulates their phylogeny, with the embryonic hemoglobins emerging first, followed by the evolution of larval and adult hemoglobins.

A study on the mixed jaw lesions associated with teeth

International Nuclear Information System (INIS)

Nah, Kyung Soo

2000-01-01

1. Retrospectively evaluate the accuracy of tentative diagnosis or impression from the clinico-radiographic materials of jaw lesions which showed mixed lesions associated with teeth. 2. To observe the diagnostic importance of the calcified part of the lesions which appear as radiopaque areas. 14 cases of jaw lesions which showed mixed lesions associated with teeth were reviewed. These lesions were mostly diagnosed as adenomatoid odontogenic tumors (6 cases) or calcifying odontogenic cysts with (4 cases) or without odontomas (4 cases). The calcified elements of the lesions which demonstrated various sizes and patterns of radiopaque shadows resembled odontoid tissues in some cases but could not be defined in some other cases radiographically. The final histopathologic diagnosis confirmed adenomatoid odontogenic tumors in 4 of the 6 cases. The remaining 2 cases turned out to be odontoma and ameloblastic fibroodontoma. The 4 cases of calcifying odontogenic cysts with odontomas were correct in 3 cases but remaining 1 case was just odontoma. The 4 cases of calcifying odontogenic cysts were proved to be odontogenic keratocyst, calcified peripheral fibroma, unicystic ameloblastoma and squamous cell carcinoma. The diagnostic accuracy of the adenomatoid odontogenic tumors and calcifying odontogenic cysts were high when the lesions show typical appearance. The calcifications which show radiopaque areas could be odontomas or dystrophic calficifations or remnants of bone fragments from resorption.

A study on the mixed jaw lesions associated with teeth

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Nah, Kyung Soo [Dept. of Dental Radiology, College of Dentistry, Pusan National University, Pusan (Korea, Republic of)

2000-03-15

1. Retrospectively evaluate the accuracy of tentative diagnosis or impression from the clinico-radiographic materials of jaw lesions which showed mixed lesions associated with teeth. 2. To observe the diagnostic importance of the calcified part of the lesions which appear as radiopaque areas. 14 cases of jaw lesions which showed mixed lesions associated with teeth were reviewed. These lesions were mostly diagnosed as adenomatoid odontogenic tumors (6 cases) or calcifying odontogenic cysts with (4 cases) or without odontomas (4 cases). The calcified elements of the lesions which demonstrated various sizes and patterns of radiopaque shadows resembled odontoid tissues in some cases but could not be defined in some other cases radiographically. The final histopathologic diagnosis confirmed adenomatoid odontogenic tumors in 4 of the 6 cases. The remaining 2 cases turned out to be odontoma and ameloblastic fibroodontoma. The 4 cases of calcifying odontogenic cysts with odontomas were correct in 3 cases but remaining 1 case was just odontoma. The 4 cases of calcifying odontogenic cysts were proved to be odontogenic keratocyst, calcified peripheral fibroma, unicystic ameloblastoma and squamous cell carcinoma. The diagnostic accuracy of the adenomatoid odontogenic tumors and calcifying odontogenic cysts were high when the lesions show typical appearance. The calcifications which show radiopaque areas could be odontomas or dystrophic calficifations or remnants of bone fragments from resorption.

Platelet Lysate: The Better Choice for Jaw Periosteal Cell Mineralization

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Yvonne Wanner

2017-01-01

Full Text Available Previously, we demonstrated a high quality of minerals formed by serum-free cultured jaw periosteal cells (JPCs by Raman spectroscopy but the mineralization extent was not satisfactory. In the present study, we analyzed the proliferation and mineralization potential of human platelet lysate- (hPL- cultured JPCs in comparison to that of FCS-cultured JPCs. By cell impedance measurements, we detected significantly higher population doubling times of PL-cultured JPCs in comparison to FCS-cultured JPCs. However, this result was not based on lower proliferation activities but on diminished cell sizes which JPCs develop under PL cultivation. The measurements of the metabolic activities clearly showed significantly higher cell proliferation rates under PL culturing. Equivalent levels of the mesenchymal cell markers CD29, CD45, CD73, CD90, and CD105 were detected, but there were significantly increased MSCA-1 levels under PL cultivation. While JPCs only occasionally mineralize under FCS culture conditions, the mineralization potential was significantly stronger under PL cultivation. Moreover, in 4 of 5 analyzed patient cells, the addition of dexamethasone was proved no longer necessary for strong mineralization of PL-cultured JPCs. We conclude that in vitro cultivation of JPCs with platelet lysate is a suitable alternative to FCS culture conditions and a powerful tool for the development of high-quality TE constructs using jaw periosteal cells.

Platelet Lysate: The Better Choice for Jaw Periosteal Cell Mineralization.

Science.gov (United States)

Wanner, Yvonne; Umrath, Felix; Waidmann, Marc; Reinert, Siegmar; Alexander, Dorothea

2017-01-01

Previously, we demonstrated a high quality of minerals formed by serum-free cultured jaw periosteal cells (JPCs) by Raman spectroscopy but the mineralization extent was not satisfactory. In the present study, we analyzed the proliferation and mineralization potential of human platelet lysate- (hPL-) cultured JPCs in comparison to that of FCS-cultured JPCs. By cell impedance measurements, we detected significantly higher population doubling times of PL-cultured JPCs in comparison to FCS-cultured JPCs. However, this result was not based on lower proliferation activities but on diminished cell sizes which JPCs develop under PL cultivation. The measurements of the metabolic activities clearly showed significantly higher cell proliferation rates under PL culturing. Equivalent levels of the mesenchymal cell markers CD29, CD45, CD73, CD90, and CD105 were detected, but there were significantly increased MSCA-1 levels under PL cultivation. While JPCs only occasionally mineralize under FCS culture conditions, the mineralization potential was significantly stronger under PL cultivation. Moreover, in 4 of 5 analyzed patient cells, the addition of dexamethasone was proved no longer necessary for strong mineralization of PL-cultured JPCs. We conclude that in vitro cultivation of JPCs with platelet lysate is a suitable alternative to FCS culture conditions and a powerful tool for the development of high-quality TE constructs using jaw periosteal cells.

Autosomal dominant type of endosteal hyperostosis with unusual manifestations of sclerosis of the jaw bones

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Nakamura, Takashi; Yamada, Naoyuki; Nonaka, Ryosuke; Sasaki, Motomasa

1987-01-01

We report three cases of autosomal dominant type endosteal hyperostosis which occurred in one Japanese family. A new pattern of sclerotic changes in the jaw bones is evident. In all members of the family there was a symmetrical thickening of the diaphyseal cortices of the long bones. The affected bones were only minimally widened and the epiphyses and metaphyses were spared. Endosteal sclerosis of the neurocranium was present with loss of the diploe. The sclerotic changes included enlargement and mottled sclerosis of both the maxilla and mandible, with multiple embedded teeth and odontomas. The ramus of the mandible was spared. Severe sclerosis of the jaw bones was present only in a 28-year-old women. The 2-year-son showed only focal sclerosis in the mandible, and his grandmother had minimal changes in the skeleton.

Study on the hard tissue changes in osteomyelitis of the jaws using CT image

International Nuclear Information System (INIS)

An, Chang Hyeon; Choi, Bo Ram; Huh, Kyung Hoe; Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul

2009-01-01

To assess the clinical findings and hard tissue changes of osteomyelitis of the jaws using computed tomographic (CT) image analysis. We reviewed and interpreted the CT images of 163 patients (64 males and 99 females, age range from 10 to 87 years) who visited the Seoul National University Dental Hospital from April 23, 2006 to December 31, 2008 and were diagnosed as osteomyelitis of the jaws through clinical, radiologic, and histopathologic examination. Each CT findings was investigated for frequency, correlation with age and gender. Of the 163 patients, 31 (19.0%) were affected on the maxilla, 135 (82.8%) were affected on the mandible, and 3 (1.8%) were affected on the both jaws simultaneously. The mean age of the patients who were affected on the maxilla was 61.0 years and that of the patients who were affected on the mandible was 56.2 years. On the maxilla, the most frequent site of disease was the posterior area (83.9%) and on the mandible, mandibular body (83.0%), followed by angle (48.1%), ramus (38.5%), condyle (13.3%), incisal area (9.6%), and coronoid process (3.0%). Among the 31 maxillary osteomyelitis, defect in the trabecular bone was observed in 28 (90.3%), osteosclerosis 20 (64.5%), defect in the cortical bone 27 (87.1%), sequestrum 17 (54.8%), and periosteal reaction 2 (6.5%). Among the 135 mandibular osteomyelitis, defect in the trabecular bone was observed in 100 (74.1%), osteosclerosis 104 (77.0%), defect in the cortical bone 116 (85.9%), sequestrum 36 (26.7%), and periosteal reaction 67 (49.6%). Of our cases, the maxillary osteomyelitis was visibly observed more frequently in females than males. The incidence is the highest in seventies (28.8%) and the lowest in teens (3.1%). The osteomyelitis of the jaws was observed more frequently in males than females before the age of 50, and observed more frequently in females after the age of 50. The most noticeable point was that the sequestrum was observed more often on maxillary osteomyelitis and the

Osteonecrosis of the jaw (ONJ) in patients who receive Bone Targeting Agents (BTAs): the power of e-learning.

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Nicolatou-Galitis, Ourania; Migliorati, Cesar

2018-01-01

The definition, pathobiology and risk factors of ONJ in cancer patients who receive BTAs are discussed in the recent ecancer module for osteonecrosis of the jaw (http://ecancer.org/education/module/276-osteonecrosis-of-the-jaw.php). ONJ prevention, early diagnosis and management are presented. The critical question of the performance of dental extraction, during BTA therapy, as indicated with the recent studies, is supported. The importance of the collaboration between dental and oncology professionals and the patients is highlighted and can be achieved through appropriate education. The ecancer modules are valuable tools for successful e-learning in medical oncology education, including ONJ.

Osteomalacia: the missing link in the pathogenesis of bisphosphonate-related osteonecrosis of the jaws?

Science.gov (United States)

Bedogni, Alberto; Saia, Giorgia; Bettini, Giordana; Tronchet, Anita; Totola, Andrea; Bedogni, Giorgio; Tregnago, Paolo; Valenti, Maria Teresa; Bertoldo, Francesco; Ferronato, Giuseppe; Nocini, Pier Francesco; Blandamura, Stella; Dalle Carbonare, Luca

2012-01-01

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a well-documented adverse event from treatment with nitrogen-containing bisphosphonates (NBPs). During a preliminary histomorphometric study aimed at assessing the rate of bone remodeling in the jaws of patients with surgically resected BRONJ, we found a defect of bone mineralization (unpublished data). We hypothesized that osteomalacia could be a risk factor for BRONJ in patients taking NBPs. Therefore, we looked for static and dynamic histomorphometric evidence of osteomalacia in biopsies from subjects with and without BRONJ. This case-control study used histomorphometric analysis of bone specimens of patients using NBPs (22 patients with BRONJ and 21 patients without BRONJ) who required oral surgical interventions for the treatment/prevention of osteonecrosis. Patients were given tetracycline hydrochloride according to a standardized protocol before taking bone biopsies from their jaws. Biopsies with evidence of osteomyelitis or necrosis at histology were excluded from the study. Osteomalacia was defined as a mineralization lag time >100 days, a corrected mean osteoid thickness >12.5 mm, and an osteoid volume >10%. In all, 77% of patients with BRONJ were osteomalacic compared with 5% of patients without BRONJ, according to histomorphometry. Because osteomalacia was found almost exclusively in NBP users with BRONJ, this is likely to be a generalized process in which the use of NBPs further deteriorates mechanisms of bone repair. Osteomalacia represents a new and previously unreported risk factor for disease development. This finding may contribute to a better understanding of the pathogenesis of this disease and help with the development of strategies to increase the safety of NBP administration.

Job-related affective well-being scale (Jaws: evidences of factor validity and reliability / Escala de bem-estar afetivo no trabalho (Jaws: evidências de validade fatorial e consistência interna

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Valdiney Veloso Gouveia

2008-01-01

Full Text Available This study aimed at adapting a measure of job-related affective well-being for the Brazilian milieu. Specifically, it was proposed to know evidences of factor validity and reliability of the Job-Related Affective Well-Being Scale (JAWS, assessing if its scores are influenced by participants' gender and age. The participants were 298 individuals employed in small or middle shopping malls in the city of João Pessoa, PB; most of them were female (76.8%, with a mean age of 26 years old (SD = 6.87. A main component analysis (with promax rotation was performed, revealing two components that jointly accounted for 48.1% of the total variance. They were named as positive affect (α = .94; 14 items and negative affect (α = .87; 13 items. A general factor of affective well-being was also identified (α = .95; 27 items. Participants' scores on these factors were not influenced by their gender or age. These findings are discussed based on literature that describes the psychometric parameters of the JAWS as well as the correlation of affects with demographic variables.

DENOSUMAB-RELATED OSTEONECROSIS OF THE JAWS: A CASE REPORT

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Milena Petkova

2017-03-01

Full Text Available Bisphosphonates are potent and effective drugs frequently used to prevent the skeletal complications associated with postmenopausal osteoporosis in women, to manage patients with multiple myeloma, hypercalcemia, and metastasis of cancer to the bone. The search for new medications with the same therapeutic effectiveness as the bisphosphonates but fewer side effects has resulted in the discovery of Denosumab, a human monoclonal antibody against the receptor activator for nuclear factor kappa B ligand (RANKL, therefore inhibiting osteoclast differentiation and function. Denosumab is a class of drugs that are entirely different from the traditional antiresorptive drugs, the bisphosphonates. Denosumab has several advantages, including better tolerability, ease of subcutaneous injection, a shorter half-life, and a reduced incidence of nephrotoxicity. Patients receiving bisphosphonates are at risk to develop a severe devastating complication - osteonecrosis of the jaws (ONJ - which is challenging to treat. Since 2010 there have been reports of ONJ in patients taking denosumab. In the 2014 position paper of the American Association of Oral and Maxillofacial Surgeons, the nomenclature “bisphosphonate-related osteonecrosis of the jaw” was changed to “medication related osteonecrosis of the jaw” (MRONJ. The change is justified to accommodate the growing number of osteonecrosis cases involving the maxilla and mandible associated with other antiresorptive (denosumab and antiangiogenic therapies. Here we report a development of denosumab-related osteonecrosis of the jaw (DRONJ - a new type of bony necrosis- in patient with bone metastases of breast cancer on Denosumab therapy. The patient has no previous history of taking bisphosphonates.

The genetic architecture of novel trophic specialists: larger effect sizes are associated with exceptional oral jaw diversification in a pupfish adaptive radiation.

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Martin, Christopher H; Erickson, Priscilla A; Miller, Craig T

2017-01-01

The genetic architecture of adaptation is fundamental to understanding the mechanisms and constraints governing diversification. However, most case studies focus on loss of complex traits or parallel speciation in similar environments. It is still unclear how the genetic architecture of these local adaptive processes compares to the architecture of evolutionary transitions contributing to morphological and ecological novelty. Here, we identify quantitative trait loci (QTL) between two trophic specialists in an excellent case study for examining the origins of ecological novelty: a sympatric radiation of pupfishes endemic to San Salvador Island, Bahamas, containing a large-jawed scale-eater and a short-jawed molluscivore with a skeletal nasal protrusion. These specialized niches and trophic traits are unique among over 2000 related species. Measurements of the fitness landscape on San Salvador demonstrate multiple fitness peaks and a larger fitness valley isolating the scale-eater from the putative ancestral intermediate phenotype of the generalist, suggesting that more large-effect QTL should contribute to its unique phenotype. We evaluated this prediction using an F2 intercross between these specialists. We present the first linkage map for pupfishes and detect significant QTL for sex and eight skeletal traits. Large-effect QTL contributed more to enlarged scale-eater jaws than the molluscivore nasal protrusion, consistent with predictions from the adaptive landscape. The microevolutionary genetic architecture of large-effect QTL for oral jaws parallels the exceptional diversification rates of oral jaws within the San Salvador radiation observed over macroevolutionary timescales and may have facilitated exceptional trophic novelty in this system. © 2016 John Wiley & Sons Ltd.

Benign tumors and tumor-like lesions of the oral cavity and jaws: An ...

African Journals Online (AJOL)

Purpose: The purpose was to examine the prevalence, gender, age and site(s) of odontogenic and nonodontogenic benign tumors, and tumor‑like lesions occurring in the oral cavity and jaws in a Turkish population, particularly, in the Eastern Turkey, and to compare findings of this study with other reports. Materials and ...

Parrotfish grazing ability: interspecific differences in relation to jaw-lever mechanics and relative weight of adductor mandibulae on an Okinawan coral reef

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Atsushi Nanami

2016-09-01

Full Text Available Parrotfishes (family Labridae: Scarini are regarded to have important roles for maintaining the ecosystem balance in coral reefs due to their removal of organic matter and calcic substrates by grazing. The purpose of the present study was to clarify the interspecific differences in grazing ability of five parrotfish species (Chlorurus sordidus, C. bowersi, Scarus rivulatus, S. niger and S. forsteni in relation to interspecific differences in jaw-lever mechanics and the relative weight of the adductor mandibulae (muscles operating jaw closing. The grazing ability was calculated by using stomach contents (CaCO3 weight/organic matter weight defined as the grazing ability index (GAI. There were significant interspecific differences in GAI (C. sordidus = C. bowersi > S. rivulatus > S. niger = S. forsteni. Teeth of C. sordidus and C. bowersi were protrusive-shape whereas teeth of S. rivulatus, S. niger and S. forsteni were flat-shape. C. sordidus and C. bowersihave jaw-lever mechanics producing a greater biting force and have a larger weight of adductor mandibulae. S. rivulatus has jaw-lever mechanics producing a greater biting force but a smaller weight of adductor mandibulae that produce an intermediate biting force. In contrast, S. niger and S. forsteni have jaw-lever mechanics producing a lesser biting force and have a smaller weight of adductor mandibulae. Feeding rates and foray size of S. rivulatus, S. niger and S. forsteni were greater than C. sordidus and C. bowersi. The degree in bioerosion (GAI × feeding rate was the largest for S. rivulatusand the smallest for S. forsteni. The degree in bioerosion for C. sordidus was larger than S. niger whereas relatively equal between C. bowersi and S. niger. These results suggest that interspecific difference in GAI was explained by interspecific differences in teeth shape, jaw-lever mechanics and relative weight of adductor mandibulae. The interspecific difference in the degree of bioerosion suggests

Parrotfish grazing ability: interspecific differences in relation to jaw-lever mechanics and relative weight of adductor mandibulae on an Okinawan coral reef.

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Nanami, Atsushi

2016-01-01

Parrotfishes (family Labridae: Scarini) are regarded to have important roles for maintaining the ecosystem balance in coral reefs due to their removal of organic matter and calcic substrates by grazing. The purpose of the present study was to clarify the interspecific differences in grazing ability of five parrotfish species (Chlorurus sordidus, C. bowersi, Scarus rivulatus, S. niger and S. forsteni) in relation to interspecific differences in jaw-lever mechanics and the relative weight of the adductor mandibulae (muscles operating jaw closing). The grazing ability was calculated by using stomach contents (CaCO3 weight/organic matter weight) defined as the grazing ability index (GAI). There were significant interspecific differences in GAI (C. sordidus = C. bowersi > S. rivulatus > S. niger = S. forsteni). Teeth of C. sordidus and C. bowersi were protrusive-shape whereas teeth of S. rivulatus, S. niger and S. forsteni were flat-shape. C. sordidus and C. bowersihave jaw-lever mechanics producing a greater biting force and have a larger weight of adductor mandibulae. S. rivulatus has jaw-lever mechanics producing a greater biting force but a smaller weight of adductor mandibulae that produce an intermediate biting force. In contrast, S. niger and S. forsteni have jaw-lever mechanics producing a lesser biting force and have a smaller weight of adductor mandibulae. Feeding rates and foray size of S. rivulatus, S. niger and S. forsteni were greater than C. sordidus and C. bowersi. The degree in bioerosion (GAI × feeding rate) was the largest for S. rivulatusand the smallest for S. forsteni. The degree in bioerosion for C. sordidus was larger than S. niger whereas relatively equal between C. bowersi and S. niger. These results suggest that interspecific difference in GAI was explained by interspecific differences in teeth shape, jaw-lever mechanics and relative weight of adductor mandibulae. The interspecific difference in the degree of bioerosion suggests the

Effects of Botulinum Toxin on Jaw Motor Events during Sleep in Sleep Bruxism Patients: A Polysomnographic Evaluation

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Shim, Young Joo; Lee, Moon Kyu; Kato, Takafumi; Park, Hyung Uk; Heo, Kyoung; Kim, Seong Taek

2014-01-01

Study Objectives: To investigate the effects of botulinum toxin type A (BoNT-A) injection on jaw motor episodes during sleep in patients with or without orofacial pain who did not respond to oral splint treatment. Methods: Twenty subjects with a clinical diagnosis of SB completed this study. Ten subjects received bilateral BoNT-A injections (25 U per muscle) into the masseter muscles only (group A), and the other 10 received the injections into both the masseter and temporalis muscles (group B). Video-polysomnographic (vPSG) recordings were made before and at 4 weeks after injection. Rhythmic masticatory muscle activity (RMMA) and orofacial activity (OFA) were scored and analyzed for several parameters (e.g., frequency of episodes, bursts per episode, episode duration). The peak amplitude of electromyographic (EMG) activity in the two muscles was also measured. Results: BoNT-A injection did not reduce the frequency, number of bursts, or duration for RMMA episodes in the two groups. The injection decreased the peak amplitude of EMG burst of RMMA episodes in the injected muscles (p < 0.001, repeated measure ANOVA) in both groups. At 4 weeks after injection, 9 subjects self-reported reduction of tooth grinding and 18 subjects self-reported reduction of morning jaw stiffness. Conclusions: A single BoNT-A injection is an effective strategy for controlling SB for at least a month. It reduces the intensity rather than the generation of the contraction in jaw-closing muscles. Future investigations on the efficacy and safety in larger samples over a longer follow-up period are needed before establishing management strategies for SB with BoNT-A. Citation: Shim YJ; Lee MK; Kato T; Park HU; Heo K; Kim ST. Effects of botulinum toxin on jaw motor events during sleep in sleep bruxism patients: a polysomnographic evaluation. J Clin Sleep Med 2014;10(3):291-298. PMID:24634627

Jaw-opening reflex and corticobulbar motor excitability changes during quiet sleep in non-human primates

DEFF Research Database (Denmark)

Yao, Dongyuan; Lavigne, Gilles J.; Lee, Jye-Chang

2013-01-01

Study Objective: To test the hypothesis that the reflex and corticobulbar motor excitability of jaw muscles is reduced during sleep. Design: Polysomnographic recordings in the electrophysiological study. Setting: University sleep research laboratories. Participants and Interventions: The reflex a...

Do patients with chronic unilateral orofacial pain due to a temporomandibular disorder show increased attending to somatosensory input at the painful side of the jaw?

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Stefaan Van Damme

2018-01-01

Full Text Available Background Patients with chronic orofacial pain due to temporomandibular disorders (TMD display alterations in somatosensory processing at the jaw, such as amplified perception of tactile stimuli, but the underlying mechanisms remain unclear. This study investigated one possible explanation, namely hypervigilance, and tested if TMD patients with unilateral pain showed increased attending to somatosensory input at the painful side of the jaw. Methods TMD patients with chronic unilateral orofacial pain (n = 20 and matched healthy volunteers (n = 20 performed a temporal order judgment (TOJ task indicated which one of two tactile stimuli, presented on each side of the jaw, they had perceived first. TOJ methodology allows examining spatial bias in somatosensory processing speed. Furthermore, after each block of trials, the participants rated the perceived intensity of tactile stimuli separately for both sides of the jaw. Finally, questionnaires assessing pain catastrophizing, fear-avoidance beliefs, and pain vigilance, were completed. Results TMD patients tended to perceive tactile stimuli at the painful jaw side as occurring earlier in time than stimuli at the non-painful side but this effect did not reach conventional levels of significance (p = .07. In the control group, tactile stimuli were perceived as occurring simultaneously. Secondary analyses indicated that the magnitude of spatial bias in the TMD group is positively associated with the extent of fear-avoidance beliefs. Overall, intensity ratings of tactile stimuli were significantly higher in the TMD group than in the control group, but there was no significant difference between the painful and non-painful jaw side in the TMD patients. Discussion The hypothesis that TMD patients with chronic unilateral orofacial pain preferentially attend to somatosensory information at the painful side of the jaw was not statistically supported, although lack of power could not be ruled out as a

The importance of dental CT for implantation in mouth, jaw, and face surgery

International Nuclear Information System (INIS)

Widlitzek, H.; Koenig, S.; Golin, U.

1996-01-01

The importance of dental CT in comparison to conventional OPT in implantation diagnostics is demonstrated in specific indication groups (atrophy of upper and lower jaw, patient after tumor and reconstructive surgery). The application of radiological techniques is illustrated in relation to diagnostic information quality, radiation exposure and cost effectiveness regarding clinical routine use. (orig.) [de

Impact of orthognathic surgery on oral health-related quality of life in patients with jaw deformities.

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Kurabe, K; Kojima, T; Kato, Y; Saito, I; Kobayashi, T

2016-12-01

The purpose of this study was to clarify the impact of orthognathic surgery on oral health-related quality of life (OHRQOL) in patients with jaw deformities. The subjects were 65 patients (21 males and 44 females) who underwent orthognathic surgery. The mean age of the patients was 23.6 years. Forty-seven patients had skeletal class III malocclusions, eight patients had skeletal class II, and 10 patients had skeletal class I with facial asymmetry and/or open bite. OHRQOL was assessed using the Japanese version of the Oral Health Impact Profile (OHIP-J54) before and 6 months after surgery. While OHIP-J54 scores in the patients before surgery were significantly higher than those in the control subjects, OHIP-J54 scores after surgery were significantly lower than those before surgery. OHIP-J54 scores in older patients were significantly higher than those in younger patients. In conclusion, most patients with jaw deformities have lower OHRQOL than individuals with normal occlusion, and orthognathic surgery has a positive impact on OHRQOL. The determination of OHRQOL in patients with jaw deformities seems to be very useful for understanding the patients' problems and for assessing the extent of changes in terms of patient well-being. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Variation in the shape and mechanical performance of the lower jaws in ceratopsid dinosaurs (Ornithischia, Ceratopsia).

Science.gov (United States)

Maiorino, Leonardo; Farke, Andrew A; Kotsakis, Tassos; Teresi, Luciano; Piras, Paolo

2015-11-01

Ceratopsidae represents a group of quadrupedal herbivorous dinosaurs that inhabited western North America and eastern Asia during the Late Cretaceous. Although horns and frills of the cranium are highly variable across species, the lower jaw historically has been considered to be relatively conservative in morphology. Here, the lower jaws from 58 specimens representing 21 ceratopsoid taxa were sampled, using geometric morphometrics and 2D finite element analysis (FEA) to explore differences in morphology and mechanical performance across Ceratopsoidea (the clade including Ceratopsidae, Turanoceratops and Zuniceratops). Principal component analyses and non-parametric permuted manovas highlight Triceratopsini as a morphologically distinct clade within the sample. A relatively robust and elongate dentary, a larger and more elongated coronoid process, and a small and dorso-ventrally compressed angular characterize this clade, as well as the absolutely larger size. By contrast, non-triceratopsin chasmosaurines, Centrosaurini and Pachyrhinosaurini have similar morphologies to each other. Zuniceratops and Avaceratops are distinct from other taxa. No differences in size between Pachyrhinosaurini and Centrosaurini are recovered using non-parametric permuted anovas. Structural performance, as evaluated using a 2D FEA, is similar across all groups as measured by overall stress, with the exception of Triceratopsini. Shape, size and stress are phylogenetically constrained. A longer dentary as well as a long coronoid process result in a lower jaw that is reconstructed as relatively much more stressed in triceratopsins. © 2015 Anatomical Society.

Multiple prismatic calcium phosphate layers in the jaws of present-day sharks (Chondrichthyes; Selachii).

Science.gov (United States)

Dingerkus, G; Séret, B; Guilbert, E

1991-01-15

Jaws of large individuals, over 2 m in total length, of the shark species Carcharodon carcharias (great white shark) and Isurus oxyrinchus (mako shark) of the family Lamnidae, and Galeocerdo cuvieri (tiger shark) and Carcharhinus leucas (bull shark) of the family Carcharhinidae were found to have multiple, up to five, layers of prismatic calcium phosphate surrounding the cartilages. Smaller individuals of these species and other known species of living chondrichthyans have only one layer of prismatic calcium phosphate surrounding the cartilages, as also do most species of fossil chondrichthyans. Two exceptions are the fossil shark genera Xenacanthus and Tamiobatis. Where it is found in living forms, this multiple layered calcification does not appear to be phylogenetic, as it appears to be lacking in other lamnid and carcharhinid genera and species. Rather it appears to be functional, only appearing in larger individuals and species of these two groups, and hence may be necessary to strengthen the jaw cartilages of such individuals for biting.

IMPACT OF ROCK HARDNESS ON FRAGMENTATION BY HYDRAULIC HAMMER AND CRUSHING IN JAW CRUSHER

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Trpimir Kujundžić

2008-12-01

Full Text Available The physical and mechanical characteristics of intact rocks depend on the way of their formation, sustained deformations and the process of wearing a specific rock has been exposed to. These characteristics have a rather high influence on the technological process of extraction and dressing of mineral raw materials. However, the mechanical characteristics of rocks due to use of explosives for their extraction in the open pit have a more significant impact. The rock blocks extracted by blasting which are larger than the opening of the primary crusher are usually fragmented by hydraulic hammer. The paper presents the results of the testing of impact of rock hardness on fragmentation of rocks by means of hydraulic hammer and during crushing in jaw crusher. The testing was carried out on the rock samples from five quarries. According to the obtained results the hardness has a considerably larger impact on the fragmentation energy by hydraulic hammer than on the crushing energy in jaw crusher.

Force and Strength Analysis of the Reel with Jaw of Torsion-bar Spring

Science.gov (United States)

Ma, Ke; Liu, Weiqi; Wang, Jiawei; Gu, Le

2017-06-01

Structure characteristics and working principle of the reel with jaw of torsion-bar spring are introduced. The reel can not only eliminate the leakage risks of hydraulic jaw, but also reduce the investment cost of enterprises and improve the surface quality of the products. The static analysis of mandrel, sector plate and oblique wedge were conducted, and the main data of stress distribution and deformation were obtained, which provide a reliable theoretical basis for the design and optimization of the reel. The research results show that the external support has a great effect on the stress and deformation of the mandrel. With the increase of the weight of steel stress increases, the drum deformation increases, but the analysis of the position of maximum stress, can be obtained to drum stress and deformation is the main reason of excessive bending moment caused by heavy steel rolls. The bending moment and deformation can be reduced significantly at the end of the steel coil, which can effectively improve the service life of the drum.

Study of the neural basis of striatal modulation of the jaw-opening reflex.

Science.gov (United States)

Barceló, Ana C; Fillipini, B; Pazo, Jorge Horacio

2010-02-01

Previous experimental data from this laboratory demonstrated the participation of the striatum and dopaminergic pathways in central nociceptive processing. The objective of this study was to examine the possible pathways and neural structures associated with the analgesic action of the striatum. The experiments were carried out in rats anesthetized with urethane. The jaw-opening reflex (JOR) was evoked by electrical stimulation of the tooth pulp of lower incisors and recorded in the anterior belly of the digastric muscles. Intrastriatal microinjection of apomorphine, a nonspecific dopamine agonist, reduced or abolished the JOR amplitude. Electrolytic or kainic acid lesions, unilateral to the apomorphine-injected striatum, of the globus pallidus, substantia nigra pars reticulata, subthalamic nucleus and bilateral lesion the rostroventromedial medulla (RVM), blocked the inhibition of the JOR by striatal stimulation. These findings suggest that the main output nuclei of the striatum and the RVM may be critical elements in the neural pathways mediating the inhibition of the reflex response, evoked in jaw muscles by noxious stimulation of dental pulp.

Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) Slit-Jaw Imaging System

Science.gov (United States)

Wilkerson, P.; Champey, P. R.; Winebarger, A. R.; Kobayashi, K.; Savage, S. L.

2017-12-01

The Marshall Grazing Incidence X-ray Spectrometer is a NASA sounding rocket payload providing a 0.6 - 2.5 nm spectrum with unprecedented spatial and spectral resolution. The instrument is comprised of a novel optical design, featuring a Wolter1 grazing incidence telescope, which produces a focused solar image on a slit plate, an identical pair of stigmatic optics, a planar diffraction grating and a low-noise detector. When MaGIXS flies on a suborbital launch in 2019, a slit-jaw camera system will reimage the focal plane of the telescope providing a reference for pointing the telescope on the solar disk and aligning the data to supporting observations from satellites and other rockets. The telescope focuses the X-ray and EUV image of the sun onto a plate covered with a phosphor coating that absorbs EUV photons, which then fluoresces in visible light. This 10-week REU project was aimed at optimizing an off-axis mounted camera with 600-line resolution NTSC video for extremely low light imaging of the slit plate. Radiometric calculations indicate an intensity of less than 1 lux at the slit jaw plane, which set the requirement for camera sensitivity. We selected a Watec 910DB EIA charge-coupled device (CCD) monochrome camera, which has a manufacturer quoted sensitivity of 0.0001 lux at F1.2. A high magnification and low distortion lens was then identified to image the slit jaw plane from a distance of approximately 10 cm. With the selected CCD camera, tests show that at extreme low-light levels, we achieve a higher resolution than expected, with only a moderate drop in frame rate. Based on sounding rocket flight heritage, the launch vehicle attitude control system is known to stabilize the instrument pointing such that jitter does not degrade video quality for context imaging. Future steps towards implementation of the imaging system will include ruggedizing the flight camera housing and mounting the selected camera and lens combination to the instrument structure.

What are the differences for IMRT plans configured with beam data collected with either the jaws or the MLCs

International Nuclear Information System (INIS)

Jolly, D.J.; Alahakone, D.; Meyer, J.

2010-01-01

Full text: The anisotropic analytic algorithm (AAA) is currently the most widely used dose calculation algorithm for photons within the Eclipse treatment planning system. Configuration of this algorithm requires field profiles, percentage depth doses and output factors for a wide range of field sizes, usually measured with the jaws defining the field. However, delivery of complex fields such as required for rotational IMRT beam shaping is done with the MLC. The purpose of this work is to determine if significant differences result between two separately configured AAA algorithms, one using beam data collected with the jaw defining the field and the other with the MLC. Methods Two separate sets of beam data were collected, one with the jaw and one with the MLC defining the field. Each set of data was then used to configure two distinct AAA algorithms. A variety of comparisons were made using various IMRT techniques including sliding window, step and shoot, RapidArc and segmented fields, calculated with both algorithms. Plan differences are presented along with verification measurements made with TLDs and the diode based ArcCheck device. Results The largest differences observed were at the surface and in highly modulated areas. The magnitude of the differences was on the order of 0.5%; with the MLC defined AAA predicting more dose than the jaw defined AAA. Discussion and Conclusion Although these initial results reveal only small differences, a full analysis of all plans will be presented before conclusions can be made as to what algorithm should be implemented clinically.

Stress distribution in the temporo-mandibular joint discs during jaw closing: a high-resolution three-dimensional finite-element model analysis.

Science.gov (United States)

Savoldelli, Charles; Bouchard, Pierre-Olivier; Loudad, Raounak; Baque, Patrick; Tillier, Yannick

2012-07-01

This study aims at analysing the stresses distribution in the temporomandibular joint (TMJ) using a complete high-resolution finite element model (FE Model). This model is used here to analyse the stresses distribution in the discs during a closing jaw cycle. In the end, this model enables the prediction of the stress evolution in the TMJ disc submitted to various loadings induced by mandibular trauma, surgery or parafunction. The geometric data for the model were obtained from MRI and CT scans images of a healthy male patient. Surface and volume meshes were successively obtained using a 3D image segmentation software (AMIRA(®)). Bone components of skull and mandible, both of joint discs, temporomandibular capsules and ligaments and dental arches were meshed as separate bodies. The volume meshes were transferred to the FE analysis software (FORGE(®)). Material properties were assigned for each region. Boundary conditions for closing jaw simulations were represented by different load directions of jaws muscles. The von Mises stresses distribution in both joint discs during closing conditions was analyzed. The pattern of von Mises stresses in the TMJ discs is non-symmetric and changed continuously during jaw movement. Maximal stress is reached on the surface disc in areas in contact with others bodies. The three-dimension finite element model of masticatory system will make it possible to simulate different conditions that appear to be important in the cascade of events leading to joint damage.

Development of Flight Slit-Jaw Optics for Chromospheric Lyman-Alpha SpectroPolarimeter

Science.gov (United States)

Kubo, Masahito; Suematsu, Yoshinori; Kano, Ryohei; Bando, Takamasa; Hara, Hirohisa; Narukage, Noriyuki; Katsukawa, Yukio; Ishikawa, Ryoko; Ishikawa, Shin-nosuke; Kobiki, Toshihiko;

Functional anatomy and kinematics of the oral jaw system during terrestrial feeding in Periophthalmus barbarus.

Science.gov (United States)

Michel, Krijn B; Adriaens, Dominique; Aerts, Peter; Dierick, Manuel; Wassenbergh, Sam Van

2014-10-01

The Atlantic mudskipper, Periophthalmus barbarus, is an amphibious fish that successfully overcomes the numerous physical challenges of capturing prey in a terrestrial environment. However, it is unclear what changes in the morphology and function of the feeding apparatus contribute to the mudskipper's successful transition from aquatic to terrestrial capture of prey. In particular, how does the mudskipper achieve effective prehension of land-based prey using its percomorph feeding apparatus? To address that question, we performed a morphological analysis of the feeding apparatus of P. barbarus based on microcomputed tomography scanning, histological sectioning, and dissections as well as a kinematic analysis based on high-speed video and X-ray video to quantify the movements of the oral jaw apparatus elements. Our results show that the neurocranium remains in a fixed position relative to the pectoral girdle as the fish pivots over its pectoral fins toward the prey. The premaxilla rotates dorsally and protrudes downward over the prey. The dentary is rotated ventrally over an angle of 120°, which is facilitated by an intramandibular joint. These motions of the neurocranium, premaxilla, and dentary reorient the mouth aperture so it is parallel to the substrate, thereby allowing the jaws to be placed over the prey. The prey is grabbed between the oral teeth or scooped into the mouth primarily via rapid closing motion of the lower jaw. This analysis of P. barbarus clarifies the morphological and kinematic characteristics required by fish to become successful terrestrial feeders at the environmental transition between water and land. © 2014 Wiley Periodicals, Inc.

Jaw-motor effects of experimental jaw-muscle pain and stress in patients with deep bite and matched control subjects

DEFF Research Database (Denmark)

Sonnesen, Liselotte; Svensson, Peter

2013-01-01

clenching, during evoked pain and stress between deep bite patients and controls was investigated. DESIGN: In 30 deep bite patients and in 30 sex-/age-matched controls with neutral occlusion EMG activity was recorded bilaterally from masseter and anterior temporalis muscles before and during evoked pain......OBJECTIVE: The effect of experimental jaw-muscle pain and stress on masticatory muscle activity in TMD-patients has been discussed. Furthermore, associations between TMD and deep bite patients have been studied. Accordingly in the present study, comparison of EMG responses at rest, maximal...... and before and during a stress task. Evoked pain was induced by injections of glutamate into the masseter (local pain) and brachioradialis (remote pain) muscles and resting EMG activity was recorded before and after 1, 2, 3, 4, 5 and 10min. A precision task was used to simulate a stressful condition and EMG...

Pneumatic muscle actuated parallel asymmetrical gripper system with one mobile jaw

Directory of Open Access Journals (Sweden)

Deaconescu Tudor

2017-01-01

Full Text Available The paper pertains to the field of the current global endeavours in industrial robot construction, the presented research being oriented towards identifying innovative constructive solutions for gripper systems. The utilisation of the linear pneumatic muscle as actuator of the gripper system ensures a construction that is light, highly compliant, and that meets the safety requirements related to interaction with humans. The paper further presents and discusses such a system of asymmetrical construction with a single mobile jaw.

Ontogeny of the Alligator Cartilago Transiliens and Its Significance for Sauropsid Jaw Muscle Evolution

Science.gov (United States)

Tsai, Henry P.; Holliday, Casey M.

2011-01-01

The cartilago transiliens is a fibrocartilaginous structure within the jaw muscles of crocodylians. The cartilago transiliens slides between the pterygoid buttress and coronoid region of the lower jaw and connects two muscles historically identified as m. pseudotemporalis superficialis and m. intramandibularis. However, the position of cartilago transiliens, and its anatomical similarities to tendon organs suggest the structure may be a sesamoid linking a single muscle. Incompressible sesamoids often form inside tendons that wrap around bone. However, such structures rarely ossify in reptiles and have thus far received scant attention. We tested the hypothesis that the cartilago transiliens is a sesamoid developed within in one muscle by investigating its structure in an ontogenetic series of Alligator mississippiensis using dissection, 3D imaging, and polarizing and standard light microscopy. In all animals studied, the cartilago transiliens receives collagen fibers and tendon insertions from its two main muscular attachments. However, whereas collagen fibers were continuous within the cartilaginous nodule of younger animals, such continuity decreased in older animals, where the fibrocartilaginous core grew to displace the fibrous region. Whereas several neighboring muscles attached to the fibrous capsule in older individuals, only two muscles had significant contributions to the structure in young animals. Our results indicate that the cartilago transiliens is likely a sesamoid formed within a single muscle (i.e., m. pseudotemporalis superficialis) as it wraps around the pterygoid buttress. This tendon organ is ubiquitous among fossil crocodyliforms indicating it is a relatively ancient, conserved structure associated with the development of the large pterygoid flanges in this clade. Finally, these findings indicate that similar tendon organs exist among potentially homologous muscle groups in birds and turtles, thus impacting inferences of jaw muscle homology

Osteonecrosis of the jaw

International Nuclear Information System (INIS)

Reid, Ian R.; Cundy, Tim

2009-01-01

Osteonecrosis of the jaw (ONJ) was first reported in the dental literature in 2003. The term was coined to describe a spectrum of dental problems seen in cancer patients treated with high doses of intravenous bisphosphonates for the prevention of skeletal-related events. By consensus, the syndrome is now defined by the presence of exposed bone in the mouth which fails to heal after appropriate intervention over a period of 6 or 8 weeks. It is most common in patients with breast or prostate cancers, or multiple myeloma treated with bisphosphonates, of whom about 5% develop the condition. In patients receiving the much lower drug doses used in osteoporosis, the incidence appears to be ∝1/100,000 patient-years, probably comparable to that in the general population. It is likely that ONJ results from direct drug toxicity to cells of bone and soft tissue. The bone in ONJ lesions does not appear to be 'frozen' but rather there is very active bone resorption taking place, which is likely to be responsible for the local release at high concentrations of bisphosphonates. Infection probably plays a pivotal role in driving this resorption, so its active management is critical. Obvious abnormalities are apparent with a variety of radiologic modalities, and it is not clear that radiographs are inferior to other approaches. Most authors favor a conservative approach to surgical debridement of the lesions. (orig.)

Developmental odontogenic cysts of jaws: a clinical study of 245 cases.

Science.gov (United States)

Yazdani, Javad; Kahnamouii, Shiva Solahaye

2009-01-01

The aim of this study was to investigate the relative frequency of developmental odontogenic cysts in an Iranian population. In this study 245 cysts from both jaws, treated in the Faculty of Dentistry at Tabriz University of Medical Sciences during a 10-year period from 1998 to 2008, were analyzed in order to evaluate the incidence of such cysts. We had permission from all the patients. Case histories of 65% of male and 35% of female patients were analyzed. The age of the patients varied from 14 to 64 years, with an average of 33.21 ± 10.89. In this 10-year study of odontogenic cysts, 97 cases were developmental odontogenic cysts with the following inci-dence: dentigerous cyst, 44%; odontogenic keratocyst, 36%; primordial cyst, 9%; Gorlin cyst, 2%; lateral periodontal cyst, 3%; eruption cyst, 3%; and gingival cyst, 3% (adults 2%, infants 1%). A total of 60% of the cysts were found in the mandible and 40% in the maxilla. Regarding the mandible, the molar region was involved in 47% of the cases, premolar region in 33% and anterior region in 20% (total = 100%). Regarding the maxilla, the canine-to-canine region was involved in 52% of the cases, premolar region in 20% and molar region in 28% (total = 100%). An important finding in this study was the fact that 39% of the jaw cysts were developmental odontogenic cysts and the most common developmental odontogenic cysts were dentigerous cyst and OKC (odontogenic keratocyst).

Improved patient repositioning accuracy by integrating an additional jaw fixation into a high precision face mask system in stereotactic radiotherapy of the head

International Nuclear Information System (INIS)

Lopatta, E.; Liesenfeld, S.M.; Bank, P.; Guenther, R.; Wiezorek, T.; Wendt, T.G.; Wurm, R.

2003-01-01

Background: For high precision radiotherapy of the neurocranium a precise, reproducible positioning technique is the basic pre-requisite. The aim of this study was to assess the influence of a modification of the commercially available stereotactical BrainLab trademark -head mask system on accuracy in patient positioning during fractionated radiotherapy. Material and Methods: 29 patients were treated with stereotactic radiotherapy of the head. Immobilization was provided by a two layer thermoplastic mask system (BrainLab trademark). 18 of these patients received an additional custom made fixation either of the upper jaw (OKF) or of the mandibula (UKF). The positioning accuracy was assessed by measurements of the shifting of anatomical landmarks in relation to therigid mask system on biplanar simulator films using a digital imaging system. Before each measurement a fine adjustment of the simulator to an optical ring system was performed. The reference radiographs were done just before CT-planning. During a 2-7 weeks lasting course of radiotherapy displacement measurements in relation to the reference images for all three dimensions (z, y and x) were done once a week. In 29 patients 844 measurements were analyzed. Results: An additional jaw fixation improves the reproducibility of patient positioning significantly in all three spatial dimensions. The standard deviation in lateral direction (x) was 0.6 mm with jaw fixation vs. 0.7 mm without jaw fixation (p [de

Stable tooth contacts in intercuspal occlusion makes for utilities of the jaw elevators during maximal voluntary clenching.

Science.gov (United States)

Wang, X-R; Zhang, Y; Xing, N; Xu, Y-F; Wang, M-Q

2013-05-01

Data are inconsistent concerning whether the level of the surface electromyographic (SEMG) activity of jaw-closing muscles increases when biting forces elevated during maximal voluntary clenching (MVC). In this study, T-Scan III system and BioEMG III system were used to record bite force, occlusal contacts and SEMG activity of the anterior temporalis (TA) and of the masseter muscles (MM) simultaneously. Recordings were obtained from 16 healthy young adult males during different conditions: (i) a fast MVC from resting position to intercuspal position (ICP); (ii) mandibular movements from ICP to protrusive or lateral edge-to-edge positions with teeth in contact with biting; (iii) a fast MVC in protrusive and lateral edge-to-edge positions. A higher level of SEMG activity was associated with a higher bite force during occluding movements (P < 0.05). However, during fast MVC from rest to ICP, the largest number of occlusal contacts was achieved and distributed more symmetrically, the highest level of biting force was obtained, but the SEMG activity of the jaw elevator muscles was reduced compared with its maximum level (P < 0.05). This phenomenon was not observed during the fast MVC in protrusive or lateral edge-to-edge positions. The present results that a lower SEMG activity was associated with the largest number of occlusal contacts and the highest level of bite force during centric MVC demonstrated a complex integration of jaw-closing muscles when a stable occlusion is present. © 2013 Blackwell Publishing Ltd.

Oral squamous cell carcinoma arising in a patient after hematopoietic stem cell transplantation with bisphosphonate-related osteonecrosis of the jaws.

Science.gov (United States)

Arduino, Paolo G; Scully, Crispian; Chiusa, Luigi; Broccoletti, Roberto

2015-01-01

A 55-year-old man with a history of acute myeloid leukaemia treated with hematopoietic stem cell transplantation and with a 5-year history of bisphosphonate-related osteonecrosis of the jaws, following 12 cycles of intravenous zoledronic acid therapy, presented in December 2009 with a history of increasingly severe unilateral lower jaw pain. Oral examination revealed, as previously, exposed bone in the left mandible, but also a new exophytic mass on the lower-left buccal mucosa. Biopsy confirmed a diagnosis of oral squamous cell carcinoma. To the best of our knowledge, this is the first report of an oral squamous cell carcinoma that appeared adjacent to an area of osteochemonecrosis.

Cone-beam computed tomography in the management of dentigerous cyst of the jaws: A report of two cases

International Nuclear Information System (INIS)

Vidya, Lakshminarayanan; Ranganathan, Kannan; Praveen, B; Gunaseelan, Rajan; Shanmugasundaram, S

2013-01-01

Cone-beam computed tomography (CBCT) is an emerging technology finding application in all branches of dentistry. The current series highlights the application of CBCT in the preoperative assessment of dentigerous cyst of the jaws

Homology of the jaw muscles in lizards and snakes-a solution from a comparative gnathostome approach.

Science.gov (United States)

Johnston, Peter

2014-03-01

Homology or shared evolutionary origin of jaw adductor muscles in lizards and snakes has been difficult to establish, although snakes clearly arose within the lizard radiation. Lizards typically have temporal adductors layered lateral to medial, and in snakes the muscles are arranged in a rostral to caudal pattern. Recent work has suggested that the jaw adductor group in gnathostomes is arranged as a folded sheet; when this theory is applied to snakes, homology with lizard morphology can be seen. This conclusion revisits the work of S.B. McDowell, J Herpetol 1986; 20:353-407, who proposed that homology involves identity of m. levator anguli oris and the loss of m. adductor mandibulae externus profundus, at least in "advanced" (colubroid) snakes. Here I advance the folded sheet hypothesis across the whole snake tree using new and literature data, and provide a solution to this homology problem. Copyright © 2014 Wiley Periodicals, Inc.

Multiple jaw cysts-unveiling the Gorlin-Goltz syndrome.

Science.gov (United States)

Manjima, S; Naik, Zameera; Keluskar, Vaishali; Bagewadi, Anjana

2015-03-01

Gorlin-Goltz syndrome or basal cell nevus syndrome is a comparatively rare syndrome characterized by basal cell nevi, odontogenic keratocysts, and skeletal anomalies. Diagnosis is based on the major and minor clinical and radiographic criteria. Dentist plays a major role in the diagnosis of this disease due to the oral and maxillofacial manifestations of the syndrome. In some cases, jaw cysts are diagnosed by routine radiographs advised by the dentists. Odontogenic keratocysts in such syndromic patients will be multiple and extensive and in some cases results in cortical expansion and facial disfigurement. Thorough clinical examination and investigations prompt an early confirmation of the syndrome, which is very essential to avoid morbidity associated with the syndrome. Here, we report a case of multiple odontogenic cysts in a 16-year-old patient which later was diagnosed as a case of Gorlin Goltz syndrome.

Evaluation of the dose calculation accuracy for small fields defined by jaw or MLC for AAA and Acuros XB algorithms.

Science.gov (United States)

Fogliata, Antonella; Lobefalo, Francesca; Reggiori, Giacomo; Stravato, Antonella; Tomatis, Stefano; Scorsetti, Marta; Cozzi, Luca

2016-10-01

Small field measurements are challenging, due to the physical characteristics coming from the lack of charged particle equilibrium, the partial occlusion of the finite radiation source, and to the detector response. These characteristics can be modeled in the dose calculations in the treatment planning systems. Aim of the present work is to evaluate the MU calculation accuracy for small fields, defined by jaw or MLC, for anisotropic analytical algorithm (AAA) and Acuros XB algorithms, relative to output measurements on the beam central axis. Single point output factor measurement was acquired with a PTW microDiamond detector for 6 MV, 6 and 10 MV unflattened beams generated by a Varian TrueBeam STx equipped with high definition-MLC. Fields defined by jaw or MLC apertures were set; jaw-defined: 0.6 × 0.6, 0.8 × 0.8, 1 × 1, 2 × 2, 3 × 3, 4 × 4, 5 × 5, and 10 × 10 cm 2 ; MLC-defined: 0.5 × 0.5 cm 2 to the maximum field defined by the jaw, with 0.5 cm stepping, and jaws set to: 2 × 2, 3 × 3, 4 × 4, 5 × 5, and 10 × 10 cm 2 . MU calculation was obtained with 1 mm grid in a virtual water phantom for the same fields, for AAA and Acuros algorithms implemented in the Varian eclipse treatment planning system (version 13.6). Configuration parameters as the effective spot size (ESS) and the dosimetric leaf gap (DLG) were varied to find the best parameter setting. Differences between calculated and measured doses were analyzed. Agreement better than 0.5% was found for field sizes equal to or larger than 2 × 2 cm 2 for both algorithms. A dose overestimation was present for smaller jaw-defined fields, with the best agreement, averaged over all the energies, of 1.6% and 4.6% for a 1 × 1 cm 2 field calculated by AAA and Acuros, respectively, for a configuration with ESS = 1 mm for both X and Y directions for AAA, and ESS = 1.5 and 0 mm for X and Y directions for Acuros. Conversely, a calculated dose underestimation was found for small MLC-defined fields, with the

Predictable Technique to Register Retruded Contact Position (RCP) Using a Disposable Jaw Relation Recording Device.

Science.gov (United States)

Daher, Tony; Lobel, William A; Massad, Joseph; Ahuja, Swati; Danilov, Zarko Jack

2015-05-01

The dental literature presents various definitions and techniques to describe and register centric relation (CR) or centric occlusion (CO). Briefly reviewing the literature in relation to CR, this article proposes the use of the term retruded contact position (RCP), clinically defined as retruded, unstrained, repeatable position and where the mandibular movements start when a Gothic arch tracing is used. With this clinical definition, a technique can be easily selected that meets all the requirements of such position. The article discusses the use of a jaw recorder that is an intraorally graphic recording device that results in a tracing of mandibular movements in one plane, with the apex of the tracing indicating the retruded, unstrained, and repeatable relationship. The intersection of the arcs produced by the right and left working movement form the apex of the Gothic arch tracing. Several clinical situations using the jaw recorder are described. Clinicians can now quickly and accurately record RCP, balance complete, partial, or implant dentures, and orthopedically reposition the mandible. The technique achieves highly reliable and reproducible results.

The Challenge Treatment of Medication Related Osteonecrosis of the Jaw: A Case Report

OpenAIRE

M Rodríguez Sánchez; Bassi AP; Carvalho PS

2015-01-01

Bisphosphonates toxicological effect on alveolar bone could be associated to medication related osteonecrosis of the jaw. (MRONJ) Oral surgical procedures as; tooth extractions, implants placements or trauma are suggested risk factors. The aim of this paper is to describe a case of MRONJ and recurrence after the first right mandibular molar extraction. A 54 years old man was referred to the Department of Surgery and Integrated Clinic of Aracatuba Dental School, Univ. Estadual Paulista - UNESP...

Retrospective analysis of 27 cases of bisphosphonate-related osteonecrosis of the jaw treated surgically or nonsurgically

Directory of Open Access Journals (Sweden)

Shin-Yu Lu

2014-06-01

Conclusion: Our study demonstrates a high success rate of conservative and surgical treatment of BRONJ. This is the first reported use of GBR to successfully treat oral BPh-related osteonecrosis of the jaw. Irrigation with antimicrobial rinses may result in pain reduction, and regression or even resolution of BRONJ.

Developmental odontogenic cysts of jaws: a clinical study of 245 cases

Directory of Open Access Journals (Sweden)

Javad Yazdani

2009-06-01

Full Text Available Background and aims. The aim of this study was to investigate the relative frequency of developmental odontogenic cysts in an Iranian population. Materials and methods. In this study 245 cysts from both jaws, treated in the Faculty of Dentistry at Tabriz University of Medical Sciences during a 10-year period from 1998 to 2008, were analyzed in order to evaluate the incidence of such cysts. We had permission from all the patients. Case histories of 65% of male and 35% of female patients were analyzed. The age of the patients varied from 14 to 64 years, with an average of 33.21 ± 10.89. Results. In this 10-year study of odontogenic cysts, 97 cases were developmental odontogenic cysts with the following incidence: dentigerous cyst, 44%; odontogenic keratocyst, 36%; primordial cyst, 9%; Gorlin cyst, 2%; lateral periodontal cyst, 3%; eruption cyst, 3%; and gingival cyst, 3% (adults 2%, infants 1%. A total of 60% of the cysts were found in the mandible and 40% in the maxilla. Regarding the mandible, the molar region was involved in 47% of the cases, premolar region in 33% and anterior region in 20% (total = 100%. Regarding the maxilla, the canine-to-canine region was involved in 52% of the cases, premolar region in 20% and molar region in 28% (total = 100%. Conclusion. An important finding in this study was the fact that 39% of the jaw cysts were developmental odontogenic cysts and the most common developmental odontogenic cysts were dentigerous cyst and OKC (odontogenic keratocyst.

Follicular cyst of the jaw developing into a keratocyst in a patient with unrecognized Gorlin-Goltz syndrome.

Science.gov (United States)

Longobardi, Gianluigi; Diana, Giovanni; Poddi, Valentina; Pagano, Immacolata

2010-05-01

Gorlin-Goltz (GG) syndrome is an inherited autosomal dominant condition. Its diagnosis may be clinically confirmed by checking either major or minor signs that define the diagnostic criteria. It may occur that, although GG syndrome is a well-known condition, only the specific symptom could be observed by different specialists. Therefore, the patient cannot be placed into an always complex clinical panel. We introduce an example in this report. Throughout a 20-year clinical history characterized by the lack of proper diagnosis and missed follow-up operations, a patient with GG syndrome underwent partial amputation of the jaw after severe complications. A 52-year-old man required an implant-prosthetic rehabilitation since becoming edentulous after a partial resection of the jaw due to a keratocyst, which was later reconstructed through a free fibula flap. The observation of a typical phenotype and various symptoms that succeeded for longer than 20 years, with anamnestic evaluation and clinical examination, led us to suspect a complex pathologic condition such as GG syndrome, which was not previously considered, although the patient had undergone several polyspecialistic evaluations. Diagnosis has been eventually confirmed by a genetic study, which was always mandatory. The simultaneous presence of muscular and skeletal malformations, basocellular nevi, and multiple cysts of the jaw can represent signs linking to a condition such as GG syndrome. There are many syndromes involving the head and neck region, and specialists are supposed to be alerted when faced with similar typical expressions associated with a characteristic soma so as to avoid delays in diagnosing the syndrome.

Thermomechanical assessment of the effects of a jaw-beam angle during beam impact on Large Hadron Collider collimators

Science.gov (United States)

Cauchi, Marija; Assmann, R. W.; Bertarelli, A.; Carra, F.; Lari, L.; Rossi, A.; Mollicone, P.; Sammut, N.

2015-02-01

The correct functioning of a collimation system is crucial to safely and successfully operate high-energy particle accelerators, such as the Large Hadron Collider (LHC). However, the requirements to handle high-intensity beams can be demanding, and accident scenarios must be well studied in order to assess if the collimator design is robust against possible error scenarios. One of the catastrophic, though not very probable, accident scenarios identified within the LHC is an asynchronous beam dump. In this case, one (or more) of the 15 precharged kicker circuits fires out of time with the abort gap, spraying beam pulses onto LHC machine elements before the machine protection system can fire the remaining kicker circuits and bring the beam to the dump. If a proton bunch directly hits a collimator during such an event, severe beam-induced damage such as magnet quenches and other equipment damage might result, with consequent downtime for the machine. This study investigates a number of newly defined jaw error cases, which include angular misalignment errors of the collimator jaw. A numerical finite element method approach is presented in order to precisely evaluate the thermomechanical response of tertiary collimators to beam impact. We identify the most critical and interesting cases, and show that a tilt of the jaw can actually mitigate the effect of an asynchronous dump on the collimators. Relevant collimator damage limits are taken into account, with the aim to identify optimal operational conditions for the LHC.

Thermomechanical assessment of the effects of a jaw-beam angle during beam impact on Large Hadron Collider collimators

Directory of Open Access Journals (Sweden)

Marija Cauchi

2015-02-01

Full Text Available The correct functioning of a collimation system is crucial to safely and successfully operate high-energy particle accelerators, such as the Large Hadron Collider (LHC. However, the requirements to handle high-intensity beams can be demanding, and accident scenarios must be well studied in order to assess if the collimator design is robust against possible error scenarios. One of the catastrophic, though not very probable, accident scenarios identified within the LHC is an asynchronous beam dump. In this case, one (or more of the 15 precharged kicker circuits fires out of time with the abort gap, spraying beam pulses onto LHC machine elements before the machine protection system can fire the remaining kicker circuits and bring the beam to the dump. If a proton bunch directly hits a collimator during such an event, severe beam-induced damage such as magnet quenches and other equipment damage might result, with consequent downtime for the machine. This study investigates a number of newly defined jaw error cases, which include angular misalignment errors of the collimator jaw. A numerical finite element method approach is presented in order to precisely evaluate the thermomechanical response of tertiary collimators to beam impact. We identify the most critical and interesting cases, and show that a tilt of the jaw can actually mitigate the effect of an asynchronous dump on the collimators. Relevant collimator damage limits are taken into account, with the aim to identify optimal operational conditions for the LHC.

Jaw-opening force test to screen for Dysphagia: preliminary results.

Science.gov (United States)

Hara, Koji; Tohara, Haruka; Wada, Satoko; Iida, Takatoshi; Ueda, Koichiro; Ansai, Toshihiro

2014-05-01

To assess the jaw-opening force test (JOFT) for dysphagia screening. Criterion standard. University dental hospital. Patients complaining of dysphagia (N=95) and with symptoms of dysphagia with chronic underlying causes (mean age ± SD, 79.3±9.61y; range, 50-94y; men: n=49; mean age ± SD, 77.03±9.81y; range, 50-94y; women: n=46; mean age ± SD, 75.42±9.73y; range, 51-93y) admitted for treatment between May 2011 and December 2012 were included. None. All patients were administered the JOFT and underwent fiberoptic endoscopic evaluation of swallowing (FEES). The mean jaw-opening strength was compared with aspiration (ASP) and pharyngeal residue observations of the FEES, which was used as the criterion standard. A receiver operating characteristic (ROC) curve analysis was performed. Forces of ≤3.2kg for men and ≤4kg for women were appropriate cutoff values for predicting ASP with a sensitivity and specificity of .57 and .79 for men and .93 and .52 for women, respectively. Based on the ROC analyses for predicting pharyngeal residue, forces of ≤5.3kg in men and ≤3.9kg in women were appropriate cutoff values, with a sensitivity and specificity of .80 and .88 for men and .83 and .81 for women, respectively. The JOFT could be a useful screening tool for predicting pharyngeal residue and could provide useful information to aid in the referral of patients for further diagnostic imaging testing. However, given its low sensitivity to ASP the JOFT should be paired with other screening tests that predict ASP. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Multiple jaw cysts-unveiling the Gorlin-Goltz syndrome

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S Manjima

2015-01-01

Full Text Available Gorlin-Goltz syndrome or basal cell nevus syndrome is a comparatively rare syndrome characterized by basal cell nevi, odontogenic keratocysts, and skeletal anomalies. Diagnosis is based on the major and minor clinical and radiographic criteria. Dentist plays a major role in the diagnosis of this disease due to the oral and maxillofacial manifestations of the syndrome. In some cases, jaw cysts are diagnosed by routine radiographs advised by the dentists. Odontogenic keratocysts in such syndromic patients will be multiple and extensive and in some cases results in cortical expansion and facial disfigurement. Thorough clinical examination and investigations prompt an early confirmation of the syndrome, which is very essential to avoid morbidity associated with the syndrome. Here, we report a case of multiple odontogenic cysts in a 16-year-old patient which later was diagnosed as a case of Gorlin Goltz syndrome.

Scintiscanning of the jaw and visceral cranium

International Nuclear Information System (INIS)

Hardt, N.; Hofer, B.

1988-01-01

The first eight chapters provide a general survey of basic principles and aspects of bone scintiscanning (radiopharmaceuticals, scintiscanning techniques, examination techniques, analytical criteria), and in contrast to these explain the criteria and limits of skeletal radiology of the skull, from which result the criteria of application of bone scintiscanning in this body region. The information obtainable by radiologic and scintigraphic examination of pathologic bone processes is compared, and the specific evaluation criteria of the scintiscan of the skull are explained as the basis of the clinical diagnosis. The following chapters go into details of combined radiologic and scintigraphic examination of bone tumours and tumour-like bone disease, of ostitis, fractures and osteotomy of the jaw, including cysts and pathologic processes of the mandibular joint. The information is explained by representative examples. Another complete chapter is devoted to the scintiscanning of bone graft and disturbed growth processes of the visceral cranium. The differential diagnostic analysis of the various pathologic processes on the basis of the scintigram is explained along the criteria of dignity, extension, dissemination, early detection, and follow-up checking. (orig./MG) [de

Perioperative antibiotic regimen in rats treated with pamidronate plus dexamethasone and subjected to dental extraction: a study of the changes in the jaws.

Science.gov (United States)

López-Jornet, Pía; Camacho-Alonso, Fabio; Martínez-Canovas, Ascensión; Molina-Miñano, Francisco; Gómez-García, Francisco; Vicente-Ortega, Vicente

2011-10-01

Osteonecrosis of the jaws is a well-known condition associated with long-term bisphosphonate use. This study analyzed the prophylactic effect of antibiotic treatment in Sprague-Dawley rats treated with pamidronate plus dexamethasone and subjected to oral surgery in the form of dental extraction. One hundred twenty animals were included in a randomized prospective study. Animals in group I (n = 60) were treated with dexamethasone 1 mg/kg and pamidronate 3 mg/kg 3 times per week for 7, 14, and 21 days. All were subjected to right mandibular or maxillary molar extraction 8, 15, and 22 days after the start of dosing. Animals in group II (n = 60) received the same treatment except for the addition of penicillin 0.1 mL/kg per day for 3 days before and 4 days after extraction. Rats in the 2 groups were sacrificed 14 and 28 days after extraction. A clinical and histologic evaluation was performed. In group I, osteonecrosis was documented in 18 cases (34.6%; affecting the upper and lower jaws in 10 and 8 cases, respectively). In group II, osteonecrosis was documented in 5 cases (9.61%; affecting the upper and lower jaws in 3 and 2 cases, respectively). The difference between the 2 groups was statistically significant (P = .002). The adoption of preventive measures (antibiotic prophylaxis) in invasive dental procedures results in a significant decrease in osteonecrosis of the jaws associated with bisphosphonate use. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Time and order of eruption of first functional teeth in the upper jaw of post-larval life of Sicyopterus japonicus (Gobiidiae: Sicydiinae) during cranial metamorphosis at the time of river recruitment.

Science.gov (United States)

Sahara, Noriyuki; Moriyama, Keita; Iida, Midori; Watanabe, Shun

2016-06-01

The present study was aimed at elucidating the time and order of eruption of first functional teeth in the upper jaw of post-larval life of Sicyopterus japonicus (S. japonicus) during cranial metamorphosis at the time of river recruitment. Fishes were caught at the post-larval stage at a river mouth and maintained for 7 days in a water tank. Each of 10 specimens was evaluated every day for 7 days by using microcomputed tomography, scanning electron microscopy, and light microscopy with peculiar attention to the development of the upper jaw teeth. Fishes caught at the river mouth were mostly transparent, with a rostral terminal mouth, and no teeth could be found in either the upper or lower jaw. At 2 days after collection, the mouth position changed from terminal to subterminal, resulting from a change in head shape. The initial eruption of first functional teeth was detected at the anterior two-thirds region of each upper jaw. These teeth erupted in adjacent positions, most had a tricuspid crown, and they represented miniature versions of adult teeth. At 5 days, the position of the mouth became further relocated from terminal rostral to ventral. The number of erupted teeth increased, followed by spreading of them anteriorly and posteriorly. At 7 days, they formed a single row of close-set tricuspid teeth along the entire length of each upper jaw. The present study demonstrated that even under laboratory conditions a rapid and drastic cranial metamorphosis took place within a week after the time of collection of post-larval S. japonicus from a river. The eruption of first functional teeth in the upper jaw of S. japonicus, which teeth are adapted to scraping algae off the substrate, was initially detected at 2 days after collection, and first functional dentition of the upper jaw was set up within 7 days after it. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multimodality Treatment for Rehabilitation of Adult Orthodontic Patient with Complicated Dental Condition and Jaw Relation

Directory of Open Access Journals (Sweden)

Yu-Cheng Liaw

2008-11-01

Full Text Available A 50-year-old man with severe malocclusion requested comprehensive oral rehabilitation. He presented with retrognathic mandible, anterior deep bite and a gummy smile in the premaxilla, and tenting occlusal plane with severe buccal crossbite of the left maxillary posterior teeth. Inappropriate fixed prostheses spanned the maxilla and the mandible with a class II jaw relationship. A detailed analysis indicated the need for orthodontic treatment, orthognathic surgery, bone graft at the deficient alveolar ridge for implant surgery and a revision of all prostheses. Over a 2-year-period of management, the patient received anterior osteotomy for intrusion of lower anterior teeth, bilateral sagittal splitting osteotomy for mandible advancement and posterior osteotomy for inward upward repositioning of posterior teeth of the left maxilla to correct major jaw deformities. The deficient alveolar ridge in the premaxilla was augmented by autogenous bone graft harvested during the orthognathic surgery. He sequentially had mini-plate and dental implant as anchorage assisting teeth alignment in the mandible. Two 3-fixture-supported implant prostheses were delivered in the premaxilla and the mandible. The improvement in cosmesis, stability and function through treatment and a 2-year clinical follow-up were considered satisfactory.

A feasibility study of using conventional jaws to deliver IMRT plans in the treatment of prostate cancer

International Nuclear Information System (INIS)

Kim, Yongbok; Verhey, Lynn J; Xia Ping

2007-01-01

The aim of this study is to investigate the feasibility of using conventional jaws to deliver inverse planned intensity-modulated radiotherapy (IMRT) plans for patients with prostate cancer. For ten patients, each had one three-dimensional conformal plan (3D plan) and seven inverse IMRT plans using direct aperture optimization. For IMRT plans using conventional jaws (JO plans), the number of apertures per beam angle was set from two to seven while three apertures per beam angle were set for the multi-leaf collimator (MLC) plans. To evaluate each planning method, we compared average dose volume histograms (DVH), the conformal index (COIN), total number of segments and total number of monitor units. Among the JO plans with the number of apertures per beam angle varying from two to seven, no difference was observed in the average DVHs, and the plan conformal index became saturated after four apertures per beam angle. Subsequently, JO plans with four apertures per beam angle (JO-4A) were compared with 3D and MLC plans. Based on the average DVHs, no difference was found among 3D, JO-4A and MLC plans with regard to the planning target volume and rectum, but the DVHs for the bladder and penile bulb were significantly better with inverse IMRT plans than those with 3D plans. When compared with the plan conformity, the average COIN values for 3D, JO-4A and MLC plans were 0.61 ± 0.07, 0.73 ± 0.05 and 0.83 ± 0.05, respectively. In conclusion, inverse IMRT plans using conventional jaws are clinically feasible, achieving better plan quality than 3D-CRT plans

Fibro-osseous lesions of the face and jaws

International Nuclear Information System (INIS)

MacDonald-Jankowski, D.S.

2004-01-01

Maxillofacial fibro-osseous lesions (FOL) consists of lesions that differ, with the exception of fibrous dysplasia, to those found in the rest of the skeleton. FOLs of the face and jaws are cemento-ossifying dysplasia, fibrous dysplasia and cemento-ossifying fibroma. Radiology is central to their diagnosis because the pathology for all FOLs is similar, although they range widely in behaviour, from dysplasia, hamartoma to benign neoplasia with occasional recurrence. Furthermore, once diagnosed the management of each is different. For cemento-ossifying dysplasia, this may mean doing nothing, simply because no treatment is generally appropriate. Almost all cemento-ossifying fibromas should be treated surgically, whereas cases of fibrous dysplasia are treated according to their clinical presentation, ranging from review and follow-up to surgery necessary to save the patient's sight or reduce deformity. The most important and frequent features of the FOLs differential diagnosis is discussed with assistance of a flow-chart

Intraosseous Leiomyoma of the Jaw in an Adolescent.

Science.gov (United States)

Valls-Ontañón, Adaia; Pozuelo-Arquimbau, Laura; Mateu-Esquerda, Gemma; Arranz-Obispo, Carlos; Cuscó-Albors, Sílvia; Melero-Luque, Mireia; Morla, Arnaud; Marí-Roig, Antoni

2017-05-15

Leiomyoma is a benign tumor of the smooth muscle that rarely occurs in the mouth as an intraosseous lesion. The purposes of this paper are to: (1) present a case of an intraosseous solid leiomyoma of the mandible in a 13-year-old child, who presented with a well-defined unilocular radiolucency in the right mandible incidentally discovered during a routine dental radiographic examination; and (2) conduct a review of the literature to describe clinicopathological features and management of intraosseous jaw leiomyoma (IJL). A total of 17 articles describing 18 cases of IJL satisfied the selection criteria; including the present patient, to date a total of 19 cases of IJL have been reported. IJL occurs mainly in young patients (36.8 percent), more often in boys (1:5:1 male-to-female ratio), and reaches a larger size in children than in adults. The treatment of choice for IJL is surgical excision, which should be as minimally invasive as possible, especially in children.

Fibro-osseous lesions of the face and jaws

Energy Technology Data Exchange (ETDEWEB)

MacDonald-Jankowski, D.S

2004-01-01

Maxillofacial fibro-osseous lesions (FOL) consists of lesions that differ, with the exception of fibrous dysplasia, to those found in the rest of the skeleton. FOLs of the face and jaws are cemento-ossifying dysplasia, fibrous dysplasia and cemento-ossifying fibroma. Radiology is central to their diagnosis because the pathology for all FOLs is similar, although they range widely in behaviour, from dysplasia, hamartoma to benign neoplasia with occasional recurrence. Furthermore, once diagnosed the management of each is different. For cemento-ossifying dysplasia, this may mean doing nothing, simply because no treatment is generally appropriate. Almost all cemento-ossifying fibromas should be treated surgically, whereas cases of fibrous dysplasia are treated according to their clinical presentation, ranging from review and follow-up to surgery necessary to save the patient's sight or reduce deformity. The most important and frequent features of the FOLs differential diagnosis is discussed with assistance of a flow-chart.

Radiation-induced osteosarcoma of the jaw treated with skull base surgery

International Nuclear Information System (INIS)

Yamamoto, Misaki; Asato, Ryo; Torii, Hiroko; Kanda, Tomoko; Tamura, Yoshihiro; Hirano, Shigeru; Ito, Juichi; Tanaka, Shinzou

2009-01-01

Head and neck osteosarcomas are rare. A 33-year-old woman received radiation therapy for lymphoepithelioma of the epipharynx in her childhood. After twenty-two years, she presented with a swelling of the right cheek. We did a work up, and diagnosed her radiation-induced osteosarcoma of the jaw. We treated her with neoadjuvant chemotherapy, surgery including skull base resection, and adjuvant chemo-therapy. A small skin recurrence developed after one year, but it was resected under local anesthesia, and there have been no recurrences since. We think that skull base surgery with a combined approach is a useful method in therapy for osteosarcomas in the skull base region. (author)

Molecular phylogenetics and diversification of trap-jaw ants in the genera Anochetus and Odontomachus (Hymenoptera: Formicidae)

Czech Academy of Sciences Publication Activity Database

Larabee, F. J.; Fisher, B. L.; Schmidt, C. A.; Matos Maravi, Pavel F.; Janda, Milan; Suarez, A. V.

2016-01-01

Roč. 103, OCT 01 (2016), s. 143-154 ISSN 1055-7903 R&D Projects: GA ČR GAP505/12/2467 Grant - others:GA JU(CZ) 156/2013/P Institutional support: RVO:60077344 Keywords : Odontomachus * Anochetus * trap-jaw ants Subject RIV: EG - Zoology Impact factor: 4.419, year: 2016 http://www.sciencedirect.com/science/article/pii/S1055790316301804

Medication--related osteonecrosis of the jaws. The first reported cases in the Baltic States and a literature review.

Science.gov (United States)

Zaleckas, Linas; Stacevičius, Mindaugas; Proškutė, Dovilė; Povilaitytė, Jurgita

2015-01-01

Medication-related osteonecrosis of the jaws (MRONJ) is a severe side effect of antiresorptive or antiangiogenic therapy that manifests as an exposed bone, accompanied by clinical signs of infection, persisting for more than 8 weeks, without history of radiation therapy or metastases to the jaws. The aim of the study was to present first MRONJ cases in Lithuania and review trends in the modern research literature on the subject. We retrospectively reviewed patient charts with a diagnosis of "Inflammatory conditions of the jaws" treated in Vilnius University Hospital Žalgiris Clinic, Department of maxillofacial surgery in 2007-2014. Patients diagnosed with MRONJ were selected for the study. Demographic data, characteristics of the disease and treatment modalities were analysed. Nine cases (five male and four female) of MRONJ were analysed. The mean patient age was 69±7,9 years. Predominant primary malignancy was prostate cancer. Osteonecrotic lesions were located both in maxilla and mandible. In all cases we started with a conservative treatment first. After the antibiotic therapy with or without sequestrectomy, the condition of all patients stabilized and improved to stage I MRONJ. MRONJ is a disturbing condition resulting in a severely worsened quality of life in the affected patients. This is the first case series of successfully treated patients suffering from stage II or III MRONJ in the Baltic States. A more comprehensive understanding of MRONJ will hopefully allow clinicians to enhance accuracy in risk assessment and forecast positive and negative outcomes of antiresorptive or antiangiogenic therapy.

Bisphosphonate-Related Osteonecrosis of the Jaw Bone: Radiological Pattern and the Potential Role of CBCT in Early Diagnosis

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James Olutayo

2010-04-01

Full Text Available Objectives: To systematize the clinico-radiological symptoms and course of bisphosphonate-related osteonecrosis of jaw bone and to evaluate the diagnostic potential of various radiological techniques to detect mild osteonecrosis in each stage of the disease.Material and Methods: The sample consisted of 22 patients previously diagnosed with extraoral malignant disease. Diagnosis was based on a clinical examination in conjunction to digital panoramic radiography and cone beam computed tomography (CBCT. Two dentomaxillofacial radiologists reviewed all images.Results: Twenty patients showed mandibular involvement clinically, while two others had a maxillary involvement. Four stages of the disease were proposed based on the clinico-radiological findings. Subclinical cortical and lamina dura thickening was detected with only three-dimensional CBCT and periapical images, while ulceration and cortical bone thickening was detected only by three-dimensional CBCT. Mixed sclerotic, lytic bone destruction involving alveolar and basal bone with or without encroachment on the mandibular canal, pathological mandibular fractures were detected by two-dimensional panoramic and three-dimensional CBCT images. Other findings are non healing extraction sockets, periapical radiolucencies, osteolysis, sequestra, oroantral fistula, and periosteal new bone formation.Conclusions: The present study showed that bisphosphonate-related osteonecrosis of jaw bone occurs in four distinct clinico-radiological stages. For mild cases, panoramic image diagnosis was much less obvious, whereas cone beam computed tomography was able to fully characterise the bony lesions and describe their extent and involvement of neighbouring structures in all cases. Thus cone beam computed tomography might better contribute to the prevention of bisphosphonate-related osteonecrosis of jaw bone as well to the disease management.

Escala de bem-estar afetivo no trabalho (Jaws: evidências de validade fatorial e consistência interna Job-related affective well-being scale (Jaws: evidences of factor validity and reliability

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Valdiney Veloso Gouveia

2008-01-01

Full Text Available O objetivo deste estudo foi adaptar uma medida de bem-estar afetivo no trabalho para o contexto brasileiro. Especificamente, pretendeu-se conhecer evidências de validade fatorial e consistência interna da Job-Related Affective Well-Being Scale (JAWS, avaliando se as pontuações nos seus fatores diferem em função do gênero e da idade dos participantes. Participaram 298 trabalhadores de centros comerciais de pequeno e médio porte da cidade de João Pessoa (PB. A maioria destes era do sexo feminino (76,8%, com idade média de 26 anos (DP = 6,87. Através de uma análise dos componentes principais (rotação promax foram identificados dois fatores que explicaram conjuntamente 48,1% da variância total: afetos positivos (α = 0,94; 14 itens e afetos negativos (α = 0,87; 13 itens; um fator geral de bem-estar afetivo no trabalho foi também computado (α = 0,95; 27 itens. As pontuações dos participantes nestes fatores não foram influenciadas pelas variáveis gênero e idade. Estes resultados são discutidos à luz do que tem sido escrito sobre os parâmetros desta escala e da relação dos afetos com estas variáveis demográficas.This study aimed at adapting a measure of job-related affective well-being for the Brazilian milieu. Specifically, it was proposed to know evidences of factor validity and reliability of the Job-Related Affective Well-Being Scale (JAWS, assessing if its scores are influenced by participants' gender and age. The participants were 298 individuals employed in small or middle shopping malls in the city of João Pessoa, PB; most of them were female (76.8%, with a mean age of 26 years old (SD = 6.87. A main component analysis (with promax rotation was performed, revealing two components that jointly accounted for 48.1% of the total variance. They were named as positive affect (α = .94; 14 items and negative affect (α = .87; 13 items. A general factor of affective well-being was also identified (α = .95; 27 items

Allometric shape change of the lower pharyngeal jaw correlates with a dietary shift to piscivory in a cichlid fish

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Hellig, Christoph J.; Kerschbaumer, Michaela; Sefc, Kristina M.; Koblmüller, Stephan

2010-07-01

The morphological versatility of the pharyngeal jaw of cichlid fishes is assumed to represent a key factor facilitating their unparalleled trophic diversification and explosive radiation. It is generally believed that the functional design of an organism relates to its ecology, and thus, specializations to different diets are typically associated with distinct morphological designs, especially manifested in the cichlids’ pharyngeal jaw apparatus. Thereby, the lower pharyngeal jaw (LPJ) incorporates some of the most predictive features for distinct diet-related morphotypes. Thus, considering that piscivorous cichlids experience an ontogenetic dietary shift from typically various kinds of invertebrates to fish, concomitant morphological changes in the LPJ are expected. Using Lepidiolamprologus elongatus, a top predator in the shallow rocky habitat of Lake Tanganyika, as model, and applying geometric and traditional morphometric techniques, we demonstrate an allometric change in ontogenetic LPJ shape development coinciding with the completion of the dietary shift toward piscivory. The piscivorous LPJ morphotype is initiated in juvenile fish by increasing elongation and narrowing of the LPJ and—when the fish reach a size of 80-90 mm standard length—further refined by the elongation of the posterior muscular processes, which serve as insertion for the fourth musculus levator externus. The enlarged muscular processes of the fully mature piscivorous morphotype provide for the construction of a powerful lever system, which allows the large individuals to process large prey fish and rely on exclusive piscivory.

A comparison of human jaw muscle cross-sectional area and volume in long- and short-face subjects, using MRI

NARCIS (Netherlands)

van Spronsena, P. H.; van Ginkel, F. C.; van Schijndel, R. A.; Castelijns, J. A.; Tuinzing, D. B.

Objective: In humans, the vertical craniofacial dimensions vary significantly with the size of the jaw muscles, which are regarded as important controlling factors of craniofacial growth. The functional relevance of the maximum cross-sectional area (CSA), indicating maximum muscle strength, is

A comparison of human jaw muscle cross-sectional area and volume in long- and short-face subjects, using MRI

NARCIS (Netherlands)

Boom, H.P.W.; van Spronsen, P.H.; van Ginkel, F.C.; van Schijndel, R.A.; Castelijns, J.A.; Tuinzing, D.B.

2008-01-01

Objective In humans, the vertical craniofacial dimensions vary significantly with the size of the jaw muscles, which are regarded as important controlling factors of craniofacial growth. The functional relevance of the maximum cross-sectional area (CSA), indicating maximum muscle strength, is

A comparison of human jaw muscle cross-sectional area and volume in long- and short-face subjects, using MRI

NARCIS (Netherlands)

Boom, H.P.; van Spronsen, P.H.; van Ginkel, F.C.; van Schijndel, R.A.; Castelijns, J.A.; Tuinzing, D.B.

2008-01-01

Objective: In humans, the vertical craniofacial dimensions vary significantly with the size of the jaw muscles, which are regarded as important controlling factors of craniofacial growth. The functional relevance of the maximum cross-sectional area (CSA), indicating maximum muscle strength, is

Immediate effect of occlusal contact pattern in lateral jaw position on the EMG activity in jaw-elevator muscles in humans.

Science.gov (United States)

Baba, K; Yugami, K; Akishige, S; Ai, M

2000-01-01

The aim of this study was to investigate the effect of experimental alterations of nonworking-side occlusal contacts on jaw-elevator muscle activity. Individual devices were fabricated to simulate various lateral occlusal relationships. Twelve human subjects were asked to carry out submaximal lateral clenching, and electromyographic (EMG) activity of the masseter and anterior and posterior temporalis muscles was measured. Clenching in a lateral mandibular position under natural conditions induced an activity pattern with a clear dominance of the anterior and posterior temporalis muscles on the working side. Working-side dominance in the anterior temporalis was reduced moderately when an experimental nonworking-side occlusal contact was added. Dominance decreased dramatically when an experimental nonworking-side interference was added. The working-side activity in the posterior temporalis was also reduced dramatically by an experimental nonworking-side interference, but not by a nonworking-side occlusal contact. None of the experimental contact patterns had a significant effect on the masseter activity. These results suggest that the nonworking-side occlusal contacts have a significant effect on clenching-induced temporalis muscle activity.

Optimizing Hybrid Occlusion in Face-Jaw-Teeth Transplantation: A Preliminary Assessment of Real-Time Cephalometry as Part of the Computer-Assisted Planning and Execution Workstation for Craniomaxillofacial Surgery.

Science.gov (United States)

Murphy, Ryan J; Basafa, Ehsan; Hashemi, Sepehr; Grant, Gerald T; Liacouras, Peter; Susarla, Srinivas M; Otake, Yoshito; Santiago, Gabriel; Armand, Mehran; Gordon, Chad R

2015-08-01

The aesthetic and functional outcomes surrounding Le Fort-based, face-jaw-teeth transplantation have been suboptimal, often leading to posttransplant class II/III skeletal profiles, palatal defects, and "hybrid malocclusion." Therefore, a novel technology-real-time cephalometry-was developed to provide the surgical team instantaneous, intraoperative knowledge of three-dimensional dentoskeletal parameters. Mock face-jaw-teeth transplantation operations were performed on plastic and cadaveric human donor/recipient pairs (n = 2). Preoperatively, cephalometric landmarks were identified on donor/recipient skeletons using segmented computed tomographic scans. The computer-assisted planning and execution workstation tracked the position of the donor face-jaw-teeth segment in real time during the placement/inset onto recipient, reporting pertinent hybrid cephalometric parameters from any movement of donor tissue. The intraoperative data measured through real-time cephalometry were compared to posttransplant measurements for accuracy assessment. In addition, posttransplant cephalometric relationships were compared to planned outcomes to determine face-jaw-teeth transplantation success. Compared with postoperative data, the real-time cephalometry-calculated intraoperative measurement errors were 1.37 ± 1.11 mm and 0.45 ± 0.28 degrees for the plastic skull and 2.99 ± 2.24 mm and 2.63 ± 1.33 degrees for the human cadaver experiments. These results were comparable to the posttransplant relations to planned outcome (human cadaver experiment, 1.39 ± 1.81 mm and 2.18 ± 1.88 degrees; plastic skull experiment, 1.06 ± 0.63 mm and 0.53 ± 0.39 degrees). Based on this preliminary testing, real-time cephalometry may be a valuable adjunct for adjusting and measuring "hybrid occlusion" in face-jaw-teeth transplantation and other orthognathic surgical procedures.

Selecting Question-Specific Genes to Reduce Incongruence in Phylogenomics: A Case Study of Jawed Vertebrate Backbone Phylogeny.

Science.gov (United States)

Chen, Meng-Yun; Liang, Dan; Zhang, Peng

2015-11-01

Incongruence between different phylogenomic analyses is the main challenge faced by phylogeneticists in the genomic era. To reduce incongruence, phylogenomic studies normally adopt some data filtering approaches, such as reducing missing data or using slowly evolving genes, to improve the signal quality of data. Here, we assembled a phylogenomic data set of 58 jawed vertebrate taxa and 4682 genes to investigate the backbone phylogeny of jawed vertebrates under both concatenation and coalescent-based frameworks. To evaluate the efficiency of extracting phylogenetic signals among different data filtering methods, we chose six highly intractable internodes within the backbone phylogeny of jawed vertebrates as our test questions. We found that our phylogenomic data set exhibits substantial conflicting signal among genes for these questions. Our analyses showed that non-specific data sets that are generated without bias toward specific questions are not sufficient to produce consistent results when there are several difficult nodes within a phylogeny. Moreover, phylogenetic accuracy based on non-specific data is considerably influenced by the size of data and the choice of tree inference methods. To address such incongruences, we selected genes that resolve a given internode but not the entire phylogeny. Notably, not only can this strategy yield correct relationships for the question, but it also reduces inconsistency associated with data sizes and inference methods. Our study highlights the importance of gene selection in phylogenomic analyses, suggesting that simply using a large amount of data cannot guarantee correct results. Constructing question-specific data sets may be more powerful for resolving problematic nodes. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of peripherally and cortically evoked swallows on jaw reflex responses in anesthetized rabbits.

Science.gov (United States)

Suzuki, Taku; Yoshihara, Midori; Sakai, Shogo; Tsuji, Kojun; Nagoya, Kouta; Magara, Jin; Tsujimura, Takanori; Inoue, Makoto

2018-05-03

This study aimed to investigate whether the jaw-opening (JOR) and jaw-closing reflexes (JCR) are modulated during not only peripherally, but also centrally, evoked swallowing. Experiments were carried out on 24 adult male Japanese white rabbits. JORs were evoked by trigeminal stimulation at 1 Hz for 30 sec. In the middle 10 sec, either the superior laryngeal nerve (SLN) or cortical swallowing area (Cx) was simultaneously stimulated to evoke swallowing. The peak-to-peak JOR amplitude was reduced during the middle and late 10-sec periods (i.e., during and after SLN or Cx stimulation), and the reduction was dependent on the current intensity of SLN/Cx stimulation: greater SLN/Cx stimulus current resulted in greater JOR inhibition. The reduction rate was significantly greater during Cx stimulation than during SLN stimulation. The amplitude returned to baseline 2 min after 10-sec SLN/Cx stimulation. The effect of co-stimulation of SLN and Cx was significantly greater than that of SLN stimulation alone. There were no significant differences in any parameters of the JCR between conditions. These results clearly showed that JOR responses were significantly suppressed, not only during peripherally evoked swallowing but also during centrally evoked swallowing, and that the inhibitory effect is likely to be larger during centrally compared with peripherally evoked swallowing. The functional implications of these results are discussed. Copyright © 2018. Published by Elsevier B.V.

GIANT CELL GRANULOMAS OF THE JAWS (ANALYSIS OF 1,083 CASES

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Ismail Yazdi

1995-07-01

Full Text Available Giant cell granulomas of the jaws are rather common in [rail, however, more reliable data need to be published In this retrospecti ve study 1,083 cases ojPGCO and CGCG (817 peripheral and 203 central were extracted from 6800 oral biopsy archives of the Oral Pathology Department and were analyzed: Age and sex ofthe patients and type and location distribution were obtained Our results show that most cases ofPGCG and CGCG occurred before"nthe fifth and during fourth decade, respectively. Slight predominance offemales was notedfor both types. Mandible wa~ often more affected (60.3%, especially in the premolarmolar region. The results obtained in this study were in agreement with other independent reports.

Pleiotropic functions of embryonic sonic hedgehog expression link jaw and taste bud amplification with eye loss during cavefish evolution.

Science.gov (United States)

Yamamoto, Yoshiyuki; Byerly, Mardi S; Jackman, William R; Jeffery, William R

2009-06-01

This study addresses the role of sonic hedgehog (shh) in increasing oral-pharyngeal constructive traits (jaws and taste buds) at the expense of eyes in the blind cavefish Astyanax mexicanus. In cavefish embryos, eye primordia degenerate under the influence of hyperactive Shh signaling. In concert, cavefish show amplified jaw size and taste bud numbers as part of a change in feeding behavior. To determine whether pleiotropic effects of hyperactive Shh signaling link these regressive and constructive traits, shh expression was compared during late development of the surface-dwelling (surface fish) and cave-dwelling (cavefish) forms of Astyanax. After an initial expansion along the midline of early embryos, shh was elevated in the oral-pharyngeal region in cavefish and later was confined to taste buds. The results of shh inhibition and overexpression experiments indicate that Shh signaling has an important role in oral and taste bud development. Conditional overexpression of an injected shh transgene at specific times in development showed that taste bud amplification and eye degeneration are sensitive to shh overexpression during the same early developmental period, although taste buds are not formed until much later. Genetic crosses between cavefish and surface fish revealed an inverse relationship between eye size and jaw size/taste bud number, supporting a link between oral-pharyngeal constructive traits and eye degeneration. The results suggest that hyperactive Shh signaling increases oral and taste bud amplification in cavefish at the expense of eyes. Therefore, selection for constructive oral-pharyngeal traits may be responsible for eye loss during cavefish evolution via pleiotropic function of the Shh signaling pathway.

Can short-term oral fine motor training affect precision of task performance and induce cortical plasticity of the jaw muscles?

DEFF Research Database (Denmark)

Hong, Zhang; Kumar, Abhishek; Kothari, Mohit

2016-01-01

The aim was to test the hypothesis that short-term oral sensorimotor training of the jaw muscles would increase the precision of task performance and induce neuroplastic changes in the corticomotor pathways, related to the masseter muscle. Fifteen healthy volunteers performed six series with ten...... trials of an oral sensorimotor task. The task was to manipulate and position a spherical chocolate candy in between the anterior teeth and split it into two equal halves. The precision of the task performance was evaluated by comparing the ratio between the two split halves. A series of "hold......-and-split" tasks was also performed before and after the training. The hold force and split force along with the electromyographic (EMG) activity of jaw muscles were recorded. Motor-evoked potentials and cortical motor maps of the right masseter muscle were evoked by transcranial magnetic stimulation...

JAWS: Just Add Water System - A device for detection of nucleic acids in Martian ice caps

DEFF Research Database (Denmark)

Hansen, Anders J.; Willerslev, Eske; Mørk, Søren

2002-01-01

with a regulation of pH and salt concentrations e.g. the MOD systems and could be installed on a planetary probe melting its way down the Martian ice caps e.g. the NASA Cryobot. JAWS can be used for detection of remains of ancient life preserved in the Martian ice as well as for detection of contamination brought...... to the planet from Earth....

Idiopathic Osteosclerosis of the Jaw in a Brazilian Population: a Retrospective Study

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Elen de Souza Tolentino

2014-01-01

Full Text Available Objectives: To report cases of idiopathic osteosclerosis (IO, to review the literature on the subject, and to discuss its main characteristics, diagnosis, differential diagnosis, and treatment. Material and methods: Retrospective analysis of 354 panoramic radiographs, searching for IO, its size, shape, location, and noting patients’ demographic information. Literature review used Medline and Lilacs databases and the terms idiopathic osteosclerosis OR bone sclerosis OR dense bone island AND jaws. Results: IO was identified in 5.6% of the radiographs (n=20 patients, 22 foci. Patients were healthy, with an age ranging from 5 to 51 years (mean=29.8, with male-female ratio of 3:2. IOs were found mainly in the premolar/molar region, at root apices, between roots, away from the teeth, laterally to the tooth, and in edentulous areas. The distribution between right and left sides of the jaw was equal for the 22 foci, with only one case in the maxilla. IOs were localized, well-defined, radiopaque, mostly round or ovoid in shape, but sometimes irregular. In some cases, IOs were similar to condensing osteitis, but differential diagnosis also considered complex odontoma, focal cemento-osseous dysplasia, and residual roots. Twenty studies on the topic were reviewed. Conclusions: Incidence of IO in the Brazilian sample was 5.6%, with age ranging from 5 to 51 years (mean=29.8, and male-female ratio of 3:2. The radiopacities occurred in different locations, with significant prevalence in the mandible. The findings and the literature review corroborate the hypothesis that IO should be considered developmental variation of normal bone that does not require treatment.

Studi Komparasi Modul Kimia Berbasis Media Screen Reader Jaws dan Braille Terhadap Prestasi, Motivasi, dan Kemandirian Belajar Peserta Didik Difabel Netra

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Jamil Suprihatiningrum

2014-12-01

Full Text Available This study aimed to compare the achievement, motivation, and independent learning of blind students who use screen reader JAWS and braille module.This research was conducted at MAN Maguwoharjo Yogyakarta involving 5 blind students in the chemistry subject of academic year 2013/2014. One student is as an instrument validation test subject, two students as subjects in the experimental class and two students as subjects in the control class. The instruments used in this study are the observation sheet,multiple choice test, questionnaire responses, motivation scale, and independent learning scale. Data of student achievement, motivation and independence scale were analyzed using nonparametric statistical test of independent samples. The result shows that no significant difference between the achievement, motivation, and independence of blind students who use screen reader JAWS module and braille module.

DEPENDENCE OF MORPHOMETRIC PARAMETERS OF THE DENTAL OCCLUSION ON THE TYPE OF THE LOWER JAW GROWTH IN CHILDREN WITH CLASS II1 DENTOFACIAL ANOMALIES WHO LINE IN THE NORTHERN UKRAINE.

Science.gov (United States)

Galich, L V; Kuroedova, V; Lakhtin, Yu; Galich, L B; Moskalenko, P

2017-03-01

The aim of the work was to study the structure of dentofacial anomalies in children and adolescents in Sumy city and Sumy oblast, to identify dentoalveolar morphological peculiarities of the occlusion in 10-13 years old patients with class ІІ1 anomalies according to Angle's classification with different types of lower jaw bone growth. A retrospective analysis of 2236 outpatient dental cards of urban and rural patients with orthodontic pathology was conducted. Patients were divided into three age groups: 6-9 years old (early mixed occlusion) - 592 children; 10-13 years old (late mixed occlusion) - 1180 children; over 13 years old (permanent occlusion) - 464 persons; besides 76 patients with class ІІ1 anomalies according to Angle's classification aged 10-13 years were examined. To determine the type of lower jaw growth, the children underwent orthopantomographic examination, diagnostic models were made and biometric indicators were calculated to determine the severity of the morphological changes. It was established that anomalies of individual teeth and dental curve dominated in all age groups (71.24%). Among the occlusion anomalies, a large part falls to class ІІ anomalies according to Angle's classification (19.18%). A third of these patients have a neutral type of lower jaw growth (36.84±5.53%), horizontal and vertical types of growth reach 18.42±4.47% and 19.74±4.56%, respectively. The combination of neutral and vertical type of growth of the lower jaw occurs in 1.7 times more than the combination of neutral and horizontal. The most pronounced morphological changes were observed in the group of patients with a horizontal type of lower jaw growth. When planning treatment and prophylactic measures among patients of the orthodontic profile, it is necessary to take into account the peculiarities of both the prevalence of pathology in the region and the morphological changes of different severity in the dental curves of the jaws.

British dental surgery and the First World War: the treatment of facial and jaw injuries from the battlefield to the home front.

Science.gov (United States)

Hussey, K D

2014-11-01

When Britain went to war in 1914, the British Expeditionary Force was deployed without a single dentist. Initially considered combatants, the only dental professionals who could serve at the Front were medically qualified dental surgeons in the Royal Army Medical Corps. In treating the traumatic facial and jaw injuries caused by trench warfare, the dental surgeons of this era earned their place on specialist surgical teams and established the principles of oral and maxillofacial surgery. This article will examine the contribution of specialist dental surgeons to the management of facial and jaw wounds in the First World War along the chain of evacuation from the battlefield to the home front, using illustrative examples from the Hunterian Museum at the Royal College of Surgeons of England.

Diagnostic value of NobelGuide to minimize the need for reconstructive surgery of jaws before implant placement: a review.

Science.gov (United States)

Scotti, Roberto; Pellegrino, Gerardo; Marchetti, Claudio; Corinaldesi, Guiseppe; Ciocca, Leonardo

2010-01-01

To test if using a CAD/CAM system might reduce the necessity of bone augmentation in patients with atrophic maxillary arches before implant therapy. Twenty male and female patients consecutively scheduled for bone augmentation of the jaw before implant surgery were included in this study, with a total of 29 jaws (maxillary and mandibular) to analyze for the implant-supported fixed prosthesis group and 19 maxillary arches for the implant-supported removable prosthesis group. NobelGuide System (Nobel Biocare), Autocad System (Autodesk), and routine manual CT measurements of available bone were used in this study. The total results of the mean values of the fixed prosthesis group plus the mean values of the removable prosthesis group showed a statistically significant difference between the NobelGuide intervention score and both manual (P = .004) and Autocad (P = .001) measurements. The NobelGuide System represents a viable diagnostic device to reduce the entity or avoid bone reconstructive surgery before implant placements in the atrophic maxilla and mandible.

Dosimetric evaluation of photon dose calculation under jaw and MLC shielding

International Nuclear Information System (INIS)

Fogliata, A.; Clivio, A.; Vanetti, E.; Nicolini, G.; Belosi, M. F.; Cozzi, L.

2013-01-01

Purpose: The accuracy of photon dose calculation algorithms in out-of-field regions is often neglected, despite its importance for organs at risk and peripheral dose evaluation. The present work has assessed this for the anisotropic analytical algorithm (AAA) and the Acuros-XB algorithms implemented in the Eclipse treatment planning system. Specifically, the regions shielded by the jaw, or the MLC, or both MLC and jaw for flattened and unflattened beams have been studied.Methods: The accuracy in out-of-field dose under different conditions was studied for two different algorithms. Measured depth doses out of the field, for different field sizes and various distances from the beam edge were compared with the corresponding AAA and Acuros-XB calculations in water. Four volumetric modulated arc therapy plans (in the RapidArc form) were optimized in a water equivalent phantom, PTW Octavius, to obtain a region always shielded by the MLC (or MLC and jaw) during the delivery. Doses to different points located in the shielded region and in a target-like structure were measured with an ion chamber, and results were compared with the AAA and Acuros-XB calculations. Photon beams of 6 and 10 MV, flattened and unflattened were used for the tests.Results: Good agreement between calculated and measured depth doses was found using both algorithms for all points measured at depth greater than 3 cm. The mean dose differences (±1SD) were −8%± 16%, −3%± 15%, −16%± 18%, and −9%± 16% for measurements vs AAA calculations and −10%± 14%, −5%± 12%, −19%± 17%, and −13%± 14% for Acuros-XB, for 6X, 6 flattening-filter free (FFF), 10X, and 10FFF beams, respectively. The same figures for dose differences relative to the open beam central axis dose were: −0.1%± 0.3%, 0.0%± 0.4%, −0.3%± 0.3%, and −0.1%± 0.3% for AAA and −0.2%± 0.4%, −0.1%± 0.4%, −0.5%± 0.5%, and −0.3%± 0.4% for Acuros-XB. Buildup dose was overestimated with AAA, while Acuros-XB gave

Retrospective cohort clinical investigation of a dental implant with a narrow diameter and short length for the partial rehabilitation of extremely atrophic jaws.

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Maló, Paulo S; de Araújo Nobre, Miguel A; Lopes, Armando V; Ferro, Ana S

2017-01-01

We investigated the short-term clinical outcomes of narrow-diameter short-length implants for the fixed-prosthetic partial rehabilitation of extremely resorbed jaws. Twenty-three patients requiring partial rehabilitations with narrow-platform short-length implants in any jaw were included in this study. In total, 30 implants 3.3 mm in diameter and 7 (n = 15 implants) or 8.5 (n = 15 implants) mm in length were inserted. The primary outcome measure was implant cumulative survival rate (CSR); the secondary outcome measures were marginal bone resorption at 1 and 3 years and the incidence of biologic and mechanical complications. Five patients (21.7%) with six implants (20%) were lost to follow-up. Two implants failed in two patients, yielding a CSR at 3 years of follow-up of 93.4%. The average (standard deviation) marginal bone resorption was 1.34 mm (0.95 mm) after the first year and 1.38 mm (0.78 mm) after the third year. Biologic complications occurred in three patients; mechanical complications occurred in three patients. Despite the limitations of the study, our findings show that the use of new narrow-diameter short-length implants for the rehabilitation of extremely atrophic regions is viable in the short-term, and can be considered a treatment alternative in extremely resorbed jaws.

A pharyngeal jaw evolutionary innovation facilitated extinction in Lake Victoria cichlids.

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McGee, Matthew D; Borstein, Samuel R; Neches, Russell Y; Buescher, Heinz H; Seehausen, Ole; Wainwright, Peter C

2015-11-27

Evolutionary innovations, traits that give species access to previously unoccupied niches, may promote speciation and adaptive radiation. Here, we show that such innovations can also result in competitive inferiority and extinction. We present evidence that the modified pharyngeal jaws of cichlid fishes and several marine fish lineages, a classic example of evolutionary innovation, are not universally beneficial. A large-scale analysis of dietary evolution across marine fish lineages reveals that the innovation compromises access to energy-rich predator niches. We show that this competitive inferiority shaped the adaptive radiation of cichlids in Lake Tanganyika and played a pivotal and previously unrecognized role in the mass extinction of cichlid fishes in Lake Victoria after Nile perch invasion. Copyright © 2015, American Association for the Advancement of Science.

A 15-year study of osseointegrated implants in the treatment of the edentulous jaw.

Science.gov (United States)

Adell, R; Lekholm, U; Rockler, B; Brånemark, P I

1981-12-01

Osseointegration implies a firm, direct and lasting connection between vital bone and screw-shaped titanium implants of defined finish and geometry-fixtures. Thus, there is no interposed tissue between fixture and bone. Osseointegration can only be achieved and maintained by a gentle surgical installation technique, a long healing time and a proper stress distribution when in function. During a 15-year period (1965-1980), 2768 fixtures were installed in 410 edentulous jaws of 371 consecutive patients. All patients were provided with facultatively removable bridges and were examined at continuous yearly controls. The surgical and prosthetic technique was developed and evaluated over a pilot period of 5 years. The results of standardized procedures applied on a consecutive clinical material with an observation time of 5-9 years were thought to properly reflect the potential of the method. In this group, 130 jaws were provided with 895 fixtures, and of these 81% of the maxillary and 91% of the mandibular fixtures remained stable, supporting bridges. In 89% of the maxillary and 100% of the mandibular cases, the bridges were continuously stable. During healing and the first year after connection of the bridge, the mean value for marginal bone loss was 1.5 mm. Thereafter only 0.1 mm was lost annually. The clinical results achieved with bridges on osseointegrated fixtures fulfill and exceed the demands set by the 1978 Harvard Conference on successful dental implantation procedures.

Hydrogen-rich saline may be an effective and specific novel treatment for osteoradionecrosis of the jaw

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Chen Y

2015-10-01

Full Text Available Yuanli Chen, Chunlin Zong, Yuxuan Guo, Lei Tian Department of Cranio-facial Trauma and Orthognathic Surgery Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Shaanxi Key Laboratory of Stomatology, Xi’an, People’s Republic of China Abstract: Hydrogen, a therapeutic medical gas, can exert antioxidant activity via selectively reducing cytotoxic reactive oxygen species such as hydroxyl radicals. Hydrogen-rich saline is an alternative form of molecular hydrogen that has been widely used in many studies, including metabolic syndrome, cerebral, hepatic, myocardial ischemia/reperfusion, and liver injuries with obstructive jaundice, with beneficial results. Osteoradionecrosis of the jaw is a serious complication following radiotherapy for head and neck cancers. It has long been known that most radiation-induced symptoms are caused by free radicals generated by radiolysis of H2O, and the hydroxyl radical is the most reactive of these. Reducing the hydroxyl radical can distinctly improve the protection of cells from radiation damage. We hypothesized that hydrogen-rich saline might be an effective and specific method of managing and preventing osteoradionecrosis of the jaw. Keywords: osteoradionecrosis, hydrogen, reactive oxygen species

Three-dimensional virtual operations can facilitate complicated surgical planning for the treatment of patients with jaw deformities associated with facial asymmetry: a case report.

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Hara, Shingo; Mitsugi, Masaharu; Kanno, Takahiro; Nomachi, Akihiko; Wajima, Takehiko; Tatemoto, Yukihiro

2013-09-01

This article describes a case we experienced in which good postsurgical facial profiles were obtained for a patient with jaw deformities associated with facial asymmetry, by implementing surgical planning with SimPlant OMS. Using this method, we conducted LF1 osteotomy, intraoral vertical ramus osteotomy (IVRO), sagittal split ramus osteotomy (SSRO), mandibular constriction and mandibular border genioplasty. Not only did we obtain a class I occlusal relationship, but the complicated surgery also improved the asymmetry of the frontal view, as well as of the profile view, of the patient. The virtual operation using three-dimensional computed tomography (3D-CT) could be especially useful for the treatment of patients with jaw deformities associated with facial asymmetry.

Evaluation of Spontaneous Bone Regeneration after Enucleation of Large Cysts of the Jaws using Radiographic Computed Software.

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Wagdargi, Shivaraj S; Rai, Kirthi Kumar; Arunkumar, K V; Katkol, Basavraj; Arakeri, Gururaj

2016-06-01

Spontaneous regeneration of bone is commonly seen in the small surgical defects caused by enucleation of cysts. However, in case of large surgical defects caused by the enucleation, spontaneous regeneration of bone is a rare phenomenon and it depends on factors, such as age of the patient, intact periosteum, and proper stabilization. The study included 16 patients, who reported to the department of oral and maxillofacial surgery with the complaint of pain and swelling in the jaws diagnosed as cyst. The sample included equal numbers of male and female subjects aged between 15 and 40 years. Panoramic radiographs were taken pre- and postoperatively on day 2 of the enucleation. The dimensions of the cyst were evaluated on the radiograph according to the proforma. Subsequent radiographs were taken at regular intervals of 1.5, 3, and 6 months using standard parameters and were analyzed using MCID™ analysis software of imaging research. Mean reduction was seen in up to 39 and 60% in the cystic cavity size and increase in the mean density up to 59 and 90.2% at 3 and 6 months intervals respectively. Spontaneous bone regeneration was seen even after primary closure of the large cystic defect without the need for placement of foreign substances or grafts and it also eliminated the complications resulting from placement of foreign substance. Further studies are required in a larger sample with longer follow-up durations to confirm the outcome of the present work for the benefit of patients. The present study depicted that spontaneous bone regeneration can occur with accepted results after simple enucleation of jaw cyst without the aid of any graft material. Hence, simple enucleation may be considered as a first line of treatment modality for cystic lesion of the jaws. This simplifies the surgical procedure, decreases the economic and biologic costs, and reduces the risk of postoperative complications. Follow-up is necessary along with patient's compliance for the success of

Finite element analysis to determine the stress distribution, displacement and safety factor on a microplate for the fractured jaw case

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Pratama, Juan; Mahardika, Muslim

2018-03-01

Microplate is a connecting plate that can be used for jaw bone fixation. In the last two decades, microplate has been used so many times to help reconstruction of fractured jaw bone which is called mandibular bone or mandible bone. The plate is used to provide stable fixation of the fractured bone tissue during healing and reconstruction process. In this study Finite Element Analysis was used to predict the stress concentration and distribution on a microplate, displacement on the microplate and also to determine the safety factor of the microplate based on maximum allowable stress value, and finally to ascertain whether microplate is safe to use or not. The microplate was produced from punching process using titanium grade 1 (pure titanium) as material with a thickness of 500 µm. The results of the research indicated that the microplate was safe to use according to the maximum stress around the hole, displacement around the hole and also the safety factor of the microplate.

Utilidad de la Ortopantografía vs TAC facial en el diagnóstico de fracturas de mandíbula Utility of orthopantography vs facial TAC in jaw fractures diagnostic

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M. P. Casteleiro Roca

2007-12-01

Full Text Available Nuestro objetivo es conocer la utilidad de la Ortopantografía frente a la TAC (Tomografía Axial Computarizada para el diagnóstico de las fracturas de mandíbula, pretendiendo implantar en nuestro hospital recomendaciones basadas en la evidencia. Llevamos a cabo una revisión sistemática en PubMed: la estrategia de búsqueda se define como "Jaw Fractures" [MeSH] AND "Tomography, X-Ray Computed" [MeSH], restringiendo dicha búsqueda a los últimos 5 años (2001-2005 y limitándola a inglés y español. Los criterios de inclusión establecidos son: diseños de estudio, revisiones sistemáticas, meta-análisis, estudios comparando utilidad de Ortopantografía frente a TAC en diagnóstico de fracturas mandibulares. Como criterios de exclusión marcamos: casos clínicos, cartas al director, no comparar Ortopantografía frente a TAC en diagnóstico de fracturas mandibulares. Obtenemos 41 artículos que analizamos y clasificamos aplicando los criterios descritos y obteniendo finalmente 3 artículos. Actualmente, como prueba única, la TAC proporciona más información diagnóstica que la Ortopantografía en las fracturas de mandíbula.We consider as objective to know the utility of Orthopantography in jaw fractures diagnostic in front of TAC, with the purpose of implanting recommendations based on evidence in the clinical practice of our hospital. We follow a systematic review in PubMed. The search strategy is defined as "Jaw Fractures" [MeSH]AND "Tomography, X-Ray Computed" [MeSH], restricted to last 5 years (2001-2005, and articles only in english and in spanish. Inclusion criteria were: study designs, systematic review, meta-analysis, comparative studies between Orthopantography and TAC in jaw fractures diagnostic. Exclusion criteria were: case-report, letters and viewpoints, studies don"t comparing Orthopantography in front of TAC in jaw fractures diagnostic. Search strategy provides 41 articles; we analyzed and classified those applying

Hyperparathyroidism-Jaw Tumor Syndrome: Results of surgical management

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Mehta, Amit; Patel, Dhaval; Rosenberg, Avi; Boufraqech, Myriem; Ellis, Ryan J.; Nilubol, Naris; Quezado, Martha M.; Marx, Stephen J.; Simonds, William F.; Kebebew, Electron

2014-01-01

Background Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is a rare autosomal dominant disease secondary to germline inactivating mutations of the tumor suppressor gene HRPT2/CDC73. The aim of the present study is to determine the optimal surgical approach to parathyroid disease in patients with HPT-JT. Method A retrospective analysis of clinical and genetic features, parathyroid operative outcomes, and disease outcomes in seven unrelated HPT-JT families. Results Seven families had five distinct germline HRPT2/CDC73 mutations. Sixteen affected family members (median age of 30.7 years) were diagnosed with primary hyperparathyroidism. Fifteen of the 16 patients underwent preoperative tumor localization studies and uncomplicated bilateral neck exploration at initial operation - all were in biochemical remission at most recent follow up. 31% of patients had multiglandular involvement. 37.5% of patients developed parathyroid carcinoma (median overall survival 8.9 years; median follow-up 7.4 years). Long-term follow-up showed 20% of patients had recurrent primary hyperparathyroidism. Conclusions Given the high risk of malignancy and multiglandular involvement in our cohort, we recommend bilateral neck exploration and en-bloc resection of parathyroid tumors suspicious for cancer and life-long postoperative follow-up. PMID:25444225

Hyperparathyroidism-jaw tumor syndrome: Results of operative management.

Science.gov (United States)

Mehta, Amit; Patel, Dhaval; Rosenberg, Avi; Boufraqech, Myriem; Ellis, Ryan J; Nilubol, Naris; Quezado, Martha M; Marx, Stephen J; Simonds, William F; Kebebew, Electron

2014-12-01

Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is a rare, autosomal-dominant disease secondary to germline-inactivating mutations of the tumor suppressor gene HRPT2/CDC73. The aim of the present study was to determine the optimal operative approach to parathyroid disease in patients with HPT-JT. A retrospective analysis of clinical and genetic features, parathyroid operative outcomes, and disease outcomes in 7 unrelated HPT-JT families. Seven families had 5 distinct germline HRPT2/CDC73 mutations. Sixteen affected family members (median age, 30.7 years) were diagnosed with primary hyperparathyroidism (PHPT). Fifteen of the 16 patients underwent preoperative tumor localization studies and uncomplicated bilateral neck exploration at initial operation; all were in biochemical remission at most recent follow-up. Of these patients, 31% had multiglandular involvement; 37.5% of the patients developed parathyroid carcinoma (median overall survival, 8.9 years; median follow-up, 7.4 years). Long-term follow-up showed that 20% of patients had recurrent PHPT. Given the high risk of malignancy and multiglandular involvement in our cohort, we recommend bilateral neck exploration and en bloc resection of parathyroid tumors suspicious for cancer and life-long postoperative follow-up. Published by Elsevier Inc.

Effect of Jaw Clenching on Balance Recovery: Dynamic Stability and Lower Extremity Joint Kinematics after Forward Loss of Balance

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Steffen eRinghof

2016-03-01

Full Text Available Postural control is crucial for most tasks of daily living, delineating postural orientation and balance, with its main goal of fall prevention. Nevertheless, falls are common events and have been associated with deficits in muscle strength and dynamic stability. Recent studies reported on improvements in rate of force development and static postural control evoked by jaw clenching activities, potentially induced by facilitation of human motor system excitability. However, there are no studies describing the effects on dynamic stability. The present study, therefore, aimed investigated the effects of submaximum jaw clenching on recovery behavior from forward loss of balance. Participants were twelve healthy young adults, who were instructed to recover balance from a simulated forward fall by taking a single step while either biting at a submaximum force or keeping the mandible at rest. Bite forces were measured by means of hydrostatic splints, whereas a 3D motion capture system was used to analyze spatiotemporal parameters and joint angles, respectively. Additionally, dynamic stability was quantified by the extrapolated CoM concept, designed to determine postural stability in dynamic situations. Paired t-tests revealed that submaximum biting did not significantly influence recovery behavior with respect to any variable under investigation. Therefore, reductions in postural sway evoked by submaximum biting are obviously not transferable to dynamic stability. It is suggested that these contradictions are the result of different motor demands associated with the abovementioned tasks. Furthermore, floor effects and the sample size might be discussed as potential reasons for the absence of significances. Notwithstanding this, the present study also revealed that bite forces under both conditions significantly increased from subjects’ release to touchdown of the recovery limb. Clenching the jaw, hence, seems to be part of a common physiological

The significance of lower jaw position in relation to postural stability. Comparison of a premanufactured occlusal splint with the Dental Power Splint.

Science.gov (United States)

Ohlendorf, D; Riegel, M; Lin Chung, T; Kopp, S

2013-01-01

The purpose of this study was to investigate the effects on postural stability of two different lower jaw positions held in place by splints with eyes open and eyes closed. The postural stability in 21 healthy adult volunteers was investigated using two different sets of occlusal conditions with the lower jaw being at rest either with the eyes opened or closed. Two occlusal splints (standard splint and DPS splint) were used in order to maintain this lower jaw position. The balance behaviour was recorded using a balance platform. In a comparison of the habitual occlusion with the two occlusal splints, the balance posturographic values with the eyes opened fell between 7-9% and those for weight distribution with the eyes closed between 22-26% (with greater improvement being achieved with DPS) with the result that the variability in the range of fluctuations was reduced. The level of positioning accuracy deteriorated with the wearing of a splint between 13% with the DPS splint and 30% with the standard splint. Gender-specific differences of minor importance in relation to the positioning accuracy were recorded, with there being significant differences in the female participants (P≤0.00). An occlusal change in the stomatognathic system impacts on postural stability. Balance deficits seem to correlate with deteriorated body sway, which, according to the results, can be improved by a myocentric bite position using a DPS splint. This is more the case with the eyes closed than with the eyes opened.

The Redox Balance in Erythrocytes, Plasma, and Periosteum of Patients with Titanium Fixation of the Jaw

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Jan Borys

2017-06-01

Full Text Available Titanium miniplates and screws are commonly used for fixation of jaw fractured or osteotomies. Despite the opinion of their biocompatibility, in clinical practice symptoms of chronic inflammation around the fixation develop in some patients, even many years after the application of miniplates and screws. The cause of these complications is still an unanswered question. Taking into account that oxidative stress is one of the toxic action of titanium, we have evaluated the antioxidant barrier as well as oxidative stress in the erythrocytes, plasma and periosteum covering the titanium fixation of the jaw. The study group was composed of 32 patients aged 20–30 with inserted miniplates and screws. The antioxidant defense: catalase (CAT, glutathione peroxidase (GPx, superoxide dismutase-1 (SOD1, uric acid (UA, total antioxidant capacity (TAC, as well as oxidative damage products: advanced oxidation protein products (AOPP, advanced glycation end products (AGE, dityrosine, kynurenine, N-formylkynurenine, tryptophan, malondialdehyde (MDA, 4-hydroxynonenal (4-HNE, total oxidant status (TOS, and oxidative status index (OSI were evaluated. SOD1 activity (↓37%, and tryptophan levels (↓34% showed a significant decrease while AOPP (↑25%, TOS (↑80% and OSI (↑101% were significantly elevated in maxillary periosteum of patients who underwent bimaxillary osteotomies as compared to the control group. SOD-1 (↓55%, TAC (↓58.6%, AGE (↓60% and N-formylkynurenine (↓34% was statistically reduced while AOPP (↑38%, MDA (↑29%, 4-HNE (↑114%, TOS (↑99%, and OSI (↑381% were significantly higher in the mandibular periosteum covering miniplates/screw compared with the control tissues. There were no correlations between antioxidants and oxidative stress markers in the periosteum of all patients and the blood. As exposure to the Ti6Al4V titanium alloy leads to disturbances of redox balance in the periosteum surrounding titanium implants of the maxilla

Bisphosphonate associated osteonecrosis of the jaw.

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Khan, Aliya A; Sándor, George K B; Dore, Edward; Morrison, Archibald D; Alsahli, Mazen; Amin, Faizan; Peters, Edmund; Hanley, David A; Chaudry, Sultan R; Lentle, Brian; Dempster, David W; Glorieux, Francis H; Neville, Alan J; Talwar, Reena M; Clokie, Cameron M; Mardini, Majd Al; Paul, Terri; Khosla, Sundeep; Josse, Robert G; Sutherland, Susan; Lam, David K; Carmichael, Robert P; Blanas, Nick; Kendler, David; Petak, Steven; Ste-Marie, Louis Georges; Brown, Jacques; Evans, A Wayne; Rios, Lorena; Compston, Juliet E

2009-03-01

In 2003, the first reports describing osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonates (BP) were published. These cases occurred in patients with cancer receiving high-dose intravenous BP; however, 5% of the cases were in patients with osteoporosis receiving low-dose bisphosphonate therapy. We present the results of a systematic review of the incidence, risk factors, diagnosis, prevention, and treatment of BP associated ONJ. We conducted a comprehensive literature search for relevant studies on BP associated ONJ in oncology and osteoporosis patients published before February 2008.All selected relevant articles were sorted by area of focus. Data for each area were abstracted by 2 independent reviewers. The results showed that the diagnosis is made clinically. Prospective data evaluating the incidence and etiologic factors are very limited. In oncology patients receiving high-dose intravenous BP, ONJ appears to be dependent on the dose and duration of therapy, with an estimated incidence of 1%-12% at 36 months of exposure. In osteoporosis patients, it is rare, with an estimated incidence < 1 case per 100,000 person-years of exposure. The incidence of ONJ in the general population is not known. Currently, there is insufficient evidence to confirm a causal link between low-dose BP use in the osteoporosis patient population and ONJ. We concluded BP associated ONJ is associated with high-dose BP therapy primarily in the oncology patient population. Prevention and treatment strategies are currently based on expert opinion and focus on maintaining good oral hygiene and conservative surgical intervention.

A novel laparoscopic grasper with two parallel jaws capable of extracting the mechanical behaviour of soft tissues.

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Nazarynasab, Dariush; Farahmand, Farzam; Mirbagheri, Alireza; Afshari, Elnaz

2017-07-01

Data related to force-deformation behaviour of soft tissue plays an important role in medical/surgical applications such as realistically modelling mechanical behaviour of soft tissue as well as minimally invasive surgery (MIS) and medical diagnosis. While the mechanical behaviour of soft tissue is very complex due to its different constitutive components, some issues increase its complexity like behavioural changes between the live and dead tissues. Indeed, an adequate quantitative description of mechanical behaviour of soft tissues requires high quality in vivo experimental data to be obtained and analysed. This paper describes a novel laparoscopic grasper with two parallel jaws capable of obtaining compressive force-deformation data related to mechanical behaviour of soft tissues. This new laparoscopic grasper includes four sections as mechanical hardware, sensory part, electrical/electronical part and data storage part. By considering a unique design for mechanical hardware, data recording conditions will be close to unconfined-compression-test conditions; so obtained data can be properly used in extracting the mechanical behaviour of soft tissues. Also, the other distinguishing feature of this new system is its applicability during different laparoscopic surgeries and subsequently obtaining in vivo data. However, more preclinical examinations are needed to evaluate the practicality of the novel laparoscopic grasper with two parallel jaws.

Endodontic management of nonrestorable teeth in patients at risk of developing osteonecrosis of the jaw: Case series

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Fahd Alsalleeh

2016-01-01

Full Text Available Osteoradionecrosis of the jaws is one of the most serious oral complications of head and neck cancer radiation therapy. It is a self-progressive process of bone destruction that is very difficult to treat. In this report, four patients who are susceptible to osteonecrosis of the jaw presented for endodontic management of nonrestorable teeth. The first patient had two molar teeth with necrotic pulp and was treated with nonsurgical root canal therapy (NSRCT followed by crown amputation and hemisection. The second patient had a molar tooth that was previously treated with acute apical abscess. Crown amputation and hemisection were performed. The third patient had a molar tooth with necrotic pulp and asymptomatic apical periodontitis. NSRCT followed by occlusal reduction were completed. The fourth patient had a molar tooth with necrotic pulp and symptomatic apical periodontitis. NSRCT and crown amputation were performed. All cases had a minimum recall of 12-months. The tooth in case #1 developed a periapical pathosis, and other teeth in case #1–#3 had healing of periapical lesions. The tooth in case #4 was exfoliated. None had developed osteonecrosis. These results suggest that NSRCT is the treatment option to manage nonrestorable teeth in postradiation patients or patients taking bisphosphonate drugs to prevent osteonecrosis.

Possible interbreeding in late Italian Neanderthals? New data from the Mezzena jaw (Monti Lessini, Verona, Italy.

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Silvana Condemi

Full Text Available In this article we examine the mandible of Riparo Mezzena a Middle Paleolithic rockshelter in the Monti Lessini (NE Italy, Verona found in 1957 in association with Charentian Mousterian lithic assemblages. Mitochondrial DNA analysis performed on this jaw and on other cranial fragments found at the same stratigraphic level has led to the identification of the only genetically typed Neanderthal of the Italian peninsula and has confirmed through direct dating that it belongs to a late Neanderthal. Our aim here is to re-evaluate the taxonomic affinities of the Mezzena mandible in a wide comparative framework using both comparative morphology and geometric morphometrics. The comparative sample includes mid-Pleistocene fossils, Neanderthals and anatomically modern humans. This study of the Mezzena jaw shows that the chin region is similar to that of other late Neanderthals which display a much more modern morphology with an incipient mental trigone (e.g. Spy 1, La Ferrassie, Saint-Césaire. In our view, this change in morphology among late Neanderthals supports the hypothesis of anatomical change of late Neanderthals and the hypothesis of a certain degree of interbreeding with AMHs that, as the dating shows, was already present in the European territory. Our observations on the chin of the Mezzena mandible lead us to support a non abrupt phylogenetic transition for this period in Europe.

Fast Automatic Beam-Based Alignment of the LHC Collimator Jaws

CERN Document Server

AUTHOR|(CDS)2080813; Assmann, R W

2014-01-01

The CERN Large Hadron Collider (LHC) in Geneva, Switzerland is the largest and most powerful particle accelerator ever built. With a circumference of 27 km, it is designed to collide particles in two counter-rotating beams at a centre-of-mass energy of 14 TeV to explore the fundamental forces and constituents of matter. Due to its potentially destructive high energy particle beams, the LHC is equipped with several machine protection systems. The LHC collimation system is tasked with scattering and absorbing beam halo particles before they can quench the superconducting magnets. The 108 collimators also protect the machine from damage in the event of very fast beam losses, and shields sensitive devices in the tunnel from radiation over years of operation. Each collimator is made up of two blocks or ‘jaws’ of carbon, tungsten or copper material. The collimator jaws need be placed symmetrically on either side of the beam trajectory, to clean halo particles with maximum efficiency. The beam orbit and beam siz...

Clinico-radiological study of fibro-osseous lesions of the jaw

International Nuclear Information System (INIS)

Nah, Kyung Sik; Park, Tae Won

1982-01-01

Since the fibro-osseous lesion is not a specific diagnostic term, the author studied clinically and radiologically 44 cases which had been diagnosed as fibro-osseous lesion in SNUDH (1972-1981.12). The obtained results were as follows. 1. Clinico-radiologically, the cases of fibro-osseous lesions were divided into two groups. 2. The first group was fibrous dysplasia(21 cases). 3. The second group was tumors of periodontal ligament origin, including ossifying fibroma, cementifying fibroma and cemento-ossifying fibroma (23 cases). 4. In most cases the chief complaint was painless swelling of the jaw and the mean age of the fibrous dysplasia (24.6 yrs) was a little younger than that of the periodontal ligament origin lesions (29.2 yrs). 5. In fibrous dysplasia, maxilla was often involved and showed ground-glass of smoke pattern radiologically. 6. The tumors of periodontal ligament origin occurred more in female, mandible and radiologically showed varying amounts of radiopaque foci in well-circumscribed osteolytic lesion.

Is Bisphosphonate-Related Osteonecrosis of the Jaw an Infection? A Histological and Microbiological Ten-Year Summary

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A. M. Hinson

2014-01-01

Full Text Available The role of infection in the etiology of bisphosphonate-related osteonecrosis of the jaw (BRONJ is poorly understood. Large-scale epidemiological descriptions of the histology and microbiology of BRONJ are not found in the literature. Herein, we present a systematic review of BRONJ histology and microbiology (including demographics, immunocompromised associations, clinical signs and symptoms, disease severity, antibiotic and surgical treatments, and recovery status validating that infection should still be considered a prime component in the multifactorial disease.

Influence of jaw tracking in intensity-modulated and volumetric-modulated arc radiotherapy for head and neck cancers: a dosimetric study

Energy Technology Data Exchange (ETDEWEB)

Mani, Karthick Raj [Research and Development Centre, Bharathiar University, Tamilnadu (India); Upadhayay, Sagar [Radiation Oncology, Kathmandu Cancer Center, Bhaktapur (Nepal); Das, K. J. Maria [Dept. of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh (India)

2017-03-15

To Study the dosimetric advantage of the Jaw tracking technique in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for Head and Neck Cancers. We retrospectively selected 10 previously treated head and neck cancer patients stage (T1/T2, N1, M0) in this study. All the patients were planned for IMRT and VMAT with simultaneous integrated boost technique. IMRT and VMAT plans were performed with jaw tracking (JT) and with static jaw (SJ) technique by keeping the same constraints and priorities for a particular patient. Target conformity, dose to the critical structures and low dose volumes were recorded and analyzed for IMRT and VMAT plans with and without JT for all the patients. The conformity index average of all patients followed by standard deviation (x¯x¯ ± σx¯σx¯) of the JT-IMRT, SJ-IMRT, JT-VMAT, and SJ-VMAT were 1.72 ± 0.56, 1.67 ± 0.57, 1.83 ± 0.65, and 1.85 ± 0.64, and homogeneity index were 0.059 ± 0.05, 0.064 ± 0.05, 0.064 ± 0.04, and 0.064 ± 0.05. JT-IMRT shows significant mean reduction in right parotid and left parotid shows of 7.64% (p < 0.001) and 7.45% (p < 0.001) compare to SJ-IMRT. JT-IMRT plans also shows considerable dose reduction to thyroid, inferior constrictors, spinal cord and brainstem compared to the SJ-IMRT plans. Significant dose reductions were observed for critical structure in the JT-IMRT compared to SJ-IMRT technique. In JT-VMAT plans dose reduction to the critical structure were not significant compared to the SJ-IMRT due to relatively lesser monitor units.

Mice deleted for cell division cycle 73 gene develop parathyroid and uterine tumours: model for the hyperparathyroidism-jaw tumour syndrome.

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Walls, G V; Stevenson, M; Lines, K E; Newey, P J; Reed, A A C; Bowl, M R; Jeyabalan, J; Harding, B; Bradley, K J; Manek, S; Chen, J; Wang, P; Williams, B O; Teh, B T; Thakker, R V

2017-07-13

The hyperparathyroidism-jaw tumour (HPT-JT) syndrome is an autosomal dominant disorder characterized by occurrence of parathyroid tumours, often atypical adenomas and carcinomas, ossifying jaw fibromas, renal tumours and uterine benign and malignant neoplasms. HPT-JT is caused by mutations of the cell division cycle 73 (CDC73) gene, located on chromosome 1q31.2 and encodes a 531 amino acid protein, parafibromin. To facilitate in vivo studies of Cdc73 in tumourigenesis we generated conventional (Cdc73 +/- ) and conditional parathyroid-specific (Cdc73 +/L /PTH-Cre and Cdc73 L/L /PTH-Cre) mouse models. Mice were aged to 18-21 months and studied for survival, tumour development and proliferation, and serum biochemistry, and compared to age-matched wild-type (Cdc73 +/+ and Cdc73 +/+ /PTH-Cre) littermates. Survival of Cdc73 +/- mice, when compared to Cdc73 +/+ mice was reduced (Cdc73 +/- =80%; Cdc73 +/+ =90% at 18 months of age, Pfourfold higher than that in parathyroid glands of wild-type littermates (P<0.0001). Cdc73 +/- , Cdc73 +/L /PTH-Cre and Cdc73 L/L /PTH-Cre mice had higher mean serum calcium concentrations than wild-type littermates, and Cdc73 +/- mice also had increased mean serum parathyroid hormone (PTH) concentrations. Parathyroid tumour development, and elevations in serum calcium and PTH, were similar in males and females. Cdc73 +/- mice did not develop bone or renal tumours but female Cdc73 +/- mice, at 18 months of age, had uterine neoplasms comprising squamous metaplasia, adenofibroma and adenomyoma. Uterine neoplasms, myometria and jaw bones of Cdc73 +/- mice had increased proliferation rates that were 2-fold higher than in Cdc73 +/+ mice (P<0.05). Thus, our studies, which have established mouse models for parathyroid tumours and uterine neoplasms that develop in the HPT-JT syndrome, provide in vivo models for future studies of these tumours.

Chromosome evaluation of Angus calves with unilateral congenital cleft lip and jaw (cheilognathoschisis).

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Swartz, H A; Vogt, D W; Kintner, L D

1982-04-01

Two purebred Angus calves with unilateral cleft lip and jaw were karyotyped and anatomically described. Both calves, 1 male and 1 female, were from the same farm and were born in March and April 1980. The defect was most pronounced in the female calf. Both calves exhibited an elevated midline of the hard palate. The female calf also manifested characteristics indicative of proportionate dwarfism. Karyotypes were constructed after a 72-hour culture of peripheral blood. The 2N number was 60 with no apparent chromosome abnormality. The coefficient of relationship between the 2 affected calves was calculated to be 0.78%. The cause of the defect could not be ascertained from the limited data available.

Two-argument total scatter factor for small fields simultaneously collimated by MLC and jaws: application to stereotactic radiosurgery and radiotherapy

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Han, Zhaohui; Friesen, Scott; Hacker, Fred; Zygmanski, Piotr

2018-01-01

Direct use of the total scatter factor (S tot) for independent monitor unit (MU) calculations can be a good alternative approach to the traditional separate treatment of head/collimator scatter (S c) and phantom scatter (S p), especially for stereotactic small fields under the simultaneous collimation of secondary jaws and tertiary multileaf collimators (MLC). We have carried out the measurement of S tot in water for field sizes down to 0.5  ×  0.5 cm2 on a Varian TrueBeam STx medical linear accelerator (linac) equipped with high definition MLCs. Both the jaw field size (c) and MLC field size (s) significantly impact the linac output factors, especially when c \\gg s and s is small (e.g. s  effectively transforms the measured trapezoidal domain in (c,s) plane to a rectangular domain to facilitate easier two-dimensional interpolation to determine S tot for arbitrary (c,s) combinations. Both the empirical fit and interpolation showed good agreement with experimental validation data.

Examination of jaws and teeth using Dental CT

International Nuclear Information System (INIS)

Nikolov, Vl.

2001-01-01

The aim of the present work was to establish a new method for dental imaging using Dental CT. Dental computer assisted tomography represents valuable addition to the diagnostics spectrum for planning oral and maxillofacial surgery. High resolution spiral CT and specially designed computer software allow representation of the jaws in different planes that are easy to match. The further allow the display of very small structures relevant to oral surgical interventions and reveal their spatial relationship in three dimensions. Dental CT is indicated, when clinical and conventional radiological techniques will not allow exact interpretation of the situation. It is modern oral implantology that primarily benefits from computer software enabling the assessment of surgical sites in the pre surgical phase. Such planning was not yet possible using two dimensional radiographic techniques. The dental-implantological part expects from radiography sharply defined contours of the external bony contours and the mandibular canal, exactly defined relation between slices and planes, no distortion in the ortho-radial planes, tools for reliable measurements of distances, angles and volumes, possibility to transmit pictures electronically or on hardcopy without loss of quality. Thus communication between dentists and radiologists may and must be intensified and supported by usage of modern telecommunication systems. (author)

Effects of increased occlusal vertical dimension on the jaw-opening reflex in adult rats.

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Makiguchi, Mio; Funaki, Yukiha; Kato, Chiho; Okihara, Hidemasa; Ishida, Takayoshi; Yabushita, Tadachika; Kokai, Satoshi; Ono, Takashi

2016-12-01

Malocclusion with deep overbite and facial esthetics improve when facial height is intentionally increased during orthodontic extrusion of the posterior teeth. Thus, a better understanding of post-treatment stability of increased occlusal vertical dimension (iOVD) in adult patients is important. We focused on the jaw-opening reflex (JOR), which plays an important role in the control of jaw movements during mastication, and investigated the effects of iOVD on the JOR in rats with an electrophysiological technique. One hundred and twenty 13-week-old male Wistar rats were randomly divided into control and experimental groups. Rats in the experimental group received a 2-mm buildup of composite resin on the maxillary molars at 13 weeks of age. The JOR was induced by low-intensity electrical stimulation of the left inferior alveolar nerve. The electromyographic responses were recorded from the digastric muscle at 13, 14, 15, 17, 19, and 23 weeks of age. JOR properties including latency, duration, and peak-to-peak amplitude were measured and compared between the groups. The latency of the JOR was significantly longer and the peak-to-peak amplitude was significantly smaller in the experimental group than in the control group from 14 to 19 weeks of age, while the reflex duration was not significantly different. Intra-group comparisons of the latency and peak-to-peak amplitudes among rats 14-19 weeks of age were significantly different between the experimental group and the control group. iOVD affected the latency and amplitude of the JOR but not the duration. The JOR adapted after 10 weeks of iOVD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Full mouth rehabilitation with retrievable metal-ceramic implant-supported fixed prostheses for a young patient with atrophic jaws: a clinical report.

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Ameri, Narges; Alikhasi, Marzieh; Rezayani, Vida

2017-09-01

Treatment of atrophic edentulous jaws with implant-supported fixed prostheses is one of the most complicated challenges in dentistry. This clinical report describes the prosthesis which consists of screw retained frameworks with individual cement retained crowns which combines the advantages of the screw retained restoration with the advantage of cement retained.

Dosimetric characteristics of a 6 MV photon beam from a linear accelerator with asymmetric collimator jaws

International Nuclear Information System (INIS)

Palta, J.R.; Ayyangar, K.M.; Suntharalingam, N.

1988-01-01

Dosimetric measurements have been made of a 6 MV photon beam from a linear accelerator equipped with asymmetric jaws. The field size factors for asymmetrically set fields are compared to those for symmetrically set fields. The change of beam quality has been measured as a function of off-axis position of the asymmetric fields to assess its effect on depth dose. Additional measurements include beam penumbra and shape of isodose curves for open and wedge fields as the field opening is moved asymmetrically from the central ray

Three-dimensional evaluation of human jaw bone microarchitecture: correlation between the microarchitectural parameters of cone beam computed tomography and micro-computer tomography.

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Kim, Jo-Eun; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Huh, Kyung-Hoe

2015-12-01

To evaluate the potential feasibility of cone beam computed tomography (CBCT) in the assessment of trabecular bone microarchitecture. Sixty-eight specimens from four pairs of human jaw were scanned using both micro-computed tomography (micro-CT) of 19.37-μm voxel size and CBCT of 100-μm voxel size. The correlation of 3-dimensional parameters between CBCT and micro-CT was evaluated. All parameters, except bone-specific surface and trabecular thickness, showed linear correlations between the 2 imaging modalities (P < .05). Among the parameters, bone volume, percent bone volume, trabecular separation, and degree of anisotropy (DA) of CBCT images showed strong correlations with those of micro-CT images. DA showed the strongest correlation (r = 0.693). Most microarchitectural parameters from CBCT were correlated with those from micro-CT. Some microarchitectural parameters, especially DA, could be used as strong predictors of bone quality in the human jaw. Copyright © 2015 Elsevier Inc. All rights reserved.

A reevaluation of the anatomy of the jaw-closing system in the extant coelacanth Latimeria chalumnae

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Dutel, Hugo; Herrel, Anthony; Clément, Gaël; Herbin, Marc

2013-11-01

The coelacanth Latimeria is the only extant representative of the Actinistia, a group of sarcopterygian fishes that originated in the Devonian. Moreover, it is the only extant vertebrate in which the neurocranium is divided into an anterior and a posterior portion that articulate by means of an intracranial joint. This joint is thought to be highly mobile, allowing an elevation of the anterior portion of the skull during prey capture. Here we provide a new description of the skull and jaw-closing system in Latimeria chalumnae in order to better understand its skull mechanics during prey capture. Based on a dissection and the CT scanning of an adult coelacanth, we provide a detailed description of the musculature and ligaments of the jaw system. We show that the m. adductor mandibulae is more complex than previously reported. We demonstrate that the basicranial muscle inserts more anteriorly than has been described previously, which has implications for its function. Moreover, the anterior insertion of the basicranial muscle does not correspond to the posterior tip of the tooth plate covering the parasphenoid, questioning previous inferences made on fossil coelacanths and other sarcopterygian fishes. Strong ligaments connect the anterior and the posterior portions of the skull at the level of the intracranial joint, as well as the notochord and the catazygals. These observations suggest that the intracranial joint is likely to be less mobile than previously thought and that its role during feeding merits to be reexamined.

Effect of Jaw Clenching on Balance Recovery: Dynamic Stability and Lower Extremity Joint Kinematics after Forward Loss of Balance

OpenAIRE

Ringhof, Steffen; Stein, Thorsten; Hellmann, Daniel; Schindler, Hans J.; Potthast, Wolfgang

2016-01-01

Postural control is crucial for most tasks of daily living, delineating postural orientation and balance, with its main goal of fall prevention. Nevertheless, falls are common events, and have been associated with deficits in muscle strength and dynamic postural stability. Recent studies reported on improvements in rate of force development and static postural control evoked by jaw clenching activities, potentially induced by facilitation of human ...

Jaws calibration method to get a homogeneous distribution of dose in the junction of hemi fields; Metodo de calibracion de mandibulas para conseguir una distribucion homogenea de dosis en la zona de union de hemicampos

Energy Technology Data Exchange (ETDEWEB)

Cenizo de Castro, E.; Garcia Pareja, S.; Moreno Saiz, C.; Hernandez Rodriguez, R.; Bodineau Gil, C.; Martin-Viera Cueto, J. A.

2011-07-01

Hemi fields treatments are widely used in radiotherapy. Because the tolerance established for the positioning of each jaw is 1 mm, may be cases of overlap or separation of up to 2 mm. This implies heterogeneity of doses up to 40% in the joint area. This paper presents an accurate method of calibration of the jaws so as to obtain homogeneous dose distributions when using this type of treatment. (Author)

Tooth axis and skeletal structures in mandibular molar vertical sections in jaw deformity with facial asymmetry using MPR images

International Nuclear Information System (INIS)

Nojima, Kunihiko; Yokose, Taishi; Ishii, Takenobu; Kobayashi, Makoto; Nishii, Yasushi

2007-01-01

The objective of the present study was to investigate frontal morphological asymmetry in the mandibular molar region in terms of tooth axis and skeletal structures using vertical MPR sections in jaw deformity accompanied by facial asymmetry. Subjects consisted of 15 patients with jaw deformity accompanied by facial asymmetry aged 17.4 years to 37.8 years. There were four men and eleven women. Based on X-ray computed tomography (CT) scans, Digital Imaging and Communications in Medicine (DICOM) viewer software was used to prepare multiplanar reconstruction (MPR) sections. The mandible was then positioned on a reference plane based on the menton and left and right gonions, and a vertical MPR section passing through the mesial root of the first mandibular molar was prepared. The following measurements were made on both the shifted and non-shifted sides: maximum buccolingual width of the mandibular body; height of the mandibular body; inclination angle of the mandibular body; degree of buccal protrusion of the mandibular body; and inclination angle of the buccolingual tooth axis of the first molar. Furthermore, degree of median deviation in the menton was measured using frontal cephalograms. Differences in morphological parameters between the shifted and non-shifted sides were assessed. Furthermore, the relationship between median deviation and asymmetry were statistically analyzed. There was no significant asymmetry in the maximum buccolingual width of the mandibular body, the height of the mandibular body or the degree of buccal protrusion of the mandibular body. However, when compared to the shifted side, the inclination angle of the buccolingual tooth axis of the first molar for the non-shifted side was significantly greater. There was a relatively strong correlation between median deviation and inclination angle of the mandibular body. The above findings clarified that, in orthognathic surgery for jaw deformity accompanied by facial asymmetry, actively improving

Tongue- and Jaw-Specific Contributions to Acoustic Vowel Contrast Changes in the Diphthong /ai/ in Response to Slow, Loud, And Clear Speech

Science.gov (United States)

Mefferd, Antje S.

2017-01-01

Purpose: This study sought to determine decoupled tongue and jaw displacement changes and their specific contributions to acoustic vowel contrast changes during slow, loud, and clear speech. Method: Twenty typical talkers repeated "see a kite again" 5 times in 4 speech conditions (typical, slow, loud, clear). Speech kinematics were…

The fabrication of a customized occlusal splint based on the merging of dynamic jaw tracking records, cone beam computed tomography, and CAD-CAM digital impression

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Katerina Aslanidou

2017-01-01

CONCLUSIONS: The SICAT software provides a three-dimensional real-dynamic simulation of mandibular movements relative to the patient-specific anatomy of the jaw; thus, it opens new possibilities and potentials for the management of temporomandibular disorders.

Pattern and presentation of odontogenic jaw cysts: a clinical experience

International Nuclear Information System (INIS)

Awan, M.U.A.; Ibrahim, M.W.

2017-01-01

Objective: To determine the pattern and presentations of odontogenic jaw cysts in patients reporting at the Armed Forces Institute of Dentistry. Study Design: Descriptive study. Place and Duration of Study: Armed Forces Institute of Dentistry, from Jan to Dec 2007. Material and Methods: Hundred patients including 70 males and 30 females with the age range 5-65 years were included in the study. History, clinical examination, radiographic examination and histopathologic examination of lesion were carried out for each patient. A proforma was filled for each patient for all relevant information, presentation and pattern. Diagnosis was confirmed by histopathology. Data were analyzed using SPSS version 10. Results: Out of total 100 patients, 58 percent were diagnosed with radicular cysts, 25 percent with dentigerous cysts, 15 percent with odontogenic keratocyst, 1 percent patient with calcifying epithelial odontogenic cyst and 1 percent patient was diagnosed with eruption cyst. Conclusion: The study demonstrates that radicular cyst was the most common odontogenic cysts followed by dentigerous and odontogenic keratocysts respectively in our study sample. (author)

Odontogenic keratocysts in the Basal Cell Nevus (Gorlin-Goltz) Syndrome associated with paresthesia of the lower jaw: Case report, retrospective analysis of a representative Czech cohort and recommendations for the early diagnosis.

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Hubacek, Milan; Kripnerova, Tereza; Nemcikova, Michaela; Krepelová, Anna; Puchmajerova, Alena; Malikova, Marcela; Havlovicová, Markéta; Cadova, Jana; Kodet, Roman; Macek, Milan; Dostalova, Tatjana

2016-09-01

Identification of early presenting signs of the Basal Cell Nevus (BCNS; synonyme Gorlin-Goltz) syndrome, which is associated with a principal triad of multiple basal cell nevi, jaw odontogenic keratocysts, and skeletal anomalies, in stomatological and neurological practices. Proposal of multidisciplinary diagnostic algorithm comprising other medical specialists, including pathology, imaging, laboratory and molecular analyses based on the study outcomes. Case report of a male patient reporting paresthesia of their lower jaw, with right facial asymmetry (maxilla and mandible) and radiological detection of large osteolytic lesions in both jaws, including a retrospective analysis of a representative Czech cohort with BCNS from within the last decade. Clinical, imaging and laboratory analyses were carried out at a national tertiary centre. A multidisciplinary clinical approach followed by surgical management lead to the identification of odontogenic cysts, which were substantiated by histological examination. DNA sequencing of the PTCH1 gene detected a c.2929dupT resulting in p. Tyr977Leufs*16 pathogenic variant. This finding confirmed the clinical and laboraoty diagnosis of BCNS. Parental DNA analysis showed that this causal genetic defect arose de novo. Surgical management and orthodontic therapy were successful. Analysis of the reported case and retrospective data analysis provided evidence that paresthesia of the lower jaw should be considered as one of the early presenting signs of this rare disorder in stomatological and neurological practice. Obtained results allowed us to formulate recommendations for diagnostic practice in stomatology and neurology.

An electromyographic study of aspects of 'deprogramming' of human jaw muscles.

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Donegan, S J; Carr, A B; Christensen, L V; Ziebert, G J

1990-11-01

Surface electromyograms from the right and left masseter and anterior temporalis muscles were used to detect peripheral correlates of deprogramming, also known as programming and reprogramming, of jaw elevator muscles. Putative deprogramming was attempted through the clinically recommended use of a leaf gauge, placed for 15 min between the maxillary and mandibular anterior teeth and disoccluding the posterior teeth by about 2 mm. Studied contractile activities were those of postural activity (subconscious, semi-isometric, minimal activity) and intercuspal teeth clenching (conscious, isometric, maximal activity). Use of the leaf gauge did not affect normalized postural activity (about 4%), the duration (about 900 ms) and static work efforts of clenching (about 1200 microV.s), the time to peak mean voltage of clenching (about 400 ms), and the peak mean voltage of clenching (about 300 microV). Activity and asymmetry indices showed that the studied motor innervation patterns were not changed by the leaf gauge.

Microscopic Evaluation of the Effect of Oral Microbiota on the Development of Bisphosphonate-Related Osteonecrosis of the Jaws in Rats

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Felipe M. Silveira

2017-01-01

Full Text Available Objectives: Osteonecrosis of the jaws is a side effect associated with the use of bisphosphonates. Using histologic analysis, this study aimed to evaluate the influence of microbial colonies in the development of osteonecrosis in the jaws of rats subjected to nitrogenous and non-nitrogenous bisphosphonates, undergoing surgical procedures. Material and Methods: Thirty-four rats (Rattus norvegicus, Wistar strain were allocated randomly into three groups: 12 animals treated with zoledronic acid; 12 animals treated with clodronate; and 10 animals treated with saline. Sixty days after the start of treatment, the animals underwent three extractions of the upper right molars. After 120 days of drug administration, the rats were killed. Histologic analysis was performed on specimens stained with hematoxylin and eosin by the technique of manual counting points using Image-Pro Plus software on images of the right hemimaxilla. Results: Osteonecrosis was induced in the test groups. There was no statistically significant association between the presence of microbial colonies and the presence of non-vital bone (Kruskal-Wallis, P > 0.05. Conclusions: Use of zoledronic acid was associated with non-vital bone and the results suggested that the presence of microbial colonies does not lead to osteonecrosis.

[Influences of balancing-side interference on jaw function].

Science.gov (United States)

Baba, K

1991-03-01

The influences of experimental balancing-side interference on the jaw function were investigated on 6 subjects. A specially designed onlay was fabricated for the lower second molar, which acted as an artificial balancing-side interference in the lateral mandibular position. The subjects were asked to do maximum clenching, lateral gliding and gum chewing with and without the device. Electromyographic activity of the masseter and the anterior and posterior temporal muscles were measured and the related mandibular movement was simultaneously recorded during these tasks. Introduction of the experimental interference caused alteration in the muscle activity as follows: 1. When the subjects exerted maximum clenching efforts in the lateral mandibular position, the ratio of the temporal muscle activity on the working-side to the balancing-side decreased, while that of the masseter muscle remained unchanged. 2. There was a tendency for the activity in the working-side posterior temporal muscle to increase during gliding from intercuspation. The ratio of the temporal muscle activity on the working-side to the balancing-side decreased during gliding into intercuspation. 3. Prolongation of the occlusal phase associated with the increase of the muscle activity was observed during gum chewing on the side opposite to the interference. It was suggested that the balancing-side interference might provoke a specific muscle activity in the temporal muscles during parafunctional clenching or grinding.

The Effect of a Condylar Repositioning Plate on Condylar Position and Relapse in Two-Jaw Surgery

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Gyu Sik Jung

2017-01-01

Full Text Available BackgroundNumerous condylar repositioning methods have been reported. However, most of them are 2-dimensional or are complex procedures that require a longer operation time and a highly trained surgeon. This study aims to introduce a new technique using a condylar repositioning plate and a centric relation splint to achieve a centric relationship.MethodsWe evaluated 387 patients who had undergone surgery for skeletal jaw deformities. During the operation, a centric relation splint, intermediate splint, final centric occlusion splint, and condylar repositioning plate along with an L-type mini-plate for LeFort I osteotomy or a bicortical screw for bilateral sagittal split ramus osteotomy were utilized for rigid fixation. The evaluation included: a physical examination to detect preoperative and postoperative temporomandibular joint dysfunction, 3-dimensional computed tomography and oblique transcranial temporomandibular joint radiography to measure 3-dimensional condylar head movement, and posteroanterior and lateral cephalometric radiography to measure the preoperative and postoperative movement of the bony segment and relapse rate.ResultsA 0.3% relapse rate was observed in the coronal plane, and a 2.8% relapse rate in the sagittal plane, which is indistinguishable from the dental relapse rate in orthodontic treatment. The condylar repositioning plate could not fully prevent movement of the condylar head, but the relapse rate was minimal, implying that the movement of the condylar head was within tolerable limits.ConclusionsOur condylar repositioning method using a centric relation splint and mini-plate in orthognathic surgery was found to be simple and effective for patients suffering from skeletal jaw deformities.

Tilting the jaw to improve the image quality or to reduce the dose in cone-beam computed tomography

International Nuclear Information System (INIS)

Luckow, Marlen; Deyhle, Hans; Beckmann, Felix; Dagassan-Berndt, Dorothea; Müller, Bert

2011-01-01

Objective: The image quality in cone-beam computed tomography (CBCT) should be improved tilting the mandible that contains two dental titanium implants, within the relevant range of motion. Materials and methods: Using the mandible of a five-month-old pig, CBCT was performed varying the accelerating voltage, beam current, the starting rotation angle of the mandible in the source-detector plane and the tilt angles of the jaw with respect to the source-detector plane. The different datasets were automatically registered with respect to micro CT data to extract the common volume and the deviance to the pre-defined standard that characterizes the image quality. Results: The variations of the accelerating voltage, beam current and the rotation within the source-detection plane provided the expected quantitative behavior indicating the appropriate choice of the imaging quality factor. The tilting of the porcine mandible by about 14° improves the image quality by almost a factor of two. Conclusions: The tilting of the mandible with two dental implants can be used to significantly reduce the artifacts of the strongly X-ray absorbing materials in the CBCT images. The comparison of 14° jaw tilting with respect to the currently recommended arrangement in plane with the teeth demonstrates that the applied exposure time and the related dose can be reduced by a factor of four without decreasing the image quality.

CNC-milled titanium frameworks supported by implants in the edentulous jaw: a 10-year comparative clinical study.

Science.gov (United States)

Örtorp, Anders; Jemt, Torsten

2012-03-01

No long-term clinical studies covering more than 5 years are available on Computer Numeric Controlled (CNC) milled titanium frameworks. To evaluate and compare the clinical and radiographic performance of implant-supported prostheses provided with CNC titanium frameworks in the edentulous jaw with prostheses with cast gold-alloy frameworks during the first 10 years of function. Altogether, 126 edentulous patients were by random provided with 67 prostheses with titanium frameworks (test) in 23 maxillas and 44 mandibles, and with 62 prostheses with gold-alloy castings (control) in 31 maxillas and 31 mandibles. Clinical and radiographic 10-year data were collected for the groups and statistically compared on patient level. The 10-year prosthesis and implant cumulative survival rate was 95.6% compared with 98.3%, and 95.0% compared with 97.9% for test and control groups, respectively (p > .05). No implants were lost after 5 years of follow-up. Smokers lost more implants than nonsmokers after 5 years of follow-up (p .05), respectively. One prosthesis was lost in each group due to loss of implants, and one prosthesis failed due to framework fracture in the test group. Two metal fractures were registered in each group. More appointments of maintenance were needed for the prostheses in the maxilla compared with those in the mandible (p CNC-milled titanium frameworks are a viable alternative to gold-alloy castings for restoring patients with implant-supported prostheses in the edentulous jaw. © 2009 Wiley Periodicals, Inc.

The evolution of pharyngognathy: a phylogenetic and functional appraisal of the pharyngeal jaw key innovation in labroid fishes and beyond.

Science.gov (United States)

Wainwright, Peter C; Smith, W Leo; Price, Samantha A; Tang, Kevin L; Sparks, John S; Ferry, Lara A; Kuhn, Kristen L; Eytan, Ron I; Near, Thomas J

2012-12-01

The perciform group Labroidei includes approximately 2600 species and comprises some of the most diverse and successful lineages of teleost fishes. Composed of four major clades, Cichlidae, Labridae (wrasses, parrotfishes, and weed whitings), Pomacentridae (damselfishes), and Embiotocidae (surfperches); labroids have been an icon for studies of biodiversity, adaptive radiation, and sexual selection. The success and diversification of labroids have been largely attributed to the presence of a major innovation in the pharyngeal jaw apparatus, pharyngognathy, which is hypothesized to increase feeding capacity and versatility. We present results of large-scale phylogenetic analyses and a survey of pharyngeal jaw functional morphology that allow us to examine the evolution of pharyngognathy in a historical context. Phylogenetic analyses were based on a sample of 188 acanthomorph (spiny-rayed fish) species, primarily percomorphs (perch-like fishes), and DNA sequence data collected from 10 nuclear loci that have been previously used to resolve higher level ray-finned fish relationships. Phylogenies inferred from this dataset using maximum likelihood, Bayesian, and species tree analyses indicate polyphyly of the traditional Labroidei and clearly separate Labridae from the remainder of the traditional labroid lineages (Cichlidae, Embiotocidae, and Pomacentridae). These three "chromide" families grouped within a newly discovered clade of 40 families and more than 4800 species (>27% of percomorphs and >16% of all ray-finned fishes), which we name Ovalentaria for its characteristic demersal, adhesive eggs with chorionic filaments. This fantastically diverse clade includes some of the most species-rich lineages of marine and freshwater fishes, including all representatives of the Cichlidae, Embiotocidae, Pomacentridae, Ambassidae, Gobiesocidae, Grammatidae, Mugilidae, Opistognathidae, Pholidichthyidae, Plesiopidae (including Notograptus), Polycentridae, Pseudochromidae

Risk factors and prediction of inflammatory complications and local secondary osteoporosis in the bone structure of jaws in dental intraosseous implantation in healthy subjects

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Mashchenko I.S.

2013-03-01

Full Text Available As a result of complex clinical, immunologic and biochemical investigations of 48 patients peculiarities of development of inflammatory com¬plications, local osteoporosis and destruction of bone tissue after performed dental intraosseous implantantion were first revealed. It was shown that multiple surgical traumas of soft tissues of jaws and bone tissue of alveolar processes with putting 4 or more implants simultaneously may lead to reducing biocidity of mucosa of jaw tissues; this promotes lesion of oral cavity hygiene and development of inflammatory process in zone of periimplant. It is set that massive accumulation of soft coat and dental calculus in the area of implant, superconstruction and marked deficit of sIgA production of oral mucosa promote development of periimplant mucositis in remote post-operative period. A sharp production of secretory ІL -1β is a risk factor in formation of general-destructive process in a periimplant zone, development of dental periimplant.

The clinical and radiologic consideration of osteosarcoma of the jaws

International Nuclear Information System (INIS)

Ko, Gi Young; Kim, Ki Duck; Park, Chang Seo

1996-01-01

The purpose of this study was to know the proper diagnosis and to establish the treatment plan of the osteosarcoma in the jaws through the clinical, radiological, and histopathologic considerations. The authors compared and analyzed t he clinicoradiologic features of the six cases of osteosarcoma, diagnosed at the dental college hospital in Yonsei University, Seoul, Korea, during the period from 1975 to 1995. The obtained results were as follows; 1. Osteosarcoma occurred in the mean age, 26.2 years, ranged from 14 to 35 years, and equally in men and women. 2. The swelling was the most common frequent presenting complaints. Other reported symptoms included pain, parasthesia of the lower lip or the lesion. 3. The average interval was seen 3.5 months before the patient had been seen by a doctor. 4. The frequency of the lesions was equally in the maxilla, 3 cases and mandible, 3 cases. 5. Radiologically, osteoblastic osteosarcoma which is seen in the 3 cases was the most frequent histologic type. Chondroblastic osteosarcoma were seen in the 2 cases. there was no correlation between the radiologic appearance and histopathologic type.

Implant Restoration of Edentulous Jaws with 3D Software Planning, Guided Surgery, Immediate Loading, and CAD-CAM Full Arch Frameworks

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Silvio Mario Meloni

2013-01-01

Full Text Available Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were placed. 117 out of 120 implants were immediately loaded. Outcome measures were implants survival, radiographic marginal bone levels and remodeling, soft tissue parameters, and complications. Results. 114 of 117 implants reached a 30 months follow-up, and no patients dropped out from the study. The cumulative survival rate was 97.7%; after 30 months, mean marginal bone level was  mm, mean marginal bone remodeling value was , mean PPD value was  mm, and mean BOP value was 4% ± 2.8%. Only minor prosthetic complications were recorded. Conclusion. Within the limitations of this study, it can be concluded that computer-guided surgery and immediate loading seem to represent a viable option for the immediate rehabilitations of completely edentulous jaws with fixed implant supported restorations. This trial is registered with Clinicaltrials.gov NCT01866696.

Bisphosphonate-Related Osteonecrosis of the Jaw: A Review of the Literature

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Eder Alberto Sigua-Rodriguez

2014-01-01

Full Text Available Bisphosphonates (BPs are a class of drugs used to treat osteoporosis and malignant bone metastasis. BPs show high binding capacity to the bone matrix, especially in sites of active bone metabolism. The American Society for Bone and Mineral Research defines BRONJ as “an area of exposed bone in the maxillofacial region that has not healed within 8 weeks after identification by a healthcare provider in a patient who is receiving or has been exposed to a bisphosphonate and has not had radiation therapy to the craniofacial region.” Bisphosphonate-related osteonecrosis of the jaw (BRONJ can adversely affect quality of life, as it may produce significant morbidity. The American Association of Oral and Maxillofacial Surgeons (AAOMS considers as vitally important that information on BRONJ be disseminated to other dental and medical specialties. The purpose of this work is to offer a perspective on how dentists should manage patients on BPs, to show the benefits of accurately diagnosing BRONJ, and to present diagnostic aids and treatments strategies for the condition.

Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws.

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Carlsson, Gunnar E

2014-08-01

To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results.

Association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism.

Science.gov (United States)

Yoshida, Yuya; Suganuma, Takeshi; Takaba, Masayuki; Ono, Yasuhiro; Abe, Yuka; Yoshizawa, Shuichiro; Sakai, Takuro; Yoshizawa, Ayako; Nakamura, Hirotaka; Kawana, Fusae; Baba, Kazuyoshi

2017-08-01

The aim of this study was to investigate the association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism. A total of 35 university students and staff members participated in this study after providing informed consent. All participants were divided into either a sleep bruxism group (n = 21) or a control group (n = 14), based on the following clinical diagnostic criteria: (1) reports of tooth-grinding sounds for at least two nights a week during the preceding 6 months by their sleep partner; (2) presence of tooth attrition with exposed dentin; (3) reports of morning masticatory muscle fatigue or tenderness; and (4) presence of masseter muscle hypertrophy. Video-polysomnography was performed in the sleep laboratory for two nights. Sleep bruxism episodes were measured using masseter electromyography, visually inspected and then categorized into phasic or tonic episodes. Phasic episodes were categorized further into episodes with or without grinding sounds as evaluated by audio signals. Sleep bruxism subjects with reported grinding sounds had a significantly higher total number of phasic episodes with grinding sounds than subjects without reported grinding sounds or controls (Kruskal-Wallis/Steel-Dwass tests; P bruxism subjects with tooth attrition exhibited significantly longer phasic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P bruxism subjects with morning masticatory muscle fatigue or tenderness exhibited significantly longer tonic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P bruxism represents different aspects of jaw motor activity during sleep. © 2016 European Sleep Research Society.

Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws

Science.gov (United States)

2014-01-01

PURPOSE To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. MATERIALS AND METHODS Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. RESULTS Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. CONCLUSION In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results. PMID:25177466

Medication-Related Osteonecrosis of Jaws: A Low-Level Laser Therapy and Antimicrobial Photodynamic Therapy Case Approach

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Mariana Comparotto Minamisako

2016-01-01

Full Text Available Medication-related osteonecrosis of the jaws (MRONJ can be considered an inability of the alveolar bone to respond to an injury, which frequently leads to severe local and systemic complications. Once the problem is installed, dentist must use all therapeutic approaches recommended. This manuscript reports a successful management of MRONJ handled with antibiotics, conservative debridement, low-level laser therapy (LLLT, and photodynamic therapy (PDT up to 12 months. As healing of MRONJ may be very slow, combined therapeutic approaches are required. Besides the recommended conventional treatment protocol, LLLT and PDT are important tools to contribute to healing and improvement of patient’s quality of life.

Retrospective Audit: Does Prior Assessment by Oral and Maxillofacial Surgeons Reduce the Risk of Osteonecrosis of The Jaw in Patients Receiving Bone-Targeted Therapies for Metastatic Cancers to the Skeleton?--Part II.

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Turner, Bruce; Ali, Sacha; Pati, Jhumur; Nargund, Vinod; Ali, Enamul; Cheng, Leo; Wells, Paula

2016-01-01

Men who receive bone-targeted therapy for metastatic prostate cancer are at increased risk of osteonecrosis of the jaw (ONJ). Development of ONJ has been associated with the administration of bone-targeted therapies in association with other risk factors. ONJ can be distressing for a patient because it can cause pain, risk of jaw fracture, body image disturbance, difficultly eating, and difficulty maintaining good oral hygiene. The aim of this article is to report results of an audit of prior assessment by oral and maxillofacial surgeons (OMFS) before initiation of bone-targeted therapies and whether it may reduce the risk of ONJ in patients receiving bone-targeted therapies for advanced cancers.

The evolution of the dorsal thalamus of jawed vertebrates, including mammals: cladistic analysis and a new hypothesis.

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Butler, A B

1994-01-01

The evolution of the dorsal thalamus in various vertebrate lineages of jawed vertebrates has been an enigma, partly due to two prevalent misconceptions: the belief that the multitude of nuclei in the dorsal thalamus of mammals could be meaningfully compared neither with the relatively few nuclei in the dorsal thalamus of anamniotes nor with the intermediate number of dorsal thalamic nuclei of other amniotes and a definition of the dorsal thalamus that too narrowly focused on the features of the dorsal thalamus of mammals. The cladistic analysis carried out here allows us to recognize which features are plesiomorphic and which apomorphic for the dorsal thalamus of jawed vertebrates and to then reconstruct the major changes that have occurred in the dorsal thalamus over evolution. Embryological data examined in the context of Von Baerian theory (embryos of later-descendant species resemble the embryos of earlier-descendant species to the point of their divergence) supports a new 'Dual Elaboration Hypothesis' of dorsal thalamic evolution generated from this cladistic analysis. From the morphotype for an early stage in the embryological development of the dorsal thalamus of jawed vertebrates, the divergent, sequential stages of the development of the dorsal thalamus are derived for each major radiation and compared. The new hypothesis holds that the dorsal thalamus comprises two basic divisions--the collothalamus and the lemnothalamus--that receive their predominant input from the midbrain roof and (plesiomorphically) from lemniscal pathways, including the optic tract, respectively. Where present, the collothalamic, midbrain-sensory relay nuclei are homologous to each other in all vertebrate radiations as discrete nuclei. Within the lemnothalamus, the dorsal lateral geniculate nucleus of mammals and the dorsal lateral optic nucleus of non-synapsid amniotes (diapsid reptiles, birds and turtles) are homologous as discrete nuclei; most or all of the ventral nuclear group

Analysis of small field percent depth dose and profiles: Comparison of measurements with various detectors and effects of detector orientation with different jaw settings

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Henry Finlay Godson

2016-01-01

Full Text Available The advent of modern technologies in radiotherapy poses an increased challenge in the determination of dosimetric parameters of small fields that exhibit a high degree of uncertainty. Percent depth dose and beam profiles were acquired using different detectors in two different orientations. The parameters such as relative surface dose (DS, depth of dose maximum (Dmax, percentage dose at 10 cm (D10, penumbral width, flatness, and symmetry were evaluated with different detectors. The dosimetric data were acquired for fields defined by jaws alone, multileaf collimator (MLC alone, and by MLC while the jaws were positioned at 0, 0.25, 0.5, and 1.0 cm away from MLC leaf-end using a Varian linear accelerator with 6 MV photon beam. The accuracy in the measurement of dosimetric parameters with various detectors for three different field definitions was evaluated. The relative DS(38.1% with photon field diode in parallel orientation was higher than electron field diode (EFD (27.9% values for 1 cm ×1 cm field. An overestimation of 5.7% and 8.6% in D10depth were observed for 1 cm ×1 cm field with RK ion chamber in parallel and perpendicular orientation, respectively, for the fields defined by MLC while jaw positioned at the edge of the field when compared to EFD values in parallel orientation. For this field definition, the in-plane penumbral widths obtained with ion chamber in parallel and perpendicular orientation were 3.9 mm, 5.6 mm for 1 cm ×1 cm field, respectively. Among all detectors used in the study, the unshielded diodes were found to be an appropriate choice of detector for the measurement of beam parameters in small fields.

Longitudinal evaluation of jaw muscle activity and mandibular kinematics in young patients with Class II malocclusion treated with the Teuscher activator.

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Cuevas, Maria-José; Cacho, Alberto; Alarcón, Jose-Antonio; Martín, Conchita

2013-05-01

A longitudinal study was performed to evaluate the jaw muscle activity and mandibular kinematics after Teuscher activator treatment and at 2 years after orthodontic treatment completion. Twenty-seven children with Class II division 1 malocclusion were evaluated before treatment (T0; mean: 11.6 years), after functional treatment (T1; mean: 12.8 years), and 2 years after orthodontic treatment (T2; mean: 18 years). Bilateral surface electromyographic activities of the anterior temporalis, posterior temporalis, masseter, and suprahyoid muscle areas were analyzed at rest and during clenching, swallowing, and mastication. Kinematic recordings of the mandibular maximum opening, lateral shift, right and left lateral excursions, and protrusion were evaluated. Compared to T0, the left masseter activity during clenching was decreased at T1 but increased at T2, similar to the other evaluated muscles. The suprahyoid activity during swallowing was increased at T1 but decreased at T2. The masseter activity during mastication was increased at T1 and further increased at T2. The left and right lateral excursions and protrusion did not show significant changes throughout the experiment. Teuscher activator and subsequent fixed orthodontic treatment improved jaw muscle function; however, a long period was needed to attain complete neuromuscular adaptation.

Duration of treatment with bisphosphonates at the time of osteonecrosis of the jaw onset in patients with rheumatoid arthritis. Review.

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Compain, H; Berquet, A; Loison-Robert, L-S; Ahossi, V; Zwetyenga, N

2018-06-01

Rheumatoid arthritis (RA) is a frequent and co-morbid condition. One of the main complications is induced osteoporosis. Treatments related to this complication significantly modify oral and implant management. Affected patients represent a population at intermediate risk of osteonecrosis of the jaw (ONJ). The objective was to search the literature for durations of treatment with bisphosphonates at the time of ONJ occurrence in patients with RA in order to obtain an average duration. A bibliographic search in the PubMed/Medline database was carried out using the following equation "(osteonecrosis and jaw) and rheumatoid arthritis" with no time limitation. The primary study endpoint was the duration of treatment with bisphosphonates (BP) at the time of ONJ onset in patients with RA. Twelve articles accounting for 50 patients were included. Patients had had a median of 46.8 months of treatment with BP before ONJ occurred. Mean, minimum and maximum treatment times were 48.68, 6 and 120 months, respectively. The standard deviation was 27.77 months. The median treatment duration in our cohort of patients with RA was less than that reported for osteoporosis. We therefore, recommend that practitioners take additional precautions regarding oral surgery or implant procedures, particularly in patients with RA who have been treated with BP for more than 4 years. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study.

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Siddiqi, A; Duncan, W J; De Silva, R K; Zafar, S

2016-01-01

Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) ( p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) ( p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions.

Impact of bisphosphonate-related osteonecrosis of the jaw on osteoporotic patients after dental extraction: a population-based cohort study.

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Yi Fang Huang

Full Text Available Little is currently known about the risk of developing bisphosphonate-related osteonecrosis of the jaw (BRONJ. This study sought to determine the incidence of BRONJ in osteoporotic patients. We also sought to identify the nature and types of risk factors of osteonecrosis of jaw (ONJ related to the use of oral bisphosphonates (BPs.Data from the National Health Insurance system of Taiwan. This cohort study included 19,399 adult osteoporosis patients received dental extraction in 2000-2010 (osteoporosis cohort and 38,669 age and gender matched comparisons selected from dental extraction people without osteoporosis and osteonecrosis history (comparison cohort. All study subjects were followed from the date of their dental extraction (index date to the development of ONJ and were included in the study up to 2011 or were lost to the study, whichever occurred first. Cox proportional hazard regression was used to estimate the hazard ratio and 95% confidence intervals for the two cohorts.Patients with osteoporosis had a significantly higher risk to develop ONJ than healthy persons (adjusted HR, 2.05; 95% confidence interval, 1.58-2.65. The risk of ONJ increased with the severity of osteoporosis, no matter whether patient with cancer or not. A cumulative effect of dental extraction frequency may increase the risk of ONJ.We concluded that ONJ is caused by a number of factors. Osteoporosis and past dental history play the very important roles, while BPs play the synergistic effect.

Florid cemento-osseous dysplasia: review of an uncommon fibro-osseous lesion of the jaw with important clinical implications.

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Fenerty, Sarah; Shaw, Wei; Verma, Rahul; Syed, Ali B; Kuklani, Riya; Yang, Jie; Ali, Sayed

2017-05-01

Florid cemento-osseous dysplasia (FCOD) is a rare, benign, multifocal fibro-osseous dysplastic process affecting tooth-bearing areas of the jaw, characterized by replacement of normal trabecular bone with osseous tissue and dense acellular cementum in a fibrous stroma. It is one clinicopathologic variant in a spectrum of related non-neoplastic fibro-osseous lesions known as cemento-osseous dysplasias (CODs), thought to arise from elements of the periodontal ligament. Diagnosis primarily relies upon radiographic and clinical findings; unnecessary biopsy should be avoided, as inoculation with oral pathogens may precipitate chronic infection in these hypovascular lesions. Appropriate management of uncomplicated FCOD consists of periodic radiographic follow-up. Accordingly, it is important that both radiologists and clinicians performing endodontic interventions possess familiarity with this entity in order to prevent misdiagnosis and inappropriate intervention, which may result in a protracted clinical course. Lesions are usually asymptomatic in the absence of infection, typically discovered on routine dental radiographs or imaging performed for unrelated indications. Radiographically, the condition typically manifests as widespread non-expansile intraosseous masses of varying internal lucency and sclerosis that surround the root apices of vital teeth or edentulous areas in the posterior jaw. While all CODs share similar microscopic features, FCOD is distinguished by its multifocal distribution, involving two or more quadrants of the maxilla and mandible, often in a bilateral symmetric fashion. The vast majority of cases are sporadic, though few exhibit an autosomal dominant familial inheritance pattern. In this pictorial review, we discuss the radiologic characteristics of this entity, pertinent clinical and histologic features, differential diagnoses, and management options.

Role of Periapical Diseases in Medication-Related Osteonecrosis of the Jaws

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Nian Jing Rao

2017-01-01

Full Text Available Objective. The present study aimed to investigate the role of periapical diseases in inducing medication-related osteonecrosis of the jaws (MRONJ using an ovariectomized (OVX mice model. Materials and Methods. Twenty C57BL/6N female mice were randomly assigned to two groups. All mice were subjected to bilateral ovariectomy and then treated with oncologic dose of zoledronic acid (ZA or vehicle for twelve weeks. Eight weeks after commence of drug administration, a pulpal exposure (PE operation was performed on the first right lower molar to induce periapical periodontitis; the contralateral non-PE tooth was used as control. All animals were sacrificed four weeks after pulpal exposure, and the mandibles were harvested for radiological and histomorphometrical analysis. Results. Micro computed tomography (μ-CT examination demonstrated that periapical diseases significantly increased alveolar bone resorption, and the resorption was greatly attenuated by ZA treatment. Concurrent ZA therapy significantly increased bone density and histological osteocyte necrosis in the presence of periapical lesions. Conclusion. ZA treatment reduced bone absorption resulting from periapical disease but increased the risk of developing MRONJ in the ovariectomized mouse model.

Large number of ultraconserved elements were already present in the jawed vertebrate ancestor.

KAUST Repository

Wang, Jianli; Lee, Alison P; Kodzius, Rimantas; Brenner, Sydney; Venkatesh, Byrappa

2009-01-01

Stephen (2008) identified 13,736 ultraconserved elements (UCEs) in placental mammals and investigated their evolution in opossum, chicken, frog, and fugu. They found that there was a massive expansion of UCEs during tetrapod evolution and the substitution rate in UCEs showed a significant decline in tetrapods compared with fugu, suggesting they were exapted in tetrapods. They considered it unlikely that these elements are ancient but evolved at a higher rate in teleost fishes. In this study, we investigated the evolution of UCEs in a cartilaginous fish, the elephant shark and show that nearly half the UCEs were present in the jawed vertebrate ancestor. The substitution rate in UCEs is higher in fugu than in elephant shark, and approximately one-third of ancient UCEs have diverged beyond recognition in teleost fishes. These data indicate that UCEs have evolved at a higher rate in teleost fishes, which may have implications for their vast diversity and evolutionary success.

Large number of ultraconserved elements were already present in the jawed vertebrate ancestor.

KAUST Repository

Wang, Jianli

2009-03-01

Stephen (2008) identified 13,736 ultraconserved elements (UCEs) in placental mammals and investigated their evolution in opossum, chicken, frog, and fugu. They found that there was a massive expansion of UCEs during tetrapod evolution and the substitution rate in UCEs showed a significant decline in tetrapods compared with fugu, suggesting they were exapted in tetrapods. They considered it unlikely that these elements are ancient but evolved at a higher rate in teleost fishes. In this study, we investigated the evolution of UCEs in a cartilaginous fish, the elephant shark and show that nearly half the UCEs were present in the jawed vertebrate ancestor. The substitution rate in UCEs is higher in fugu than in elephant shark, and approximately one-third of ancient UCEs have diverged beyond recognition in teleost fishes. These data indicate that UCEs have evolved at a higher rate in teleost fishes, which may have implications for their vast diversity and evolutionary success.

Effect of occlusal contact stability on the jaw closing point during tapping movements.

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Nishigawa, Keisuke; Suzuki, Yoshitake; Ishikawa, Teruaki; Bando, Eiichi

2012-04-01

We studied the relationship between tapping point reproducibility and stability of occlusal contacts at maximum intercuspation. Tapping movements of 12 adult volunteers who had dentition with natural teeth were recorded, and distances between the tapping point (TP) and the intercuspal position (ICP) at the incisal point were calculated. Occlusal contacts at the ICP of individual subjects were also evaluated with black-colored silicone impression material. The correlation between TP-ICP distance and occlusal contact stability was studied. TP-ICP distance exhibited negative correlations with the total number of teeth showing occlusal contact at the ICP. Standard deviations of TP-ICP distance also negatively correlated with the extension of occlusal contact area over dentition. This finding indicates that occlusal contacts at the ICP affect the kinematic behavior of tapping movements. The results of this study also suggest that jaw movement data may provide useful clinical information for the evaluation of occlusal contact at ICP. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Intraosseous Benign Lesions of the Jaws: A Radiographic Study

International Nuclear Information System (INIS)

Javadian Langaroodi, Adineh; Lari, Sima Sadat; Shokri, Abbas; Hoseini Zarch, Seyed Hossein; Jamshidi, Shokofeh; Akbari, Peyman

2014-01-01

Benign maxillo-mandibular tumors and cysts, which are relatively common findings on radiographs, namely the ubiquitous panoramic view, have to be dealt with by dentists on a daily basis. The aim of this study is to evaluate the panoramic radiographic findings pertaining to benign and tumoral lesions in the maxilla and mandible. Applying a case series method, panoramic images of 61 patients with cysts, benign tumors and tumor-like lesions in the jaws who were referred to Hamedan dental school between 2009 and 2011 were evaluated by two radiologists. They were both blind to histopathological results as well as the objectives of our study. Lesions were assessed based on their location, periphery, internal structure and impaction on the surrounding structures. Then the obtained data were analyzed using descriptive tables. Cysts were mostly more common in men despite the equal propensity of both genders to benign tumors. In contrast, women showed a higher frequency of tumor-like lesions. The most common site of involvement was the posterior mandible, with peri-apical tooth lesions as the most prevalent dental association. Radiographically, what we most encountered was unilocular radiolucency pertaining to cysts and benign tumors; nevertheless, tumor-like lesions tended to present with a well-defined radiopacity. Despite its known shortcomings, like every other diagnostic tool, panoramic radiography can contribute to the early detection of maxillary/mandibular lesions that in turn enable the dentist to devise an appropriate treatment plan

Clinical experiences of implant-supported prostheses with laser-welded titanium frameworks in the partially edentulous jaw: a 5-year follow-up study.

Science.gov (United States)

Ortorp, A; Jemt, T

1999-01-01

Titanium frameworks have been used in the endentulous implant patient for the last 10 years. However, knowledge of titanium frameworks for the partially dentate patient is limited. To report the 5-year clinical performance of implant-supported prostheses with laser-welded titanium frameworks in the partially edentulous jaw. A consecutive group of 383 partially edentulous patients were, on a routine basis, provided with fixed partial prostheses supported by Brånemark implants in the mandible or maxilla. Besides conventional frameworks in cast gold alloy, 58 patients were provided with titanium frameworks with three different veneering techniques, and clinical and radiographic 5-year data were collected for this group. The overall cumulative survival rate was 95.6% for titanium-framework prostheses and 93.6% for implants. Average bone loss during the follow-up period was 0.4 mm. The most common complications were minor veneering fractures. Loose and fractured implant screw components were fewer than 2%. An observation was that patients on medications for cardiovascular problems may lose more implants than others (p laser-welded titanium frameworks was similar to that reported for conventional cast frames in partially edentulous jaws. Low-fusing porcelain veneers also showed clinical performance comparable to that reported for conventional porcelain-fused-to-metal techniques.

Parrotfish grazing ability: interspecific differences in relation to jaw-lever mechanics and relative weight of adductor mandibulae on an Okinawan coral reef

OpenAIRE

Nanami, Atsushi

2016-01-01

Parrotfishes (family Labridae: Scarini) are regarded to have important roles for maintaining the ecosystem balance in coral reefs due to their removal of organic matter and calcic substrates by grazing. The purpose of the present study was to clarify the interspecific differences in grazing ability of five parrotfish species (Chlorurus sordidus, C. bowersi, Scarus rivulatus, S. niger and S. forsteni) in relation to interspecific differences in jaw-lever mechanics and the relative weight of th...

Intraoperative efficiency of fluorescence imaging by Visually Enhanced Lesion Scope (VELscope) in patients with bisphosphonate related osteonecrosis of the jaw (BRONJ).

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Assaf, Alexandre T; Zrnc, Tomislav A; Riecke, Björn; Wikner, Johannes; Zustin, Jozef; Friedrich, Reinhard E; Heiland, Max; Smeets, Ralf; Gröbe, Alexander

2014-07-01

The purpose of this study was to determine the potential of tissue fluorescence imaging by using Visually Enhanced Lesion Scope (VELscope) for the detection of osteonecrosis of the jaw induced by bisphosphonates (BRONJ). We investigated 20 patients (11 females and 9 males; mean age 74 years, standard deviation ± 6.4 years), over a period of 18 month with the diagnosis of BRONJ in this prospective cohort study. All patients received doxycycline as a fluorescending marker for osseous structures. VELscope has been used intraoperatively using the loss of fluorescence to detect presence of osteonecrosis. Osseous biopsies were taken to confirm definite histopathological diagnosis of BRONJ in each case. Diagnosis of BRONJ was confirmed for every patient. In all patients except one, VELscope was sufficient to differentiate between healthy and necrotic bone by visual fluorescence retention (VFR) and visual fluorescence loss (VFL). 19 cases out of a total of 20 showed no signs of recurrence of BRONJ during follow-up (mean 12 months, range 4-18 months). VELscope examination is a suitable tool to visualize necrotic areas of the bone in patients with bisphosphonate related osteonecrosis of the jaw. Loss of fluorescence in necrotic bone areas is useful intraoperatively as a tool for fluorescence-guided bone resection with relevant clinical interpretation. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Effects of orthognathic surgery for class III malocclusion on signs and symptoms of temporomandibular disorders and on pressure pain thresholds of the jaw muscles.

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Farella, M; Michelotti, A; Bocchino, T; Cimino, R; Laino, A; Steenks, M H

2007-07-01

The aim of this longitudinal study was to determine the effects of orthognathic surgery on signs and symptoms of temporomandibular disorders (TMD) and on pressure pain thresholds (PPTs) of the jaw muscles. Fourteen consecutive class III patients undergoing pre-surgical orthodontic treatment were treated by combined Le Fort I osteotomy and bilateral sagittal ramus osteotomy. The clinical examination included the assessment of signs and symptoms of TMD and the assessment of PPTs of the masseter and temporalis muscles. Anamnestic, clinical and algometric data were collected during five sessions over a 1-year period. Seven out of 14 patients presented with disc displacement with reduction at baseline, whereas four patients (two of them were new cases) did so at the end of follow up (p>0.05). None of the patients were diagnosed with myofascial pain of the jaw muscles at the beginning or end of follow up. PPTs of the masseter and temporalis muscles did not change significantly from baseline values throughout the whole study period. The occurrence of signs and symptoms of TMD fluctuates with an unpredictable pattern after orthognathic surgery for class III malocclusions.

Emergence of the acute-phase protein hemopexin in jawed vertebrates.

Science.gov (United States)

Dooley, Helen; Buckingham, E Bryan; Criscitiello, Michael F; Flajnik, Martin F

2010-01-01

When released from damaged erythrocytes free heme not only provides a source of iron for invading bacteria but also highly toxic due to its ability to catalyze free radical formation. Hemopexin (Hx) binds free heme with very high-affinity and thus protects against heme toxicity, sequesters heme from pathogens, and helps conserve valuable iron. Hx is also an acute-phase serum protein (APP), whose expression is induced by inflammation. To date Hx has been identified as far back in phylogeny as bony fish where it is called warm-temperature acclimation-related 65 kDa protein (WAP65), as serum protein levels are increased at elevated environmental temperatures as well as by infection. During analysis of nurse shark (Ginglymostoma cirratum) plasma we isolated a Ni(2+)-binding serum glycoprotein and characterized it as the APP Hx. We subsequently cloned Hx from nurse shark and another cartilaginous fish species, the little skate Leucoraja erinacea. Functional analysis showed shark Hx, like that of mammals, binds heme but is found at unusually high levels in normal shark serum. As an Hx orthologue could not be found in the genomes of jawless vertebrates or lower deuterostomes it appears to have arisen just prior to the emergence of jawed vertebrates, coincident with the second round of genome-wide duplication and the appearance of tetrameric hemoglobin (Hb). Copyright © 2010 Elsevier Ltd. All rights reserved.

Dental extraction following zoledronate, induces osteonecrosis in rat's jaw.

Science.gov (United States)

Vidal-Gutiérrez, X; Gómez-Clavel, J-F; Gaitán-Cepeda, L-A

2017-03-01

Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) is clinically characterized by the presence of exposed bone in the oral cavity that persists for more than eight weeks. Previous attempts to establish an animal model have not sufficiently considered disease features. Our aim was to establish an inexpensive and replicable animal model that develops BRONJ in a short time. Thirty-two male Wistar rats were randomly divided into two groups: control and experimental. In the experimental group, we administered 0.06mg/kg intraperitoneal dose of zoledronic acid (ZA) 7 and 14 days prior to maxillary second molar extraction. At two, four and six weeks after tooth extraction, the animals were euthanized, and we dissected the maxilla following histological procedures. We stained serial slides with hematoxylin and eosin and Masson's trichrome. The samples were harvested for macroscopic, radiologic and histological evaluation of bone changes. At two weeks postextraction, we observed exposed necrotic bone in dental socket areas in experimental groups. Radiological analysis revealed osteolytic lesions accompanied by extensive destruction and sequestrum formation in the same group. Histological examination confirmed the absence of necrotic bone in control groups in contrast with the experimental groups. The percentage of empty lacunae and the number of osteoclasts and the necrotic bone area were significantly increased (p<0.05) in the experimental groups. The animal model using ZA administration to prior dental extraction successfully mimicked human BRONJ lesions. Also, the model was easily replicated, inexpensive and showed different features than other previous BRONJ models.

Developmental and evolutionary significance of the mandibular arch and prechordal/premandibular cranium in vertebrates: revising the heterotopy scenario of gnathostome jaw evolution

Science.gov (United States)

Kuratani, Shigeru; Adachi, Noritaka; Wada, Naoyuki; Oisi, Yasuhiro; Sugahara, Fumiaki

2013-01-01

The cephalic neural crest produces streams of migrating cells that populate pharyngeal arches and a more rostral, premandibular domain, to give rise to an extensive ectomesenchyme in the embryonic vertebrate head. The crest cells forming the trigeminal stream are the major source of the craniofacial skeleton; however, there is no clear distinction between the mandibular arch and the premandibular domain in this ectomesenchyme. The question regarding the evolution of the gnathostome jaw is, in part, a question about the differentiation of the mandibular arch, the rostralmost component of the pharynx, and in part a question about the developmental fate of the premandibular domain. We address the developmental definition of the mandibular arch in connection with the developmental origin of the trabeculae, paired cartilaginous elements generally believed to develop in the premandibular domain, and also of enigmatic cartilaginous elements called polar cartilages. Based on comparative embryology, we propose that the mandibular arch ectomesenchyme in gnathostomes can be defined as a Dlx1-positive domain, and that the polar cartilages, which develop from the Dlx1-negative premandibular ectomesenchyme, would represent merely posterior parts of the trabeculae. We also show, in the lamprey embryo, early migration of mandibular arch mesenchyme into the premandibular domain, and propose an updated version of the heterotopy theory on the origin of the jaw. PMID:22500853

On the role of periodic structures in the lower jaw of the atlantic bottlenose dolphin (Tursiops truncatus)

International Nuclear Information System (INIS)

Dible, S A; Flint, J A; Lepper, P A

2009-01-01

This paper proposes the application of band-gap theory to hearing in the atlantic bottlenose dolphin (Tursiops truncatus). Using the transmission line modelling (TLM) technique and published computed tomography (CT) data of an atlantic bottlenose dolphin (Tursiops truncatus), a series of sound propagation experiments have been carried out. It is shown that the teeth in the lower jaw can be viewed as a periodic array of scattering elements which result in the formation of an acoustic stop band (or band gap) that is angular dependent. It is shown through simple and complex geometry simulations that performance enhancements such as improved gain and isolation between the two receive paths can be achieved. This mechanism has the potential to be exploited in direction-finding sonar

On the role of periodic structures in the lower jaw of the atlantic bottlenose dolphin (Tursiops truncatus)

Energy Technology Data Exchange (ETDEWEB)

Dible, S A; Flint, J A; Lepper, P A [Electronic and Electrical Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom)], E-mail: james.flint@ieee.org

2009-03-01

This paper proposes the application of band-gap theory to hearing in the atlantic bottlenose dolphin (Tursiops truncatus). Using the transmission line modelling (TLM) technique and published computed tomography (CT) data of an atlantic bottlenose dolphin (Tursiops truncatus), a series of sound propagation experiments have been carried out. It is shown that the teeth in the lower jaw can be viewed as a periodic array of scattering elements which result in the formation of an acoustic stop band (or band gap) that is angular dependent. It is shown through simple and complex geometry simulations that performance enhancements such as improved gain and isolation between the two receive paths can be achieved. This mechanism has the potential to be exploited in direction-finding sonar.

Dentoalveolar trauma and minor trauma as precipitating factors for medication-related osteonecrosis of the jaw (ONJ)

DEFF Research Database (Denmark)

Yazdi, Pouya Masroori; Schiodt, Morten

2015-01-01

OBJECTIVE: Medication-related osteonecrosis of the jaw (ONJ) is often preceded by dentoalveolar trauma. The aim of this study was to examine the frequency of dentoalveolar trauma precipitated ONJ and compare trauma-precipitated ONJ with spontaneously developing ONJ. STUDY DESIGN......: This was a retrospective study. All patients were examined according to a standard ONJ chart. RESULTS: Among 149 consecutive ONJ patients from the Copenhagen Cohort, 95 (64%) had a dentoalveolar trauma before referral (trauma group): dental extractions (n = 80); denture-related sore mouth (n = 12); and others (n = 3......). The remaining 54 patients had spontaneous ONJ (spontaneous group). The mean time from oral trauma to referral for ONJ was 8 months. CONCLUSION: This study documented that dentoalveolar trauma precipitated ONJ in the majority of cases. However, even minor trauma, such as intubation and impression tray lesions...

A mono isocentric radiotherapy technique for craniospinal irradiation using asymmetric jaws

International Nuclear Information System (INIS)

Isin, G; Oezyar, E.; Guerdalli, S.; Arslan, G.; Uzal, D.; Atahan, I. L.

1995-01-01

Dose distribution across the junction of matching of craniospinal fields (lateral cranial fields and posterior spinal field) is important as severe complications may result if the beams overlap or disease may recurs if the gapping is too conservative. Various techniques have been used to achieve an effective transverse plane match and half-beam block technique is one of these techniques. Here, we describe a mono isocentric technique for the treatment of craniospinal fields using the asymmetric jaws of our linear accelerator (Philips SL-25). Before the clinical application of this non-standard technique, basic dosimetry parameters are evaluated. Asymmetric collimator dose distributions for various asymmetric field sizes were obtained and compared with symmetric dose distributions for 6 MV x-ray. A computerized 3-D water phantom with a pair of ionization chambers (reference and field) was used for dose profiles, isodose distributions and Percentage Depth Dose (PDD) for various asymmetric field sizes and different off axis distances. The measured values of off axis ratios for the interested depths were used in MU calculations. This new mono isocentric technique provides an ideal dose distribution at match-line as there is no need to move the patient during treatment. Use of heavy secondary cerrobend blocks (beam splitters) is eliminated. This technique provides the ease of consequent daily set-up's and fulfills the requirements for a conformal radiotherapy

Bisphosphonates and oral pathology II. Osteonecrosis of the jaws: review of the literature before 2005.

Science.gov (United States)

Estefanía Fresco, Ruth; Ponte Fernández, Ruth; Aguirre Urizar, José Manuel

2006-11-01

Bisphosphonates are bone-turnover modulating drugs which are used in the management of a number of bone diseases ranging from osteoporosis to neoplasic pathology-associated osteolysis. In the last years a number of cases of osteonecrosis of the jaws associated with these drugs have been reported. In this review we analyze the cases published in the literature indexed from 2003 to December 2005. During this period 246 cases were reported, being more frequently associated with women in the sixth decade of life. More frequently associated bisphosphonates were the nitrogenated bisphosphonates (pamidronate, zolendronic acid) and the most common oral antecedent was a dental extraction. Nevertheless more than 25% of the cases were spontaneous. The most frequent site was the mandible and most of the cases presented clinical evidence of bone exposure and pain. Different treatments have been proposed with different antibiotic therapies with or without surgery, showing in general terms an uncertain prognosis with low healing rates.

Treatment of hemimandibular paresthesia in a patient with bisphosphonate-related osteonecrosis of the jaw (BRONJ) by combining surgical resection and PRGF-Endoret.

Science.gov (United States)

Anitua, E; Begoña, L; Orive, G

2013-12-01

We report a case of a 50-year-old patient with bisphosphonate-related osteonecrosis of the jaws (BRONJs) whose symptoms included severe pain and hemimandibular paraesthesia. The treatment included resection of necrotic bone and the application of plasma rich in growth factors (PRGF(®)-Endoret(®)). We closed the ulcer in the soft tissue and her pain and paraesthesia improved. One year postoperatively sensitivity was totally recovered, pain was absent and bone was partially regenerated. Copyright © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Dosimetric Comparison of Split Field and Fixed Jaw Techniques for Large IMRT Target Volumes in the Head and Neck

International Nuclear Information System (INIS)

Srivastava, Shiv P.; Das, Indra J.; Kumar, Arvind; Johnstone, Peter A.S.

2011-01-01

Some treatment planning systems (TPSs), when used for large-field (>14 cm) intensity-modulated radiation therapy (IMRT), create split fields that produce excessive multiple-leaf collimator segments, match-line dose inhomogeneity, and higher treatment times than nonsplit fields. A new method using a fixed-jaw technique (FJT) forces the jaw to stay at a fixed position during optimization and is proposed to reduce problems associated with split fields. Dosimetric comparisons between split-field technique (SFT) and FJT used for IMRT treatment is presented. Five patients with head and neck malignancies and regional target volumes were studied and compared with both techniques. Treatment planning was performed on an Eclipse TPS using beam data generated for Varian 2100C linear accelerator. A standard beam arrangement consisting of nine coplanar fields, equally spaced, was used in both techniques. Institutional dose-volume constraints used in head and neck cancer were kept the same for both techniques. The dosimetric coverage for the target volumes between SFT and FJT for head and neck IMRT plan is identical within ±1% up to 90% dose. Similarly, the organs at risk (OARs) have dose-volume coverage nearly identical for all patients. When the total monitor unit (MU) and segments were analyzed, SFT produces statistically significant higher segments (17.3 ± 6.3%) and higher MU (13.7 ± 4.4%) than the FJT. There is no match line in FJT and hence dose uniformity in the target volume is superior to the SFT. Dosimetrically, SFT and FJT are similar for dose-volume coverage; however, the FJT method provides better logistics, lower MU, shorter treatment time, and better dose uniformity. The number of segments and MU also has been correlated with the whole body radiation dose with long-term complications. Thus, FJT should be the preferred option over SFT for large target volumes.

Validity of linear measurements of the jaws using ultralow-dose MDCT and the iterative techniques of ASIR and MBIR.

Science.gov (United States)

Al-Ekrish, Asma'a A; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Widmann, Gerlig

2016-10-01

To assess the comparability of linear measurements of dental implant sites recorded from multidetector computed tomography (MDCT) images obtained using standard-dose filtered backprojection (FBP) technique with those from various ultralow doses combined with FBP, adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR) techniques. The results of the study may contribute to MDCT dose optimization for dental implant site imaging. MDCT scans of two cadavers were acquired using a standard reference protocol and four ultralow-dose test protocols (TP). The volume CT dose index of the different dose protocols ranged from a maximum of 30.48-36.71 mGy to a minimum of 0.44-0.53 mGy. All scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Linear measurements were recorded from standardized images of the jaws by two examiners. Intra- and inter-examiner reliability of the measurements were analyzed using Cronbach's alpha and inter-item correlation. Agreement between the measurements obtained with the reference-dose/FBP protocol and each of the test protocols was determined with Bland-Altman plots and linear regression. Statistical significance was set at a P-value of 0.05. No systematic variation was found between the linear measurements obtained with the reference protocol and the other imaging protocols. The only exceptions were TP3/ASIR-50 (bone kernel) and TP4/ASIR-100 (bone and standard kernels). The mean measurement differences between these three protocols and the reference protocol were within ±0.1 mm, with the 95 % confidence interval limits being within the range of ±1.15 mm. A nearly 97.5 % reduction in dose did not significantly affect the height and width measurements of edentulous jaws regardless of the reconstruction algorithm used.

Evaluation of the accuracy of panoramic radiography in linear measurements of the jaws

International Nuclear Information System (INIS)

Hoseini, S. H.; Bagherpour, A.; Javadian Langaroodi, A.; Ahmadian Yazdi, A.; Safaei, A.

2011-01-01

Panoramic radiography has a great place among imaging techniques because of its enormous advantages. One of the characteristics of an ideal imaging technique is to supply precise measurement. The purpose of the current study was to evaluate the accuracy of linear measurements of the jaws on panoramic radiographs. Patients and Methods: In this study, the vertical distances between the metal markers were measured by panoramic radiography in seven sites of two skulls in various head positions. Then the radiographic measurements were compared with the actual values. Results: Eighty three percent of the measurements were underestimated, 8.5% were overestimated on panoramic radiography and 8.5% of the measurements had no difference with the real measurements. Overestimation was not greater than 1 mm. The difference between actual and radiographic measurements was less in the posterior areas and in the mandible . In all head positions, the greatest difference between actual and radiographic measurements occurred in the anterior area. Conclusion: Based on the results of this study, linear measurements on panoramic radiography are more reliable in the posterior areas and may be used in early clinical measurements.

Dental implants for severely atrophied jaws due to ectodermal dysplasia

Directory of Open Access Journals (Sweden)

Preetha Balaji

2015-01-01

Full Text Available The aim was to present the successful esthetical and functional rehabilitation of partial anodontia in a case of severe ectodermal dysplasia with complete atrophy of the jaws. A 17-year-old male with Class III malocclusion with partial anodontia sought dental implant treatment. His expectation was that of Class I occlusion. The challenge in the case was to match the expectation, reality, and the clinical possibilities. Ridge augmentation was performed with a combination of rib graft and recombinant human bone morphogenetic protein-2. Simultaneously, 6 implants (Nobel Biocare™ - Tapered Groovy were placed in maxillary arch and 10 in the mandible. Simultaneous placement ensured faster and better osseointegration though a mild compromise of the primary stability was observed initially. After adequate healing, Customized Zirconia Procera™ system was used to build the framework. Zirconia crown was cemented to the framework. Radiological and clinical evidence of osseointegration was observed in all 16 dental implants. Successful conversion of Class III to Class I occlusion was achieved with the combination of preprosthetic alveolar ridge augmentation, Procera™ Implant Bridge system. Abnormal angulations and or placement of dental implants would result in failure of the implant. Hence conversion of Class III to Class I occlusion needs complete and complex treatment planning so that the entire masticatory apparatus is sufficiently remodeled. Planning should consider the resultant vectors that would otherwise result in failure of framework or compromise the secondary stability of the dental implant during function. A successful case of rehabilitation of complex partial anodontia is presented.

Mouse preferential incising force orientation changes during jaw closing muscle hyperalgesia and is sex dependent.

Science.gov (United States)

Widmer, C G; Morris-Wiman, J

2016-12-01

Mouse incising is controlled by a central pattern generator and this activity can change in the presence of pain. The incising frequency and maximum force generation decreases with pain. In this study, we used repetitive acidic injections in the left masseter muscle of male and female mice to determine differences between baseline and jaw muscle pain conditions and the effect of sex on preferential incising direction. A within subject design was used to evaluate data previously acquired using multi-axis force data (X, Y and Z) from the 4th baseline recording day and day 7 post-injection (day of maximal pain response) for each mouse of each sex. A total of 34 female and male (age 3-9months) CD-1 mice were evaluated. After mathematically rotating the X and Y axes to align the Y axis to be parallel to the wire struts of the cage top, data were analyzed to determine incising direction preference during baseline (non-pain) and pain (day 7) conditions and between sex. Radar plots of X-Y, X-Z and Y-Z axes depicted the average direction of incising preference between baseline and pain conditions for each sex. Statistical differences among groups were tested using a mixed model ANOVA. Similar to previous findings, female mice had a more robust difference in incising direction preference when comparing male and female pain conditions and this was most evident in the X-Z axes. The incising frequencies most commonly affected were 5.3, 6.2 and 7.6Hz. Male mice varied little in their incising direction preference between the baseline and pain conditions. In addition, statistical comparison of ratios of the percent of time spent incising in the Z versus X axes for each incising frequency found that the incising preference was not different when comparing 5.3 and 7.6Hz frequencies. Finally, female mice used a novel approach to minimize pain while incising by rotating their head and body nearly 180 degrees while males did not use this strategy as frequently. The preferred incising

The Effect of early physiotherapy on the recovery of mandibular function after orthognathic surgery for Class III correction: part I--jaw-motion analysis.

Science.gov (United States)

Teng, Terry Te-Yi; Ko, Ellen Wen-Ching; Huang, Chiung Shing; Chen, Yu-Ray

2015-01-01

The aim of this prospective study was to compare the mandibular range of motion in Class III patients with and without early physiotherapy after orthognathic surgery (OGS). This study consisted of 63 Class III patients who underwent 2-jaw OGS. The experimental group comprised 31 patients who received early systematic physical rehabilitation. The control group consisted of 32 patients who did not have physical rehabilitation. Twelve variables of 3-dimensional (3D) jaw-motion analysis (JMA) were recorded before surgery (T1) and 6 weeks (T2) and 6 months (T3) after surgery. A 2-sample t test was conducted to compare the JMA results between the two groups at different time points. At T2, the JMA data were measured to be 77.5%-145.7% of presurgical values in the experimental group, and 60.3%-90.6% in the control group. At T3, the measurements were 112.2%-179.2% of presurgical values in the experimental group, and 77.6%-157.2% in the control group. The patients in the experimental group exhibited more favorable recovery than did those in the control group, from T1 to T2 and T1 to T3. However, after termination of physiotherapy, no significant difference in the extent of recovery was observed between groups up to 6 months after OGS. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Primary chronic osteomyelitis of the jaw--a microbial investigation using cultivation and DNA analysis: a pilot study.

Science.gov (United States)

Frid, Paula; Tornes, Knut; Nielsen, Øyunn; Skaug, Nils

2009-05-01

The aims of this study were to investigate the infectious etiology of primary chronic osteomyelitis (PCO) of the jaw using an extraoral sampling approach and molecular methods. In this pilot study, bone biopsies from the mandibles of 5 patients with PCO were sampled with an extraoral sterile approach. Cultivation and polymerase chain reaction (PCR) were performed. Two of the biopsies yielded growth of Propionebacterium acnes. One biopsy also demonstrated Staphylococcus capitis. The biopsies with bacterial growth were also positive for the same bacteria by PCR analysis. No specific bacterial etiology was demonstrated. However, the results of bacterial cultivation and PCR analysis were in agreement. Based on these findings, the molecular procedure used in this study can be considered to be suitable for identification of bacterial specimens in mandibular biopsies. Further studies are needed with larger patient populations to confirm these findings.

Dental-CT and pathologic conditions of the jaw; Dental-CT bei pathologischen Veraenderungen im Bereich des Kiefers

Energy Technology Data Exchange (ETDEWEB)

Abrahams, J.J. [Yale Univ., New Haven, CT (United States). Dept. of Diagnostic Radiology

1999-12-01

CT with multiplanar reconstruction of the jaws (DentaScan{sup TM}) is the method of choice for the radiographic assessment of the mandible and maxilla. It is instrumental in delineating the relationship between bony lesions and the adjacent anatomy. Therefore, this technique allows precise evaluation of the intricate details of the oral cavity. Using it, distinct characterization of pathology including infectious, metabolic, congenital and neoplastic lesions can be obtained. (orig.) [German] Die CT mit multiplanarer Rekonstruktion des Kiefers (Dental-CT/Denta-Scan{sup TM}) ist die Methode der Wahl zur radiologischen Untersuchung der Mandibula und Maxilla. Sie ist insbesondere bei der Abgrenzung knoecherner Laesionen von benachbarten anatomischen Strukturen hilfreich. Daher erlaubt diese Technik eine praezise Evaluation der komplizierten Details der Mundhoehle. Durch die Verwendung dieser Technik wird eine genaue Charakterisierung von Pathologien, unter Einschluss infektioeser, metabolischer, kongenitaler und neoplastischer Laesionen ermoeglicht. (orig.)

Design and methods for a Scandinavian pharmacovigilance study of osteonecrosis of the jaw and serious infections among cancer patients treated with antiresorptive agents for the prevention of skeletal-related events

DEFF Research Database (Denmark)

Acquavella, John; Ehrenstein, Vera; Schiødt, Morten

2016-01-01

OBJECTIVE: Osteonecrosis of the jaw (ONJ) is a recognized complication of potent antiresorptive therapies, especially at the doses indicated to prevent skeletal complications for cancer patients with bone metastases. This paper describes the rationale and methods for a prospective, post-authoriza......OBJECTIVE: Osteonecrosis of the jaw (ONJ) is a recognized complication of potent antiresorptive therapies, especially at the doses indicated to prevent skeletal complications for cancer patients with bone metastases. This paper describes the rationale and methods for a prospective, post...... (120 mg subcutaneously) or zoledronic acid (4 mg intravenously, adjusted for renal function). Patients will be identified using routinely collected data combined with medical chart review in Denmark, Sweden, and Norway. Followup will extend from the first administration of antiresorptive treatment...... to the earliest of death, loss-to-follow-up, or 5 years after therapy initiation. Results will be reported for three treatment cohorts: denosumab-naïve patients, zoledronic acid-naïve patients, and patients who switch from bisphosphonate treatment to denosumab. ONJ cases will be identified in three newly...

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication.

Science.gov (United States)

Giurgea, Georgiana-Aura; Haumer, Markus; Mlekusch, Irene; Sabeti-Sandor, Schila; Dick, Petra; Schillinger, Martin; Minar, Erich; Mlekusch, Wolfgang

2017-07-01

We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication. Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls. A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls. Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

Algorithm for planning a double-jaw orthognathic surgery using a computer-aided surgical simulation (CASS) protocol. Part 1: planning sequence

Science.gov (United States)

Xia, J. J.; Gateno, J.; Teichgraeber, J. F.; Yuan, P.; Chen, K.-C.; Li, J.; Zhang, X.; Tang, Z.; Alfi, D. M.

2015-01-01

The success of craniomaxillofacial (CMF) surgery depends not only on the surgical techniques, but also on an accurate surgical plan. The adoption of computer-aided surgical simulation (CASS) has created a paradigm shift in surgical planning. However, planning an orthognathic operation using CASS differs fundamentally from planning using traditional methods. With this in mind, the Surgical Planning Laboratory of Houston Methodist Research Institute has developed a CASS protocol designed specifically for orthognathic surgery. The purpose of this article is to present an algorithm using virtual tools for planning a double-jaw orthognathic operation. This paper will serve as an operation manual for surgeons wanting to incorporate CASS into their clinical practice. PMID:26573562

Effects of orthognathic surgery on psychological status of patients with jaw deformities.

Science.gov (United States)

Takatsuji, H; Kobayashi, T; Kojima, T; Hasebe, D; Izumi, N; Saito, I; Saito, C

2015-09-01

The purpose of this study was to determine the effect of orthognathic surgery on psychological status. The subjects were 119 patients (38 males and 81 females, mean age 25.5±9.4 years) who underwent orthognathic surgery. They were divided into class III (84 patients), class II (20 patients), and class I (15 patients) groups according to the anteroposterior skeletal pattern, and they were also divided into an asymmetry group (51 patients) and a symmetry group (68 patients). We assessed psychological status using the Minnesota Multiphasic Personality Inventory (MMPI) before surgery and at more than 6 months after surgery. The MMPI scores for the depression, hysteria, psychasthenia, and social introversion scales were significantly higher than standard values before surgery, and the hypomania scale significantly lower. The cannot say scale, depression scale, and hysteria scale decreased significantly after surgery. A comparison of MMPI scores among the groups showed the depression scale in the class III group to be higher than those in the class I and II groups; there was no significant difference between the asymmetry and symmetry groups. In conclusion, orthognathic surgery has a positive influence on the psychological status of patients with jaw deformities, especially patients with skeletal class III malocclusion. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Bisphosphonate-associated osteonecrosis of jaw reoccurrence after methotrexate therapy: a case report.

Science.gov (United States)

Alsalleeh, Fahd; Keippel, Jeffery; Adams, Lyde; Bavitz, Bruce

2014-09-01

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a well-known complication caused by amino-bisphosphonate therapy. We document one case of BRONJ associated with oral administration of methotrexate, a known immunosuppressive drug used to treat rheumatoid arthritis. A 66-year-old woman was referred for evaluation and endodontic surgery of recently re-treated tooth 13. Tooth 14 was extracted 3 months prior, and the extraction site had not completely healed. Her medical history revealed rheumatoid arthritis and osteoporosis. She had been taking Fosamax (alendronate) 70 mg daily. Because of adequate root canal therapy of tooth 13, endodontic surgery was performed. Five months after apicoectomy, her symptoms had not changed. Tooth 13 was extracted, and the socket healed without complications. The socket of extracted tooth 14 was also healing. At the 3-month recall visit, bone exposure and purulent discharge at the site of extracted tooth 14 were noted. The patient had recently received methotrexate. The methotrexate was discontinued, and she was given course of amoxicillin. At the 18-month follow-up, the healing progressed, and the wound was closed. A medication that suppresses the immune system such as methotrexate may complicate the management of BRONJ. Once a diagnosis of BRONJ is made, a closely monitored conservative approach is recommended. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Tumor suppressor gene mutation in a patient with a history of hyperparathyroidism-jaw tumor syndrome and healed generalized osteitis fibrosa cystica: a case report and genetic pathophysiology review.

Science.gov (United States)

Parfitt, Joshua; Harris, Malcolm; Wright, John M; Kalamchi, Sabah

2015-01-01

Hyperparathyroidism-jaw tumor (HPT-JT) was first observed by Jackson in 1958 in a family who exhibited hyperparathyroidism and recurrent pancreatitis. The author noticed the presence of jaw tumors in the affected family and reported them as fibrous dysplasia. However, it was not until 1990 that a familial variety of hyperparathyroidism with fibro-osseous jaw tumors was recognized as HPT-JT syndrome and reported as a clinically and genetically distinct syndrome. Hyperparathyroidism generally arises from glandular hyperplasia or parathyroid adenomas, with only about 1% of cases resulting from parathyroid carcinoma. However, parathyroid carcinoma develops in about 15% of HPT-JT patients. The true incidence of HPT-JT is unknown, although the prevalence of about 100 published cases suggests its rarity. Twenty percent of HPT-JT cases have renal hamartomas or tumors, and female patients with HPT-JT have been reported to have carcinoma of the uterus. This syndrome appears to arise from a variety of mutations that deactivate the tumor suppressor gene CDC73 (also known as HRPT2) and its production of the tumor suppressor protein parafibromin. Functional parafibromin has 531 amino acids, and mutations result in a short nonfunctional protein. CDC73 disorders exhibit dominant germline gene behavior, with varying degrees of penetration. In most cases an affected person has 1 parent with the condition, which raises the need for family investigation and genetic counseling. We report a case of HPT-JT syndrome in a male patient who presented to the local community hospital 6 years previously with a history of back pain. Investigations showed elevated serum parathyroid hormone and calcium levels, and a technetium 99m sestamibi parathyroid scan showed increased activity at the site of the lower left gland that proved to be a substernal parathyroid carcinoma. The patient's parathyroid hormone level dropped from 126 to 97 pg/mL at 5 minutes and was 65 pg/mL at 10 minutes after excision

Recurrent hyperparathyroidism and a novel nonsense mutation in a patient with hyperparathyriodism-jaw tumor syndrome.

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Abdulla, Amer G; O'Leary, Erin M; Isorena, Jennifer P; Diaz, Miguel Fernando Palma; Yeh, Michael W

2013-01-01

To present the case of a hyperparathyroidism-jaw tumor (HPT-JT) patient with a novel nonsense mutation of the CDC73 gene. We present the case of a patient with a history of three prior maxillectomies and two prior parathyroidectomies who presented with recurrent primary hyperparathyroidism (PHPT). We also briefly review the literature pertaining to HPT-JT. Genetic analysis revealed a novel nonsense mutation (c.85G>T; pGlu29) in exon 1 of CDC73. The patient's son underwent genetic testing for a CDC73 mutation and was found to be negative. HPT-JT is a rare condition characterized by PHPT and benign tumors of the mandible and maxilla. Up to 15% of HPT-JT patients with PHPT have parathyroid carcinoma. HPT-JT is associated with an inactivating mutation of CDC73, a gene that codes for the tumor suppressor protein parafibromin. This report expands our understanding of the genetics underlying this rare disorder and emphasizes the importance of early detection in order to prevent hypercalcemic complications such as parathyroid carcinoma.

The clinical and radiologic consideration of cementifying and ossifying fibroma of the jaws

International Nuclear Information System (INIS)

Jo, Eun Young; Kim, Kee Deog; Park, Chang Seo

1997-01-01

The purpose of this study was to know the proper diagnosis and to establish the treatment plan of cementifying and ossifying fibroma in the jaws through the clinical, radiological, and histopathologic considerations. The authors compared and analyzed the clinicoradiologic features of the thirteen cases of cementifying and ossifying fibroma, diagnosed at the Dental college hospital in Yonsei university, Seoul, Korea, during the period from 1980 to 1995. The obtained results were as follows : 1. Cementifying and ossifying fibroma occurred in the mean age, 44 years, ranged from 29 to 65 years and the male to female ratio was approximately 1:5. 2. Swelling was the most common frequent presenting complaints. Other reported symptoms included pain, tooth mobility and symptom. 3. The frequency of the lesions was twelve cases in the mandible and one case in the maxilla. And eleven of thirteen cases were distributed on the premolar and molar region. 4. Radiologically, eight of thirteen cases were well defined lesions, five cases were relatively well defined lesions. And nine of thirteen cases were mixed lesions, three cases were radiopaque lesions, and only one case was purely radiolucent lesion. 5. Histologically, seven of thirteen cases were classified ossifying fibroma, four cases were cemento-ossifying fibroma, and two cases were cementifying fibroma.

Bisphosphonate-Related Osteonecrosis of the Jaws. A Severe Side Effect of Bisphosphonate Therapy

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Zuzana Janovská

2012-01-01

Full Text Available Bisphosphonates (BP are potent inhibitors of bone resorption used mainly in the treatment of metastatic bone disease and osteoporosis. By inhibiting bone resorption, they prevent complications as pathological fracture, pain, tumor-induced hypercalcemia. Even though patient’s benefit of BP therapy is huge, various side effects may develop. Bisphosphonate-related osteonecrosis of the jaws (BRONJ is among the most serious ones. Oncologic patients receiving high doses of BP intravenously are at high risk of BRONJ development. BPs impair bone turnover leading to compromised bone healing which may result in the exposure of necrotic bone in the oral cavity frequently following tooth extraction or trauma of the oral mucosa. Frank bone exposure may be complicated by secondary infection leading to osteomyelitis development with various symptoms and radiological findings. In the management of BRONJ, conservative therapy aiming to reduce the symptoms plays the main role. In patients with extensive bone involvement resective surgery may lead to complete recovery, provided that the procedure is correctly indicated. Since the treatment of BRONJ is difficult, prevention is the main goal. Therefore in high risk patients dental preventive measures should be taken prior to bisphosphonate administration. This requires adequate communication between the prescribing physician, the patient and the dentist.

The impact of functional jaw orthopedics in subjects with unfavorable Class II skeletal patterns.

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Baccetti, Tiziano; McNamara, James A

2010-01-01

To evaluate the outcomes of functional jaw orthopedics (FJO) followed by fixed appliances in Class II patients showing cephalometric signs predictive of unfavorable responsiveness to orthopedic treatment. A total of 48 treated subjects (20 males, 28 females) with unfavorable Class II malocclusions were treated with FJO at the adolescent growth spurt, followed by fixed appliances. Treatment outcomes were compared with the growth changes in a matched control group of untreated subjects with "unfavorable" Class II malocclusions. A significant prevalence rate of successful outcome was recorded within the treated group (64.5%). When compared with the untreated controls, both the overall treated group and the successful treated subgroup revealed a significant reduction in maxillary growth and sagittal position, along with a significant enhancement in mandibular length, sagittal advancement of the mandible, and significant improvements in the maxillo-mandibular relationships. Both overjet and molar relation showed significant favorable changes in the treated group. FJO at the pubertal spurt followed by fixed appliances is a viable therapeutical option in patients with "unfavorable" Class II malocclusions, although skeletal changes are of minor entity. Copyright © 2010 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.

Asymptomatic radiopaque lesions of the jaws. A radiographic study using cone-beam computed tomography

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Araki, Masao; Matsumoto, Naoyuki; Matsumoto, Kunihito; Ohnishi, Masaaki; Honda, Kazuya; Komiyama, Kazuo

2011-01-01

Panoramic radiography and cone-beam computed tomography (CT) were used to analyze asymptomatic radiopaque lesions in the jaw bones and determine the diagnostic relevance of the lesions based on their relationships to teeth and site of origin. One hundred radiopaque lesions detected between 1998 and 2002 were examined by both panoramic radiography and cone-beam CT. On the basis of panoramic radiographs, the region was classified as periapical, body, or edentulous, and the site was classified as molar or premolar. Follow-up data from medical records were available for only 36 of these cases. The study protocol for simultaneous use of cone-beam CT was approved by the ethics review board of our institution. A large majority of radiopaque lesions were observed in premolar and molar sites of the mandible; 60% of lesions were periapical, 24% were in the body, and 16% were in the edentulous region. An interesting type of radiopaque lesion, which we named a pearl shell structure (PSS), was observed on cone-beam CT in 34 of the 100 lesions. The PSS is a distinctive structure, and this finding on cone-beam CT likely represents the start of bone formation before bone sclerosis. (author)

Dental radiography: efficacy in the assessment of intraosseous lesions of the face and jaws in asymptomatic patients

International Nuclear Information System (INIS)

Zeichner, S.J.; Ruttimann, U.E.; Webber, R.L.

1987-01-01

In this investigation the efficacy of dental radiography for the detection of occult intraosseous lesions of the face and jaws was evaluated. An analysis of 30 million health insurance records indicated that the period prevalence of malignant lesions was less than 5 cases/million/year, and for benign lesions approximately 100 cases/million/year. Data from a controlled observer-performance study showed that radiographic sensitivities ranged between 50% and 80%. The cost per true-positive finding was estimated to be +8.6 million per malignant case and +430,000 per benign case. An assessment of the dosimetric literature indicated that the benefits of radiographic screening as a means for early detection of a malignancy appear to be counterbalanced by the risk of causing a radiation-induced malignancy. Taken together, these data demonstrate that dental radiography is not efficacious for the purpose of detecting occult lesions

A clinical and radiographic study of cystogenic ameloblastoma of the jaws

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Lee, Won Yeop; Park, Tae Won

1988-01-01

The purpose of this study is to investigate on the clinical and radiographic patterns of cystogenic ameloblastoma of the jaws. The author studied 64 cases of cystogenic ameloblastoma with regard to age, sex distribution, the side of the lesion and several radiographic features. The results were as follows: 1. The average age was found to be 23.0 years, with a range of 4 to 56 years. The incidence was highest in the second and third decades (72%) and total 64 cases consists of 36 males and 28 females. 2. Fifty-nine cases were found in mandible and 5 cases in maxilla. 3. The specific site distribution was found to be 57.8% ramus, coronoid process and condyle, 34.4% premolar-molar region, and 7.8% were located in mandibular symphysis bilaterally. 4. From the total 64 cases, 28 (44%) were associated with an impacted tooth, especially mandibular second and third molar, 36 (52%) failed to show any association with tooth impaction. It was found that the average age for impaction-associated tumors was 19.8% years, which was statistically significant. 5. Fifty-three (82%) cases showed unilocular radiolucencies, eleven (17%) cases showed multilocular radiolucencies. It was found that the average age for unilocular lesions was 22.3 years whereas lesions showing multilocularity occurred at an average age of 26.4 years, which was not statistically significant. 6. Of the 21 patients who had been followed for more than 2 years, only 4 patients treated by enucleation or curettage recurred (19% recurrence).

Repeated Evolution of Power-Amplified Predatory Strikes in Trap-Jaw Spiders.

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Wood, Hannah M; Parkinson, Dilworth Y; Griswold, Charles E; Gillespie, Rosemary G; Elias, Damian O

2016-04-25

Small animals possess intriguing morphological and behavioral traits that allow them to capture prey, including innovative structural mechanisms that produce ballistic movements by amplifying power [1-6]. Power amplification occurs when an organism produces a relatively high power output by releasing slowly stored energy almost instantaneously, resulting in movements that surpass the maximal power output of muscles [7]. For example, trap-jaw, power-amplified mechanisms have been described for several ant genera [5, 8], which have evolved some of the fastest known movements in the animal kingdom [6]. However, power-amplified predatory strikes were not previously known in one of the largest animal classes, the arachnids. Mecysmaucheniidae spiders, which occur only in New Zealand and southern South America, are tiny, cryptic, ground-dwelling spiders that rely on hunting rather than web-building to capture prey [9]. Analysis of high-speed video revealed that power-amplified mechanisms occur in some mecysmaucheniid species, with the fastest species being two orders of magnitude faster than the slowest species. Molecular phylogenetic analysis revealed that power-amplified cheliceral strikes have evolved four times independently within the family. Furthermore, we identified morphological innovations that directly relate to cheliceral function: a highly modified carapace in which the cheliceral muscles are oriented horizontally; modification of a cheliceral sclerite to have muscle attachments; and, in the power-amplified species, a thicker clypeus and clypeal apodemes. These structural innovations may have set the stage for the parallel evolution of ballistic predatory strikes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bisphosphonate-related osteonecrosis of the jaw in a multiple myeloma patient: A case report with characteristic radiographic features

International Nuclear Information System (INIS)

Lee, Byung Do; Kwon, Kyung Hwan; Park, Moo Rim

2015-01-01

A 59-year-old male who had suffered from multiple myeloma for nine years and had been administered bisphosphonates for seven years visited a dental hospital for pain relief due to extensive caries in his left maxillary molars. The molars were extracted, leaving an exposed wound for three months. The radiograph showed sequestra formation and irregular bone destruction in the left maxilla. Sudden pain and gingival swelling in the right mandibular molar area occurred six months later. The interseptum of the right lower second molar was observed to be necrotic during surgery. These findings coincided with the features of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this case, the long intravenous administration of bisphosphonates and tooth extraction were likely the etiologic factors of BRONJ in a patient with multiple myeloma; moreover, the bilateral occurrence of BRONJ is a characteristic feature

Bisphosphonate-related osteonecrosis of the jaw in a multiple myeloma patient: A case report with characteristic radiographic features.

Science.gov (United States)

Lee, Byung-Do; Park, Moo-Rim; Kwon, Kyung-Hwan

2015-09-01

A 59-year-old male who had suffered from multiple myeloma for nine years and had been administered bisphosphonates for seven years visited a dental hospital for pain relief due to extensive caries in his left maxillary molars. The molars were extracted, leaving an exposed wound for three months. The radiograph showed sequestra formation and irregular bone destruction in the left maxilla. Sudden pain and gingival swelling in the right mandibular molar area occurred six months later. The interseptum of the right lower second molar was observed to be necrotic during surgery. These findings coincided with the features of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this case, the long intravenous administration of bisphosphonates and tooth extraction were likely the etiologic factors of BRONJ in a patient with multiple myeloma; moreover, the bilateral occurrence of BRONJ is a characteristic feature.

Bisphosphonate-related osteonecrosis of the jaw in a multiple myeloma patient: A case report with characteristic radiographic features

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Lee, Byung Do; Kwon, Kyung Hwan [College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Park, Moo Rim [Dept. of Internal Medicine, School of Medicine, Wonkwang University, Iksan (Korea, Republic of)

2015-09-15

A 59-year-old male who had suffered from multiple myeloma for nine years and had been administered bisphosphonates for seven years visited a dental hospital for pain relief due to extensive caries in his left maxillary molars. The molars were extracted, leaving an exposed wound for three months. The radiograph showed sequestra formation and irregular bone destruction in the left maxilla. Sudden pain and gingival swelling in the right mandibular molar area occurred six months later. The interseptum of the right lower second molar was observed to be necrotic during surgery. These findings coincided with the features of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this case, the long intravenous administration of bisphosphonates and tooth extraction were likely the etiologic factors of BRONJ in a patient with multiple myeloma; moreover, the bilateral occurrence of BRONJ is a characteristic feature.

Surface electromyographic evaluation of jaw muscles in children with unilateral crossbite and lateral shift in the early mixed dentition. Sexual dimorphism

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Lenguas, Leticia; Alarcón, José-Antonio; Venancio, Filipa; Kassem, Marta

2012-01-01

Objectives: To examine the activity of jaw muscles at rest and during maximal voluntary clenching (MVC) in children with unilateral posterior crossbite (UPXB) and functional lateral shift in the early mixed dentition and to evaluate sex differences. Material and Methods: The sample included 30 children (15 males, 15 females) aged 6 to 10 years old, with UPXB and functional mandibular lateral shift (≥1.5 mm) in the early mixed dentition. sEMG activity coming from the muscle areas (anterior temporalis [AT], posterior temporalis [PT], masseter [MA] and suprahyoid [SH]) were obtained from both the crossbite (XB) and noncrossbite (NONXB) sides at mandibular rest position. sEMG acti-vity of the bilateral AT and MA muscles sides was obtained during MVC. Asymmetry and activity indexes were calculated for each muscle area at rest and during MVC; the MA/TA ratio during MVC was also determined. Results: At rest, no differences were found between sexes for any muscle areas or asymmetry and activity indexes. No differences were found between XB and NONXB sides. During MVC, however, significant sex differences were found in AT and MA activity, with higher sEMG values in males than in females, on both XB and NONXB sides. Asymmetry indexes, activity indexes and MA/AT ratios did not show significant differences between the sexes. Activity was symmetric both in males and in females. Conclusions: At rest, no sex differences were found, but during MVC males showed higher activity than did females in both XB and NONXB AT and MA muscle areas. Muscular activity was symmetrical at rest and during MVC in both sexes. Sexual dimorphism should be considered in the diagnosis and treatment of UPXB and lateral shift in the early mixed dentition. Key words:Unilateral crossbite, mandibular shift, jaw muscles, sEMG, early mixed dentition. PMID:22926468

Influence of the Lower Jaw Position on the Running Pattern.

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Christian Maurer

Full Text Available The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions.Twenty healthy young recreational runners (mean age = 33.9±5.8 years participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK. Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM were used for movement pattern identification.Subjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition.The influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be considered when choosing the

CONDUCTO ALVEOLAR INFERIOR. CORRELATO ANATOMO-IMAGENOLOGICO E IMPLICANCIA EN LOS PROCEDIMIENTOS QUIRURGICOS DE MANDIBULA. Inferior alveolar canal. Imaginological anatomical correlation and implication in jaw surgical procedures

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Andrés C Limardo

2016-03-01

Full Text Available Introducción: Las lesiones iatrogénicas del nervio dentario inferior son complicaciones documentadas de diversos procedimientos quirúrgicos en la mandíbula. Debido a ello se justifica una descripción más detallada con referencias morfométricas de dicho conducto, como así también una correlación con imágenes. Materiales y métodos: Se realizó un estudio descriptivo observacional con una muestra de 44 hemimandíbulas secas y 100 tomografías computadas de mandíbulas de pacientes al azar. Se realizaron mediciones del foramen mandibular y mentoniano con respecto a bordes mandibulares. Se hicieron cortes en la rama y el cuerpo con sus respectivas mediciones. Se utilizaron Tomografías Computadas Cone Beam 3D de 100 pacientes las cuales fueron procesadas por el programa Compudent Navigator 3D®. Utilizando este programa se pudieron realizar las mismas mediciones que en los preparados anatómicos, como así también la reconstrucción del conducto. En una segunda etapa se realizó una correlación entre los valores morfométricos del estudio anatómico y se comparó con los estudios por imágenes (TC con reconstrucción 3D Dental Scan. Resultados: Se expresaron en tablas con diversas variables. Discusión: Los textos clásicos de anatomía y los libros de cirugía de la especialidad describen en detalle el recorrido y las relaciones del CAI, y presentan datos morfométricos pero no lo hacen en poblaciones locales. Como conclusión podemos afirmar que, tomando como punto de partida la anatomía y correlacionándola con la imagenologia, podemos llegar a evitar lesiones del nervio alveolar inferior en el transcurso de diversos procedimientos realizados en la mandíbula. Introduction: Iatrogenic inferior alveolar nerve injuries are documented complications of different surgical procedures in the jaw. It should justify a more detailed description with morphometric references of the duct and a correlation with images. Materials and method: A

Lyophilized allogeneic bone grafts for cystic and discontinuity defects of the jaws

International Nuclear Information System (INIS)

Pill Hoon Choung; Eun Seok Kim

1999-01-01

Allogenic bone grafts have been used after various processing in each institute was made by lyophilized allogenic bone and used for maxillofacial reconstruction. Three types of lyophilized allogenic bone grafts as powder, chip and block form were performed to reconstruct the following defects: 1) maxillectomy, 2) mandiblectomy, 3) cystectomy, 4) cleft alveolus, 5) gap in orthognathic osteotomy, 6) peri-implant defect, 7) extraction socket, and 8) facial contouring. Above defects can be classified as cystic and discontinuity defects of the maxilia and the mandible. Because discontinuity defects have more difficult problems to reconstruct considering mechanical strength of the allogenic bone. We performed allogenic bone grafts on 50 cystic defects and 12 discontinuity defects of the jaws. Among them, 3 cases were removed due to infection, and the others had no complications. In reconstruction of cystic defects, the defects were filled with allogenic chip which were made from allogenic block bone at the surgery, which later were changed to host bone. Three cases of them showed tooth eruption through the allogenic bone grafting site, changing the eruption pathway, which was interrupted by the lesion. in reconstruction of discontinuity defects, usually allogenic bone has been used as a tray, in which PMCB or demineralized bone chips were filled. But we tried to reconstruct this discontinuity defect using allogeneic bone block without inside filling of PMCB different from tray type. We will present the results of allogenic bone grafts using cranial bone, costochondral graft, and the mandible

Osteonecrosis of the jaws. Clinicopathologic and radiologic characteristics, preventive and therapeutic Strategies

International Nuclear Information System (INIS)

Vassiliou, Vassilios; Tselis, Nikolaos; Kardamakis, Dimitrios

2010-01-01

Background: bisphosphonate (BP) use has increased dramatically in recent years, becoming an integral part of the overall antineoplastic management of patients with metastatic bone disease. Even though their application has shown to be effective in reducing pain and minimizing the risk of skeletal-related events, their administration may bring also adverse events such osteonecrosis of the jaws (ONJ). Methods: after a thorough review of the literature, important aspects of the pathophysiology, diagnosis, prevention, and treatment of ONJ are presented. Results: ONJ is evident in up to 10% of patients receiving intravenous BP treatment. Despite the fact that its exact pathophysiology is unknown, it is characterized by bone necrosis that can occur either spontaneously or after dental surgery or tooth extraction. Panoramic radiographs are useful for the diagnosis and routine assessment of patients and computed tomography can differentiate between ONJ and metastatic disease. Additionally, magnetic resonance imaging depicts local disease extension readily, and scintigraphy is the most sensitive imaging modality for detecting early involvement. Preventive measures and routine dental evaluations are essential components of the overall patient management. In the event of ONJ, stage I or II should be managed conservatively, whereas more advanced stages (III and IV) should be treated surgically. Conclusion: ONJ is a well-defined clinical entity that all medical and dental doctors should be aware of, since if it is not dealt with readily and effectively, it may deteriorate the clinical status and quality of life of affected patients. (orig.)

Evaluation of bone alterations in the jaws of HIV-infected menopausal women

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Bruno Vieira Caputo

2013-06-01

Full Text Available The advent of highly active antiretroviral therapy (HAART has caused a reduction in mortality, thus contributing to an increase in the number of women with HIVࢧAIDS who reach the climacteric period, experience decline in ovarian function, and develop complications of viral infection and HAART, which can accelerate bone loss. The aim of this study was to detect possible alterations in the jaws of HIV-infected women by panoramic radiography. The study comprised a total of 120 women above 40 years of age who were divided into the following two groups: women who are HIV positive (Group I and women with no known HIV infection (Group II. Measurement of the following three radiomorphometric indexes was performed by panoramic radiography: Mental Index (MI, Panoramic Mandibular Index (PMI and Antegonial Depth (AD. A total of 70% of women in the control group and 50% of women in the HIV group were in the postmenopausal period, and the average values of both MI (p = 0.0054 and AD (p < 0.0001 for this period were lower in the HIV group than in the control group. For patients who were in the premenopausal period, the average AD was lower in the HIV group than in the control group (p = 0.0003. Despite the difference in the average age between groups, greater bone resorption in the mandible was found in the group of HIV-positive women.

Fibrosarcoma of the jaws: two cases of primary tumors with intraosseous growth.

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Angiero, Francesca; Rizzuti, Tommaso; Crippa, Rolando; Stefani, Michele

2007-01-01

Fibrosarcoma (FS) is a malignant mesenchymal neoplasm of the fibroblasts that rarely affects the oral cavity. Two cases of primary FS of the jaws with intraosseous growth (2 men, aged 53 and 71 years) are described. Microscopically, in one case the tumor showed an intense proliferation of spindle-shaped cells, varying little in size and shape and arranged in parallel bands, partly crossing each other, with significant mitotic activity and nuclear pleomorphism; the second case was characterized by low cellularity comprising spindle-shaped cells, deposited in a variably fibrous and myxoid stroma. On immunohistochemistry, cells in both cases were strongly immunoreactive for MIB-1 and vimentin, focally positive for CD68, and negative for S-100 protein, pancytokeratin, HMB45, CD34, desmin, smooth muscle actin (SMA) and epithelial membrane antigen (EMA). Based on clinical, histological and immunohistochemical findings, the final diagnosis was FS in the first case, myxofibrosarcoma in the second. Treatment was radical surgery with mandibular reconstruction. After two years, the first patient displayed multiple metastases and died during the third year after the initial diagnosis; the second patient was still alive and doing well five years after treatment. We discuss the differential diagnosis versus other forms of sarcoma, examining the morphological appearance that is frequently very similar, the immunohistochemical expression of MIB-1, vimentin, S-100, CD-34, CD68, EMA, as well as conventional clinicopathological features that may help to distinguish FS from other sarcomas.

Electron Beam Melting Manufacturing Technology for Individually Manufactured Jaw Prosthesis: A Case Report.

Science.gov (United States)

Suska, Felicia; Kjeller, Göran; Tarnow, Peter; Hryha, Eduard; Nyborg, Lars; Snis, Anders; Palmquist, Anders

2016-08-01

In the field of maxillofacial reconstruction, additive manufacturing technologies, specifically electron beam melting (EBM), offer clinicians the potential for patient-customized design of jaw prostheses, which match both load-bearing and esthetic demands. The technique allows an innovative, functional design, combining integrated porous regions for bone ingrowth and secondary biological fixation with solid load-bearing regions ensuring the biomechanical performance. A patient-specific mandibular prosthesis manufactured using EBM was successfully used to reconstruct a patient's mandibular defect after en bloc resection. Over a 9-month follow-up period, the patient had no complications. A short operating time, good esthetic outcome, and high level of patient satisfaction as measured by quality-of-life questionnaires-the European Organisation for Research and Treatment of Cancer QLQ-C30 (30-item quality-of-life core questionnaire) and H&N35 (head and neck cancer module)-were reported for this case. Individually planned and designed EBM-produced prostheses may be suggested as a possible future alternative to fibular grafts or other reconstructive methods. However, the role of porosity, the role of geometry, and the optimal combination of solid and porous parts, as well as surface properties in relation to soft tissues, should be carefully evaluated in long-term clinical trials. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Anatomy, function, and evolution of jaw and hyobranchial muscles in cryptobranchoid salamander larvae.

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Kleinteich, Thomas; Herzen, Julia; Beckmann, Felix; Matsui, Masafumi; Haas, Alexander

2014-02-01

Larval salamanders (Lissamphibia: Caudata) are known to be effective suction feeders in their aquatic environments, although they will eventually transform into terrestrial tongue feeding adults during metamorphosis. Early tetrapods may have had a similar biphasic life cycle and this makes larval salamanders a particularly interesting model to study the anatomy, function, development, and evolution of the feeding apparatus in terrestrial vertebrates. Here, we provide a description of the muscles that are involved in the feeding strike in salamander larvae of the Hynobiidae and compare them to larvae of the paedomorphic Cryptobranchidae. We provide a functional and evolutionary interpretation for the observed muscle characters. The cranial muscles in larvae from species of the Hynobiidae and Cryptobranchidae are generally very similar. Most notable are the differences in the presence of the m. hyomandibularis, a muscle that connects the hyobranchial apparatus with the lower jaw. We found this muscle only in Onychodactylus japonicus (Hynobiidae) but not in other hynobiid or cryptobranchid salamanders. Interestingly, the m. hyomandibularis in O. japonicus originates from the ceratobranchial I and not the ceratohyal, and thus exhibits what was previously assumed to be the derived condition. Finally, we applied a biomechanical model to simulate suction feeding in larval salamanders. We provide evidence that a flattened shape of the hyobranchial apparatus in its resting position is beneficial for a fast and successful suction feeding strike. Copyright © 2013 Wiley Periodicals, Inc.

Osteonecrose dos maxilares associada ao uso de bisfosfonatos: importante complicação do tratamento oncológico Bisphosphonate-associated jaws osteonecrosis: an important complication of oncology treatment

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Marco Antonio T. Martins

2009-02-01

Full Text Available Os bisfosfonatos são um grupo de medicamentos utilizados no tratamento de doenças malignas metastáticas e em outras doenças ósseas como osteoporose e doença de Paget. A despeito dos seus benefícios, uma importante complicação denominada de osteonecrose dos maxilares vem sendo observada nos pacientes usuários crônicos dos bisfosfonatos que se caracteriza clinicamente por exposições ósseas na região maxilofacial persistente, acompanhadas de osteomielite, geralmente sintomáticas e cujo tratamento é complexo. Este estudo tem por objetivo revisar a literatura sobre a osteonecrose associada ao uso dos bisfosfonatos, em especial, em oncologia, no período de 2003 a 2008. Serão apresentados e discutidos os fatores de risco, aspectos etiopatogênicos, clínicos, imagenológicos, terapêuticos e preventivos desta doença. Devido à dificuldade de tratamento da osteonecrose associada aos bisfosfonatos, o foco deve ser a prevenção, sendo o ideal a eliminação de quadros infecciosos orais antes da terapia com os bisfosfonatos ter sido iniciada e minimizar traumas em boca após o uso destes medicamentos.Bisphosphonates are drugs used in the treatment of malignant metastatic diseases and in other bone lesions such as osteoporosis and Paget´s disease. Besides their benefits, jaw osteonecrosis, an important side effect, has been observed in long-term users of these drugs. Jaw osteonecrosis is clinically characterized by prolonged maxillary and mandible bone exposure accompanied by osteomyelitis. These lesions are usually symptomatic and difficult to treat. This study has the objective of reviewing publications from 2003 to 2008 about bisphosphonate-associated jaw osteonecrosis, in particular in relation to oncology. Risk factors, and etiopathological, clinical, radiographic, therapeutic, and preventive aspects of this condition are presented and discussed. Due to the difficulty to treat this disease, the focus must be prevention, with the

Bisphosphonate-related osteonecrosis of the jaw: historical, ethical, and legal issues associated with prescribing.

Science.gov (United States)

Faiman, Beth; Pillai, Aiswarya Lekshmi Pillai Chandran; Benghiac, Ana Gabriela

2013-01-01

The long-term effects of many drugs are unknown. Established risks are communicated to patients who participate in clinical trials during the informed consent process. However, unknown and unanticipated side effects of medications may occur years after treatment. Patients with metastatic bone cancer experience an imbalance between tumor cells and the bone marrow microenvironment. Increased cytokine release, osteoclastic activity, and uncoupled osteoblastic activity lead to weakened bone structure and osteolytic lesions. The bisphosphonates are a class of drugs available in IV and oral formulations to treat and prevent bone loss and decrease the risk of skeletal-related events. Intravenous bisphosphonates such as zoledronic acid and pamidronate disodium are approved by the US Food and Drug Administration for the treatment of bone pain and hypercalcemia of malignancy and the prevention of painful bone fractures in patients with metastatic bone cancer. Oral bisphosphonates such as alendronate, risedronate, and etidronate are used to reduce the risk of skeletal fractures in patients with osteoporosis and in breast cancer. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a rare but painful complication of treatment characterized by infection, exposed bone, and poor wound healing. In this article, we discuss BRONJ and identify past, present, and future ethical and legal issues surrounding bisphosphonate administration.

Central ossifying fibroma, periapical cemento-osseous dysplasia and complex odontoma occurring in the same jaw

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Farzaneh Agha Hosseini

2011-05-01

Full Text Available Central ossifying fibroma is a rare, benign fibro-osseous lesion that arises from the periodontal ligament. Periapical cemento-osseous dysplasia is another variant of fibro-osseous lesion which occurs in the anterior region of the mandible of females. Odontoma is a benign odontogenic tumor that contains enamel, dentine cement and pulp tissue. A 46-year-old woman was referred to the Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, with two nonpainful swellings on both sides of the mandible, which had been slowly growing over a period of one year. Our differential diagnosis was florid cemento-osseous dysplasia, focal cemento-osseous dysplasia for the right side, complex odontoma for the left side and periapical cement-osseous dysplasia for the anterior side. The historical feature revealed ossifying fibroma, complex odontoma and periapical cemento-osseous dysplasia. The occurrence of these three lesions in the same jaw has been rarely reported in the literature. The relationship between the occurrence of these three lesions is not obvious it could be coincidental. It seems that more case reports are needed to establish the relationship between them.

Early developed section of the jaw as an index of prenatal growth conditions in adult roe deer Capreolus capreolus

DEFF Research Database (Denmark)

Høye, Toke Thomas; Forchhammer, Mads Cedergreen

2006-01-01

-maturing bones are poor predictors of resource limitations during early development, as later benign conditions may lead to compensatory growth. We analysed the temporal growth dynamics of different sections of the lower jaw of roe deer Capreolus capreolus and found that the medioanterior section of the lower......Increasing evidence suggests that conditions in early life have important consequences for ultimate body size and fitness. Skeletal parts are often used as retrospective indices of body size and growth constraints because of their resistance to seasonal variation in resource availability. Yet, slow...... post partum and, as such, potentially leaves a fingerprint of prenatal growth conditions that is evident even in adult individuals. This supports earlier findings in ungulates of a shift in skeletal growth spurts after weaning, and suggests that the choice of skeletal index for population and cohort...

Osteonecrosis de los maxilares inducida por bifosfonatos: prevención y actitud terapéutica Bisphosphonate induced osteonecrosis of the jaws: prevention and therapeutic approach

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F.J. Barrientos Lezcano

2007-10-01

Full Text Available Introducción. La osteonecrosis maxilar o mandibular por bifosfonatos puede convertirse en una epidemia debido a la amplia difusión de estos fármacos entre la población. Material y método. Se muestra un protocolo para la prevención y el tratamiento de esta enfermedad. Se presentan tres casos de osteonecrosis maxilar/mandibular. Resultados. Es difícil lograr una curación completa; sin embargo es posible detener la progresión de la enfermedad. Discusión. La cirugía y la suspensión de la terapia con bifosfonatos han demostrado poca utilidad. Los antibióticos y los enjuagues con clorhexidina son las únicas medidas eficaces. Conclusiones. Es imprescindible una planificación adecuada previa a la instauración del tratamiento con bifosfonatos. Ante una osteonecrosis establecida, la actitud debe ser conservadora.Introduction. Bisphosphonate-induced osteonecrosis of the jaws might reach epidemic proportions due to the widespread use of this therapy. Materials and methods. A protocol for prevention and treatment of this pathology is shown. Three clinical cases are reported. Results. It is quite difficult to reach restitutio ad integrum, but stopping the progress of the disease is possible. Discussion. Surgical treatment and cessation of bisphosphonate therapy are of no use. Only antibiotics and oral chlorhexidine have shown some benefits. Conclusions. An accurate preventive attitude is mandatory prior to undergoing bisphosphonate therapy. If osteonecrosis of the jaws is present, management should be conservative.

PERIAPICAL LESIONS OF THE JAWS: A REVIEW OF 104 CASES IN IBADAN

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Akinyamoju, AO; Gbadebo, SO; Adeyemi, BF

2014-01-01

Background: Periapical lesions (PLs) occur as a result of pulpal inflammation and may rarely be seen in the absence of pulpal diseases. They are the most common pathological lesions affecting the alveolar bone. Objective: This study aims to describe the clinicopathological features of PLs of the jaws with emphasis on the two most common types. Methods: Histopathology records of PLs diagnosed from January 1990 to December 2012 at the Department of Oral Pathology, University College Hospital Ibadan, were examined and categorized into periapical cysts (PCs); periapical granuloma (PGs) and others. Clinical data and histopathological features of these PLs were reviewed and analyzed. Results: One hundred and four lesions met the criteria for this study and consisted of PGs with 71 (68.3%) cases and PCs with 31 (29.8%) cases and one case each of apical scar and pleomorphic adenoma. Age range of cases was 9 to 80 years (mean=35.6 ± 15.8years) with a peak at age group of 20-29 years. Females were more frequently affected with 51.9% of cases. PLs were most frequently diagnosed in the anterior maxillary region with 58 (56.9%) cases, while the most frequently involved tooth was the left maxillary central incisor with 23 (22.1%) cases. Conclusion: Findings in this study are consistent with those of previous studies. It is important for all periapical pathological specimens to be submitted for histological examination to establish an accurate diagnosis and aid in the identification of sinister lesions that may present in the Periradicular region of teeth. PMID:25960702

Two new species of shovel-jaw carp Onychostoma (Teleostei: Cyprinidae) from southern Vietnam.

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Hoang, Huy Duc; Pham, Hung Manh; Tran, Ngan Trong

2015-05-22

Two new species of large shovel-jaw carps in the genus Onychostoma are described from the upper Krong No and middle Dong Nai drainages of the Langbiang Plateau in southern Vietnam. These new species are known from streams in montane mixed pine and evergreen forests between 140 and 1112 m. Their populations are isolated in the headwaters of the upper Sre Pok River of the Mekong basin and in the middle of the Dong Nai basin. Both species are differentiated from their congeners by a combination of the following characters: transverse mouth opening width greater than head width, 14-17 predorsal scales, caudal-peduncle length 3.9-4.2 times in SL, no barbels in adults and juveniles, a strong serrated last simple ray of the dorsal fin, and small eye diameter (20.3-21.5% HL). Onychostoma krongnoensis sp. nov. is differentiated from Onychostoma dongnaiensis sp. nov. by body depth (4.0 vs. 3.2 times in SL), predorsal scale number (14-17 vs. 14-15), dorsal-fin length (4.5 vs. 4.2 times in SL), caudal-peduncle length (3.9 vs. 4.2 times in SL), colour in life (dark vs. bright), and by mitochondrial DNA (0.2% sequence divergence). Molecular evidence indicates that both species are members of Onychostoma and are distinct from all congeners sampled (uncorrected sequence divergences at the 16S rRNA gene of >2.0% for all Onychostoma for which homologous 16S rRNA sequences are available).

Chronological Age as Factor Influencing the Dental Implant Osseointegration in the Jaw Bone

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Jan Papež

2018-04-01

Full Text Available The objectives of this study were to evaluate osseointegration of dental implant in the jaw bone in the young and elderly population and comparing the results to assess indicators and risk factors as age for the success or failure of dental implants. A retrospective study of 107 implants (Impladent, LASAK, Czech Republic was prepared. The patients at implants surgery were divided in three groups. The patients were followed-up for a 7-year period. We evaluated osseointegration from long term point of view as a change of marginal bone levels close to dental implant. Marginal bone levels were recorded and analysed with regard to different patient- and implant-related factors. An influence of chronological age on change of marginal bone levels during 6-year retrospective study vas evaluated. The study examined 47 patient charts and 107 implants from the Second Faculty of Medicine, Charles University and University Hospital Motol. We proved that young healthy patients with long bridges or Branemarks have the same progression of marginal bone levels changes. The chronological age hasn’t therefore direct influence on the osseointegration from long term point of view. But we found that the length of dental suprastrucure-prosthetic construction negatively influences marginal bone changes, though these results weren’t statistically significant. More extensive dental implant suprastrucure undergoes smaller osseointegration. On the other hand the length of dental suprastrucure (prosthetic construction negatively influences dental osseointegration in both groups of patient.

Tapered, Double-Lead Threads Single Implants Placed in Fresh Extraction Sockets and Healed Sites of the Posterior Jaws: A Multicenter Randomized Controlled Trial with 1 to 3 Years of Follow-Up.

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Cucchi, Alessandro; Vignudelli, Elisabetta; Franco, Simonetta; Levrini, Luca; Castellani, Dario; Pagliani, Luca; Rea, Massimiliano; Modena, Claudio; Sandri, Giulio; Longhi, Carlo

2017-01-01

To evaluate the survival, success, and complication rates of tapered double-lead threads single implants, placed in fresh extraction sockets and healed sites of the posterior jaws. The enrolled patients were randomly divided into 2 groups: in the test group (TG), all implants were inserted at the time of tooth extraction; in the control group (CG), all implants were placed 3 months after extraction. The implants were followed for a period of 1 to 3 years after loading. The main outcomes were implant survival, complications, and implant-crown success. Ninety-two patients had 97 installed implants (49 in the TG, 48 in the CG). Only two implants failed, in the TG; the survival rates were therefore 95.9% (47/49) and 100% (48/48) for TG and CG, respectively. In the surviving implants, no complications were reported, for an implant-crown success of 100%. Although a significant difference was found in the levels of primary stability between TG and CG, single implants placed in fresh extraction sockets and healed sites of the posterior jaws had similar survival and complication rates. Crestal bone levels and peri-implant bone resorption showed similar values. A longer follow-up period is however required, to confirm these positive outcomes.

Local anesthetic effect of docosahexaenoic acid on the nociceptive jaw-opening reflex in rats.

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Mitome, Kazuki; Takehana, Shiori; Oshima, Katsuo; Shimazu, Yoshihito; Takeda, Mamoru

2018-02-23

Although docosahexaenoic acid (DHA) administration suppresses sodium channels in primary afferent sensory neurons, the acute local effect of DHA on the trigeminal nociceptive reflex remains to be elucidated, in vivo. Therefore, the aim of the present study was to investigate whether local administration of DHA attenuates the nociceptive jaw-opening reflex (JOR) in vivo in the rat. The JOR evoked by electrical stimulation of the tongue was recorded by a digastric muscle electromyogram (dEMG) in pentobarbital-anesthetized rats. The amplitude of the dEMG response was significantly increased in proportion to the electrical stimulation intensity (1-5 x threshold). At 3 x threshold, local administration of DHA (0.1, 10 and 25 mM) dose-dependently inhibited the dEMG response, and lasted 40 min. Maximum inhibition of the dEMG signal amplitude was seen within approximately 10 min. The mean magnitude of inhibition of the dEMG signal amplitude by DHA (25 mM) was almost equal to the local anesthetic, 1% lidocaine (37 mM), a sodium channel blocker. These findings suggest that DHA attenuates the nociceptive JOR via possibly blocking sodium channels, and strongly support the idea that DHA is a potential therapeutic agent and complementary alternative medicine for the prevention of acute trigeminal nociception. Copyright © 2018 Elsevier B.V. and Japan Neuroscience Society. All rights reserved.

Central ossifying fibroma, periapical cemento-osseous dysplasia and complex odon-toma occurring in the same jaw.

Science.gov (United States)

Hosseini, Farzaneh Agha; Moslemi, Elham

2011-05-16

Central ossifying fibroma is a rare, benign fibro-osseous lesion that arises from the periodontal ligament. Periapical cemento-osseous dysplasia is another variant of fibro-osseous lesion which occurs in the anterior region of the mandible of females. Odontoma is a benign odontogenic tumor that contains enamel, dentine cement and pulp tissue. A 46-year-old woman was referred to the Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, with two non-painful swellings on both sides of the mandible, which had been slowly growing over a period of one year. Our differential diagnosis was florid cemento-osseous dysplasia, focal cemento-osseous dysplasia for the right side, complex odontoma for the left side and periapical cement-osseous dysplasia for the anterior side. The historical feature revealed ossifying fibroma, complex odontoma and periapical cemento-osseous dysplasia. The occurrence of these three lesions in the same jaw has been rarely reported in the literature. The relationship between the occurrence of these three lesions is not obvious it could be coincidental. It seems that more case reports are needed to establish the relationship between them.

Breast cancer in the lower jaw after reconstructive surgery with a pectoralis major myocutaneous flap (PMMC - A case report

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Nestle-Kraemling C

2011-12-01

Full Text Available Abstract For head and neck as well as for oromaxillofacial surgery, the use of the pectoralis major myocutaneous (PMMC flap is a standard reconstructive technique after radical surgery for cancers in this region. We report to our knowledge for the first development of breast cancer in the PMMC flap in a 79 year old patient, who had undergone several operations in the past for recurring squamous cell carcinoma of the jaw. The occurrence of a secondary malignancy within the donor tissue after flap transfer is rare, but especially in the case of transferred breast tissue and the currently high incidence of breast cancer theoretically possible. Therefore preoperative screening mammography seems advisable to exclude a preexisting breast cancer in female patients undergoing such reconstruction surgery. Therapy for breast cancer under these circumstances is individual and consists of radical tumor resection followed by radiation if applicable and a standard systemic therapeutic regimen on the background of the patients individual prognosis due to the primary cancer.

Osteonecrosis de los maxilares asociada al uso de bifosfonatos: revisión de ocho casos Bisphosphonate-related jaw osteonecrosis: Review of eight cases

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J. Joshi Otero

2011-03-01

Full Text Available Introducción: A finales de 2003 se comienzan a publicar en forma creciente los primeros casos de exposición ósea en los maxilares con evolución tórpida, asociados al uso de bifosfonatos por vía intravenosa. Estos fármacos son usados en pacientes con osteoporosis, mieloma múltiple, hipercalcemia maligna y cáncer de pulmón, mama y próstata, principalmente por su capacidad de inhibir la resorción ósea. Material y método: Estudio prospectivo de los pacientes en el Hospital Virgen Macarena que presentaban lesiones maxilares asociadas al uso de bifosfonatos desde el año 2006 hasta la actualidad. Las variables que valoramos en el paciente son: sexo, edad, tratamiento con bifosfonatos, inicio de la osteonecrosis, relación con tratamientos dentales, tratamiento realizado y evolución. Resultados: Se estudiaron 8 pacientes con osteonecrosis maxilar secundaria a tratamiento con bifosfonatos intravenosos u orales por su patología previa oncológica u osteoporótica que fueron tratados según su estadio clínico-radiológico con antibioterapia, legrado y/o exéresis del secuestro según el caso. Presentamos los resultados con un seguimiento mínimo de 15 meses. Conclusiones: El aumento en la incidencia de la osteomielitis maxilar en los pacientes asociados al uso de bifosfonatos y la dificultad para su tratamiento hacen necesario establecer pautas terapéuticas estandarizadas. En nuestra experiencia, el tratamiento conservador basado en la antibioterapia además del legrado de la zona bajo anestesia local permite el control y la curación del proceso en algunos de los pacientes con OMRB grado II.Background: In late 2003, an increasing number of case reports began to appear on bone exposure of the jaw with a torpid evolution in association with intravenous bisphosphonate use. Bisphosphonates are used to inhibit bone resorption in patients with osteoporosis, multiple myeloma, hypercalcemia of malignancy, lung cancer, breast cancer and prostate

Delayed Diagnosis of Osteonecrosis of the Jaw (ONJ Associated with Bevacizumab Therapy in Colorectal Cancer Patients: Report of Two Cases

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Francesco Erovigni

2016-10-01

Full Text Available Medication-induced Osteonecrosis of the Jaw (MRONJ has been reported not only after use of antiresorptive agents (bisphosphonates and denosumab, but also in cancer patients receiving antiangiogenic agents, alone or combined with antiresorptive drugs. We report two cases of MRONJ observed in colorectal cancer patients after bevacizumab therapy only. MRONJ was diagnosed, respectively, two and seven months after a tooth extraction; both the patients had received two courses of bevacizumab infusions (for a total of 29 and 10 administrations, respectively. We discuss if tooth extraction during or after antiangiogenic therapy could be a potential trigger of MRONJ, but also if an underlying bone disease not evident before oral surgery might be a possible cause. A careful drug history has to be registered by dental specialists in cancer patients before oral surgery and adequate imaging might be obtained to avoid a delayed diagnosis.

First report of a cystic malformation on the upper jaw of hatchery-reared allis shad Alosa alosa.

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Wünnemann, H; Bergmann, S M; Eskens, U; Scharbert, A; Hundt, M; Lierz, M

2017-01-01

The anadromous allis shad Alosa alosa has suffered dramatic population declines throughout Europe and is currently considered as endangered throughout its entire distribution range. In order to reestablish allis shad in the River Rhine, which formerly housed one of the largest and most important populations, an EU-LIFE Project 'The re-introduction of allis shad in the Rhine system' was started in 2007. In course of the LIFE+ Projects, allis shad larvae bred from genitor fish of the Gironde-Garonne-Dordogne population in France were reared in a pilot ex situ stock plant pilot facility in Aßlar, Germany. At an age of 1-2 months, about 100% of these fish developed approximately 0.5- to 0.8-cm large, fluid-filled, transparent cysts in conjunction with the upper jaw. The performed microbiological, virological, parasitological and histological examinations did not detect any infectious agents. Possible causative agents are discussed with regard to environmental factors and the nutrition of larvae. In conclusion, the observed malformations are considered a sign for a severe health problem and therefore a risk for the successful breeding of allis shad in aquaculture. © 2016 John Wiley & Sons Ltd.

Measurement of anatomical structure of jaw bone trabecula with micro-CT and its accuracy evaluation

International Nuclear Information System (INIS)

Jin Guangchun; Zhang Xiaoyan; Jiang Ling; Li Xianglin; Zhang Di; Li Weixing; Jin Xizhen; Jin Dongchun

2011-01-01

Objective: To measure the anatomic structures of the jaw and to discuss the accuracy of the method. Methods: The mandibular specimens were divided into ankle condylar group (3 specimens, regular trabecular architecture and mandibular body group (5 specimens, irregular trabecular trabecular architecture). Fifteen volumes of interests (VOI) were created in each group and the total of thirty were measured. The mean value and standard deviation of each parameter at each reconstruction voxel size were calculated. Repeated ANOVA test was used to determine whether the significant differences in the values existed between each parameter. Results: The structure model index (SMI) value in mandibular body group had significant difference (P<0.05) at all reconstruction voxel sizes compared with 18 μm group; but in condyle group, the reconstruction voxel size of 36 μm was not significant (P>0.05). The differences of trabecular thickness (Tb. Th), trabecular number (Tb. N) and trabecular separation (Tb. Sp) values between condyle and mandibular body groups were significant at all reconstruction voxel sizes (P<0.05). In condyle group, except for Tb. Th, Tb. N and Tb. Sp, the most parameter values were not significant at reconstruction pixel size of 36μm. In the mandible body group, the differences of all parameter values between different pixel sizes were significant. Conclusion: Micro-CT can reflect the anatomical changes of bone trabecula structure. (authors)

Application of concentrated growth factors in reconstruction of bone defects after removal of large jaw cysts: The two cases report

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Mirković Siniša

2015-01-01

Full Text Available Introduction. Coagulation and blood clot formation in bone defects is sometimes followed by retraction of a blood clot and serum extrusion, thus producing peripheral serum-filled spaces between bony wall and coagulum. This can result in a higher incidence of postoperative complications. Stabilization of blood coagulum, which enables successful primary healing, may be accomplished by autotransplantation, allotransplantation, xenotransplantation, or application of autologous platelet concentrate and concentrated growth factors (CGF. Case report. Two patients with large cystic lesions in the upper and lower jaw were presented. In both patients postoperative bony defects were filled with autologous fibrin rich blocks containing CGF. Postoperative course passed uneventfully. Conclusion. Application of fibrin rich blocks containing CGF is one of the possible methods for reconstruction of bone defects. CGF can be applied alone or mixed with a bone graft. The method is relatively simple, without risk of transmissible and allergic diseases and economically feasible.

Interactive 3D imaging technologies: application in advanced methods of jaw bone reconstruction using stem cells/pre-osteoblasts in oral surgery.

Science.gov (United States)

Wojtowicz, Andrzej; Jodko, Monika; Perek, Jan; Popowski, Wojciech

2014-09-01

Cone beam computed tomography has created a specific revolution in maxillofacial imaging, facilitating the transition of diagnosis from 2D to 3D, and expanded the role of imaging from diagnosis to the possibility of actual planning. There are many varieties of cone beam computed tomography-related software available, from basic DICOM viewers to very advanced planning modules, such as InVivo Anatomage, and SimPlant (Materialise Dental). Through the use of these programs scans can be processed into a three-dimensional high-quality simulation which enables planning of the overall treatment. In this article methods of visualization are demonstrated and compared, in the example of 2 cases of reconstruction of advanced jaw bone defects using tissue engineering. Advanced imaging methods allow one to plan a miniinvasive treatment, including assessment of the bone defect's shape and localization, planning a surgical approach and individual graft preparation.

Evaluation influence of machining parameters on shape form errors in turning of machine parts clamped in the chuck with adaptive jaws

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I.V. Lutsiv

2017-12-01

Full Text Available The paper deals with the derivation problem of the dependence of machine part geometric form deviation in cross section area on clamping diameter as well as cutting speed, feed and cutting depth in semi finish machining. The analysis of single factor circular deviation dependences on machining conditions values is performed. Using the special software application package the laboratory conditions experiment results are analyzed. The dispersion analysis including options for main linear and quadratic effects evaluation is given and the simplification model of experiment results is obtained. It presents the evaluation empiric dependence of cutting conditions and clamping diameter influence on shape error forming (dynamic error. It is found that to obtain the necessary form accuracy in machining with lathe chuck equipped with the adaptive clamping jaws it is desirable to control the most statistically significant factors that actually are the cutting depth and feed.

Concomitant duplications of opioid peptide and receptor genes before the origin of jawed vertebrates.

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Görel Sundström

Full Text Available BACKGROUND: The opioid system is involved in reward and pain mechanisms and consists in mammals of four receptors and several peptides. The peptides are derived from four prepropeptide genes, PENK, PDYN, PNOC and POMC, encoding enkephalins, dynorphins, orphanin/nociceptin and beta-endorphin, respectively. Previously we have described how two rounds of genome doubling (2R before the origin of jawed vertebrates formed the receptor family. METHODOLOGY/PRINCIPAL FINDINGS: Opioid peptide gene family members were investigated using a combination of sequence-based phylogeny and chromosomal locations of the peptide genes in various vertebrates. Several adjacent gene families were investigated similarly. The results show that the ancestral peptide gene gave rise to two additional copies in the genome doublings. The fourth member was generated by a local gene duplication, as the genes encoding POMC and PNOC are located on the same chromosome in the chicken genome and all three teleost genomes that we have studied. A translocation has disrupted this synteny in mammals. The PDYN gene seems to have been lost in chicken, but not in zebra finch. Duplicates of some peptide genes have arisen in the teleost fishes. Within the prepropeptide precursors, peptides have been lost or gained in different lineages. CONCLUSIONS/SIGNIFICANCE: The ancestral peptide and receptor genes were located on the same chromosome and were thus duplicated concomitantly. However, subsequently genetic linkage has been lost. In conclusion, the system of opioid peptides and receptors was largely formed by the genome doublings that took place early in vertebrate evolution.

Narrow- (3.0 mm) Versus Standard-Diameter (4.0 and 4.5 mm) Implants for Splinted Partial Fixed Restoration of Posterior Mandibular and Maxillary Jaws: A 5-Year Retrospective Cohort Study.

Science.gov (United States)

Pieri, Francesco; Forlivesi, Caterina; Caselli, Ernesto; Corinaldesi, Giuseppe

2017-04-01

Evidence concerning predictability of narrow-diameter implants (NDIs) (3.0 mm) and standard-diameter implants (SDIs) (4.0 to 4.5 mm) supporting fixed partial dentures (FPDs) in posterior mandibular and maxillary jaws. All patients treated with at least two adjacent NDIs or SDIs according to available bone thickness and with a minimum follow-up of 5 years after placement were invited to undergo a clinical and radiologic examination. Outcome measures were implant and FPD failures, biologic and prosthetic complications, and marginal bone loss. A total of 107 out of 127 patients attended the examination: 49 (113 implants) of the NDI group, and 58 (126 implants) of the SDI group. Two NDIs failed in one patient versus four SDIs in four patients (P = 0.37). One FPD failed in the NDI group versus two FPDs in the SDI group (P >0.99). Nine biologic complications occurred in the NDI group and twelve in the SDI group (P = 0.81). Twelve prosthetic complications occurred in the NDI group and only two in the SDI group (P = 0.001). Peri-implant marginal bone loss at 5 years was 0.95 ± 0.84 mm for the NDI group and 1.2 ± 0.86 mm for the SDI group (P = 0.06). Five-year data indicate that FPD treatment in posterior mandibular and maxillary jaws with NDIs was as reliable as with SDIs, although NDIs showed a higher risk of prosthetic complications.

For the development of therapy with ionising radiation in tooth, mouth and jaw medicine. An historical summary

International Nuclear Information System (INIS)

Halbleib, T.

1983-01-01

Based on the corresponding literature study, the development of therapy with ionising radiation, especially in the areas of tooth, mouth and jaw medicine, is reported from the discovery of X-rays up till the present. First from 1915 on did the X-ray antiphlogistic irradiation with in importance, from 1925 to about 1940 it played a domineering role, after the war was hardly still in use and since 1970 is considered in the stomatological sector obsolete. In comparison, already in 1905 there were individual successes in tumor therapy using X radiation. After many failures and competition with the method of radium therapy in the following years, a new upswing in X-radiation came starting in around 1930 with the introduction of the Chaoul contact therapy. The high point of this development is the introduction of supervolt therapy starting around 1965. It is the result of comprehensive research in the area of radiation physics. As a result of further developed techniques there were soon combined and competing procedures available, whose results, however, have not been adequately compared and documented. From 1970 on electronic data processing has primarily taken over individual irradiation planning (cobalt 60 and electron irradiation), predictions about clinically relevant therapy successes are not present at this time. (TRV) [de

Technetium-99 conjugated with methylene diphosphonate ameliorates ovariectomy-induced osteoporotic phenotype without causing osteonecrosis in the jaw.

Science.gov (United States)

Zhao, Yinghua; Wang, Lei; Liu, Yi; Akiyama, Kentaro; Chen, Chider; Atsuta, Ikiru; Zhou, Tao; Duan, Xiaohong; Jin, Yan; Shi, Songtao

2012-12-01

Technetium-99 conjugated with methylene diphosphonate ((99)Tc-MDP) is a novel bisphosphonate derivative without radioactivity and has been successfully used to treat arthritis in China for years. Since bisphosphonate therapy has the potential to induce bisphosphonate-related osteonecrosis of the jaw (BRONJ), we examined whether (99)Tc-MDP represents a new class of bisphosphonate for antiresorptive therapy to ameliorate estrogen deficiency-induced bone resorption with less risk of causing BRONJ. We showed that (99)Tc-MDP-treated, ovariectomized (OVX) mice had significantly improved bone mineral density and trabecular bone volume in comparison to the untreated OVX group by inhibiting osteoclasts and enhancing osteogenic differentiation of bone marrow mesenchymal stem cells. To determine the potential of inducing BRONJ, (99)Tc-MDP/dexamethasone (Dex) or zoledronate/Dex was administered into C57BL/6J mice via the tail vein, followed by extraction of maxillary first molars. Interestingly, (99)Tc-MDP treatment showed less risk to induce osteonecrosis in the maxillary bones compared to zoledronate treatment group, partially because (99)Tc-MDP neither suppressed adaptive regulatory T cells nor activated the inflammatory T-helper-producing interleukin-17 cells. Taken together, our findings demonstrate that (99)Tc-MDP therapy may be a promising approach in the treatment of osteoporosis with less risk of causing BRONJ.

Effect of bisphosphonates on macrophagic THP-1 cell survival in bisphosphonate-related osteonecrosis of the jaw (BRONJ).

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Hoefert, Sebastian; Sade Hoefert, Claudia; Munz, Adelheid; Schmitz, Inge; Grimm, Martin; Yuan, Anna; Northoff, Hinnak; Reinert, Siegmar; Alexander, Dorothea

2016-03-01

Immune deficiency and bacterial infection have been suggested to play a role in the pathophysiology of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Zoledronate was previously found to promote THP-1 cell death. To examine this hypothesis with all commonly prescribed bisphosphonates, we tested the effect of (nitrogen-containing) ibandronate, risedronate, alendronate, pamidronate, and (non-nitrogen-containing) clodronate on macrophagic THP-1 cells. Activated THP-1 cells were exposed to .5 to 50 μM of nitrogen-containing bisphosphonates and .5 to 500 μM of clodronate. Cell adherence and survival were assessed in vitro using the xCELLigence real-time monitoring system. Results were confirmed histologically and verified with Live/Dead staining. All bisphosphonates inhibited THP-1 cell adherence and survival dose and time dependently, significant for zoledronate, alendronate, pamidronate, and clodronate in high concentrations (50 μM and 500 μM; P THP-1 cell survival compared with controls (P THP-1 cells exhibited no cytomorphologic changes at all concentrations. Commonly prescribed bisphosphonates inhibit the survival of macrophagic THP-1 cells dose-dependently without altering morphology. This may suggest a local immune dysfunction reflective of individual bisphosphonate potency leading to the pathogenesis of BRONJ. Copyright © 2016 Elsevier Inc. All rights reserved.

Laser and Platelet-Rich Plasma to treat Medication-Related Osteonecrosis of the Jaws (MRONJ): a case report.

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Fornaini, Carlo; Cella, Luigi; Oppici, Aldo; Parlatore, Anna; Clini, Fabio; Fontana, Matteo; Lagori, Giuseppe; Merigo, Elisabetta

2017-09-30

The appropriate management of Medication-Related OsteoNecrosis of the Jaw (MRONJ) is still a challenge for dentists and oral surgeons and in these last years high-technology instruments have been proposed at the different steps of interventions, also combined with promoters of tissue repair.The aim of this report is to show the advantages of a combined approach (laser and PRP) for the treatment of MRONJ. It is described the case of a patient positive for MRONJ observed at the Odontostomatology and Maxillo-Facial Surgery Unit of the Hospital of Piacenza where surgical approach was performed by using different devices: Er:YAG laser (2940 nm) to remove and vaporize necrotic hard tissue until bleeding bone; Platelet-Rich Plasma (PRP) to stimulate hard and soft tissue healing; diode laser (808 nm) to biostimulate the surgical site. At the time of suture removal, wound closure was observed and the complete healing of the MRONJ site was observed for the 2 years follow up. This case may suggest that this kind of combined approach during all the steps of MRONJ treatment allows to perform a faster and less invasive surgery with a more comfortable postoperative healing process and it represents an innovative approach in this severe adverse event.

Potential risk factors for jaw osteoradionecrosis after radiotherapy for head and neck cancer

International Nuclear Information System (INIS)

Kuhnt, Thomas; Stang, Andreas; Wienke, Andreas; Vordermark, Dirk; Schweyen, Ramona; Hey, Jeremias

2016-01-01

To identify potential risk factors for the development of jaw osteoradionecrosis (ORN) after 3D-conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) among patients with newly diagnosed head and neck cancer. This study included 776 patients who underwent 3D-CRT or IMRT for head and neck cancer at the Department of Radiotherapy at the University Hospital Halle-Wittenberg between 2003 and 2013. Sex, dental status prior to radiotherapy, tumor site, bone surgery during tumor resection, concomitant chemotherapy, and the development of advanced ORN were documented for each patient. ORN was classified as grade 3, 4, or 5 according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer classification or grade 3 or 4 according to the late effects in normal tissues/subjective, objective, management, and analytic scale. The cumulative incidence of ORN was estimated. Cox regression analysis was used to identify prognostic risk factors for the development of ORN. Fifty-one patients developed advanced ORN (relative frequency 6.6 %, cumulative incidence 12.4 %). The highest risk was found in patients who had undergone primary bone surgery during tumor resection (hazard ratio [HR] = 5.87; 95 % confidence interval [CI]: 3.09–11.19) and in patients with tumors located in the oral cavity (HR = 4.69; 95 % CI: 1.33–16.52). Sex, dentition (dentulous vs. edentulous), and chemotherapy had no clinically relevant influence. In contrast to most previous studies, we noted a low cumulative incidence of advanced ORN. Patients with tumors located in the oral cavity and those who undergo bone surgery during tumor resection prior to RT may be considered a high-risk group for the development of ORN

Leucocyte-rich and platelet-rich fibrin for the treatment of bisphosphonate-related osteonecrosis of the jaw: a prospective feasibility study.

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Kim, Jin-Woo; Kim, Sun-Jong; Kim, Myung-Rae

2014-11-01

Our aim was to assess the feasibility of using leucocyte-rich and platelet-rich fibrin (L-PRF) for the treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in a single group study. After treatment with L-PRF, the response of each patient was recorded 1 month and 4 months postoperatively. Further assessments were made of the site, stage, concentration of c-terminal crosslinked telopepide of type 1 collagen, and actinomycosis. Among the total of 34 patients, 26 (77%) showed complete resolution, 6 (18%) had delayed resolution, and 2 (6%) showed no resolution. There was a significant association between the response to treatment and the stage of BRONJ (p=0.002) but no other significant associations were detected. This study has shown that it is feasible to use L-PRF for the treatment of BRONJ, but the effectiveness cannot be judged with this study design. Randomised prospective trials are needed to confirm this. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

United Kingdom nationwide study of avascular necrosis of the jaws including bisphosphonate-related necrosis.

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Rogers, S N; Palmer, N O A; Lowe, D; Randall, C

2015-02-01

We aimed to record all new patients who presented to departments of oral surgery, oral medicine, and oral and maxillofacial surgery, and to dental hospitals in the UK, with avascular necrosis of the jaws including bisphosphonate-related necrosis (BRONJ) over a 2-year period (1 June 2009-31 May 2011). They were eligible irrespective of age, cause, or coexisting conditions. Data on incidence, clinical characteristics, risk factors, and coexisting conditions were collected. A total of 383 cases were registered: 369 were described as BRONJ, 5 as avascular necrosis, and 9 were unknown. Bisphosphonates had been given orally in 207 (56%), intravenously in 125 (34%), both orally and intravenously in 27 (7%), and was unknown in 9 (2%); one had been given denosumab. The main risk factor was dental extraction, and the mandible was commonly affected. The median duration of administration until onset of BRONJ was 3 years in those treated intravenously and 4 years in those treated orally. Levels of engagement with the study varied between regions, and extrapolation from the 2 most involved (Merseyside and Northern Ireland) found around 8.2-12.8 cases/million/year, which is 508-793 patients/year across the UK. To our knowledge this is one of the first studies to estimate national rates of BRONJ. It confirms that the risk and incidence are low. With changes in trends for antiresorptive bone medication, and increasing numbers of elderly people, it would be useful to repeat the registration in the future. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The influence of altered working-side occlusal guidance on masticatory muscles and related jaw movement.

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Belser, U C; Hannam, A G

1985-03-01

The effect of four different occlusal situations (group function, canine guidance, working side occlusal interference, and hyperbalancing occlusal interference) on EMG activity in jaw elevator muscles and related mandibular movement was investigated on 12 subjects. With a computer-based system, EMG and displacement signals were collected simultaneously during specific functional (unilateral chewing) and parafunctional tasks (mandibular gliding movements and various tooth clenching efforts) and analyzed quantitatively. When a naturally acquired group function was temporarily and artificially changed into a dominant canine guidance, a significant general reduction of elevator muscle activity was observed when subjects exerted full isometric tooth-clenching efforts in a lateral mandibular position. The original muscular coordination pattern (relative contraction from muscle to muscle) remained unaltered during this test. With respect to unilateral chewing, no significant alterations in the activity or coordination of the muscles occurred when an artificial canine guidance was introduced. Introduction of a hyperbalancing occlusal contact caused significant alterations in muscle activity and coordination during maximal tooth clenching in a lateral mandibular position. A marked shift of temporal muscle EMG activity toward the side of the interference and unchanged bilateral activity of the two masseter muscles were observed. The results suggest that canine-protected occlusions do not significantly alter muscle activity during mastication but significantly reduce muscle activity during parafunctional clenching. They also suggest that non-working side contacts dramatically alter the distribution of muscle activity during parafunctional clenching, and that this redistribution may affect the nature of reaction forces at the temporomandibular joints.

Effect of hypnosis on masseter EMG recorded during the 'resting' and a slightly open jaw posture.

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Al-Enaizan, N; Davey, K J; Lyons, M F; Cadden, S W

2015-11-01

The aim of this experimental study was to determine whether minimal levels of electromyographic activity in the masseter muscle are altered when individuals are in a verified hypnotic state. Experiments were performed on 17 volunteer subjects (8 male, 9 female) all of whom gave informed consent. The subjects were dentate and had no symptoms of pain or masticatory dysfunction. Surface electromyograms (EMGs) were made from the masseter muscles and quantified by integration following full-wave rectification and averaging. The EMGs were obtained (i) with the mandible in 'resting' posture; (ii) with the mandible voluntarily lowered (but with the lips closed); (iii) during maximum voluntary clenching (MVC). The first two recordings were made before, during and after the subjects were in a hypnotic state. Susceptibility to hypnosis was assessed with Spiegel's eye-roll test, and the existence of the hypnotic state was verified by changes in ventilatory pattern. On average, EMG levels expressed as percentages of MVC were less: (i) when the jaw was deliberately lowered as opposed to being in the postural position: (ii) during hypnosis compared with during the pre- and post-hypnotic periods. However, analysis of variance followed by post hoc tests with multiple comparison corrections (Bonferroni) revealed that only the differences between the level during hypnosis and those before and after hypnosis were statistically significant (P hypnosis, it appears that part of that EMG is of biological origin. © 2015 John Wiley & Sons Ltd.

Cephalometric evaluation of the pharyngeal airway space after orthognathic surgery and distraction osteogenesis of the jaw bones

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S Ganapathy Sriram

2014-01-01

Full Text Available Objective: Orthognathic surgeries and distraction osteogenesis (DO of the jaw bones cause a change in the pharyngeal airway space (PAS. The aim of our study was to evaluate the magnitude of changes occurring in the pharyngeal airway after mandibular set-back surgeries and DO of maxilla/mandible. Materials and Methods: The study undertaken was a retrospective cephalometric study. Subjects included in our study had undergone mandibular set-back surgery or DO of maxilla/mandible. Lateral cephalograms of the subjects taken pre-operatively (T0, immediate post-operatively (T1 and after a minimum follow-up period of 6 months (T2 were studied. The cephalograms were traced manually and the following parameters were evaluated: Surface area of the PAS, pharyngeal airway width at the level of the base of the tongue, position of the hyoid bone and the tongue. Repeated measure ANOVA test was done to assess the presence of any significant changes in the proposed parameters at T0, T1 and T2. A correlation analysis was made between the mandibular/maxillary movements and the corresponding changes in the PAS. Results: Surgical movements of maxilla and mandible do have an effect on the pharyngeal airway. Conclusion: It was clearly evident that the effects of mandibular movements on the PAS and the hyoid bone is more significant than the maxillary movements.

Identification of predisposing factors for osteonecrosis of the jaw after marginal mandibulectomy in the surgical management of oral squamous cell carcinoma.

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Ito, Ran; Huang, Jung-Ju; Hsieh, Wei-Chuan; Kao, Huang-Kai; Lao, William Wei-Kai; Fang, Ku-Hao; Huang, Yenlin; Chang, Yu-Liang; Cheng, Ming-Huei; Chang, Kai-Ping

2018-03-01

The aim of this study is to evaluate osteonecrosis of the jaw (ONJ) with the extent of marginal mandibulectomy. Between January 2006 and December 2012, 3087 patients undergoing ablative resection were consecutively enrolled. Among them, 345 cases undergoing marginal mandibulectomy were retrospectively reviewed. The occurrence of ONJ was 5.51% and associated with body mass index, overall stage, diabetes, concomitant mandibulotomy, and radiotherapy (P = 0.023, 0.033, 0.009, 0.016, and 0.006, respectively). As for bone parameters based on radiological measurements after marginal mandibulectomy, resected bone height, remaining bone height to original bone height ratio, and resected bone height to original bone height ratio were associated with ONJ. In multivariate logistic analyses, concomitant mandibulotomy, radiotherapy, diabetes, resected bone height of >14.5 mm, resected bone height to original bone height ratio of >49.5%, and remaining bone height to original bone height ratio of marginal mandibulectomy; more caution is necessitated in performing marginal mandibulectomy in patients with multiple risks to prevent ONJ. © 2017 Wiley Periodicals, Inc.

Intensity modulated radiotherapy with fixed collimator jaws for locoregional left-sided breast cancer irradiation.

Science.gov (United States)

Wang, Juanqi; Yang, Zhaozhi; Hu, Weigang; Chen, Zhi; Yu, Xiaoli; Guo, Xiaomao

2017-05-16

The purpose of this study is to evaluate the intensity modulated radiotherapy (IMRT) with the fixed collimator jaws technique (FJT) for the left breast and regional lymph node. The targeted breast tissue and the lymph nodes, and the normal tissues were contoured for 16 left-sided breast cancer patients previously treated with radiotherapy after lumpectomy. For each patient, treatment plans using different planning techniques, i.e., volumetric modulated arc therapy (VMAT), tangential IMRT (tangential-IMRT), and IMRT with FJT (FJT-IMRT) were developed for dosimetric comparisons. A dose of 50Gy was prescribed to the planning target volume. The dose-volume histograms were generated, and the paired t-test was used to analyze the dose differences. FJT-IMRT had similar mean heart volume receiving 30Gy (V30 Gy) with tangential-IMRT (1.5% and 1.6%, p = 0.41), but inferior to the VMAT (0.8%, p < 0.001). In the average heart mean dose comparison, FJT-IMRT had the lowest value, and it was 0.6Gy lower than that for the VMAT plans (p < 0.01). A significant dose increase in the contralateral breast and lung was observed in VMAT plans. Compared with tangential-IMRT and VMAT plans, FJT-IMRT reduced the mean dose of thyroid, humeral head and cervical esophageal by 47.6% (p < 0.01) and 45.7% (p < 0.01), 74.3% (p =< 0.01) and 73% (p =< 0.01), and 26.7% (p =< 0.01) and 29.2% (p =< 0.01). In conclusion, compared with tangential-IMRT and VMAT, FJT-IMRT plan has the lowest thyroid, humeral head and cervical esophageal mean dose and it can be a reasonable treatment option for a certain subgroup of patients, such as young left-breast cancer patients and/or patients with previous thyroid disease.

Improved patient repositioning accuracy by integrating an additional jaw fixation into a high precision face mask system in stereotactic radiotherapy of the head; Verbesserte lagerungsreproduzierbarkeit eines nichtinvasiven hochpraezisionsmaskensystems in der stereotaktischen Radiotherapie durch eine integrierte kieferfixierung

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Lopatta, E.; Liesenfeld, S.M.; Bank, P.; Guenther, R.; Wiezorek, T.; Wendt, T.G. [Klinik fuer Radiologie, Abt. fuer Strahlentherapie, Friedrich-Schiller-Univ. Jena (Germany); Wurm, R. [Campus Charite Mitte, Klinik fuer Strahlentherapie, Berlin (Germany)

2003-08-01

Background: For high precision radiotherapy of the neurocranium a precise, reproducible positioning technique is the basic pre-requisite. The aim of this study was to assess the influence of a modification of the commercially available stereotactical BrainLab {sup trademark} -head mask system on accuracy in patient positioning during fractionated radiotherapy. Material and Methods: 29 patients were treated with stereotactic radiotherapy of the head. Immobilization was provided by a two layer thermoplastic mask system (BrainLab trademark). 18 of these patients received an additional custom made fixation either of the upper jaw (OKF) or of the mandibula (UKF). The positioning accuracy was assessed by measurements of the shifting of anatomical landmarks in relation to therigid mask system on biplanar simulator films using a digital imaging system. Before each measurement a fine adjustment of the simulator to an optical ring system was performed. The reference radiographs were done just before CT-planning. During a 2-7 weeks lasting course of radiotherapy displacement measurements in relation to the reference images for all three dimensions (z, y and x) were done once a week. In 29 patients 844 measurements were analyzed. Results: An additional jaw fixation improves the reproducibility of patient positioning significantly in all three spatial dimensions. The standard deviation in lateral direction (x) was 0.6 mm with jaw fixation vs. 0.7 mm without jaw fixation (p < 0.001); in longitudinal direction (z) (measured in 0 radiographs) 0.5 mm vs. 1.3 mm (p < 0.001); in longitudinal direction measured in 90 (orig.) [German] Hintergrund: Eine Grundvoraussetzung fuer die Praezisionsbestrahlung im Bereich des Neurokraniums ist eine genaue, reproduzierbare Lagerungstechnik. Die vorliegende Arbeit untersucht den Einfluss einer Modifikation am kommerziell erhaeltlichen stereotaktischen BrainLab trademark -Kopfmaskensystem auf die Lagerungsgenauigkeit waehrend einer fraktionierten

Population Genetic Structure and Genetic Diversity in Twisted-Jaw Fish, Belodontichthys truncatus Kottelat & Ng, 1999 (Siluriformes: Siluridae, from Mekong Basin

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Surapon Yodsiri

2017-01-01

Full Text Available The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.

Quantitative ultrasound at the hand phalanges in patients with bisphosphonate-related osteonecrosis of the jaws

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Ana Carolina Fragoso MOTTA

2015-01-01

Full Text Available Patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ who received intravenous or oral bisphosphonates (BP were selected for determination of their bone microarchitecture as a risk predictor of BRONJ development. The diagnosis of BRONJ was made based on clinical and radiographic findings. The control group consisted of healthy patients. All patients underwent quantitative and qualitative ultrasound measurements of bone at the hand phalanges carried out using the DBM Sonic BP. Ultrasound bone profile index (UBPI, amplitude-dependent speed of sound (AD-SoS, bone biophysics profile (BBP, and bone transmission time (BTT were measured. The BRONJ group consisted of 17 patients (62 ± 4.24; range: 45-82; 10 (58.8% were male and seven (41.1% were female, of whom 11 (64.7% suffered from multiple myeloma, three (17.6% from osteoporosis, one (5.8% from prostate cancer, one (5.8% from kidney cancer, and one (5.8% from leukemia. Fourteen (82.3% of them received intravenous BP whereas three (17.6% received oral BP. Nine (9/17; 52.9% patients developed bone exposure: two in the maxilla and seven in the mandible. Regarding quantitative parameters, Ad-SoS was low in the BRONJ group, but not significant. The UBPI score was significantly reduced in BRONJ patients with exposed bone when compared to controls (0.47 ± 0.12 vs. 0.70 ± 0.15; p = 0.004. The present study demonstrated that quantitative ultrasound was able to show bone microarchitecture alterations in BRONJ patients, and suggests that these analyses may be an important tool for early detection of bone degeneration associated with BRONJ.

Head, Neck, and Oral Cancer

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Full Text Available ... out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment of jaws ... out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment of jaws ...

Obstructive Sleep Apnea

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Full Text Available ... out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment of jaws ... out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment of jaws ...

Administration of Anesthesia

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Full Text Available ... out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment of jaws ... out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment of jaws ...

Risk factors of osteonecrosis of the jaw after tooth extraction in osteoporotic patients on oral bisphosphonates

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Jeong, Ho Gui; Hwang, Jae Joon; Lee, Jeong Hee; Kim, Young Hyun; Na, Ji Yeon; Han, Sang Sun [Dept. of Oral and Maxillofacial Radiology, Yonsei University, College of Dentistry, Seoul (Korea, Republic of)

2017-03-15

The aim of this study was to investigate the incidence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) after tooth extraction in patients with osteoporosis on oral bisphosphonates in Korea and to evaluate local factors affecting the development of BRONJ. The clinical records of 320 patients who underwent dental extraction while receiving oral bisphosphonates were reviewed. All patients had a healing period of more than 6 months following the extractions. Each patient's clinical record was used to assess the incidence of BRONJ; if BRONJ occurred, a further radiographic investigation was carried out to obtain a more definitive diagnosis. Various local factors including age, gender, extraction site, drug type, duration of administration, and C-terminal telopeptide (CTx) level were retrieved from the patients' clinical records for evaluating their effect on the incidence of BRONJ. Among the 320 osteoporotic patients who underwent tooth extraction, 11 developed BRONJ, reflecting an incidence rate of 3.44%. Out of the local factors that may affect the incidence of BRONJ, gender, drug type, and CTx level showed no statistically significant effects, while statistically significant associations were found for age, extraction site, and duration of administration. The incidence of BRONJ increased with age, was greater in the mandible than the maxilla, and was associated with a duration of administration of more than 3 years. Tooth extraction in patients on oral bisphosphonates requires careful consideration of their age, the extraction site, and the duration of administration, and close postoperative follow-up should be carried out to facilitate effective early management.