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Sample records for central incisors based

  1. The primary Maxillary Central Incisor in the Solitary Median Maxillary Central Incisor syndrome

    DEFF Research Database (Denmark)

    Kjaer, I; Balslev-Olesen, M

    2012-01-01

    Solitary Median Maxillary Central Incisor (SMMCI) is a developmental anomaly in the permanent dentition with one single central incisor in the maxilla, positioned exactly in the midline. This condition has been associated with extra- and intraoral malformations in the frontonasal segment of the c...

  2. Two root canals in maxillary central incisor

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    Fábio de Almeida Gomes

    2011-07-01

    Full Text Available Introduction and objective: The success of endodontic treatment requires the knowledge of tooth morphology and its variations. Case report: This clinical article reports an unusual root canal configuration that was detected in a maxillary central incisor with two root canals, demonstrated by radiographic and computerized tomography exams. Conclusion: Knowledge of endodontic anatomy as well as the obtainment of both preoperative radiographs and tomography is important to detect abnormal tooth morphology.

  3. Interceptive management of winged maxillary central incisors

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    Mamta Dali

    2013-01-01

    Full Text Available Introduction: Winged maxillary incisors are a well-recognized clinical finding, which can result in psychological trauma to children at growing age. Interceptive treatment is usually carried out in mixed dentition period in order to reduce the severity of a developing malocclusion in future. Case Report: This paper reports a case of 6-years-old female patient with winged maxillary central incisor being treated with derotation technique using the beggs brackets along with nance palatal arch space maintainer. Discussion: The major advantages in carrying out this treatment with fixed brackets are the ease with which the force magnitude and vector can be controlled much more precisely than with a removable appliance, minimal discomfort to the patient and reduces the need for patient co-operation.

  4. Solitary median maxillary central incisor (SMMCI syndrome

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    Hall Roger K

    2006-04-01

    Full Text Available Abstract Solitary median maxillary central incisor syndrome (SMMCI is a complex disorder consisting of multiple, mainly midline defects of development resulting from unknown factor(s operating in utero about the 35th–38th day(s from conception. It is estimated to occur in 1:50,000 live births. Aetiology is uncertain. Missense mutation in the SHH gene (I111F at 7q36 may be associated with SMMCI. The SMMCI tooth differs from the normal central incisor, in that the crown form is symmetric; it develops and erupts precisely in the midline of the maxillary dental arch in both primary and permanent dentitions. Congenital nasal malformation (choanal atresia, midnasal stenosis or congenital pyriform aperture stenosis is positively associated with SMMCI. The presence of an SMMCI tooth can predict associated anomalies and in particular the serious anomaly holoprosencephaly. Common congenital anomalies associated with SMMCI are: severe to mild intellectual disability, congenital heart disease, cleft lip and/or palate and less frequently, microcephaly, hypopituitarism, hypotelorism, convergent strabismus, oesophageal and duodenal atresia, cervical hemivertebrae, cervical dermoid, hypothyroidism, scoliosis, absent kidney, micropenis and ambiguous genitalia. Short stature is present in half the children. Diagnosis should be made by eight months of age, but can be made at birth and even prenatally at 18–22 weeks from the routine mid-trimester ultrasound scan. Management depends upon the individual anomalies present. Choanal stenosis requires emergency surgical treatment. Short stature may require growth hormone therapy. SMMCI tooth itself is mainly an aesthetic problem, which is ideally managed by combined orthodontic, prosthodontic and oral surgical treatment; alternatively, it can be left untreated.

  5. Review of Dilaceration of Maxillary Central Incisor: A Mutidisciplinary Challenge.

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    Walia, Pawanjit Singh; Rohilla, Ajit Kumar; Choudhary, Shweta; Kaur, Ravneet

    2016-01-01

    Traumatic injuries to primary dentition may interfere with the development of permanent dentition. Among the many malformations, dilaceration is particularly important to the clinician. Management of dilacerated maxillary central incisor requires a multidisciplinary approach. The main purpose of this review is to present the etiological factors, the mechanism, clinical features, radiographic features and treatment of dilaceration of the maxillary central incisors. How to cite this article: Walia PS, Rohilla AK, Choudhary S, Kaur R. Review of Dilaceration of Maxillary Central Incisor: A Multidisciplinary Challenge. Int J Clin Pediatr Dent 2016;9(1):90-98.

  6. A facial talon cusp on maxillary permanent central incisors

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    Suneelkumar Chinni

    2012-01-01

    Full Text Available Talon cusp is a dental anomaly that occurs as an accessory cusp like structure, from the cingulum of maxillary and mandibular anterior teeth. Lingual location is usually considered pathognomic. This case report discuss about the unusual appearance of talon cusp on the facial surface of the maxillary left permanent central incisor and a mild talon cusp on the facial surface of the maxillary right permanent central incisor.

  7. Extraction of Maxillary Central Incisors: An Orthodontic-Restorative Treatment

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    Zohreh Hedayati

    2014-01-01

    Full Text Available Malformed central incisors with poor prognosis could be candidates for extraction especially in crowded dental arches. This case report refers to a 12-year-old boy who suffered from malformed upper central incisors associated with severe attrition. Upper lateral incisors were positioned palatally and canines were rotated and positioned in the high buccal area. The patient had class II malocclusion and space deficiency in both dental arches. Due to incisal wear and malformed short maxillary central incisors and the need for root canal therapy with a major crown build-up, these teeth were extracted. The maxillary lateral incisors were substituted. Thus the maxillary canines were substituted for lateral incisors and the first premolars were substituted for canines. In the lower dental arch the first bicuspids were extracted. Composite resin build-up was performed on the maxillary lateral incisors and canines. This allowed for the crowding and the malocclusion to be corrected. Subsequent gingivectomy improved the patient's gingival margins and smile esthetics one month after orthodontic therapy.

  8. An efficient biomechanical approach for the management of an impacted maxillary central incisor.

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    Chandhoke, Taranpreet K; Agarwal, Sachin; Feldman, Jonathan; Shah, Raja A; Upadhyay, Madhur; Nanda, Ravindra

    2014-08-01

    Treatment of an impacted maxillary central incisor poses a unique challenge to the orthodontist because of its position within the esthetic zone, requiring careful management of the soft tissues and an effective biomechanical setup for alignment. This article describes a novel method of extending an extrusion wire from cross tubes attached on the base archwire for forced eruption of impacted central incisors. The effectiveness and versatility of this method are demonstrated with 2 patients.

  9. Dental transposition of canine and lateral incisor and impacted central incisor treatment: A case report

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    Tarcisio Jacinto Gebert

    2014-01-01

    Full Text Available INTRODUCTION: Dental transposition and impaction are disorders related to ectopic eruption or failure in tooth eruption, which can affect child physical, mental and social development and may be difficult to be clinically solved. METHODS: We describe a case of transposition between the upper left canine and lateral incisor associated with impaction of the central incisor on the same side, in a 12-year-old patient. Conservative treatment involving surgical-orthodontic correction of transposed teeth and traction of the central incisor was conducted. CONCLUSION: The option of correcting transposition and orthodontic traction by means of the segmented arch technique with devices such as cantilever and TMA rectangular wire loops, although a complex alternative, was proved to be esthetically and functionally effective.

  10. Management of maxillary alveolar bone fracture and severely intruded maxillary central incisor: report of a case.

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    Yonezawa, Hisanobu; Yanamoto, Souichi; Hoshino, Tomonori; Yamada, Shin-Ichi; Fujiwara, Taku; Umeda, Masahiro

    2013-10-01

    An 11-year-old male who injured his maxilla and right maxillary central incisor and lip during a fall was presented to our hospital. His lower lip and upper gingiva were lacerated with swelling and epistaxis, and he had a maxillary alveolar bone fracture and severe intrusion of the right maxillary central incisor, which had penetrated the floor of the nasal cavity with avulsion. Under local anesthesia, we repositioned the incisor and bone segment and fixed them with a titanium micromesh plate and self-tapping screws and splints. The incisor was also treated by root canal 3 days after the operation and was restored with a crown. We performed root canal filling 1 month later. Five months later, the plate and screws were removed. In prognosis of our case, no symptoms of inflammatory root resorption or ankylosis have observed for more than 1 year and 6 months of follow up based on both clinical and radiographic findings.

  11. Esthetic periodontal surgery for impacted dilacerated maxillary central incisors.

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    Wei, Yu-Ju; Lin, Yi-Chun; Kaung, Shou-Shin; Yang, Shue-Fen; Lee, Shyh-Yuan; Lai, Yu-Lin

    2012-10-01

    Clinicians do not frequently see impacted dilacerated maxillary incisors in their patients. When they do, there are several diagnostic and management challenges for correcting root dilacerations. An unfavorable esthetic outcome might occur as a result of soft-tissue complications during surgical eruption procedures. We present 2 patients with an impacted and dilacerated maxillary central incisor. Computed tomography scans with 3-dimensional reformation were used to accurately assess the positions of the dilacerated teeth, the degree of dilaceration, and the stage of root formation. The therapy primarily involved 2-stage crown exposure surgery combined with orthodontic traction. An apicoectomy was performed on 1 dilacerated tooth; the other exhibited pulp vitality. This article highlights the periodontal surgical strategies for the esthetic management of inverted crowns. Through periodontal plastic surgery and interdisciplinary cooperation, the impacted dilacerated central incisors were properly aligned, and successful esthetic results were achieved.

  12. Elastic Band Causing Exfoliation of the Upper Permanent Central Incisors

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    Monica Ghislaine Oliveira Alves

    2015-01-01

    Full Text Available Objective. This study reports a case in which elastic band use culminated in the loss of the incisors. Case Report. An 11-year-old white girl was seen complaining of pain, with purulent discharge and severe tooth mobility. The bone destruction detected radiographically in the region, despite its single location and absence in posterior quadrants of the maxilla and/or mandible, was similar to that observed in Langerhans cell disease. To our surprise, an elastic band involving the midportion of the roots of the two upper central incisors was found during biopsy. The debris was removed and a metal wire was placed in permanent maxillary right and left incisors. The patient was followed up, but no improvement in tooth mobility was observed. Bone loss increased, and internal resorption and root exposure occurred, which culminated in the extraction of permanent maxillary right and left incisors. Conclusion. The present case highlights the fact that professionals sometimes are confronted by anamnestic reports never seen before.

  13. Fragment Reattachment after Atypical Crown Fracture in Maxillary Central Incisor

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    Vanessa Torraca Peraro Vaz

    2014-01-01

    Full Text Available Background. Fracture by trauma is one of the most common types of dental injury in the permanent dentition among children and teenagers. Aim. The aim of this study was to report the treatment performed to an atypical dental trauma case in a maxillary central incisor of a young patient by means of reattachment of the tooth fragment. Case Description. A 12-year-old male patient suffered a vertical crown fracture to the maxillary right central incisor. After clinical and radiographic examinations, a conservative restorative treatment which consisted in the reattachment of the tooth fragment with flow resin was performed in order to preserve the dental element and to obtain maximum aesthetics. Conclusion. The reattachment of fractured fragment is a fast and easy technique that can be used successfully as an option to restore dental element which suffered trauma. Clinical Significance. This technique restores the aesthetics and function of the dental element with minimal discomfort to the patient.

  14. A maxillary central incisor with four root canals

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    Fábio de Almeida-Gomes

    2012-01-01

    Full Text Available The objective of the present study is to present a case report of endodontic treatment of a maxillary central incisor with 1 root and 4 root canals. The success of endodontic treatment requires knowledge of dental anatomy and its variations. This clinical article reports an unusual anatomy detected in a maxillary central incisor with 4 root canals with an associated periapical lesion. The incidence of 4 root canals in this tooth is rare. However, it must be taken into consideration, the clinical and radiographic evaluations during the endodontic treatment in order to enhance the diagnostic. Many times, the presence of a supernumerary canal is noticed only after canal treatment due to continuing post-operative discomfort or treatment failure.

  15. 3 '2' 1: Orthodontic re-positioning of canines into central incisors.

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    Mahdmina, A; Malik, O; Ashley, M; Waring, D

    2012-04-27

    Resorption of lateral incisors caused by impacted maxillary canines is frequently reported. However, resorption of the central incisor is less common and management of such a finding can prove to be a challenge for the clinician. This article reviews the literature of impacted canines and incisor resorption. The management of two cases of severe central incisor resorption caused by an impacted maxillary canine is also described.

  16. Internal root resorption in the maxillary central incisor

    OpenAIRE

    2010-01-01

    Introduction: Internal root resorption is a chronic inflammatory process initiated within the pulp space with the loss of dentin. The clastic cells present in the pulp tissue trigger a progressive resorption phenomenon. Case report and conclusion: This paper reports a clinical case of an internal root resorption in the permanent central incisor, at the middle third of the root canal. Because it is asymptomatic,internal root resorption needs an early diagnosis in order to institute the endodon...

  17. Management of avulsed permanent maxillary central incisors during endotracheal intubation

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    Ritesh R Kalaskar

    2016-01-01

    Full Text Available Avulsion is serious injury that may encounter during endotracheal intubation and its management often presents a challenge. Replantation of the avulsed tooth can restore esthetic appearance and occlusal function shortly after the injury. The present article describes the management of air-dried maxillary permanent incisors that have been avulsed due to direct laryngoscopy during the induction of general anesthesia for tonsillectomy procedure. The replanted maxillary central incisors had maintained its function and esthetic for 1 year after replantation. Children in a mixed dentition phase are high-risk group children for traumatic dental injury during laryngoscopy; therefore, Anesthetic Departments should have local protocols to refer patients for dental treatment postoperatively in the event of trauma.

  18. Eruption age of permanent mandibular first molars and central incisors in the south Indian population

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    Gupta Rakhi

    2007-01-01

    Full Text Available Objective: The existing eruption schedules for permanent and deciduous dentition are based on studies in the Western population. Since Indians differ from Westerners racially, genetically, and environmentally, these studies fail to provide relevant guidance on the eruption schedule in the Indian population. This study aims at determining the eruption pattern of permanent mandibular molars and central incisors in the south Indian population. Materials and Methods: 10,156 apparently healthy Indian children in the age-group of 6-9 years were examined with mouth mirror and probe under adequate illumination for the status of the eruption of the permanent mandibular first molar and permanent mandibular central incisor. Pearson′s Chi-square test with Yates′ continuity correction was used to calculate the P -value for comparison of proportion between girls and boys. The values obtained in our study were compared with the standard values. The Z-test with continuity correction was used to calculate the P -value. Results: As per our study, the permanent mandibular first molars and central incisors erupted one to two years later compared to the values reported in Westerners. The earlier eruption of the permanent mandibular first molars compared to the permanent mandibular central incisors, as well as the earlier eruption of both the teeth in girls compared to boys, were in accordance with the existing literature. Conclusion: The eruption age reported by us may form a standard reference for eruption age in Indians.

  19. Lengths of the maxillary central incisor, the nasal bone, and the anterior cranial base in different skeletal malocclusions

    DEFF Research Database (Denmark)

    Arntsen, Torill; Kjær, Inger; Sonnesen, Liselotte

    2009-01-01

    Objective. Based on the results of previous studies of osseous structures within the frontonasal field in patients with a known malformation in the frontonasal field, the aim of the present study was to clarify whether the same structures were malformed in patients with severe skeletal malocclusi...

  20. Treatment of cariously involved fused maxillary primary lateral and central incisors.

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    ElBadrawy, H E; Diab, M

    2001-01-01

    A 3-and-a-half-year-old male child presented with fused cariously involved right maxillary primary central and lateral incisors as well as a previously traumatized non-vital left primary central incisor with a draining fistula. The child also had other restorative needs and the decision taken was to address all needs under a G.A. With respect to the fused incisors, these were split and root canals treatment was performed for all three incisors which were then restored with stainless steel crowns with esthetic facings.

  1. Dilaceration of Mandibular Central Incisor: a case report

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    Senem Yigit Ozer

    2011-01-01

    Full Text Available Dilaceration of teeth can ocur as a result of trauma to its primary predecessors. Crown dilaceration is more rare than root dilacerations. This report describes a rare case of crown dilaceration of the mandibular central incisor caused by trauma. Periapical radiography and cone beam computed tomography scans revealed a severe crown dilaceration in the labial direction. After conventional root canal treatment, a glass fiber-reinforced post was placed and the tooth was restored using the original crown which was removed from the root before root canal obturation. One year after the treatment, the tooth was clinically intact without mobility and there was no sensitivity during percussion. Radiographic examination revealed that the periodontal tissues were healthy and there was no sign of root resorption. It was concluded that correct diagnosis and prompt treatment help to achieve desirable esthetics and function for crown dilecaration.

  2. Craniofacial morphology of the frontonasal segment in patients with one or two macrodontic maxillary central incisors.

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    Kenrad, Astrid Breum; Christensen, Ib Jarle; Kjær, Inger

    2013-06-01

    The purpose was to describe the craniofacial morphology of the frontonasal segment in patients with one or two macrodontic central incisors. Latero-lateral head radiographs from 21 patients were analyzed. Cephalometric analyses were performed with focus on the morphology of the frontonasal segment of the cranium, including nasal bone, maxilla, thickness of the frontal bone, sella turcica, and the anterior cranial fossa. The macrodontic incisors are located in this frontonasal segment. Increased values compared with normal were observed in the following: the length of the nasal bone (P = 0.038), the thickness of the frontal bone (P = 0.003), the length of the sella turcica (P = 0.006), the cranial base angle (P = 0.036), the length of the anterior cranial fossa (P = 0.002), and the height (P = 0.042) and length (P = 0.011) of the maxilla. The prognathia of the maxilla was significantly decreased (P = 0.003). The depth of the sella turcica and the inclination of the maxilla were normal. This study is a new example of how the morphology of the dentition and the underlying jaw (the frontonasal segment) are interrelated. It is also an example of how the maxillary incisors and jaws are interrelated with the anterior cranial base, including the sella turcica morphology.

  3. Correlation Between Maxillary Central Incisor Crown Morphology And Mandibular Dental Arch Form In Normal Occlusion Subjects

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    Paranhos, Luiz Renato; Lima,Carolina Souto; Silva,Ricardo Henrique Alves da; Daruge Júnior,Eduardo; Torres,Fernando Cesar

    2012-01-01

    The aim of this study was to evaluate the correlation between the morphology of the mandibular dental arch and the maxillary central incisor crown. Cast models from 51 Caucasian individuals, older than 15 years, with optimal occlusion, no previous orthodontic treatment, featuring 4 of the 6 keys to normal occlusion by Andrews (the first being mandatory) were observed. The models were digitalized using a 3D scanner, and images of the maxillary central incisor and mandibular dental arch were ob...

  4. Movement of an upper central incisor across the midline in a patient with cleft of primary palate.

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    Manosudprasit, Montian; Wangsrimongkol, Tasanee; Pisek, Poonsak; Chittiwatanapong, Nisa

    2013-09-01

    Orthodontic treatment for a 10-years-old girl, with repaired bilateral cleft lip and left incomplete unilateral alveolar cleft, was performed by moving her right maxillary central incisor across the midline to replace her congenital missing central incisor and then moving the right lateral incisor toward the midline to act as a new central incisor. A malformed supernumerary tooth, positioned between the right central and lateral incisor, was extracted during incisor movement. Significant lip profile improvement was accomplished by maxillary and mandibular anterior teeth retraction into three-premolar extraction spaces. Not only natural functional occlusion, deviated midpalatal suture along the central incisor, and no obvious root resorption were obtained but also narrowing the alveolar bone cleft which was beneficial for bone continuity supporting dental structures, satisfactory results were possible for the patient with primary palate cleft.

  5. Managing the severely proclined maxillary anteriors by extracting traumatized right maxillary central incisor

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    Mahesh Jain

    2014-01-01

    Full Text Available A 14-year-old girl reported with severely proclined maxillary anterior teeth with fractured and discolored right maxillary central incisor with questionable prognosis. Autotransplantation of premolar to replace central incisor was considered a risky option as patient was 14-year-old with presence of advanced root development of premolar. The immediate placement of the prosthetic implant was also not possible because of patient′s age. Therefore, it was decided to use the space obtained by extracting questionable maxillary right central incisor for orthodontic purpose and also sacrificing the healthy premolar is invariably an excessive biological cost for a modest functional and aesthetic gain. Hence, the treatment plan for this case includes extraction of right maxillary central incisor and left maxillary first premolar, movement of right maxillary lateral incisor mesially, achieving normal axial inclination of maxillary anteriors with normal overjet and overbite. Mandibular arch was treated nonextraction due to congenitally missing central incisors with presence of normally inclined lower anteriors thereby maintaining Angles class I occlusion. Tipping, usually, seen in Begg mechanotherapy was used for our advantage to correct severely proclined maxillary anteriors with simultaneous bite opening mechanics. Case was completed in 19 months and posttreatment records including photographs, radiographs and study models were made. Begg wrap around the retainer was placed in the maxillary arch allowing natural settling of occlusion.

  6. Impacted maxillary canine on the position of the central incisor: surgical-orthodontic repositioning.

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    Farronato, G; Giannini, L; Folegatti, C; Brotto, E; Galbiati, G; Maspero, C

    2013-04-01

    The aim of this article is to describe a case of a young orthodontic patient in which an impacted maxillary canine was repositioned in the central incisor position. A severe resorption of the root of the central right maxillary incisor by ectopic eruption of the impacted right maxillary canine is described. The canine was repositioned in the incisor's position to avoid resorption of the roots of the adjacent teeth during the disinclusion. The central incisor was extracted and the canine was extruded by a closed eruption technique. When the canine eruption was complete, the tip, the torque and the morphology of the canine were modified in order to make it look like an incisor. Nowadays the therapy with dental implants is the best choice, if the position of impacted teeth is difficult to reach. This case report describes a successful management of an impacted upper right canine aligned in the upper right central incisor position. Accurate diagnosis, conservative management of the soft tissues, anchorage unit and the direction of the orthodontic traction are important factors for the success treatment.

  7. Clinical and radiographic evaluation of maxillary central incisors exposure in patients undergoing maxillary advancement

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    Guilherme dos Santos Trento

    2015-12-01

    Full Text Available Abstract Introduction: Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics. Objective: This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement. Methods: A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%. Results: After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002. Conclusions: Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness.

  8. Unusual ectopic eruption of a permanent central incisor following an intrusion injury to the primary tooth.

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    Canoglu, Ebru; Akcan, Cenk Ahmet; Baharoglu, Erdinç; Gungor, H Cem; Cehreli, Zafer C

    2008-10-01

    Intrusive luxation of primary teeth carries a high risk of damage to underlying permanent tooth germs. Ectopic eruption of permanent incisors is an unusual outcome of traumatic injury to their predecessors. In this case report, we describe the multidisciplinary management of the consequences of a primary tooth intrusion that led to severe ectopic eruption of the permanent left central incisor in a horizontal position at the level of the labial sulcus.

  9. Orthodontic Management of a Severely Rotated Maxillary Central Incisor in the Mixed Dentition: A Case Report

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    Arezoo Jahanbin

    2014-06-01

    Full Text Available The aim of this case report was to introduce an appliance for correcting severe rotation of anterior teeth in the mixed dentition period. A 9-year-old Iranian boy with a mixed dentition Class I malocclusion complained of a severely rotated of upper right central incisor. There was a mesiodens between the central incisors. The supernumerary tooth was first extracted and then a Whip appliance which is composed of a removable plate, a cantilever spring and a central bracket on the rotated tooth was utilized. After 8 months, the upper right central incisor was orthodontically brought into proper alignment. Circumferential supracrestal fibrotomy was performed on the overcorrected tooth. One week after surgery, the device was removed and the retention was started. The whip appliance is a removable appliance that can effectively correct severe rotation of anterior teeth especially during the mixed dentition period.

  10. Bilateral presence of two root canals in maxillary central incisors: A rare case study

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    M Kavitha

    2014-01-01

    Full Text Available Success in root canal treatment is achieved after thorough cleaning and shaping followed by complete obturation of the canal system. Therefore, endodontic therapy requires specific and complete knowledge of the internal and external dental anatomy, and its variations in presentation. The internal anatomy of the maxillary central incisor is well-known and usually presents one root canal system. This case report describes an endodontic treatment of traumatized both maxillary central incisors with two canal systems. Knowledge of dental anatomy is fundamental for proper endodontic practice. When root canal treatment is performed, the clinician should be aware that both external and internal anatomy may be abnormal.

  11. Bilateral presence of two root canals in maxillary central incisors: A rare case study.

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    Kavitha, M; Gokul, Kannan; Ramaprabha, B; Lakshmi, Amudha

    2014-04-01

    Success in root canal treatment is achieved after thorough cleaning and shaping followed by complete obturation of the canal system. Therefore, endodontic therapy requires specific and complete knowledge of the internal and external dental anatomy, and its variations in presentation. The internal anatomy of the maxillary central incisor is well-known and usually presents one root canal system. This case report describes an endodontic treatment of traumatized both maxillary central incisors with two canal systems. Knowledge of dental anatomy is fundamental for proper endodontic practice. When root canal treatment is performed, the clinician should be aware that both external and internal anatomy may be abnormal.

  12. Maxillary canine substitution for the severely resorbed root of central incisor: 12-year follow-up.

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    Koga, Yoshiyuki; Park, Jae Hyun; Tai, Kiyoshi

    2013-01-01

    Ectopically erupting maxillary canines can cause problems that necessitate surgical, orthodontic, and restorative treatment. When a canine eruption disturbance causes resorption and requires subsequent extraction of the affected teeth, the resulting spaces are candidates for orthodontic repositioning and recontouring of the remaining teeth. To achieve successful results, the clinician must have a proper knowledge of tooth anatomy, root angulation, gingival margin position, restorative techniques, and occlusion. A collaborative effort from the pediatric dentist, orthodontist, and surgeon is required to produce an esthetic and functional result. This case report describes the substitution of maxillary canines for both the left central and right lateral incisors and substitution of the maxillary right lateral incisor for the maxillary right central incisor.

  13. Type II dens evaginatus of maxillary central incisor: An alternative approach

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    Mansour Alrejaie

    2015-01-01

    Full Text Available Dens evaginatus is the developmental anomaly of tooth that exhibits protrusion of a tubercle from occlusal surfaces of premolar, and lingual surfaces of maxillary central incisor and lateral incisors. Dens evaginatus is common in Caucasian population. Saudi Arabia is also well evidenced of such cases. These tubercles have an enamel layer covering dentin core containing a thin extension of pulp. These cusp-like protrusions are susceptible to pulp exposure from wear or fracture because of malocclusion. Type II dens evaginatus involves normal pulp with immature root apex. Materials to enhance the pulpal recession or pulpotomy procedures indicated in such cases require long time and efforts to ensure pulpal recession or root maturity, respectively. Also prolonged treatment has risk of fracture of the cusp and reinfection and requires patient commitment for the follow-up procedures. Present case describes the use of mineral trioxide aggregate (MTA in type II dens evaginatus of maxillary central incisor.

  14. Stress prediction in a central incisor with intra-radicular restorations

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    Martha Vasconcellos Amarante

    2011-01-01

    Full Text Available A 2D finite element analysis was applied to calculate shear and von Mises equivalent stresses developed, under masticatory loading, in an upper central incisor restored with cast gold post and carbon fiber reinforced epoxy resin post. Based on the predicted shear stress levels, it is concluded that the gold post model is more prone to shear failure along the post-dentin interface. Whereas shear stress concentration also occurs in both models at the core-crown interface, the stress level predicted there is higher for the carbon fiber post model which would be more susceptible to crown displacement. Finally, the prediction of von Mises equivalent stress indicates a non-uniform distribution, with the stress preferentially concentrated in the gold post along its interface with the tooth dentin. For the carbon fiber post restored model, on the other hand, the von Mises stresses are more uniformly distributed achieving its maximum level in the tooth dentin.

  15. Craniofacial morphology of the frontonasal segment in patients with one or two macrodontic maxillary central incisors

    DEFF Research Database (Denmark)

    Kenrad, Astrid Breum; Christensen, Ib Jarle; Kjær, Inger

    2013-01-01

    SUMMARYThe purpose was to describe the craniofacial morphology of the frontonasal segment in patients with one or two macrodontic central incisors.Latero-lateral head radiographs from 21 patients were analyzed. Cephalometric analyses were performed with focus on the morphology of the frontonasal ...

  16. Management of coronal fracture of traumatized central incisor: Report of two cases

    Directory of Open Access Journals (Sweden)

    Saad Mohammad Hassan Al-Zubaidi

    2017-01-01

    Full Text Available Two cases of traumatized permanent maxillary central incisors with complicated crown fractures of young patients are reported. Partial pulpotomy by Cvek technique was performed using mineral trioxide aggregate filling material. The tooth fragment was reattached to the tooth structure with composite resin. Follow-up revealed normal pulpal response, complete apical closer, and dentin bridge formation.

  17. Correlation between maxillary central incisor crown morphology and mandibular dental arch form in normal occlusion subjects.

    Science.gov (United States)

    Paranhos, Luiz Renato; Lima, Carolina Souto; da Silva, Ricardo Henrique Alves; Daruge Júnior, Eduardo; Torres, Fernando Cesar

    2012-01-01

    The aim of this study was to evaluate the correlation between the morphology of the mandibular dental arch and the maxillary central incisor crown. Cast models from 51 Caucasian individuals, older than 15 years, with optimal occlusion, no previous orthodontic treatment, featuring 4 of the 6 keys to normal occlusion by Andrews (the first being mandatory) were observed. The models were digitalized using a 3D scanner, and images of the maxillary central incisor and mandibular dental arch were obtained. These were printed and placed in an album below pre-set models of arches and dental crowns, and distributed to 12 dental surgeons, who were asked to choose which shape was most in accordance with the models and crown presented. The Kappa test was performed to evaluate the concordance among evaluators while the chi-square test was used to verify the association between the dental arch and central incisor morphology, at a 5% significance level. The Kappa test showed moderate agreement among evaluators for both variables of this study, and the chi-square test showed no significant association between tooth shape and mandibular dental arch morphology. It may be concluded that the use of arch morphology as a diagnostic method to determine the shape of the maxillary central incisor is not appropriate. Further research is necessary to assess tooth shape using a stricter scientific basis.

  18. Central incisor loss after delayed replantation following avulsion: a contemporary restorative and adjunctive orthodontic management approach.

    Science.gov (United States)

    Savi, Andrea; Turillazzi, Oliviero; Cocconi, Renato; Bonanini, Mauro; Pizzi, Silvia; Manfredi, Maddalena

    2012-04-01

    Delayed replantation of an avulsed tooth may result in rapid root resorption or, more frequently, dental ankylosis with subsequent bone substitution. If this process develop slowly, it is possible to observe that tooth loss is characterized by a well conserved alveolus with regard to bone preservation, particularly in vertical dimension. This clinical case reports a dental trauma of a central incisor in a young boy characterized by tooth avulsion and its delayed replantation. After 10 years, dental ankylosis of the incisor was recorded and the patient underwent a prosthetic-orthodontic rehabilitation using CAD-CAM technology and no-prep veneers.

  19. Crowns to create esthetics for mal-aligned central incisors: a case report.

    Science.gov (United States)

    Savadi, Ravindra C; Savadi, Anupama R; Kumar, Preeti Satheesh

    2011-06-01

    This case report describes the smile design of crowded upper central anteriors in a female patient aged 25 years. The patient wanted the correction to be completed in a short period of time. A smile design schedule was drawn up involving root canal treatment of the central incisors and placing posts in both the teeth. All ceramic crowns were then fabricated to establish a very satisfactory and pleasing esthetics.

  20. Compound odontoma associated with mandibular impacted permanent central incisor: a case report

    Directory of Open Access Journals (Sweden)

    Ugur Gurer

    2012-04-01

    Full Text Available

    Odontomas are the most common benign odontogenic tumors that are hamartomas composed of various dental tissues, and there are two types, complex and compound. Compound odontomas are more prevalent than complex odontomas and consist of many teeth–like structures. Most of such lesions are asymptomatic. These lesions are generally diagnosed by routine radiological examination. The compound type is generally found in the anterior region of the maxilla. The etiology of these lesions has not been precisely explained. If there is absence of any contraindication, the treatment for odontomas is surgical excision.

    This article describes a case of compound odontoma associated with impacted central mandibular right permanent incisor in a 12–year–old female due to trauma. The odontoma was surgically removed with an impacted central incisor.

  1. A Case Report of Dilacerated Crown of a Permanent Mandibular Central Incisor.

    Science.gov (United States)

    Bolhari, Behnam; Pirmoazen, Salma; Taftian, Ensieh; Dehghan, Somayeh

    2016-11-01

    Trauma to primary teeth can lead to devastating sequels in development of permanent successors. The disturbance may range from enamel hypoplasia and/or hypo-calcification to arrest of dental bud development. Crown dilaceration of permanent teeth is one of the consequences of trauma to deciduous teeth mainly due to intrusion or avulsion. This report presents a mandibular central incisor with dilacerated crown and yellowish discoloration with symptomatic apical abscess. History revealed avulsion of primary mandibular central incisors. The purpose of this report is to present: 1. Reasons of dilacerated crown, yellowish discoloration and necrotic pulp in this case, 2. Treatment options in different types of crown dilacerations and also in this case. The tooth was successfully managed by nonsurgical root canal therapy and restoration with composite resin to restore esthetics. We emphasize that trauma to deciduous teeth should not be understated, and regular follow up is essential.

  2. A Case Report of Dilacerated Crown of a Permanent Mandibular Central Incisor

    OpenAIRE

    Bolhari, Behnam; Pirmoazen, Salma; Taftian, Ensieh; Dehghan, Somayeh

    2016-01-01

    Trauma to primary teeth can lead to devastating sequels in development of permanent successors. The disturbance may range from enamel hypoplasia and/or hypo-calcification to arrest of dental bud development. Crown dilaceration of permanent teeth is one of the consequences of trauma to deciduous teeth mainly due to intrusion or avulsion. This report presents a mandibular central incisor with dilacerated crown and yellowish discoloration with symptomatic apical abscess. History revealed avulsio...

  3. A Case Report of Dilacerated Crown of a Permanent Mandibular Central Incisor

    OpenAIRE

    Behnam Bolhari; Salma Pirmoazen; Ensieh Taftian; Somayeh Dehghan

    2017-01-01

    Trauma to primary teeth can lead to devastating sequels in development of permanent successors. The disturbance may range from enamel hypoplasia and/or hypo-calcification to arrest of dental bud development. Crown dilaceration of permanent teeth is one of the consequences of trauma to deciduous teeth mainly due to intrusion or avulsion. This report presents a mandibular central incisor with dilacerated crown and yellowish discoloration with symptomatic apical abscess. History revealed avulsio...

  4. Rare Root Morphology of a Maxillary Central Incisor Associated With Gingival Hyperplasia

    OpenAIRE

    Monea, Monica; Moldovan, Cosmin

    2016-01-01

    Abstract Dilaceration is a developmental disturbance characterized by the angulation of the crown or root of a permanent tooth, which is often related to trauma of primary dentition. We report a case of a dilacerated root in a maxillary central incisor associated with gingival hyperplasia in a patient under fixed orthodontic treatment, a combination of pathological conditions that had never been mentioned before in the scientific literature. A 10-year-old female patient presented to the Depar...

  5. Labial Talon Cusp on Maxillary Central Incisors: A Rare Developmental Dental Anomaly

    OpenAIRE

    Glavina, Domagoj; Škrinjarić, Tomislav

    2005-01-01

    Labial talon cusp, or dens evaginatus is a very rare dental anomaly of unclear etiology and significance. It can occur as an isolated finding or be associated with other dental anomalies or some syndromes. The present report describes two Caucasian males with labial talon cusp on maxillary permanent left central incisors. In both cases accessory cusp caused plaque accumulation and marginal gingivitis. One case displayed affected tooth to be in cross bite position causing occlusal trauma. No o...

  6. Agenesis of Permanent Mandibular Central Incisors: A Concordant Condition in Siblings

    Science.gov (United States)

    Namineni, Srinivas; Tupalli, Abhinaya Reddy; Challa, Santhosh Kumar

    2016-01-01

    ABSTRACT Concordance is an identical expression of phenotype in two related individuals. Concordance expression of hypodontia is an uncommon condition where associated individuals are affected with exactly similar kind and number of missing teeth. There is very limited documentation of this condition either in twins or in siblings, and literature shows paucity of data with regard to this anomaly. To the best of our knowledge, there is only one such case reported in the literature, which has actually showed similar missing lower central incisors in siblings. This report presents a case of two girl siblings aged 11 and 13 years with congenital bilateral missing of permanent mandibular central incisors, which is an absolute concordant condition. Apart from discussing etiology, clinical implications and management, this article highlights the significance of concordant and discordant condition of hypodontia and expression of this condition in twins and siblings. How to cite this article: Kagitha PK, Namineni S, Tupalli AR, Challa SK. Agenesis of Permanent Mandibular Central Incisors: A Concordant Condition in Siblings. Int J Clin Pediatr Dent 2016;9(1):74-77. PMID:27274160

  7. Ferrule Designs and Stress Distribution in Endodontically Treated Upper Central Incisors: 3D Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    A. Hassan Ahangari

    2008-09-01

    Full Text Available Objective: The main goal of this study was to evaluate stress distribution of endodonti-cally treated maxillary central incisors restored with glass fiber posts, composite resin cores, and crowns with different ferrule designs.Materials and Methods: Four three-dimensional models of a maxillary central incisor were modeled in SolidWorks 2006. Tooth with no ferrule, tooth with a 2 mm circumferen-tial ferrule, tooth with a 2 mm beveled ferrule and tooth with a 0.5 mm circumferential ferrule. The teeth were restored with glass fiber posts, composite resin cores, and full ce-ramics crowns. Each model was loaded (1 N on the palatal side at an angle of 45 degrees to tooth long axis. Von Mises stress findings along the inner surface of the root canals were assessed and compared.Results: The Von Mises Stress at CEJ was the highest in the model without a ferrule when compared to the other models (without ferrule 0.0696, short ferrule 0.0492, cylindrical fer-rule 0.0248, and beveled ferrule 0.0387 MPa.Conclusion: Endodontically treated maxillary central incisors with a ferrule length vary-ing between 0.5 mm and 2.0 mm exhibit lower stress distribution compared to those with-out a ferrule. Keeping a long ferrule is suggested to decrease the stress at the cervical area of restored teeth.

  8. Contour changes in human alveolar bone following tooth extraction of the maxillary central incisor.

    Science.gov (United States)

    Li, Bei; Wang, Yao

    2014-12-01

    The purpose of this study was to apply cone-beam computed tomography (CBCT) to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original morphological evidence for aesthetic implant treatment in the maxillary anterior area. Forty patients were recruited into the study. Each patient had two CBCT scans (CBCT I and CBCT II), one taken before and one taken three months after tooth extraction of maxillary central incisor (test tooth T). A fixed anatomic reference point was used to orient the starting axial slice of the two scans. On three CBCT I axial slices, which represented the deep, middle, and shallow layers of the socket, labial and palatal alveolar bone widths of T were measured. The number of sagittal slices from the start point to the pulp centre of T was recorded. On three CBCT II axial slices, the pulp centres of extracted T were oriented according to the number of moved sagittal slices recorded in CBCT I. Labial and palatal alveolar bone widths at the oriented sites were measured. On the CBCT I axial slice which represented the middle layer of the socket, sagittal slices were reconstructed. Relevant distances of T on the sagittal slice were measured, as were the alveolar bone width and tooth length of the opposite central incisor. On the CBCT II axial slice, which represented the middle layer of the socket, relevant distances recorded in CBCT I were transferred on the sagittal slice. The height reduction of alveolar bone on labial and palatal sides was measured, as were the alveolar bone width and tooth length of the opposite central incisor at the oriented site. Intraobserver reliability assessed by intraclass correlation coefficients (ICCs) was high. Paired sample t-tests were performed. The alveolar bone width and tooth length of the opposite central incisor showed no statistical differences (P<0.05). The labial alveolar bone widths of T at the deep, middle, and shallow layers all showed

  9. Revascularization of an impacted, immature dilacerated permanent maxillary central incisor associated with odontoma and a supernumerary tooth

    Directory of Open Access Journals (Sweden)

    Priya Subramaniam

    2013-01-01

    Full Text Available To intentionally replant an impacted immature permanent maxillary central incisor in the mixed dentition period followed by revascularization in order to achieve apical root closure. A 9-year-old boy presented with retained maxillary left primary incisors. Radiographic evaluation revealed the presence of a supernumerary tooth and an odontoma associated with an impacted permanent maxillary left central incisor, having root dilaceration. Treatment included surgical removal of mesiodens and odontoma. The impacted dilacerated permanent central incisor was removed and intentionally replanted, followed by revascularization of pulp. During the follow-up, root end closure with narrowing of canal space was observed, patient has been asymptomatic and the tooth remains vital. Revascularization of the immature reimplanted tooth showed continued root development and thickening of the lateral dentinal walls through deposition of new hard tissue and narrowing of the canal space.

  10. Ectopic eruption of maxillary central incisor through abnormally thickened labial frenum: An unusual presentation

    Directory of Open Access Journals (Sweden)

    Neeraj Gugnani

    2017-01-01

    Full Text Available Ectopic eruption is a deviation from the normal eruption pattern, making the tooth erupt out of its normal position, and possibly causing resorption of adjacent primary teeth. A wide range of etiological factors may be responsible for ectopic eruption of the teeth, so their management depends on the correction of the established etiological factor. The present case report describes an unusual case of ectopically erupted central incisor encased within an abnormally thickened labial frenum, which was treated by orthodontic repositioning of the ectopically erupting tooth after frenectomy.

  11. Ectopic eruption of maxillary central incisor through abnormally thickened labial frenum: An unusual presentation.

    Science.gov (United States)

    Gugnani, Neeraj; Pandit, I K; Gupta, Monika; Gugnani, Shalini; Vishnoi, Ashmi; Sabharwal, Ozasvita; Manhas, Swati

    2017-01-01

    Ectopic eruption is a deviation from the normal eruption pattern, making the tooth erupt out of its normal position, and possibly causing resorption of adjacent primary teeth. A wide range of etiological factors may be responsible for ectopic eruption of the teeth, so their management depends on the correction of the established etiological factor. The present case report describes an unusual case of ectopically erupted central incisor encased within an abnormally thickened labial frenum, which was treated by orthodontic repositioning of the ectopically erupting tooth after frenectomy.

  12. Evaluation of the force applied by the tongue and lip on the maxillary central incisor tooth

    OpenAIRE

    Valentim,Amanda Freitas; Furlan,Renata Maria Moreira Moraes; Perilo,Tatiana Vargas de Castro; Berbert, Monalise Costa Batista; Motta, Andréa Rodrigues; Casas, Estevam Barbosa de Las

    2014-01-01

    PURPOSE: To describe the development and testing of a system that measures forces exerted by the tongue and upper lip on a tooth during rest and during swallowing. METHODS: Twenty-eight subjects, aged 19-31 years (mean: 23.2 years) were submitted to measurement of forces exerted by the upper lip and tongue on the maxillary right central incisor tooth. Flexiforce resistive sensors were fixed on the labial and lingual surfaces of the tooth. They were connected to an amplifier circuit and a data...

  13. Compound odontoma associated with an unerupted rotated and dilacerated maxillary central incisor

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    Vinaya Kumar Kulkarni

    2011-01-01

    Full Text Available Odontomas are benign tumors containing various component tissues of teeth. They usually remain asymptomatic and are diagnosed on routine radiographs. Clinically, they are often associated with delayed eruption or impaction of permanent teeth and retained primary teeth. A case of compound odontoma in association with an unerupted, rotated and dilacerated maxillary permanent right central incisor in a 12-year-old boy is reported. Such combination is rare, making it an interesting case for reporting. We have also discussed the clinical features, diagnosis and treatment of such a condition.

  14. Labial talon cusp on maxillary central incisors: a rare developmental dental anomaly.

    Science.gov (United States)

    Glavina, Domagoj; Skrinjarić, Tomislav

    2005-06-01

    Labial talon cusp, or dens evaginatus is a very rare dental anomaly of unclear etiology and significance. It can occur as an isolated finding or be associated with other dental anomalies or some syndromes. The present report describes two Caucasian males with labial talon cusp on maxillary permanent left central incisors. In both cases accessory cusp caused plaque accumulation and marginal gingivitis. One case displayed affected tooth to be in cross bite position causing occlusal trauma. No other dental anomalies in either case, neither association with some syndromes were noted. This rare anomaly requires careful dental and physical examination of the affected patient since its finding can be of clinical and genetic significance.

  15. Temporary management of permanent central incisors loss caused by trauma in primary dentition with natural crowns: a case report.

    Science.gov (United States)

    Tüzüner, Tamer; Kuşgöz, Adem; Nur, Bilge Gülsüm

    2009-10-01

    Primary teeth injuries may cause developmental disturbances in the permanent dentition and loss of permanent incisors could be treated with different options. In this case report, an 11-year-old boy, with a history of trauma at the age of 4 years, is presented. Premature loss of permanent upper right central and upper left central teeth because of the mobility and arrest in root development were treated using patient's own natural crowns on a removable appliance. This treatment option could be considered as an esthetic and functional temporary management of permanent central incisors loss until the definitive treatment will be completed in the future.

  16. 上颌埋伏阻生中切牙的影像学分类%Imaging classification of maxillary impacted central incisors

    Institute of Scientific and Technical Information of China (English)

    王镶珊; 胡荣党

    2012-01-01

    PURPOSE: To investigate the classification of maxillary impacted central incisors through three-dimensional images. METHODS: Based on the original Dicom data of the spiral computed tomography of 103 patients with maxillary impacted central incisors, the three-dimensional images of maxillary impacted central incisors were reconstructed by Mimics 10.0 software, and the characteristics were analyzed and a classification was proposed. RESULTS: There were 106 teeth included in this study, 74 teeth were located labially, including 33 inverted impacted teeth, 28 horizontally impacted teeth, and 13 inclined teeth. 20 teeth were located in the palatal side, including 11 inclined teeth and 9 horizontally impacted teeth. 12 teeth were within the bone, which can be divided into three categories based on the position of the crown and in accordance with the vertical, liar to near, and horizontal direction. Type I was labially impacted incisor, including 3 subdivisions: labially inclined impacted, labially horizontal impacted and labially inverted i mpacted. Type II was palatally impacted incisor, including 2 subdivisions: palatally inclined impacted and palatally horizontal impacted. Type 111 was vertically impacted incisor. CONCLUSIONS: The maxillary impacted incisors can be divided into 3 categories based on three-dimensional directions, and subdivisions can be created in each group including labially (inclined, horizontal, inverted) impacted incisors, palatally (inclined, horizontal) impacted incisor and vertically impacted incisors.%目的:探讨上颌埋伏阻生中切牙的三维图像分类特征.方法:根据103例上颌中切牙埋伏阻生患者螺旋CT的Dicom原始数据,应用Mimics10.0软件重建出上颌埋伏阻生中切牙的三维图像,分析上颌埋伏阻生中切牙的阻生特点,并对其进行分类.结果:共有埋伏牙106颗.74颗牙为唇侧阻生,倒置阻生33颗,水平阻生28颗,倾斜阻生13颗;20颗为腭侧阻生,倾斜阻生11

  17. Retreatment of failed regenerative endodontic of orthodontically treated immature permanent maxillary central incisor: a case report

    Science.gov (United States)

    Al-Tammami, Musaed Fahad

    2017-01-01

    A revascularization procedure was shown to be the best alternative therapy for immature teeth with necrotic pulp and apical infection. A 12 year old female with a history of trauma to her upper central incisor and a sinus tract was referred for endodontic treatment. She was an active orthodontic patient and had undergone regenerative endodontic treatment for the past 2 years. Clinical examination revealed no response to sensibility, percussion, and palpation tests. The preoperative radiograph showed an open apex and apical rarefaction. The case was diagnosed as previously treated tooth with asymptomatic apical periodontitis. Regenerative endodontic retreatment was performed, and the case was followed for 3 years. Clinical, radiographic, and cone-beam computed tomography follow-up examination revealed an asymptomatic tooth, with evidence of periapical healing and root maturation. PMID:28194367

  18. Management of recurrent fracture of central incisor with internal resorption using light transmitting (luminex) post.

    Science.gov (United States)

    Hariharan, V S; Nandlal, B; Srilatha, K T

    2010-01-01

    The normal root canal anatomy may be altered in various pathological processes and making it very difficult and at times impossible to achieve ideal obturation by normal methods. Internal resorption is one among them. There are several treatment protocols advised for this pathological condition. A crown-root fracture is defined as a fracture involving enamel, dentin and cementum and accounts for 5% of all traumatic injuries to the permanent dentition. In anterior teeth, these fractures are usually caused by direct trauma and often complicated in fully erupted teeth. In cases where the fracture line extends down along the long axis of the root, extraction of the tooth is indicated. The purpose of this report is to present the use of light transmitting post system to reinforce the crown root fractured maxillary central incisor due to trauma and internal resorption.

  19. Management of recurrent fracture of central incisor with internal resorption using light transmitting (luminex post

    Directory of Open Access Journals (Sweden)

    Hariharan V

    2010-01-01

    Full Text Available The normal root canal anatomy may be altered in various pathological processes and making it very difficult and at times impossible to achieve ideal obturation by normal methods. Internal resorption is one among them. There are several treatment protocols advised for this pathological condition. A crown-root fracture is defined as a fracture involving enamel, dentin and cementum and accounts for 5% of all traumatic injuries to the permanent dentition. In anterior teeth, these fractures are usually caused by direct trauma and often complicated in fully erupted teeth. In cases where the fracture line extends down along the long axis of the root, extraction of the tooth is indicated. The purpose of this report is to present the use of light transmitting post system to reinforce the crown root fractured maxillary central incisor due to trauma and internal resorption.

  20. Multidisciplinary management of subgingival crown-root fracture of an immature permanent maxillary central incisor

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    Samir Zahedpasha

    2012-01-01

    Full Text Available This case report describes the multidisciplinary management of subgingival horizontal crown-root fracture of an immature permanent maxillary central incisor in a 10-year-old boy. After removal of the fractured fragment, pulpotomy was performed within 48 h from the injury to promote apexogenesis. The tooth was orthodontically extruded until the fracture line was located above the alveolar bone level. Frenectomy, supracrestal fiberotomy, and crown lengthening were performed after adequate stabilization of the extruded tooth for 5 months. Finally, the tooth was restored with composite resin by using the acid etch technique. This report highlights that a multidisciplinary treatment approach with strict cooperation among specialists to manage a complicated crown-root fracture can save and restore a traumatized immature permanent tooth.

  1. Multidisciplinary management of subgingival crown–root fracture of an immature permanent maxillary central incisor

    Science.gov (United States)

    Zahedpasha, Samir; Safarcherati, Hengameh; Rahmati-Kamel, Manouchehr; Mehrani-Sabet, Javad

    2012-01-01

    This case report describes the multidisciplinary management of subgingival horizontal crown-root fracture of an immature permanent maxillary central incisor in a 10-year-old boy. After removal of the fractured fragment, pulpotomy was performed within 48 h from the injury to promote apexogenesis. The tooth was orthodontically extruded until the fracture line was located above the alveolar bone level. Frenectomy, supracrestal fiberotomy, and crown lengthening were performed after adequate stabilization of the extruded tooth for 5 months. Finally, the tooth was restored with composite resin by using the acid etch technique. This report highlights that a multidisciplinary treatment approach with strict cooperation among specialists to manage a complicated crown-root fracture can save and restore a traumatized immature permanent tooth. PMID:23087746

  2. Multidisciplinary management of subgingival crown-root fracture of an immature permanent maxillary central incisor.

    Science.gov (United States)

    Zahedpasha, Samir; Safarcherati, Hengameh; Rahmati-Kamel, Manouchehr; Mehrani-Sabet, Javad

    2012-05-01

    This case report describes the multidisciplinary management of subgingival horizontal crown-root fracture of an immature permanent maxillary central incisor in a 10-year-old boy. After removal of the fractured fragment, pulpotomy was performed within 48 h from the injury to promote apexogenesis. The tooth was orthodontically extruded until the fracture line was located above the alveolar bone level. Frenectomy, supracrestal fiberotomy, and crown lengthening were performed after adequate stabilization of the extruded tooth for 5 months. Finally, the tooth was restored with composite resin by using the acid etch technique. This report highlights that a multidisciplinary treatment approach with strict cooperation among specialists to manage a complicated crown-root fracture can save and restore a traumatized immature permanent tooth.

  3. A Case Report of Compound Odontoma Associated with an Unerupted Maxillary Central Incisor

    Directory of Open Access Journals (Sweden)

    Eda Arat Maden

    2014-02-01

    Full Text Available Odontomas generally appear as small, solitary or multiple radio-opaque lesions found on routine radiographic examinations. Traditionally, odontomas are the most common type of odontogenic tumor and they are generally asymptomatic. Occasionally, odontomas may cause disturbances in the eruption of teeth, such as impaction, delay eruption or retention of primary teeth. In general, odontomas occur more often in the permanent dentition. This is a case report of a compound composite odontoma in an 8-year-old boy, which has resulted in failure of eruption of the permanent upper right central incisor while the contra-lateral tooth had erupted. [Arch Clin Exp Surg 2014; 3(1.000: 47-51

  4. Biologic restoration of a traumatized maxillary central incisor in a toddler: A case report

    Directory of Open Access Journals (Sweden)

    Sheen Ann John

    2014-01-01

    Full Text Available Trauma to the anterior teeth is relatively common in young children and teenagers. Traumatized anterior teeth require quick functional and aesthetic repair, and poses a challenge to the dental practitioner owing to the lack of co-operation ceded and the longer time invested. Reattachment of tooth fragment should be the first choice to restoring teeth when a usable fragment is available, since it gives a psychological and aesthetic advantage over the conventional technique. With the vast improvement in adhesive technology, reattachment is definitely a predictable treatment option for very young children. This paper describes the treatment of a 2½ year old female child who sustained crown-root fracture, extending subgingivally, in primary upper central incisor.

  5. Maturogenesis of Two Maxillary Central Incisors: A Case Report with 10 Years of Follow Up

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    Abdollah Ghorbanzadeh

    2015-10-01

    Full Text Available This case report describes the treatment of two immature maxillary central incisors in a 7- year-old female patient. She suffered complicated crown fracture because of trauma, and the root formation was incomplete. White mineral trioxide aggregate (MTA was selected as the pulp-capping material after cervical pulpotomy to preserve the pulp tissue vitality and achieve maturogenesis. Follow-up evaluations showed successful treatment in terms of preservation of pulp vitality and demonstrated marked continuous physiological root devel- opment. During 10 years of follow-up, both teeth were clinically asymptomatic, and radio- graphic evaluations showed apparent root regeneration with apical root-end closure without pulp or periapical pathosis.

  6. Comparison between Obando´s anthropometric formula and Mondelli´s formula to estimate central incisor width.

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    Sara Rodríguez-Alayza

    2016-05-01

    Full Text Available Objective: to compare Mondelli’s formula with Obando’s anthropometric formula in order to determine the mesiodistal width of maxillary central incisor. Materials and Methods: 100 adults (50 women were selected. The mesiodistal width of maxillary central incisor was measured. Maximum smile was used for Mondelli’s formula. Inter-alar distance and longitudinal axis of the ear were used for Obando’s formula. Correlations and differences between estimates of both formulas and the actual mesiodistal width of the central incisor were estimated. Results: Obando’s formula presented a strong correlation (r=0.8846 with the mesiodistal width, with no statistically significant differences between the two measures (p>0.05. Mondelli’s formula presented a moderate negative correlation with the mesiodistal width (r=-0.3401 and a statistically significant difference with respect to the mesiodistal width (p<0.0001, in both men and women. Conclusion: Obando’s formula estimated more accurately the mesiodistal width of the central incisor in comparison to Mondelli’s formula in the Peruvian population.

  7. A CAD-CAM prosthodontic option and gingival zenith position for a rotated maxillary right central incisor: An evaluation

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    Mukesh Singhal

    2012-01-01

    Conclusion: Digital imaging provides an immediate treatment option for the patients. Software also provides an interim aid, for the clinician as well as technician, in the form of two-dimensional photographs. CAD-CAM is entirely a helping instrument against the conservative prosthetic options and gingival zenith position for a rotated central incisor. It helps in patient education and in motivation.

  8. Moving an ankylosed central incisor using orthodontics, surgery and distraction osteogenesis.

    Science.gov (United States)

    Isaacson, R J; Strauss, R A; Bridges-Poquis, A; Peluso, A R; Lindauer, S J

    2001-10-01

    When a dentist replants an avulsed tooth, the repair process sometimes results in the cementum of the root and the alveolar bone fusing together, with the replanted tooth becoming ankylosed. When this occurs, the usual process of tooth movement with bone deposition and bone resorption at the periodontium cannot function. If dental ankylosis occurs in the maxillary incisor of a growing child, the ankylosed tooth also cannot move vertically with the subsequent vertical growth of the alveolar process. This results in the ankylosed tooth leaving the plane of occlusion and often becoming esthetically objectionable. This report describes a 12-year-old female with a central incisor that was replanted 5 years earlier, became ankylosed, and left the occlusal plane following subsequent normal vertical growth of the alveolar process. When growth was judged near completion, the tooth was moved back to the occlusal plane using a combination of orthodontics, surgical block osteotomy, and distraction osteogenesis to reposition the tooth at the proper vertical position in the arch. This approach had the advantage of bringing both the incisal edge and the gingival margin of the clinical crown to the proper height in the arch relative to their antimeres. Previous treatment procedures for ankylosed teeth have often involved the extraction of the affected tooth. When this is done, a vertical defect in the alveolar process results that often requires additional bone surgery to reconstruct the vertical height of the alveolar process. If the tooth is then replaced, the replacement tooth must reach from the final occlusal plane to the deficient ridge. This results in an excessively long clinical crown with a gingival height that does not match the adjacent teeth.

  9. Relationship between the morphology of the maxillary central incisor and horizontal and vertical measurements of the face

    Directory of Open Access Journals (Sweden)

    Gisela Crippa Furtado

    2014-01-01

    Full Text Available Purpose: In order to assist in the selection of artificial teeth for complete dentures, this study aimed to assess the relationship between horizontal and vertical measurements of the face and the morphology of the maxillary central incisor. Materials and Methods: This was a study of 50 plaster casts and 100 teleradiographs - 50 in lateral norm and 50 in frontal norm, belonging to 50 individuals, Caucasian, with a naturally optimal occlusion, matching at least four of the six keys of Andrews. Images of the upper central incisors were obtained by scanning the plaster casts (three-dimensional and subjectively classified by three examiners as oval, triangular or quadrangular. Facial measures (vertical and horizontal were defined by means of teleradiographs. In order to check inter-examiner agreement on the classification of central incisor, the Kappa test was used. To verify whether data had normal distribution, the Kolmogorov-Smirnov test was used ( P > 0.2 was used. One-way analysis of variance was employed to assess the association between variables (P > 0.05. Results: When vertical measurements were compared with the three incisor shapes, there was no statistically significant difference (P > 0.05: Triangular (0.54, oval (0.63 and quadrangular (0.51. Similarly, no difference (P > 0.05 was found for facial width (139.08, 143.37, 141.65, maxillary width (76.68, 78.99, 76.91 and mandibular width (103.47, 105.50, 103.11. Conclusions: The majority of cases showed that horizontal and vertical measurements of the face cannot be used as a reference for determining the morphology of the maxillary central incisor crown. It is relevant to analyze and compare other morphological structures to improve the oral health-related quality of life for the conventional denture wearer.

  10. Finite element analysis of stress concentration in three popular brands of fiber posts systems used for maxillary central incisor teeth

    Directory of Open Access Journals (Sweden)

    Shalini Aggarwal

    2011-01-01

    Full Text Available Aims and Objectives: To study the stress concentrations in endodontically treated maxillary central incisor teeth restored with 3 different fiber post systems subjected to various oblique occlusal loads. Materials and Methods: FEM analysis was used to analyze stress concentrations generated in maxillary anterior teeth. Computer aided designing was used to create a 2-D model of an upper central incisor. Post systems analyzed were the DT Light Post (RDT, Bisco, Luscent Anchor (Dentatus & RelyX (3M-ESPE. The entire design assembly was subjected to analysis by ANSYS for oblique loading forces of 25N, 80N & 125 N Results: The resultant data showed that the RelyX generated the least amount of stress concentration. Conclusions: Minimal stress buildups contribute to the longevity of the restorations. Thus RelyX by virtue of judicious stress distribution is the better option for restoration of grossly decayed teeth.

  11. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    Science.gov (United States)

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (pmaterials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface.

  12. Family-Based Genetic Association for Molar-Incisor Hypomineralization.

    Science.gov (United States)

    Jeremias, Fabiano; Pierri, Ricardo A G; Souza, Juliana F; Fragelli, Camila Maria B; Restrepo, Manuel; Finoti, Livia S; Bussaneli, Diego G; Cordeiro, Rita C L; Secolin, Rodrigo; Maurer-Morelli, Claudia V; Scarel-Caminaga, Raquel M; Santos-Pinto, Lourdes

    2016-01-01

    Despite some evidence of genetic and environmental factors on molar-incisor hypomineralization (MIH), its aetiology remains unclear. This family-based genetic association study aimed more comprehensively to investigate the genetic carriage potentially involved in MIH development. DNA was obtained from buccal cells of 391 individuals who were birth family members of 101 Brazilian nuclear families. Sixty-three single nucleotide polymorphisms (SNPs) were investigated in 21 candidate genes related to amelogenesis using the TaqMan™ OpenArray™ Genotyping platform. All SNPs were genotyped in 165 birth family members unaffected by MIH, 96 with unknown MIH status and 130 affected individuals (50.7% with severe MIH). Association analysis was performed by the transmission/disequilibrium test (TDT), and statistical results were corrected using the false discovery rate. Significant results were obtained for SNPs rs7821494 (FAM83H gene, OR = 3.7; 95% CI = 1.75-7.78), rs34367704 (AMBN gene, OR = 2.7; 95% CI = 1.16-6.58), rs3789334 (BMP2 gene, OR = 2.9; 95% CI = 1.34-6.35), rs6099486 (BMP7 gene, OR = 2.2; 95% CI = 1.14-4.38), rs762642 (BMP4 gene, OR = 2.3; 95% CI = 1.38-3.65), rs7664896 (ENAM gene, OR = 2.1; 95% CI = 1.19-3.51), rs1711399 (MMP20 gene, OR = 0.4; 95% CI = 0.20-0.72), rs1711423 (MMP20 gene, OR = 2.1; 95% CI = 1.18-3.61), rs2278163 (DLX3 gene, OR = 2.8; 95% CI = 1.26-6.41), rs6996321 (FGFR1 gene, OR = 2.7; 95% CI = 1.20-5.88), and rs5979395 (AMELX gene, OR = 11.7; 95% CI = 1.63-84.74). Through this family-based association study, we concluded that variations in genes related to amelogenesis were associated with the susceptibility to develop MIH. This result is in agreement with the multifactorial idea of the MIH aetiology, but further studies are necessary to investigate more thoroughly the factors that could influence MIH.

  13. Strain Distribution in Root Surface Dentin of Maxillary Central Incisors during Lateral Compaction.

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    Raphael Pilo

    Full Text Available To precisely quantify the circumferential strains created along the radicular dentin of maxillary incisors during a simulated clinical procedure of lateral compaction.Six miniature strain gauges were bonded on the roots of fourteen recently extracted maxillary central incisors that were subjected to root canal instrumentation. The strain gauges were bonded at three levels (apical, middle, and coronal and four aspects (buccal, lingual, mesial, and distal of the roots. Each tooth was embedded in a PVC cylinder containing polyvinyl-siloxane impression material. Root filling was then performed by simulating the clinical procedure of lateral compaction using nickel-titanium finger spreaders. The force applied to the spreader and the strains developing in the surface root dentin were continuously recorded at a frequency of 10 Hz.The highest strains that developed during lateral compaction were in the mesial and distal aspects at the apical level of the root. The magnitudes of the maximal mesial/distal strains at the apical as well as the mid-root levels were approximately 2.5-3 times higher than those at the buccal/lingual aspects (p = 0.041. The strains decreased significantly (p<0.04 from the apical through the mid-root levels to the coronal level, yielding gradients of 2.5- and 6-fold, respectively. The mesial and distal strains were consistently tensile and did not differ significantly; however, the buccal strains were generally 35-65% higher than the lingual strains (p = 0.078. Lateral compaction resulted in the gradual build-up of residual strains, resulting in generation of a 'stair-step' curve. These strains declined gradually and almost completely disappeared after 1000 sec.With proper mounting of several miniature strain gauges at various levels and aspects of the root, significant circumferential strains can be monitored under clinically relevant compaction forces. The residual strains at the end of lateral compaction are not stored in the

  14. Treatment of maxillary central incisor with external root resorption using mineral trioxide aggregate: 18 months follow-up

    OpenAIRE

    2013-01-01

    External cervical resorption is the loss of dental hard tissue as a result of odontoclastic action; it usually begins on the cervical region of the root surface of the teeth. This case report demonstrates an external cervical resorption in a maxillary central incisor of a 24-year-old male patient. After surgical intervention and root canal treatment, the resorption was subsequently sealed with mineral trioxide aggregate. The 18 months follow-up demonstrates no pathological changes on clinical...

  15. Repair of incomplete horizontal mid-root fracture of maxillary central incisor with mineral trioxide aggregate: A follow up report

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    Ashwinkumar Krushnarao Chute

    2014-01-01

    Full Text Available Incomplete horizontal fractures occur in teeth with developing root as it cannot withstand traumatic force during injury. Diagnosis and management of such cases are difficult. Cone Beam Computed Tomography (CBCT served as efficient diagnostic tool and follow up measure and the use of Mineral Trioxide Aggregate in treatment had shown a better prognostic importance. In present case, treatment outcome of one year is reported in incompletely fractured mid-root of central incisor and the clinical approach is discussed.

  16. Treatment of maxillary central incisor with external root resorption using mineral trioxide aggregate: 18 months follow-up.

    Science.gov (United States)

    Gandi, Padma; Disha, Saraswathi

    2013-07-09

    External cervical resorption is the loss of dental hard tissue as a result of odontoclastic action; it usually begins on the cervical region of the root surface of the teeth. This case report demonstrates an external cervical resorption in a maxillary central incisor of a 24-year-old male patient. After surgical intervention and root canal treatment, the resorption was subsequently sealed with mineral trioxide aggregate. The 18 months follow-up demonstrates no pathological changes on clinical and radiographic examination. This case report presents a treatment strategy that might improve the healing outcomes for patients with external cervical resorption.

  17. Treatment of a maxillary central incisor with class III invasive cervical resorption and compromised ferrule: a clinical report.

    Science.gov (United States)

    Harris, Bryan T; Caicedo, Ricardo; Lin, Wei-Shao; Morton, Dean

    2014-05-01

    This clinical report presents the treatment of a maxillary central incisor with class III invasive cervical resorption and a compromised ferrule. Nonsurgical endodontic therapy combined with periodontal surgery was provided for debridement. Direct light-polymerizing resin-modified glass ionomer cement and a zirconia crown were used to repair the defect. Symptomatic endodontic complication was diagnosed with localized cone beam computed tomography at 6-month follow-up, and periapical microsurgery was rendered. The patient was followed-up for 30 months after treatment and had no further complications.

  18. Prosthetic rehabilitation and management of an MTA-treated maxillary central incisor with root perforation and severe internal resorption.

    Science.gov (United States)

    Abuabara, Allan; Costa, Rogério G; Morais, Eduardo C; Furuse, Adilson Y; Gonzaga, Carla C; Filho, Flares Baratto

    2013-07-01

    Root canal perforation and root resorption are challenging clinical conditions to correctly diagnose and treat, especially when they occur in anterior teeth. This clinical report describes the computed tomography findings, endodontic treatment, prosthetic rehabilitation, and clinical outcome of an iatrogenic root perforation and internal resorption in a maxillary central incisor. The case management consisted of endodontic retreatment, periodontal surgery, and prosthetic rehabilitation. Gray mineral trioxide aggregate (MTA) was used to fill the resorption space and seal the perforation. The prosthetic treatment was performed with glass fiber-reinforced dowels and all-ceramic crowns. No signs or symptoms, including discomfort, pain, or esthetic defects were observed in 30 months of follow-up.

  19. Compound odontoma associated with an unerupted and dilacerated maxillary primary central incisor in a young patient.

    Science.gov (United States)

    Yeung, K H; Cheung, R C T; Tsang, M M H

    2003-05-01

    The occurrence of odontoma in the primary dentition is uncommon. There are very few reports of non-eruption of a dilacerated primary tooth in the literature. A rare case of compound odontoma in association with an unerupted dilacerated maxillary primary incisor in a young patient is reported. There was also a developing supernumerary tooth in the vicinity of the odontoma. The clinical features and management of these conditions are discussed. The relevant literature is reviewed. A possible causal relationship between odontoma and dilaceration is highlighted.

  20. A Fused Maxillary Central Incisor and Its Multidisciplinary Treatment: An 18-Year Follow-Up

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    Lluís Brunet-Llobet

    2014-01-01

    Full Text Available Fused teeth may cause aesthetic, spacing, periodontal, eruption, and caries problems. The present case report describes a 7-year-old boy patient with a chief complaint of unerupted maxillary incisor. Radiographic examination indicated a fused tooth which had two fused roots but two independent root canals. A complex management of a fused tooth is really difficult to standardize. In this case an orthodontic, endodontic, and surgical treatment (intentional replantation allowed the tooth to be retained until 18 years following intervention. Maintenance of the root and alveolar bone in young adults at least until full skeletal maturation should be the main treatment objective.

  1. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up.

    Science.gov (United States)

    Singla, Shilpy; Gupta, Sachin

    2016-01-01

    Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development.

  2. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up

    Science.gov (United States)

    Singla, Shilpy; Gupta, Sachin

    2016-01-01

    Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development. PMID:27307685

  3. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up

    Directory of Open Access Journals (Sweden)

    Shilpy Singla

    2016-01-01

    Full Text Available Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development.

  4. A rare case of dilated invaginated odontome with talon cusp in a permanent maxillary central incisor diagnosed by cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jaya, Ranganathan; Kumar, Rangarajan Sundaresan Mohan; Srinivasan, Ramasamy [Dept. of Conservative Dentistry and Endodontics, Priyadarshini Dental College and Hospital, Chennai (India)

    2013-09-15

    It has been a challenge to establish the accurate diagnosis of developmental tooth anomalies based on periapical radiographs. Recently, three-dimensional imaging by cone beam computed tomography has provided useful information to investigate the complex anatomy of and establish the proper management for tooth anomalies. The most severe variant of dens invaginatus, known as dilated odontome, is a rare occurrence, and the cone beam computed tomographic findings of this anomaly have never been reported for an erupted permanent maxillary central incisor. The occurrence of talon cusp occurring along with dens invaginatus is also unusual. The aim of this report was to show the importance of cone beam computed tomography in contributing to the accurate diagnosis and evaluation of the complex anatomy of this rare anomaly.

  5. Replantation of an Avulsed Central Incisor after Long Extra- Alveolar Period. (Case Report

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    Seraj B

    2000-05-01

    Full Text Available A case involving the replantation of an avulsed incisor after long extra-oral period (8 days is reported. After cleaning the root surface, the tooth was soaked in fluoride gel for 20 minutes and root canal therapy was performed extraorally. The tooth was stabilized by wire and composite for six weeks. The patient has been periodically recalled and the tooth monitored for 36 months after replantation. Only minor external surface resorption was observed in the periapical area on the rodiograph, which was taken immediately before removal of the splint and the rate of subsequent replacement resorption has been acceptable. It should be considered that and extended extraoral period is not an absolute contraindication to replantation. Teeth replanted after long extra- alveolar periods can function for a long period of time and thus postpone prosthetic treatment.

  6. Endodontic and Prosthetic Management of a Mid-Root and Crown Fracture of a Maxillary Central Incisor

    Directory of Open Access Journals (Sweden)

    Koidou Vasiliki P.

    2014-11-01

    Full Text Available Root fractures are relatively uncommon among other dental traumas and mostly affect the anterior dentition. This case report presents the endodontic and prosthodontic management of a maxillary central incisor with a combined fracture in the middle third of the root and the crown, as well as the 7-year follow up of the case. The healing potential of a horizontal root fracture in the middle third of the root is highlighted when appropriate treatment is applied. MTA used for obturation of the coronal fragment, induced hard tissue formation apically and promoted healing in the area, while the 2mm MTA left as apical barrier at the second stage of re-treatment and obturation with gutta-percha prevented its extrusion. The multidisciplinary approach in the management of such cases ensures a long term survival.

  7. The effect of post-core and ferrule on the fracture resistance of endodontically treated maxillary central incisors

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    Sendhilnathan Dakshinamurthy

    2008-01-01

    Full Text Available Aim: To evaluate the effect of post reinforcement, post type and ferrule on the fracture resistance of endodontically treated maxillary central incisors. Materials and Methods: Sixty central incisor teeth were selected and grouped into six groups, viz. A, B, C, D, E, and F, each consisting of 10 specimens. Group A specimens were not subjected to any restorative treatment. Group B specimens were endodontically treated and crowned. Specimens of groups C and D were restored with custom cast post and core. Specimens of groups E and F were treated with prefabricated titanium post and composite core. Specimens of groups C and E were restored with porcelain-fused metal (PFM crown having 2 mm ferrule. Specimens of groups D and F were restored with PFM crown having no ferrule. All the specimens were subjected to load (newton, N on the lingual surface at a 135° angle to the long axis with a universal testing machine until it fractured. The fracture load and mode of fracture of each specimen were noted. One-way analysis of variance with Tukey honestly significant difference procedure was employed to identify the significant difference among the groups at 5% level (P < 0.05. Results: There were significant differences among the six groups studied (P < 0.0001. The highest fracture strength was recorded with specimen of group C (1376.7 N. There were significant differences between groups A and D versus groups B, E, and F. There were no significant differences between groups B, E, and F. Cervical root fracture was the predominant mode of failure in all the groups except group A. Conclusion: The results showed that endodontically treated teeth restored with custom cast post core were as strong as the untreated group. Teeth restored with custom cast post core were better resistant to fracture than teeth restored with prefabricated titanium post and composite core. Ferrule is more important in custom cast post core than in prefabricated post and composite core.

  8. Approximation and contact of the maxillary central incisor roots with the incisive canal after maximum retraction with temporary anchorage devices: Report of 2 patients.

    Science.gov (United States)

    Chung, Chooryung J; Choi, Yoon Jeong; Kim, Kyung-Ho

    2015-09-01

    The incisive canal is located on the median plane of the maxilla, posterior to the roots of the central incisor. Although the incisive canal is not considered an anatomic structure that may limit tooth movement, it has recently gained attention regarding the possibilities of surgical invasion and associated complications because of its proximity to the maxillary central incisors. In the 2 illustrated cases, lip protrusion was improved by en-masse bodily retraction of the anterior teeth (>8 mm) using temporary anchorage devices. Three-dimensional cone-beam computed tomography showed that the maxillary incisor roots were approximated to the incisive canal after maximum retraction. One central incisor root was in direct contact with the incisive canal with severe root resorption, but tooth vitality and the overall occlusion were stable in the long term without any sensory dysfunction. The apparent root resorption may be mainly related to the large amounts of anterior retraction and root movement in the 2 patients. However, the anatomic location of the incisive canal and the possibilities of its invasion after tooth movement should be closely monitored when maximum retraction is planned, to prevent potential complications.

  9. Finite element analysis of periodontal tissue stress distribution of labial inverted impacted maxillary central incisor%上颌唇向倒置埋伏中切牙牙周应力分布的有限元研究

    Institute of Scientific and Technical Information of China (English)

    回记芳; 张晗; 曲晓东; 闫伟军; 邵玶

    2015-01-01

    目的:建立上颌唇向倒置埋伏中切牙及其支持组织的三维模型,分析其在不同工况下的牙周应力分布,为治疗上颌埋伏中切牙提供参考。方法利用锥形束CT(CBCT)原始数据,结合Mimics 10.01和Ansys 14.0软件建立上颌唇向倒置埋伏中切牙及其牙周组织的有限元模型。在埋伏牙切端沿其长轴垂直方向,分别加载20、30、40、50、60、70 g集中力,并测定不同工况下牙周膜Von Mises应力分布。结果牙周膜应力随牵引力的增加而增大,30 g力时最大Von Mises应力值为24919.0 Pa,在牙周膜的最适应力范围内且接近其最大值。结论矫治初期,上颌唇向倒置埋伏中切牙的适宜牵引力较小,约为30 g。%Objective This study aims to do the following: construct a three-dimensional finite element model of an labial inverted impacted maxillary central incisor and its supporting tissues, analyze stress distribution in the periodontal tissue when various tractions are exerted, and provide references for treating impacted maxillary central incisor. Methods A three-dimensional finite element model of labial inverted impacted maxillary central incisor and its periodontal tissues was established using Mimics 10.01 and Ansys 14.0 software based on original cone beam computed tomography (CBCT) data. Various traction values (20, 30, 40, 50, 60, and 70 g) were exerted on the incisal margin in the direction perpendicular to the impacted tooth. Different Von Mises stress values were determined. Results Stress distribution on the periodontal ligament increased with traction size. When 30 g traction was exerted on the labial inverted impacted maxillary central incisor, the Von Mises stress was 24 919.0 Pa, which was within the range of the optimum force and close to its maximum value. Conclusion The optimum traction for early orthodontic treatment of labial inverted impacted maxillary central incisor is nearly 30 g.

  10. Surgical exposure dan perawatan ortodontik pada impaksi gigi insisif sentral rahang atas (Surgical exposure and orthodontic treatment on labially impacted maxillary central incisor

    Directory of Open Access Journals (Sweden)

    Bingah Fitri Melati

    2014-06-01

    Full Text Available Background: As a clinician we have to concern for an unerupted teeth especially in mixed dentition. Eruption failure can also be caused by early loss of deciduous teeth. Purpose: To report a case of unerupted maxillary central incisor caused by early loss of deciduous teeth due to trauma and the combination of excisional and orthodontic treatment. Case: A 8-years-old girl in mixed dentition phase came to Universitas Airlangga Dental Hospital with chief complaint of unerupted right maxillary central incisor while the left central incisor and both lateral incisor had erupted already. She had trauma when she was 1 year old and loss mostly her primary maxillary central incisors. An intraoral examination revealed lack of space in #11 region with root retained of #51, bulge was palpated in vestibulum and periapical radiograph showed that a delayed eruption upper central incisor without presence of disturbance. Case management: The exposure of the tooth was under local anesthesia a year after the orthodontic performed to make enough space for traction the tooth. A button was placed at palatal and used elastic strait to traction the tooth. After 3 months, bracket placed at labial to positioning until leveled and aligned with adjacent teeth. Conclusion: A simple excisional and orthodontic treatment were succesfully treated the labially impacted teeth.Latar belakang: Sebagai seorang klinisi kita harus memperhatikan apabila terdapat gigi yang belum erupsi terutama pada fase gigi pergantian. Kegagalan erupsi gigi juga dapat disebabkan karena tanggal premature gigi sulung. Tujuan: Melaporkan kasus impaksi gigi insisif sentral rahang atas yang disebabkan kehilangan premature gigi sulung karena trauma dengan kombinasi eksisi sederhana dan perawatan ortodontik. Kasus: Anak perempuan usia 8 tahun pada fase gigi pergantian datang ke Rumah Sakit Gigi dan Mulut Universitas Airlangga dengan keluhan gigi insisif sentral kanan rahang atasnya (#11 belum erupsi meskipun

  11. Agreement in the diagnosis of dental fluorosis in central incisors performed by a standardized photographic method and clinical examination.

    Science.gov (United States)

    Martins, Carolina Castro; Chalub, Loliza; Lima-Arsati, Ynara Bosco; Pordeus, Isabela Almeida; Paiva, Saul Martins

    2009-05-01

    The aim of this study was to assess agreement in the diagnosis of dental fluorosis performed by a standardized digital photographic method and a clinical examination (gold standard). 49 children (aged 7-9 years) were clinically evaluated by a trained examiner for the assessment of dental fluorosis. Central incisors were evaluated for the presence or absence of dental fluorosis and were photographed with a digital camera. Photographs were presented to three pediatric dentists, who examined the images. Data were analyzed using Cohen's kappa and validity values. Agreement in the diagnosis performed by the photographic method and clinical examination was good (0.67) and accuracy was 83.7%. The prevalence of dental fluorosis was reported to be higher in the clinical examination (49%) compared with the photographic method (36.7%). The photographic method presented higher specificity (96%) than sensitivity (70.8%), a positive predictive value (PPV) of 94.4% and a negative predictive value (NPV) of 77.4%. The diagnosis of dental fluorosis performed using the photographic method presented high specificity and PPV, which indicates that the method is reproducible and reliable for recording dental fluorosis.

  12. Management of a rare case of impacted primary central incisors in a 3-year-old child

    Directory of Open Access Journals (Sweden)

    A Sharma

    2012-01-01

    Full Text Available Impaction of primary anterior teeth is very rare. A tooth that fails to erupt into normal functional position by the time it normally should is considered impacted. A rare case of impacted dilacerated maxillary primary incisors in a 3-year-old child is presented. The diagnostic position of impacted primary incisors was determined using conical beam computed tomography (CBCT to assist in surgical intervention with least surgical trauma to the tissues.

  13. The Effects of Post Diameter on Stress Distribution in Maxillary Central Incisor, A Three Dimensional Finite Element Study

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    A. Monzavi

    2004-06-01

    Full Text Available Statement of Problem: Currently there are three recognized theories about the diameter of prepared dowel space in endodontically treated teeth. Diameter of the dowel is commonly contributed to the root fracture.Purpose: This study used a 3 dimensional (3D finite element method to predict stress distribution in endodontically treated central maxillary tooth with cast post and core with various post diameter according to three philosophies about post diameter (Conservational,Proportional, Preservational.Materials and Methods: In this study three 3D models of central maxillary incisors with different post diameter were created and depend on the size of post called narrow, medium and thick model with post diameter of 1.1mm, 1.7 mm and 2.6 mm of in (CEJrespectively. A load of 100 N was applied to cingulum fossa from lingual direction with 45-degree angle to long axis of tooth and maximum tensile, compressive and Von Misses stresses and their distribution in dentin and post was studied.Results: The post in narrow, medium and thick models produced a similar magnitude of tensile, compressive and Von Misses stresses in dentin. Stress distribution was also similar in all models. Peak stresses in dentin were slightly decreased when post diameter increased from narrow to thick model. In all models peak tensile stresses in dentin occurred in the coronally one third of the lingual surface of the root, whereas peak compressive stresseswere evident in the coronal one third of the facial surface of the root.Conclusion: There were not significant differences stress distribution pattern and magnitude in dentin between the three theories of post diameter.

  14. Maxillary canine-to-maxillary incisor transposition.

    Science.gov (United States)

    Lin, Yng-Tzer J

    2013-01-01

    Dental transposition is the positional interchange of two adjacent teeth. Canine transpositions are usually accompanied by other dental anomalies, such as: impaction of the incisors; missing teeth; peg-shaped lateral incisors; severe rotation or malposition of adjacent teeth; dilacerations; and malformations. Local pathologic processes, such as tumors, cysts, retained primary canines, and supernumerary teeth, might be responsible for canine transposition. The purpose of this paper was to present a rare case of maxillary canine-to-maxillary incisor transposition in an 8-year-old girl. The patient presented with noneruption of the permanent maxillary left central incisor, and a radiographic examination revealed an impacted dilacerated incisor. The central incisor was extracted because the root was severely dilacerated. At the 3-year follow-up, an oral examination revealed that the canine had transposed to the extraction site. Through orthodontic traction, combined with reshaping of the tooth, the transposed canine was successfully positioned into the incisor position.

  15. Amalgamation of allogenic bone graft, platelet-rich fibrin gel, and PRF membrane in auto-transplantation of an impacted central incisor.

    Science.gov (United States)

    Chaudhary, Zainab; Kumar, Yuvika Raj; Mohanty, Sujata; Khetrapal, Ambica

    2015-01-01

    "Social six" teeth refers to the maxillary incisors and canines that play a vital role in the appearance of an individual and absence of any one of them has a significant psycho-social impact. Hence, early treatment and rehabilitation of the same are extremely important. A multitude of treatment options ranging from orthodontic extrusion, extraction followed by implant placement, fixed partial denture, and auto-transplantation have been advocated. This case report discusses the unique amalgamation of platelet-rich fibrin (PRF), demineralized freeze-dried bone graft with use of PRF membrane during auto-transplantation of an impacted central incisor. The authors have focused on maximum usage of autogenous materials in the most economic and least invasive manner. Furthermore, this amalgamation has been used to provide rehabilitation in the least span of time.

  16. Amalgamation of allogenic bone graft, platelet-rich fibrin gel, and PRF membrane in auto-transplantation of an impacted central incisor

    Directory of Open Access Journals (Sweden)

    Zainab Chaudhary

    2015-01-01

    Full Text Available "Social six" teeth refers to the maxillary incisors and canines that play a vital role in the appearance of an individual and absence of any one of them has a significant psycho-social impact. Hence, early treatment and rehabilitation of the same are extremely important. A multitude of treatment options ranging from orthodontic extrusion, extraction followed by implant placement, fixed partial denture, and auto-transplantation have been advocated. This case report discusses the unique amalgamation of platelet-rich fibrin (PRF, demineralized freeze-dried bone graft with use of PRF membrane during auto-transplantation of an impacted central incisor. The authors have focused on maximum usage of autogenous materials in the most economic and least invasive manner. Furthermore, this amalgamation has been used to provide rehabilitation in the least span of time.

  17. A comparative study to evaluate the vertical position of maxillary central incisor and canine in relation to incisive papilla line

    Directory of Open Access Journals (Sweden)

    Mayank Shah

    2014-01-01

    Full Text Available Objectives: The aim of the study was to determine the vertical distance of maxillary central incisor (CI and maxillary canine (CA from the incisive papilla (IP line and their variation with age and sex. Materials and Methods: A total of 120 dentulous subjects following the inclusion and exclusion criteria were randomly selected from the local population. On the basis of gender and age, subjects were divided into four groups: M a , M b , F a and F b . Maxillary impressions of selected subjects were made and corresponding casts were retrieved. The cast was positioned on the surveyor and the center of IP was transferred to the labial side of maxillary right CI and CA regions with the help of analyzing rod of the surveyor and a line was drawn in this region which was referred to as "IP line." The measurements were made from the IP line to the mesio-incisal line angle of right maxillary CI-IP and cusp tip of right maxillary CA with the help of digital vernier caliper (CA to IP. Result: The mean vertical distance of maxillary CI-IP ranged from 6.31 ± 0.74 mm to 7.04 ± 0.87 mm and the mean vertical distance of maxillary CA-IP ranged from 5.83 ± 0.80 mm to 6.30 ± 0.82 mm. Conclusion: The CA position in relation to the IP line is more stable to its position than the CI position irrespective of age and sex.

  18. Management of foreign object in the root canal of central incisor tooth

    Directory of Open Access Journals (Sweden)

    Mothanna Alrahabi

    2014-01-01

    Full Text Available There are several reports describing the impaction of foreign objects into the exposed pulp chambers and canals by patients, especially children as they often have the habit of inserting foreign objects in the oral cavity. These objects will become a potent source of infection.This case report describes the retrieval of a foreign object impacted into the root canal of a 12-year-old male patient who was referred to the endodontic specialty clinic at Taibah University College of Dentistry. The patient′s chief complaint was a pain in the upper left central tooth. Clinical examination revealed a complicated enamel-dentin fracture with a large caries cavity. A periapical radiographic image showed a radiopaque object in the root canal system. Stainless steel Hedstrom files were used to retrieve the object from the canal. Following a proper cleaning and shaping of the root canal system, an intra-canal calcium hydroxide dressing was placed for 1 week. The root canal system was then filled with sealer and gutta-percha using the lateral compaction technique and the tooth received an aesthetic restoration.

  19. 倒位埋伏阻生上中切牙的临床矫治探索%Exploration of orthodontic treatment about inverse impacted maxillary central incisor

    Institute of Scientific and Technical Information of China (English)

    姜世同; 王作君; 安忠军; 焦广军; 姜良坤; 罗圆圆

    2011-01-01

    目的 探索倒位埋伏阻生上颌中切牙的矫治方法,以提高临床矫治效果和保留更多的倒位阻生牙.方法对8例患者的9颗倒位埋伏阻生的上中切牙采用开拓间隙、手术开窗牵引、固定人工支点协助调向、排齐、反向控根等方法进行矫治.结果9颗倒位阻生的上中切牙中,有8颗经过15~30个月的矫治达到正常位置,牙齿稳定,功能正常.剩余1颗因牵引15个月无明显移位而拔除,见其牙根短小并弯曲180°.结论牙根发育正常或牙根略短小,以及牙根弯曲度小于100°且不伴有短小的倒位埋伏阻生上中切牙,通过系列矫治,完全可以保留并行使正常的功能.利用可调式固定人工支点,协助矫治倒位埋伏阻生上中切牙,具有调向准确、迅速、易控和缩短反向控根时间等特点,可有效缩短疗程,提高疗效.%Objective To explore the method of orthodontic treatment of inverse impacted maxillary central incisor to improve clinical treatment effect and retain more inverse impacted incisor. Methods 8 patients with 9 inverse impacted maxillary central incisors were treated with methods of opening space, surgical fenestration and traction, fixed artificial fulcrum to adjust direction aligned, reverse root control and so on. Results Inverse impacted maxillary central incisors have normal position, stability teeth root and proper function after 15 to 30 months of orthodontic treatment. Another incisor without clear displacement was extracted after 15 months of orthodontic traction, because its root was short and bend 180°. Conclusion Inverse impacted maxillary central incisor with normal root or slightly short root, or bent root less than 100° can be retained and keep normal function completely through a series of orthodontic treatment. Fixed adjustable artificial fulcrum can assist in treating inverse impacted maxillary central incisor. It can effectively shorten the course of treatment and improve efficacy.

  20. Effect of labiolingual inclination of a maxillary central incisor and surrounding alveolar bone loss on periodontal stress: A finite element analysis

    Science.gov (United States)

    Choi, Sung-Hwan; Kim, Young-Hoon; Lee, Kee-Joon

    2016-01-01

    Objective The aim of this study was to investigate whether labial tooth inclination and alveolar bone loss affect the moment per unit of force (Mt/F) in controlled tipping and consequent stresses on the periodontal ligament (PDL). Methods Three-dimensional models (n = 20) of maxillary central incisors were created with different labial inclinations (5°, 10°, 15°, and 20°) and different amounts of alveolar bone loss (0, 2, 4, and 6 mm). The Mt/F necessary for controlled tipping (Mt/Fcont) and the principal stresses on the PDL were calculated for each model separately in a finite element analysis. Results As labial inclination increased, Mt/Fcont and the length of the moment arm decreased. In contrast, increased alveolar bone loss caused increases in Mt/Fcont and the length of the moment arm. When Mt/F was near Mt/Fcont, increases in Mt/F caused compressive stresses to move from a predominantly labial apical region to a palatal apical position, and tensile stresses in the labial area moved from a cervical position to a mid-root position. Although controlled tipping was applied to the incisors, increases in alveolar bone loss and labial tooth inclination caused increases in maximum compressive and tensile stresses at the root apices. Conclusions Increases in alveolar bone loss and labial tooth inclination caused increases in stresses that might cause root resorption at the root apex, despite the application of controlled tipping to the incisors. PMID:27226961

  1. 上颌埋伏阻生中切牙的临床研究%The clinical investigation of the maxillary impacted central incisor

    Institute of Scientific and Technical Information of China (English)

    王镶珊; 胡荣党

    2012-01-01

    of maxillary impacted central incisors was 1.18% in orthodontic patients at department of orthodontics,school of Stomatology,Wenzhou Medical College.It was more popular in female.Most of the maxillary impacted incisors were labially located. Surgical exposure combined with orthodontic treatment were most commonly used in the treatment of maxillary impacted incisors.

  2. 上颌中切牙倒置埋伏阻生的临床矫治%Orthodontic treatment of inversely impacted central incisors in the maxillae

    Institute of Scientific and Technical Information of China (English)

    王德顺; 卢保全; 张凯; 胡业响; 张兴华

    2001-01-01

    目的:探讨上颌中切牙倒置埋伏阻生的矫治方法。方法:对11例倒置埋伏阻生的上中切牙(2例含牙囊肿),先行手术开窗显露牙冠,然后在“U”型保护罩的支持下用活动或固定正畸技术进行矫治。结果:活动矫正器经24~30个月,固定矫正器8~12个月使倒置埋伏阻生牙进入牙弓排齐。结论:倒置埋伏阻生的上颌中切牙,通过手术和正畸技术,完全能排入正常牙列,不需拔除。%Objective:To investigate the method of orthodontic treatment ofthe inversely impacted central incisors in the maxillae.Methods:Surgical exposures were made in 11 cases of the inversely impacted upper central incisors(2 with denta lyst).Treatments were performed under the protection of “U”.Results:The invensely impacted teeth were aligned after using moving appliance for 24~30 months,and fixed appliance for 8~12 months.Conclusions:The inversely impacted central incisors in the maxillae could be aligned by orthodontic operation.The teeth need not be extracted.

  3. Histomorphometric analysis of inflammatory response and necrosis in re-implanted central incisor of rats treated with low-level laser therapy.

    Science.gov (United States)

    Vilela, Rianne Gomes; Gjerde, Kjersti; Frigo, Lucio; Leal Junior, Ernesto Cesar Pinto; Lopes-Martins, Rodrigo Alvaro Brandão; Kleine, Brígida Mônica; Prokopowitsch, Igor

    2012-05-01

    Low-level laser therapy is a tool employed in the management of post-operative inflammation process and in the enhancement of reparative process. The aim of the study was to perform histological evaluation of dental and periodontal ligament of rats central upper-left incisor teeth re-implanted and irradiated with low-level laser (InGaAl, 685 nm, 50 J/cm(2)) 15, 30, and 60 days after re-implantation. Seventy-two male rats had the central upper left incisor removed and kept for 15 min on dry gauze before replantation. Laser was irradiated over the root surface and empty alveolus prior replantation and over surrounding mucosa after the re-implantation. After histological procedures, all slices were analyzed regarding external resorption area and histological aspects. We observed an increase of root resorption (p resorption areas than the control group in all experimental periods. Additionally, histological analysis revealed less inflammatory cells and necrotic areas in laser groups.

  4. Finite elements study of the Flexi Post and Flexi Flange post systems in a maxillary central incisor Estudo pelo método dos elementos finitos dos pinos Flexi Post e Flexi Flange em um incisivo central superior

    Directory of Open Access Journals (Sweden)

    Hugo Roberto Lewgoy

    2003-06-01

    Full Text Available The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors. The post systems used in this investigation were the stainless steel or titanium Flexi Post/Flexi Flange. Composite resin was used as core material and resin cement was the cement material of choice to seat a full porcelain crown. The bi-dimensional mathematical model was created from pictures taken from an intact human maxillary central incisor and prefabricated posts. This image was transferred to a personal computer in the MSC/Nastran 4.5 software. A static and linear analysis treatment was performed when a 45º load of 100 N was applied on the lingual surface of the tooth. Based on the results obtained, it can be concluded that the post design and its material can alter the stress pattern distribution.A utilização de pinos intra-radiculares tem se mostrado uma excelente alternativa para dentes endodonticamente tratados. Este trabalho teve como objetivo avaliar, utilizando o Método dos Elementos Finitos (MEF, como pinos intra-radiculares pré-fabricados metálicos podem alterar o padrão das tensões geradas de von Mises e de máxima tração e compressão na raiz dental. A comparação foi realizada entre os pinos pré-fabricados Flexi Post/Flexi Flange de aço inoxidável e titânio com preenchimento coronário em resina composta. Os pinos intra-radiculares foram fixados com um cimento resinoso e recobertos por uma coroa total cerâmica. A partir de fotografias da peça anatômica e dos pinos estudados, foram criados modelos matemáticos bidimensionais no programa MSC/Nastran 4.5 e, após aplicação de uma força de 100 N a 45 graus na superf

  5. 上颌中切牙埋伏阻生的临床分析%Clinical analysis of maxillary central incisors with impaction

    Institute of Scientific and Technical Information of China (English)

    陈琳; 钟燕雷; 郭红梅; 田春娟

    2012-01-01

    Objective To analyze the incidence,etiology and clinical treatment of the impacted maxillary central incisors.Methods A retrospective study was conducted on 29 cases of impacted maxillary central incisors that were randomly selected from the 1000 patients.Age of the patient was ranged from 7 to 23 years with median 11.1 years.Numbers of impacted teeth were 32,in which 22teeth were intraosseous impaction and others were extraosseous.The incidence,etiology,sites and direction of impacted teeth and their treatment approaches were explored in this study.Results Impac tion of maxillary central incisors occurred more frequently in females than in males,with a ratio of 1.0 ∶ 1.2.The ratio of intraosseous impaction to extraosseous one was 11 ∶ 5.The insufficient eruption space of maxillary central incisors was present in 65% patients,but intermediate and severe crowded teeth only accounted for 15%.The incidence of the abnormal site and position of impacted teeth reached 71 %.The clinical approach and solution were surgical-orthodontic treatment,transplantation or removal of impacted teeth.Conclusions The main cause is abnormity of teeth in the shape and position.Most of the impacted maxillary central incisors could be moved to the correct position by effective treatment.%目的 分析上颌中切牙埋伏阻生的发病率、病因及治疗结果,以期对临床治疗有所帮助.方法 随机抽取的1000例患者中确诊29例为上颌中切牙埋伏阻生,年龄为7~23岁,平均11.1岁.埋伏牙总数32枚,骨内埋伏有22枚,骨外埋伏10枚.对临床发病率、病因、埋伏阻生的位置和方向以及临床治疗方法和结果等方面进行回顾性研究.结果 男性发病率小于女性,男∶女为1.0∶ 1.2,骨内埋伏阻生与骨外之比为11∶5.有65%的患者存在上颌中切牙萌出间隙不足,但是属于中重度拥挤的仅占15%.埋伏牙自身形态和位置异常的发病率高达71%.临床治疗方法

  6. 上颌中切牙不同修复方式的有限元分析%Finite element analysis for restoration of maxillary central incisor

    Institute of Scientific and Technical Information of China (English)

    康成容; 魏素华; 王玉栋; 张美超; 李梁; 潘宣

    2011-01-01

    目的:应用有限元法研究上颌中切牙采用不同修复方式时牙本质和全瓷冠的应力变化情况,并分析对组织应力大小和分布的影响.方法:采用螺旋CT扫描,运用Mimics软件、Ansys软件建立3种不同牙体量上颌中切牙的三维有限元模型,分别采用全瓷冠修复和纤维桩全瓷冠修复,模拟45°切龈向咬合加载,记录牙本质、全瓷冠的Von Mises应力和最大拉应力.结果:相同牙体量时,上颌中切牙采用纤维桩全瓷冠修复后牙本质和全瓷冠的应力值均小于仅采用全瓷冠修复时的应力值,而应力分布基本相似.结论:全瓷冠联合纤维桩修复可有效降低上颌中切牙牙本质和全瓷冠的应力峰值,并且不改变原有应力分布模式,有利于降低牙折和修复失败的风险.%Objective:To study the stress at maxillary central incisor restored with different methods using finite element models, and to analyze the role of restoration methods in determining stress distribution over the dentin and all-ceramic crown. Methods:Three dimensional finite element models of maxillary central incisor with different remaining tooth structure were established with spiral CT, Mimics and Ansys. The maxillary central incisors were restored with all-ceramic crown and fiber post all-ceramic crown,respectively. A 100N static load was applied at 45 degree to the long axis of the tooth at incisal 1/3. The Von Mises stress and maximal tensile stress of dentin and all-ceramic crown were recorded. Results: With the same remaining structure, smaller stress level was recorded in dentin and all-ceramic crown of maxillary central incisor restored with fiber post all-ceramic crown as compared with those restored with all-ceramic crown. Similar distribution of the stress was found between the two groups. Conclusion: Combination of all-ceramic crown and fiber post can reduce the stress level in dentin and all-ceramic crown of maxillary central incisor effectively but

  7. Evaluation of the mineralization degree of the vestibular surface of the upper central incisors with a 655-nm diode laser in mouth breathers: preliminary results

    Science.gov (United States)

    Pinheiro Ladalardo, Thereza C. C. G.; Cappellette, Mario, Jr.; Zanin, Fatima A. A.; Brugnera, Aldo, Jr.; Anthero de Azevedo, Ramiro; Pignatari, Shirley; Weckx, Luc L. M.

    2003-06-01

    Mouth breathing unbalances the physiological mechanisms of the dental surface hydration by compromising lip closure, and, very often, causing the vestibular positioning of upper incisors. That variance leads to the interruption of the dental demineralization and remineralization feedback, prevailing a demineralized condition of the dental surface which increases caries risk. The laser fluorescence examination allows an early demineralization diagnosis, thus it makes possible through preventive measures to minimize the risk factor - dental mineral structure loss - in the bacterial infection of the demineralized area, and hence, preventing invasive therapeutical procedures. A DIAGNOdent apparatus was used to evaluate the mineralization degree of the upper central incisors in 40 patients - twenty of them with a mouth breathing diagnosis; the remaining twenty were nasal breathers (control group). Age ranging from 6 to 12 years, both male and female. To measure the vestibular surface of the incisors, it was divided into 3 segments: cervical, medial and incisal. The average of the results pertaining to the mouth breathing patients was as follows: tooth 11 cervical third - 5.45, medial third - 7.15, incisal third - 7.95, and tooth 21 - cervical third - 5.95, medial third - 7.25, incisal third - 8.15. The control patients, nasal breathers, presented the following results: tooth 11 cervical third - 1.75, medial third - 2.30, incisal third - 1.85, and tooth 21 - cervical third - 1.80, medial third - 2.20, incisal third - 2.15. The mouth breathing patients showed demineralization in the teeth examined at the initial stage, subclinical, comparing with the control patients, nasal breathers, who did not present any mineral deficit in these teeth.

  8. Endodontic and esthetic management of a dilacerated maxillary central incisor having two root canals using cone beam computed tomography as a diagnostic aid.

    Science.gov (United States)

    Sharma, Sarang; Grover, Shibani; Sharma, Vivek; Srivastava, Dhirendra; Mittal, Meenu

    2014-01-01

    Traumatic injuries to the primary dentition are quite common. When primary teeth are subjected to trauma, force transmission and/or invasion of the underlying tooth germs lying in close proximity can result in a variety of disturbances in the permanent successors. Few of these disturbances include hypoplasia, dilaceration, or alteration in the eruption sequence and pattern. Dilaceration is defined as an angulation or sharp bend or curve in the linear relationship of the crown of a tooth to its root. A rare case of maxillary left central incisor having crown dilaceration and Vertucci's type II canal configuration with symptomatic periapical periodontitis is reported. Cone beam computed tomography was used for better understanding of the anomaly and complicated root canal morphology. The tooth was successfully managed by nonsurgical root canal therapy and restoration with resin composite to restore esthetics.

  9. Influence of implant position on clinical crown length and peri-implant soft tissue dimensions at implant-supported single crowns replacing maxillary central incisors

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana

    2013-01-01

    as controls. Paired sample t-testand Pearson´s correlation analysis were used to analyze implant position, dimension of crownand papilla fill.Cohen’s ¿ andSpearman correlation were used to validate the PIS.The implant-supported crown was statistically longer than the contra-lateral tooth......The aims of the present study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors, and to validate the papilla index score (PIS). Twenty-five patients, who had lost one......, and there was significant correlation between the oro-facial position of the implant and the crown length difference (r=.607, p=.001). The distalpapilla was significantly shorter than the mesialpapilla at implant-supported crowns (p

  10. Management of recently traumatized maxillary central incisors by partial pulpotomy using MTA: Case reports with two-year follow-up

    Directory of Open Access Journals (Sweden)

    Abarajithan M

    2010-01-01

    Full Text Available In traumatized, young, permanent teeth, pulpotomy is classically undertaken to promote apexogenesis. The objective is to promote root development and apical closure. Once root end development and apical closure is achieved, the root canal treatment is completed. However, it has been suggested that mere pulp exposure does not cause pulpitis in the absence of bacteria. Recent studies have proposed that as long as a good seal is ensured, root canal treatment may not be necessary following pulpotomy.In this article we report two cases of traumatized, fully matured, maxillary permanent central incisors, which have been treated with mineral trioxide aggregate following partial pulpotomy, with a two-year follow-up.

  11. Endodontic and Esthetic Management of a Dilacerated Maxillary Central Incisor Having Two Root Canals Using Cone Beam Computed Tomography as a Diagnostic Aid

    Directory of Open Access Journals (Sweden)

    Sarang Sharma

    2014-01-01

    Full Text Available Traumatic injuries to the primary dentition are quite common. When primary teeth are subjected to trauma, force transmission and/or invasion of the underlying tooth germs lying in close proximity can result in a variety of disturbances in the permanent successors. Few of these disturbances include hypoplasia, dilaceration, or alteration in the eruption sequence and pattern. Dilaceration is defined as an angulation or sharp bend or curve in the linear relationship of the crown of a tooth to its root. A rare case of maxillary left central incisor having crown dilaceration and Vertucci’s type II canal configuration with symptomatic periapical periodontitis is reported. Cone beam computed tomography was used for better understanding of the anomaly and complicated root canal morphology. The tooth was successfully managed by nonsurgical root canal therapy and restoration with resin composite to restore esthetics.

  12. Endodontic treatment of a geminated maxillary incisor

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo da Silveira Bueno

    2011-04-01

    Full Text Available Introduction: Gemination is a tooth anomaly caused when a single tooth bud attempts to divide. This results in a tooth with a size greater than normal, but with only one root canal. Therefore, due to its features and singularities, this geminated tooth demands careful attention for endodontic treatment Objective and case report: The purpose of this case report is to describe the endodontic treatment of a geminated maxillary central incisor. Conclusion: A good planning of all treatment stages, based on a careful clinical and radiographic examination, it is essential to reach the success in the endodontic treatment of geminated teeth.

  13. Unusual Transalveolar and Transmuco-Gingival Root Avulsion of a Fractured Primary Central Incisor: A Case with an 8-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    E. Ferrés-Amat

    2015-01-01

    Full Text Available The purpose of this unique case report is to describe a very unusual dentoalveolar fracture associated with avulsion of the near-complete root. A 3-year-old male patient came for consultation after a dentoalveolar trauma with a “fragment that looks like canine” found in his mouth by his mother. This boy suffered root fracture of the upper primary central right incisor, accompanied by transalveolar and transmuco-gingival avulsion of the tooth root fragment, leaving the crown in its position in the dental arch. Clinical and radiological examinations were performed in order to follow up the case: 15 days, one month, and three months after trauma, the crown had a slight mobility without other clinical or radiological signs. After six months, the upper primary central right incisor’s crown was exfoliated. Open bite due to the persistence of the pacifier habit favored the crown retention in the mouth. This case emphasizes the importance of primary diagnosis and follow-up of trauma cases. To the best of our knowledge, this kind of dental injury has not been previously described in the literature nor in the current Dental Trauma guidelines for the management of traumatic dental injuries in the primary dentition.

  14. 锥形束CT在上颌埋伏中切牙诊断中的应用%Application of cone beam computed tomography in the diagnosis of unerupted maxillary central incisor

    Institute of Scientific and Technical Information of China (English)

    顾月光; 王珊; 谷妍; 赵春洋; 许远; 刘可; 王林

    2012-01-01

    目的:探讨锥形束CT(CBCT)在上颌埋伏中切牙诊断中的作用.方法:选择正畸临床33例上颌中切牙埋伏阻生患者作为研究对象,拍摄全景片和CBCT,由10位正畸医生对33例埋伏牙患者的全景片和CBCT分别进行测量、分析,填写研究表格.所得数据用SPSS 17.0软件,采用McNemar检验、Kappa检验和配对t检验进行统计学分析.结果:CBCT与全景片对埋伏牙是否弯根、近中切角距中线距离和有无多生牙等分析项目没有统计学差异,其余分析项目均有统计学差异.结论:对上颌埋伏中切牙诊断,CBCT更直观、三维测量更精确,更好地指导临床.%Objective: To study the effect of cone beam computed tomography (CBCT) in the diagnosis of unerupted maxillary central incisor. Methods: 33 patients undergoing orthodontic treatment were included. For each unerupted maxillary central incisor, panoramic radiograph( PR) and CBCT were used in diagnosis. Ten orthodontic dentists completed the table which had been formulated. The images were measured and the data analysis was performed using McNemar test, Kappa test and paired t-test by SPSS 17. 0 soft ware. Results: The dimension data of the central incisor, the distance between the mesial incisor angle and the midline of the arch, dilacera-tion of the central incisor root and the existence supernumerary teeth obtained by PR and CBCT showed no statistic difference, while the other analysis items did. Conclusion: CBCT diagnosis of the unerupted incisor is more direct and more accuracy than panoramic radiograph.

  15. Color changes of vital central upper incisor after chairside heat bleaching%活体上颌中切牙加热漂白后的颜色值变化

    Institute of Scientific and Technical Information of China (English)

    周俊杰; 谢海峰; 陈晨

    2014-01-01

    AIM:To evaluate the color changes of healthy central upper incisor after chairside bleaching. METHODS:Color changes of 16 healthy central upper incisors before and after chairside heat bleaching by wy10 were determined using a dental colorimeter,and color difference values were calculated.RESULTS:Color difference values were 4.23 ±2.21 after bleaching.Paired t-test showed that L* parameter of the central upper incisors increased (P<0.05)and b* parameters decreased (P<0.05)after bleaching.CONCLUSION:Chairside heat bleaching re-sult in lighter and blue-converse of healthy central upper incisors.%目的:观察患者接受牙齿椅旁恒温外漂白治疗后健康上颌中切牙的颜色值变化。方法:利用牙科色度计采集16例健康上颌中切牙漂白前后的L*、a*、b*颜色参数值,分析各参数的变化以及计算漂白后牙齿颜色变化的色差值。结果:漂白后牙色平均改善了6±3个色阶。漂白前后的色差值为4.23±2.21。配对t检验结果显示,上颌中切牙漂白后L*值显著增加,b*值显著降低,a*值无明显变化趋势。结论:牙齿椅旁恒温外漂白治疗能够增加健康上颌中切牙的明度,颜色向蓝色转变。

  16. Orthodontic management of an impacted maxillary incisor due to odontoma

    Directory of Open Access Journals (Sweden)

    Rahul S Baldawa

    2011-01-01

    Full Text Available Odontomas are a heterogeneous group of jaw bone lesions, classified as odontogenic tumors which usually include well-diversified dental tissues. Odontomas are the most common type of odontogenic tumors and generally they are asymptomatic. Two types of odontomas are described: compound and complex based on either the appearance of well-organized tooth-like structures (compound odontomas or on a mass of disorganized odontogenic tissues (complex odontomas. Compound odontomas have a predilection for the anterior maxilla, whereas complex odontomas have a predilection for the posterior mandible. Odontomas frequently interfere with eruption of teeth leading to their impaction. This is a case report of a 14-year-old girl with an unerupted maxillary right central incisor due to a complex composite odontoma a rare occurrence in anterior maxilla. Surgical excision of the odontoma and orthodontic treatment to get the impacted maxillary right central incisor into alignment is discussed.

  17. Lower molar and incisor displacement associated with mandibular remodeling.

    Science.gov (United States)

    Baumrind, S; Bravo, L A; Ben-Bassat, Y; Curry, S; Korn, E L

    1997-01-01

    The purpose of this study was to quantify the amount of alveolar modeling at the apices of the mandibular incisor and first molar specifically associated with appositional and resorptive changes on the lower border of the mandible during growth and treatment. Cephalometric data from superimpositions on anterior cranial base, mandibular implants of the Björk type, and anatomical "best fit" of mandibular border structures were integrated using a recently developed strategy, which is described. Data were available at annual intervals between 8.5 and 15.5 years for a previously described sample of approximately 30 children with implants. The average magnitudes of the changes at the root apices of the mandibular first molar and central incisor associated with modeling/remodeling of the mandibular border and symphysis were unexpectedly small. At the molar apex, mean values approximated zero in both anteroposterior and vertical directions. At the incisor apex, mean values approximated zero in the anteroposterior direction and averaged less than 0.15 mm/year in the vertical direction. Standard deviations were roughly equal for the molar and the incisor in both the anteroposterior and vertical directions. Dental displacement associated with surface modeling plays a smaller role in final tooth position in the mandible than in the maxilla. It may also be reasonably inferred that anatomical best-fit superimpositions made in the absence of implants give a more complete picture of hard tissue turnover in the mandible than they do in the maxilla.

  18. 上颌中切牙阻生对颅面结构的影响及其矫治%Influence of impacted maxillary central incisor on craniofacial structure and its orthodontic treatment

    Institute of Scientific and Technical Information of China (English)

    雷浪; 柯晓菁; 李厚轩; 李煌; 闫福华

    2016-01-01

    目的:研究上颌中切牙埋伏阻生对颅面结构的影响并探讨其矫治方法。方法63例上颌中切牙埋伏阻生的病例,按照其牙列发育情况分为混合牙列组(32例)和恒牙列组(31例)。描记所有患者的头颅侧位片,测量15项角度和6项线距,将其测量值与对应的正常牙合对照组进行比较。结果上颌切牙埋伏病例的发病因素中,多生牙、含牙囊肿或牙瘤、外伤和不明原因各占6.3%、6.3%、12.4%和73%。头影测量显示上颌中切牙阻生病例SNA和ANB角较对照组显著减小(P<0.05),并伴有牙性变化即上颌切牙唇倾、下颌切牙舌倾(P<0.05)。在牙根发育早期( Nolla法第7期和第8期),13颗埋伏切牙中12颗正畸牵引成功;在牙根发育晚期(第9期和第10期),15颗埋伏切牙中7颗牵引成功。结论上颌中切牙埋伏阻生后,上颌发育受限;早期矫治可以提高埋伏牙成功率,同时有利于牙根发育。%Objective To explore the influence of impacted maxillary central incisor on craniofacial structure and its orthodontic treatment. Methods A total of 63 subjects with impacted upper central incisors were selected and catego-rized into the mixed ( n=32) and permanent dentition group ( n=31) . By using the lateral cephalograms of each subject, 15 angular and 6 linear measurements were made. The cephalometric data were analyzed and compared to data of its cor-responding control group with normal occlusion. Results Among the etiological factors of all 63 cases with impacted up-per incisors, supernumerary teeth, dentigerous cyst or odontoma, mechanical trauma and idiopathic factors comprise of 6. 3%, 6. 3%, 12. 4% and 73% respectively. Cephalometric analysis demonstrated a more retruded position of"A" point with decreased SNA and ANB angle in incisor impaction group. Dental compensations followed the decreased ANB angle with more proclined upper incisor and more upright lower incisor. In early stage of root development

  19. Contour changes in human alveolar bone following tooth extraction of the maxillary central incisor%人类上颌中切牙拔除后牙槽骨外形变化的研究

    Institute of Scientific and Technical Information of China (English)

    Bei LI; Yao WANG‡

    2014-01-01

    The purpose of this study was to apply cone-beam computed tomography (CBCT) to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original mor-phological evidence for aesthetic implant treatment in the maxilary anterior area. Forty patients were recruited into the study. Each patient had two CBCT scans (CBCT I and CBCT II), one taken before and one taken three months after tooth extraction of maxillary central incisor (test tooth T). A fixed anatomic reference point was used to orient the starting axial slice of the two scans. On three CBCT I axial slices, which represented the deep, middle, and shallow layers of the socket, labial and palatal alveolar bone widths of T were measured. The number of sagittal slices from the start point to the pulp centre of T was recorded. On three CBCT II axial slices, the pulp centres of extracted T were oriented according to the number of moved sagittal slices recorded in CBCT I. Labial and palatal alveolar bone widths at the oriented sites were measured. On the CBCT I axial slice which represented the middle layer of the socket, sagittal slices were reconstructed. Relevant distances of T on the sagittal slice were measured, as were the alveolar bone width and tooth length of the opposite central incisor. On the CBCT II axial slice, which represented the middle layer of the socket, relevant distances recorded in CBCT I were transferred on the sagittal slice. The height reduction of alveolar bone on labial and palatal sides was measured, as were the alveolar bone width and tooth length of the opposite central incisor at the oriented site. Intraobserver reliability assessed by intraclass correlation coefficients (ICCs) was high. Paired samplet-tests were performed. The alveolar bone width and tooth length of the opposite central incisor showed no statistical differences (P<0.05). The labial alveolar bone widths of T at the deep, middle, and shalow layers al showed

  20. 使用导杆式矫治器治疗腭侧阻生上中切牙%The orthodontic treatment of palatal impacted maxillary central incisors with guide rod appliance

    Institute of Scientific and Technical Information of China (English)

    戴微微; 林燕; 孙浩; 孙超凡; 王昕; 胡荣党

    2013-01-01

    目的 分析上颌腭侧埋伏阻生中切牙的正畸矫治效果及导杆式矫治器的治疗作用.方法 利用导杆式矫治器治疗7例上颌单侧中切牙腭侧埋伏的患牙,以对侧自然萌出中切牙作为对照.矫治前后拍摄全景片,测量矫治后埋伏牙和对照牙的牙全长、解剖牙根长度、解剖牙冠长度、根长/冠长,用SPSS 17.0软件进行成组t检验.结果 6例腭侧埋伏中切牙经牵引萌出后排齐,牙髓和牙周状况良好.萌出后埋伏牙解剖牙根长度比对照组牙根短4.00 mm(P=0.020),根长/冠长值平均为1.36±0.31,小于对照组(P=0.048).其中1例因埋伏牙骨粘连,牵引16个月后无移动而放弃牵引.结论 矫治后腭侧埋伏中切牙有足够的长度,应保留埋伏牙;导杆式矫治器是治疗上颌腭侧埋伏中切牙的一种有效方法.%Objective To analyze the effects and features of guide rod appliance on palatal impacted central incisors.Methods 7 palatal impacted central incisors were treated with guide rod appliance,the normal erupted contralateral central incisors were used as control.Pre-and Posttreatment panoramic radiograph were measured and the following data were collected:(1) The length of the impacted central incisors and the contralateral control teeth; (2) The length of the anatomical roots; (3) The length of the anatomical crowns; (4) Root/Crown length ratio.The measures were compared using two sample t-test with SPSS17.0.Results Six impacted central incisors were treated to normal position.Their pulp and periodontal attachment were normal.The length of the impacted central incisors was 4.00 mm shorter than the control group (P=0.020).The ratio of Root/Crown length is 1.36 ± 0.31,which is smaller than that of the control group (P =0.048).One tooth demonstrated ankylosis for that 16 months of orthodontic extrusion showed no movement and gave up treatment.Conclusions The length of the impacted tooth's root was acceptable after treatment.The guide

  1. 埋伏弯根上颌中切牙序列矫治的研究%Sequence orthodontic treatment of impacted dilacerated maxillary central incisors

    Institute of Scientific and Technical Information of China (English)

    郑怡; 庞煊奈; 南澜; 莫水学

    2012-01-01

    目的 探讨埋伏弯根上颌中切牙有效的正畸牵引治疗方法.方法 选择11例患者共12颗埋伏弯根上颌中切牙为研究对象,常规拍摄定位X线片,配合口内检查、模型分析等,确定埋伏牙的位置及其与邻牙的相互关系,采用封闭式导萌、选择性根管治疗及根尖切除术、修复治疗等方法进行矫治.结果 12颗埋伏牙通过治疗后顺利进入正常牙列,未见牙根吸收粘连,建立了良好的咬合关系.9例唇侧埋伏弯根上颌中切牙患者的临床牙冠唇倾角度较大,4例根尖位于唇侧黏膜下,进行了根管治疗加根尖切除术,其中1例行烤瓷冠改形修复;其余5例未做根管治疗,暂行观察.2例腭侧埋伏弯根上颌中切牙的疗效稳定.结论 埋伏弯根上颌中切牙采用序列矫治可以取得良好的美观和功能效果.%Objective To explore an effective orthodontic method for treating impacted dilacerated maxillary central incisors. Methods 12 impacted teeth of 11 cases were chosen. The position of the impacted teeth and the relations with neighbour tissues weie assessed by X-ray images, oral examination and plaster model, etc. The impacted teeth were induced to erupt with the closed-eruption technique and fixed orthodontic appliances, root canal therapy, apicoectomy and prosthetic treatment. Results 12 impacted teeth were moved into arches, and the occlusal relationship was normal. There were no root resorption or conglutination in those impacted teeth. The labial impacted teeth of nine cases had bigger labial crown torsion. The root apexes of four impacted teeth were palpable under mucosa of the labial sulcus and operated by root canal therapy and apicoectomy. One of them received prosthetic treatment Others (five cases) hadn't accepted root canal therapy, and were observed temporarily. The effects of two palatal impacted teeth was stable. Conclusion It was a good method to expand indication with sequence orthodontic treatment. The

  2. Surgical endodontic management of infected lateral canals of maxillary incisors

    Science.gov (United States)

    2015-01-01

    This case report presents surgical endodontic management outcomes of maxillary incisors that were infected via the lateral canals. Two cases are presented in which endodontically-treated maxillary central incisors had sustained lateral canal infections. A surgical endodontic treatment was performed on both teeth. Flap elevation revealed vertical bone destruction along the root surface and infected lateral canals, and microscopy revealed that the lateral canals were the origin of the lesions. After the infected lateral canals were surgically managed, both teeth were asymptomatic and labial fistulas were resolved. There were no clinical or radiographic signs of surgical endodontic management failure at follow-up visits. This case report highlights the clinical significance and surgical endodontic management of infected lateral canal of maxillary incisor. It is important to be aware of root canal anatomy variability in maxillary incisors. Maxillary central incisors infected via the lateral canal can be successfully managed by surgical endodontic treatment. PMID:25671217

  3. Multi-disciplinary management of a patient with a post-traumatised incisor presenting concurrent replacement and inflammatory resorption: a case report.

    Science.gov (United States)

    Doğramaci, Esma J; Rossi-Fedele, Giampiero; Jonest, Allan G

    2015-11-01

    This case report describes the multidisciplinary management of a young male who presented with a Class I incisor relationship and bi-maxillary dento-alveolar protrusion on a Class I skeletal base. The occlusion was complicated by an ankylosed and moderately infra-positioned upper left permanent central incisor, an anterior crossbite, crowding, a reduced overbite and centreline discrepancy. The incisor was traumatised and avulsed when the root was immature and the tooth was reimplanted with delay. On referral for orthodontic treatment at age 11 .5 years, the upper left central incisor was experiencing ankylosis-related (osseous replacement) resorption and external root resorption simultaneously. Aside from the orthodontic aims, it was important to address the disrupted alveolar development to facilitate later prosthodontic replacement of the upper left permanent central incisor by idealising the inter-coronal and inter-radicular spaces. Treatment consisted of fixed orthodontic appliances in conjunction with the extraction of all second premolars and the upper left permanent central incisor with episodic surgical curettage. An upper Hawlix retainer was provided immediately at debond and a cantilevered resin-retained bridge was placed four months later.

  4. MANDIBULAR INCISOR EXTRACTION: A 5-YEAR FOLLOW-UP

    Directory of Open Access Journals (Sweden)

    Kadir BEYCAN

    2016-10-01

    Full Text Available This case report presents the mandibular incisor extraction treatment of a patient with dental Class I malocclusion and lower crowding, in whom one mandibular incisor extraction was selected as the treatment of choice to improve the dental occlusion. A 19-year-old male patient’s chief complaint was the crowding of lower incisors. He had a straight profile with normal upper and lower lip projection. Upper and lower dental midlines were coincident with the facial midline. The patient had Class I molar and canine relationships on both sides. He had Class I skeletal relationship, low angle vertical pattern, and proclined upper and lower incisors. The treatment plan included the extraction of lower right central incisor to resolve the crowding. At the end of 16-month active fixed treatment, lower dental crowding was resolved. At the 5-year follow-up, the patient had a stable occlusion, with the results of the orthodontic treatment maintained.

  5. The effects of impacted premaxillary supernumerary teeth on permanent incisors

    Science.gov (United States)

    Jung, Yun-Hoa; Kim, Ji-Yeon

    2016-01-01

    Purpose The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. Materials and Methods The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Results Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Conclusion Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape. PMID:28035303

  6. 椅旁操作次数对恒温漂白活体上中切牙疗效的影响%The effect of chairside heat bleaching times on healthy central upper incisors

    Institute of Scientific and Technical Information of China (English)

    奚晓菁; 章非敏; 谢海峰; 周俊杰

    2015-01-01

    Objective To study the effect of different chairside heat bleaching times on the healthy central upper incisors. Methods The subjects were treated with chairside heat bleaching for three times (an interval of one day),45 minutes each time. Color param-eters of the six healthy central upper incisors before and after each time of bleaching by Wy10 were determined using a dental colorime-ter and a VITA classical shade guide. The statistical analysis of the results was performed using paired t-test. Results Paired t-test showed that L* and W(Lab)parameters of all the central upper incisors increased(P 1. 7). Conclusions The increase in the number of operation times leads to the improvement of the heat bleaching effect.%目的:本实验旨在研究不同椅旁操作次数对活体上中切牙恒温漂白疗效的影响。方法受试者接受连续3次(每次间隔1 d)、每次45 min 的恒温漂白治疗,以比色仪测量每次漂白前后上中切牙的L*、a*、b*颜色参数值,分析变化,并记录比色板比色结果。所得数据以配对t 检验进行统计分析。结果统计分析显示,所有受试者接受漂白后牙体的L*、W (Lab)增大,b*降低,即牙齿的亮度和白度值增加,颜色向蓝色转变,且随漂白次数增多幅度变大,差别有统计学差异(P <0.05)。每次漂白操作后牙体颜色变化的色差均大于1.7个NBS 单位,说明每次漂白后的颜色变化均能被肉眼辨别。结论增加漂白次数能提高漂白疗效。

  7. Case report: endodontic and surgical treatment of an upper central incisor with external root resorption and radicular cyst following a traumatic tooth avulsion.

    Science.gov (United States)

    Lux, Hans-Christian; Goetz, Falko; Hellwig, Elmar

    2010-11-01

    In the age group between 6 and 12 years, trauma to the upper incisors happens frequently. In the case of avulsion, a replantation is the state-of-the-art treatment; however, it may lead to several complications, particularly if suitable posttraumatic management is not carried out. External cervical resorptions as well as apical granuloma and cysts due to microbial contamination of the root canal are common complications. In the presented trauma case, a conservative approach was chosen to treat a large cystic lesion combined with cervical and apical resorptions. After initial placement of Ledermix and calcium hydroxide into the root canal, a marsupialization with the temporary insertion of an obturator was performed. The gradual reduction led to a fast recovery of the bony defect and a root canal filling was placed. The 2-year follow-up showed an improved condition. All adjacent teeth remained vital during the course of the treatment.

  8. Molar incisor hypomineralization, prevalence, and etiology.

    Science.gov (United States)

    Allazzam, Sulaiman Mohammed; Alaki, Sumer Madani; El Meligy, Omar Abdel Sadek

    2014-01-01

    Aim. To evaluate the prevalence and possible etiological factors associated with molar incisor hypomineralization (MIH) among a group of children in Jeddah, Saudi Arabia. Methods. A group of 8-12-year-old children were recruited (n = 267) from the Pediatric Dental Clinics at the Faculty of Dentistry, King Abdulaziz University. Children had at least one first permanent molar (FPM), erupted or partially erupted. Demographic information, children's medical history, and pregnancy-related data were obtained. The crowns of the FPM and permanent incisors were examined for demarcated opacities, posteruptive breakdown (PEB), atypical restorations, and extracted FPMs. Children were considered to have MIH if one or more FPM with or without involvement of incisors met the diagnostic criteria. Results. MIH showed a prevalence of 8.6%. Demarcated opacities were the most common form. Maxillary central incisors were more affected than mandibular (P = 0.01). The condition was more prevalent in children with history of illnesses during the first four years of life including tonsillitis (P = 0.001), adenoiditis (P = 0.001), asthma (P = 0.001), fever (P = 0.014), and antibiotics intake (P = 0.001). Conclusions. The prevalence of MIH is significantly associated with childhood illnesses during the first four years of life including asthma, adenoid infections, tonsillitis, fever, and antibiotics intake.

  9. Molar Incisor Hypomineralization, Prevalence, and Etiology

    Directory of Open Access Journals (Sweden)

    Sulaiman Mohammed Allazzam

    2014-01-01

    Full Text Available Aim. To evaluate the prevalence and possible etiological factors associated with molar incisor hypomineralization (MIH among a group of children in Jeddah, Saudi Arabia. Methods. A group of 8-12-year-old children were recruited (n=267  from the Pediatric Dental Clinics at the Faculty of Dentistry, King Abdulaziz University. Children had at least one first permanent molar (FPM, erupted or partially erupted. Demographic information, children’s medical history, and pregnancy-related data were obtained. The crowns of the FPM and permanent incisors were examined for demarcated opacities, posteruptive breakdown (PEB, atypical restorations, and extracted FPMs. Children were considered to have MIH if one or more FPM with or without involvement of incisors met the diagnostic criteria. Results. MIH showed a prevalence of 8.6%. Demarcated opacities were the most common form. Maxillary central incisors were more affected than mandibular (P=0.01. The condition was more prevalent in children with history of illnesses during the first four years of life including tonsillitis (P=0.001, adenoiditis (P=0.001, asthma (P=0.001, fever (P=0.014, and antibiotics intake (P=0.001. Conclusions. The prevalence of MIH is significantly associated with childhood illnesses during the first four years of life including asthma, adenoid infections, tonsillitis, fever, and antibiotics intake.

  10. Treatment of mandibular anterior crowding with incisor extraction using lingual orthodontics: a case report.

    Science.gov (United States)

    Viswanath, Divya; Shetty, Sandeep; Mascarenhas, Rohan; Husain, Akhter

    2010-01-01

    A 20-year-old woman presented with a labially displaced mandibular right central incisor with severe attrition. Her maxillary dentition was well-aligned, and she had a straight profile. The respective central incisor was extracted. Subsequently, all teeth were aligned and the extraction space was closed with 2D lingual brackets. The result was esthetically pleasing.

  11. Deciduous molar hypomineralization and molar incisor hypomineralization

    NARCIS (Netherlands)

    Elfrink, M.E.C.; ten Cate, J.M.; Jaddoe, V.W.V.; Hofman, A.; Moll, H.A.; Veerkamp, J.S.J.

    2012-01-01

    This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between Deciduous Molar Hypomineralization (DMH) and Molar Incisor Hypomineralization (MIH). First permanent molars develop dur

  12. Congenitally missing maxillary lateral incisors and orthodontic treatment considerations for the single-tooth implant.

    Science.gov (United States)

    Richardson, G; Russell, K A

    2001-01-01

    Implant restorations have become a primary treatment option for the replacement of congenitally missing lateral incisors. The central incisor and canine often erupt in less than optimal positions adjacent to the edentulous lateral incisor space, and therefore preprosthetic orthodontic treatment is frequently required. Derotation of the central incisor and canine, space closure and correction of root proximities may be required to create appropriate space in which to place the implant and achieve an esthetic restoration. This paper discusses aspects of preprosthetic orthodontic diagnosis and treatment that need to be considered with implant restorations.

  13. Apexogenesis and revascularization treatment procedures for two traumatized immature permanent maxillary incisors: a case report.

    Science.gov (United States)

    Forghani, Maryam; Parisay, Iman; Maghsoudlou, Amir

    2013-08-01

    Traumatic injuries to an immature permanent tooth may result in cessation of dentin deposition and root maturation. Endodontic treatment is often complicated in premature tooth with an uncertain prognosis. This article describes successful treatment of two traumatized maxillary central incisors with complicated crown fracture three months after trauma. The radiographic examination showed immature roots in maxillary central incisors of a 9-year-old boy with a radiolucent lesion adjacent to the right central incisor. Apexogenesis was performed for the left central incisor and revascularization treatment was considered for the right one. In 18-month clinical and radiographic follow-up both teeth were asymptomatic, roots continued to develop, and periapical radiolucency of the right central incisor healed. Considering the root development of these contralateral teeth it can be concluded that revascularization is an appropriate treatment method in immature necrotic teeth.

  14. Intrusion of incisors in adult patients with marginal bone loss.

    Science.gov (United States)

    Melsen, B; Agerbaek, N; Markenstam, G

    1989-09-01

    Elongated and spaced incisors are common problems in patients suffering from severe periodontal disease. Thirty patients characterized by marginal bone loss and deep overbite were treated by intrusion of incisors. Three different methods for intrusion were applied: (1) J hooks and extraoral high-pull headgear, (2) utility arches, (3) intrusion bent into a loop in a 0.17 x 0.25-inch wire, and (4) base arch as described by Burstone. The intrusion was evaluated from the displacement of the apex, incision, and the center of resistance of the most prominent or elongated central incisor. Change in the marginal bone level and the amount of root resorption were evaluated on standardized intraoral radiographs. The pockets were assessed by standardized probing and the clinical crown length was measured on study casts. The results showed that the true intrusion of the center of resistance varied from 0 to 3.5 mm and was most pronounced when intrusion was performed with a base arch. The clinical crown length was generally reduced by 0.5 to 1.0 mm. The marginal bone level approached the cementoenamel junction in all but six cases. All cases demonstrated root resorption varying from 1 to 3 mm. The total amount of alveolar support--that is, the calculated area of the alveolar wall--was unaltered or increased in 19 of the 30 cases. The dependency of the results on the oral hygiene, the force distribution, and the perioral function was evaluated in relation to the individual cases. It was obvious that intrusion was best performed when (1) forces were low (5 to 15 gm per tooth) with the line of action of the force passing through or close to the center of resistance, (2) the gingiva status was healthy, and (3) no interference with perioral function was present.

  15. 替牙期牵引上颌埋伏阻生中切牙的疗效观察%Evaluation of the orthodontic treatment outcome in patients with impacted maxillary central incisor in the mixed dentition

    Institute of Scientific and Technical Information of China (English)

    程灿; 李小彤; 刘鹤

    2016-01-01

    Objective To evaluate the orthodontic treatment outcome in patients with impacted maxillary central incisor in the mixed dentition.Methods Nine patients,aged 8 to 11 years,with impacted maxillary central incisor were treated orthodontically.The cone-beam CT(CBCT) was taken before treatment,after treatment and one year out of retention to evaluate the root length,root canal wall thickness,width of the apical foramen,and degree of root bending,alveolar bone height and thickness.The crown-to-root ratio was calculated.The periodontal and endodontic conditions were evaluated.The parameters of the treated incisors and contralateral ones served as controls were compared.Results Nine impacted teeth were treated successfully.Throughout the treatment,the root of impacted central incisor continued to develop and the alveolar bones also continued to develop and remodel.The condition of the alveolar bone of vertically impacted teeth was better than that of horizontally impacted ones.No periodontal pocket or pulp necrosis was found after treatment.Seven patients were examined one year after treatment.No significant difference was found in root length,palatal alveolar bone level and palatal alveolar bone thickness.The control group root length was (13.07±2.15) mm,the treatment group root length was (12.06±2.00) mm.No further alveolar bone loss,gingival recession and pulp necrosis were found.The control group labial and palatal alveolar bone levels were (0.90 ± 0.62),(0.45 ± 0.52) mm,labial and palatal alveolar bone thickness were (0.85 ±0.14),(1.21 ±0.41) mm.The treatment group labial and palatal alveolar bone levels were (2.18 ± 1.59) mm,(0.57 ± 0.71) mm,labial and palatal alveolar bone thickness were (0.48 ± 0.29),(1.43 ± 0.31) mm.Conclusions Orthodontic therapy for impacted maxillary central incisor in the mixed dentition could promote root development and alveolar bone remodeling.Good periodontal and endodontic conditions were achieved.%目的 在替牙期对埋伏

  16. Effect of coffe and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching

    Science.gov (United States)

    PIROLO, Rodrigo; MONDELLI, Rafael Francisco Lia; CORRER, Gisele Maria; GONZAGA, Carla Castiglia; FURUSE, Adilson Yoshio

    2014-01-01

    There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. Objective: To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Materials and methods: Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05). Results: Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001). All specimens presented a decrease in brightness (negative ∆L). The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively). Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. Conclusion: The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching. PMID:25075672

  17. Effect of coffe and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching

    Directory of Open Access Journals (Sweden)

    Rodrigo PIROLO

    2014-12-01

    Full Text Available There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. Objective: To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Materials and methods: Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E and lightness (∆L variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05. Results: Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001. All specimens presented a decrease in brightness (negative ∆L. The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively. Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. Conclusion: The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching.

  18. Finite element stress analysis of all-ceramic crown of the upper central incisor in differential thickness%不同厚度上颌中切牙全瓷冠应力分布的有限元研究

    Institute of Scientific and Technical Information of China (English)

    胡建; 章非敏; 戴宁; 李泷杲; 顾卫平; 马骏驰

    2012-01-01

    Objective To investigate the stress distributions under load in an all-ceramic crown of the upper central incisor in differential thickness. Methods The 3-dimensional finite element model of all-ceramic crown of the upper central incisor in differential thickness was applied with differential loads(100, 150, 200 N). The stress values and distributions of all-ceramic crown were calculated and expressed. Results The tendency of stress distributions in all-ceramic crown of differential thickness and loads was similar. The maximal stress intensity value was located in the loading site and the cervical region. As the thickness of all-ceramic crown increased, the stress concentration reduced. When the load increased, the stress values increased, especially in the loading site and the cervical region. Conclusion The increasing of the thickness of all-ceramic crown will decrease stress concentration. Because stress concentration is mainly in cervical region and loading site, these regions should be cared in fabrication of all-ceramic crown.%目的 研究不同厚度上颌中切牙全瓷冠受载时的应力分布特点.方法 利用上颌中切牙全瓷冠的三维有限元模型,对3种不同厚度的全瓷冠分别进行100、150、200 N载荷模拟加载,并进行力学分析.结果 不同厚度全瓷冠不同载荷下的应力分布趋势相似,应力集中于冠的颈缘及加载点.随着厚度增加,应力集中趋势明显减弱.随着载荷增加,各部位的等效应力相应增加,加载点及颈缘尤为明显.结论 全瓷冠厚度的增加可降低应力集中.颈缘和加载点为应力集中区,全冠制作时应注意加强该区域.

  19. Molar Incisor Hypomineralization.

    Science.gov (United States)

    Rao, Murali H; Aluru, Srikanth C; Jayam, Cheranjeevi; Bandlapalli, Anila; Patel, Nikunj

    2016-07-01

    Molar incisor hypomineralization (MIH) is a developmental defect affecting teeth. High prevalence rates of MIH and its clinical implications are significant for both the patients and clinicians. A wide variation in defect prevalence (2.4-40.2%) is reported. It seems to differ with regions and various birth cohorts. Some of the recent prevalence studies are tabulated. Patient implications include hypersensitive teeth, rapid progression of caries, mastication impairment due to rapid attrition, and esthetic repercussions. Implications for clinicians include complexity in treatment planning and treatment implementation, poor prognosis of the restorations, difficulty in achieving pain control during treatment, and behavior management problems. Intention of this paper is to review the etio-pathogenesis, prevalence, clinical features, diagnostic features, and eventually present a sequential treatment approach, i.e., in accordance with current clinical practice guidelines.

  20. ["Molar-incisor hypomineralization"].

    Science.gov (United States)

    Kellerhoff, Nadja-Marina; Lussi, Adrian

    2004-01-01

    Hypocalcification of the enamel is the most common developmental disorder observed in teeth. The prevalence of this kind of hypomineralisation is about 10-19%. These molars are often referred to as cheese molars, because the lesions clinically resemble cheese in color and consistency. Other descriptions are: idiopathic enamel hypomineralisation in the permanent first molars, idiopathic enamel opacities in the permanent first molars, non fluoride enamel hypomineralisation in the permanent first molars, non-endemic mottling of enamel in the permanent first molars. Molar-Incisor Hypomineralisation is today the proposed expression for this disease. Occlusal surfaces of the first permanent molar are most commonly affected. The lesions are more frequent in the upper jaw than in the lower jaw. The incisors are affected to a lesser degree than the molars. Several aetiological factors can cause these defects. Some studies show a relation between intake of dioxins via mother's milk after prolonged breast feeding and developmental defects of the child's teeth. Because the ameloblasts are very sensitive to oxygen supply, complications involving oxygen shortages during birth or respiratory diseases such as asthma or bronchitis and pneumonia are discussed as further aetiological factors. Renal insufficiency, hypoparothyroidism, diarrhoea, malabsorption and malnutrition and high-fever diseases can be other reasons for the occurrence of these defects. Defective enamel can be a locus of lowered resistance for caries. Histologically there are areas of porosity of varying degrees. The affected teeth can be very sensitive to air, cold, warm and mechanical stimuli. Toothbrushing may create toothache in these teeth. We therefore suggest that these patients receive intensified prevention with fluoride varnish, a fissure sealing, GIZ, composits, stainless steel crowns or implants. In some cases an interdisciplinary approach with an orthodontist can result in the extraction of the molars

  1. The rat incisor in toxicologic pathology

    NARCIS (Netherlands)

    Kuijpers, M.H.M.; Kooij, A.J. van de; Slootweg, P.J.

    1996-01-01

    Microscopic examination of the incisors of rats and mice may reveal toxicologically significant changes. First, the incisor morphology reflects the nutritional status of the animal: fluctuations of mineral metabolism and vitamin availability are disclosed by the rodent incisors, because the incisors

  2. Pulp revascularization after repositioning of impacted incisor with a dilacerated root and a detached apex.

    Science.gov (United States)

    Plakwicz, Paweł; Kapuścińska, Agnieszka; Kukuła, Krzysztof; Czochrowska, Ewa Monika

    2015-06-01

    Severely impacted and dilacerated incisors are rarely considered for surgical exposure because they may not respond favorably to orthodontic extrusion. These incisors are often extracted, resulting in the need for tooth replacement; however, prosthetic solutions are limited in growing patients. Transalveolar autotransplantation of an impacted incisor may be the only method to preserve the natural tooth and maintain the shape of the alveolus. The severely impacted upper central incisor (#9) with a developing root was diagnosed in a 9-year-old girl. The unfavorable tooth position and dilaceration of its root made orthodontic extrusion of the impacted incisor impossible. Initial orthodontic space opening at the recipient site was performed before the surgery. Transalveolar transplantation of the impacted incisor to its normal position was performed to avoid tooth extraction. The incisor was later aligned using fixed orthodontic appliances. At the 5-year follow-up, the transplanted incisor presented features that were typical of a revascularized tooth (ie, obliteration of root canal but a positive response to vitality tests). Healthy periodontal tissues and continued root development were also noted. However, the root apex, which separated from the transplant at the time of the surgery, continued formation in its initial position. Transalveolar transplantation of an unfavorably impacted upper central incisor with a dilacerated root is a successful treatment, which stands the test of time. The early stage of root development allowed revascularization of the tooth despite dilaceration of the root and detachment of its apex.

  3. Orthodontic retraction of autotransplanted premolar to replace ankylosed maxillary incisor with replacement resorption.

    Science.gov (United States)

    Choi, Yoon Jeong; Shin, Sujung; Kim, Kyung-Ho; Chung, Chooryung J

    2014-04-01

    This case report describes the successful treatment of an adult with lip protrusion and a previously traumatized maxillary central incisor that had experienced replacement root resorption. An extracted premolar was transplanted into the incisor space and retracted orthodontically. Autotransplantation was successful with complete root formation and, combined with orthodontic treatment, provided a satisfying esthetic outcome.

  4. Social judgments made by children (10–15 year old) in relation to visible incisors trauma: School-based cross-sectional study in Khartoum state, Sudan

    Science.gov (United States)

    Awooda, Elhadi Mohieldin; Ali, Yasmeen Abdul-Hai

    2015-01-01

    Background: Dento-alveolar trauma is a very common occurrence in childhood; however, there is a paucity of data about children's judgments in relation to dental status. There is a significant correlation between the children's incisor teeth status and the social judgments made by their peers. Aim: The purpose of this study was to determine whether the social attributes of a school child would be influenced by his or her incisor teeth status. Also, it is aimed to determine the judgment between male and female children and different age groups within the same class. Setting and Design: A descriptive cross-sectional study conducted among 178 male and female children from year 5 (age 10–11 years) of primary school and year 2 of secondary school (age 14–15 years) within Khartoum state. Materials and Methods: Students were invited to look at colored photographs of four different children's faces and to make a social judgment about these children's photographs. Using a previously validated child-centered questionnaire, participants rated subjects using a four-point Likert scale for three negative and six positive attributes. Statistical Analysis: Total attribute scores were tested for significant differences, according to whether the subject had visible incisor trauma or not, using t-test and analysis of variance (ANOVA) test with the level of significance set at P ≤ 0.05. Results: Children with visible incisor trauma were given more negative attributes than children without incisor trauma (P = 0.05). Results were similar in both genders and both school years. Younger students within the same class gave more negative attributes toward children with visible incisor trauma than their older peers, with P = 0.04 and P = 0.9 for children aged 10 years and 11 years, respectively. Conclusion: The data confirmed results of previous studies that children with visible incisor trauma are seen more negatively than those without visible incisor trauma. PMID:26539397

  5. 上颌双侧中切牙外伤行冠延长术后的修复设计%Design of bilateral maxillary central incisor prosthesis after surgical crown lengthening

    Institute of Scientific and Technical Information of China (English)

    牛建杰; 杨帆

    2014-01-01

    目的:比较上颌双侧中切牙外伤行冠延长术后,不同修复设计对牙槽骨应力及牙齿动度的影响。方法:通过逆向工程技术建立齿冠延长术后不同骨下降高度的三维有限元模型,并将其设计为单冠、二联冠、三联冠、四联冠修复;然后用三维有限元法分析降低不同牙槽骨高度对桩核冠修复后牙槽骨应力分布及牙齿动度的影响。结果:随着牙槽骨高度的降低,所有修复形式组的牙槽骨应力及牙齿位移都有所上升,其中单冠修复组的增加幅度最大;当骨高度下降1 mm和2 mm时,单冠和3种联冠修复均能满足牙周潜力的要求;而骨下降高度为3 mm时,单冠修复组的应力值超过了牙周潜力的范围,二联冠修复接近牙周潜力,三联冠及四联冠修复均小于牙周潜力。结论:去骨高度在2 mm以内时,单冠和二联冠修复均可,但二联冠可以降低手术后造成的不利影响;当去骨高度为3 mm时,必须采用联冠修复,最好选用三联冠修复。%AIM:To investigate the effects of different prosthetic designs on the alveolar bone stress distri-bution and tooth moblilty of bilateral maxillary central incisors after surgical crown lengthening.METHODS:A three dimensional finite element model(3DFEM)of crowns with different alveolar bone height aroud the bilateral maxillary incisors was established by reverse modeling method.According to the design of prosthesis,the models was divided into 4 groups:single crown,2-unit combined crowns,3-unit combined crowns and 4-unit combined crowns.The alveolar bone stress distribution and terminal mobility with different crown design was analyzed using the 3DFEM.RESULTS:The maximum von Mises stress in the alveolar bone and the terminal mobility of the crown increased with the reduction of alveolar bone height.When the bone height reduced by less than 2 mm,all designs of restorations meet the require-ments of periodontal

  6. Esthetic restoration of infra-occluded retained primary mandibular incisors with all-ceramic crowns in adult dentition.

    Science.gov (United States)

    Hsu, Kuang-Wei; Shen, Yu-Fu

    2004-12-01

    The prevalence of hypodontia is reported to be between 1.5% to 10% in the permanent dentition. In the anterior teeth, maxillary lateral incisors and mandibular central incisors are the most frequently involved teeth. This causes esthetic problems for the patient. Several reports have focused on restoration of retained maxillary primary anterior teeth, but none have described restoration of retained mandibular primary incisors. This clinical report describes the restoration of infra-occluded retained primary mandibular central incisors of a 17 year-old girl diagnosed with hypodontia. All-ceramic crowns made with computer-aided design/ computer-aided manufacturing technology were used to restore the teeth incisally and interproximally. Due to a relatively short root length and inadequate crown-root ratio, the primary mandibular central incisors were splinted and adjusted to distribute the protrusive force evenly across the maxillary and mandibular incisors. Functional and esthetic results were achieved.

  7. Orthodontic intrusion of maxillary incisors: a 3D finite element method study

    Directory of Open Access Journals (Sweden)

    Armando Yukio Saga

    2016-02-01

    Full Text Available Objective: In orthodontic treatment, intrusion movement of maxillary incisors is often necessary. Therefore, the objective of this investigation is to evaluate the initial distribution patterns and magnitude of compressive stress in the periodontal ligament (PDL in a simulation of orthodontic intrusion of maxillary incisors, considering the points of force application. Methods: Anatomic 3D models reconstructed from cone-beam computed tomography scans were used to simulate maxillary incisors intrusion loading. The points of force application selected were: centered between central incisors brackets (LOAD 1; bilaterally between the brackets of central and lateral incisors (LOAD 2; bilaterally distal to the brackets of lateral incisors (LOAD 3; bilaterally 7 mm distal to the center of brackets of lateral incisors (LOAD 4. Results and Conclusions: Stress concentrated at the PDL apex region, irrespective of the point of orthodontic force application. The four load models showed distinct contour plots and compressive stress values over the midsagittal reference line. The contour plots of central and lateral incisors were not similar in the same load model. LOAD 3 resulted in more balanced compressive stress distribution.

  8. Dual embryonic origin of maxillary lateral incisors: clinical implications in patients with cleft lip and palate

    Directory of Open Access Journals (Sweden)

    Daniela Gamba Garib

    2015-10-01

    Full Text Available Introduction:Cleft lip and palate are craniofacial anomalies highly prevalent in the overall population. In oral clefts involving the alveolar ridge, variations of number, shape, size and position are observed in maxillary lateral incisors. The objective of this manuscript is to elucidate the embryonic origin of maxillary lateral incisors in order to understand the etiology of these variations.Contextualization: The hypothesis that orofacial clefts would split maxillary lateral incisor buds has been previously reported. However, recent studies showed that maxillary lateral incisors have dual embryonic origin, being partially formed by both the medial nasal process and the maxillary process. In other words, the mesial half of the lateral incisor seems to come from the medial nasal process while the distal half of the lateral incisor originates from the maxillary process. In cleft patients, these processes do not fuse, which results in different numerical and positional patterns for lateral incisors relating to the alveolar cleft. In addition to these considerations, this study proposes a nomenclature for maxillary lateral incisors in patients with cleft lip and palate, based on embryology and lateral incisors position in relation to the alveolar cleft.Conclusion:Embryological knowledge on the dual origin of maxillary lateral incisors and the use of a proper nomenclature for their numerical and positional variations renders appropriate communication among professionals and treatment planning easier, in addition to standardizing research analysis.

  9. Evaluating Stress Distribution Pattern in Periodontal Ligament of Maxillary Incisors during Intrusion Assessed by the Finite Element Method

    Directory of Open Access Journals (Sweden)

    Parisa Salehi

    2015-12-01

    Full Text Available Statement of the Problem: The use of miniscrews has expedited the true maxillary incisor intrusion and has minimized untoward side effects such as labial tipping. Purpose: The aim of this study was to assess the stress distribution in the periodontal ligament of maxillary incisors when addressed to different models of intrusion mechanics using miniscrews by employing finite element methods. The degree of relative and absolute intrusion of maxillary incisors in different conditions was also evaluated. Materials and Method: Finite element model of maxillary central incisor to first premolar was generated by assembling images obtained from a three-dimensional model of maxillary dentition. Four different conditions of intrusion mechanics were simulated with different placement sites of miniscrews as well as different points of force application. In each model, 25-g force was applied to maxillary incisors via miniscrews. Results: In all four models, increased stress values were identified in the apical region of lateral incisor. Proclination of maxillary incisors was also reported in all the four models. The minimum absolute intrusion was observed when the miniscrew was placed between the lateral incisor and canine and the force was applied at right angles to the archwire, which is very common in clinical practice. Conclusion: From the results yield by this study, it seems that the apical region of lateral incisor is the most susceptible region to root resorption during anterior intrusion. When the minimum flaring of maxillary incisors is required in clinical situations, it is suggested to place the miniscrew halfway between the roots of lateral incisor and canine with the force applied to the archwire between central and lateral incisor. In order to achieve maximum absolute intrusion, it is advised to place miniscrew between the roots of central and lateral incisors with the force applied at a right angle to the archwire between these two teeth.

  10. Evaluating Stress Distribution Pattern in Periodontal Ligament of Maxillary Incisors during Intrusion Assessed by the Finite Element Method

    Science.gov (United States)

    Salehi, Parisa; Gerami, Alayar; Najafi, Amirhosein; Torkan, Sepideh

    2015-01-01

    Statement of the Problem The use of miniscrews has expedited the true maxillary incisor intrusion and has minimized untoward side effects such as labial tipping. Purpose The aim of this study was to assess the stress distribution in the periodontal ligament of maxillary incisors when addressed to different models of intrusion mechanics using miniscrews by employing finite element methods. The degree of relative and absolute intrusion of maxillary incisors in different conditions was also evaluated. Materials and Method Finite element model of maxillary central incisor to first premolar was generated by assembling images obtained from a three-dimensional model of maxillary dentition. Four different conditions of intrusion mechanics were simulated with different placement sites of miniscrews as well as different points of force application. In each model, 25-g force was applied to maxillary incisors via miniscrews. Results In all four models, increased stress values were identified in the apical region of lateral incisor. Proclination of maxillary incisors was also reported in all the four models. The minimum absolute intrusion was observed when the miniscrew was placed between the lateral incisor and canine and the force was applied at right angles to the archwire, which is very common in clinical practice. Conclusion From the results yield by this study, it seems that the apical region of lateral incisor is the most susceptible region to root resorption during anterior intrusion. When the minimum flaring of maxillary incisors is required in clinical situations, it is suggested to place the miniscrew halfway between the roots of lateral incisor and canine with the force applied to the archwire between central and lateral incisor. In order to achieve maximum absolute intrusion, it is advised to place miniscrew between the roots of central and lateral incisors with the force applied at a right angle to the archwire between these two teeth. PMID:26636119

  11. Maxillary lateral incisor implants: planning with the aid of orthodontics.

    Science.gov (United States)

    Kokich, Vincent G

    2007-04-01

    This article has discussed six guidelines for managing adolescent orthodontic patients who are missing their maxillary lateral incisors and will require implants to replace these teeth. The space for the crown and implant, the space between the apices of the roots of the central incisor and canine, the possibility of implant site development, the effect of space opening on the integrity of the adjacent papillae, the impact of altered passive eruption, and the method for determining the age of implant placement have been discussed in detail. The intent of this article has been to emphasize the importance of interdisciplinary decision-making when planning implants in young adolescent patients who are congenitally missing their maxillary lateral incisors.

  12. Distribuição de tensões em modelo fotoelástico decorrente da intrusão dos incisivos inferiores por meio do arco base de Ricketts Stress distribution in a photoelastic model resulting from intrusion of mandibular incisors using Ricketts utility arch

    Directory of Open Access Journals (Sweden)

    Cristiane Aparecida de Assis Claro

    2011-10-01

    Full Text Available OBJETIVO: o presente estudo analisou a distribuição de tensões, em modelo fotoelástico, gerada por arco base de intrusão de incisivos inferiores. Compararam-se as tensões entre os terços radiculares de cada incisivo e, ainda, verificou-se a existência de diferenças de concentrações de tensões entre incisivos. MÉTODOS: foram confeccionados 15 arcos base de intrusão e a força de ativação foi mensurada em 50gf na região da linha média. O modelo fotoelástico foi observado em polariscópio circular, na configuração de campo escuro, e fotografado. As fotografias frontais foram analisadas e as ordens de franjas em cada região registradas. A análise de Kappa ponderado identificou a repetibilidade do método. A comparação entre as tensões foi realizada pelo teste de Kruskal-Wallis complementado com teste de Dunn com nível alfa de 5%. RESULTADOS E CONCLUSÕES: os resultados identificaram que as maiores magnitudes de tensões foram observadas nas regiões cervicais. Ao se comparar as ordens de franjas entre os dentes, as maiores magnitudes de tensões foram observadas nos incisivos centrais. Portanto, a região cervical pode estar mais sujeita a reabsorções, assim como os incisivos centrais, por concentrarem maiores tensões.OBJECTIVE: The present study is concerned with stress distribution in a photoelastic model, caused by lower incisor intrusion using utility arch. The stress levels on the radicular thirds of each lower incisors were compared and the stress concentration differences on each incisor were evaluated. METHODS: Fifteen intrusion utility arches were made up. The activation force of 50 gf was measured in the midline. The photoelastic model was observed using a circular polariscope in a dark field configuration, and, then, photographed. Frontal photographs were analyzed, and the fringe order in each region was registered. The method replicability was assessed by the Kappa weighted analysis. The comparison between

  13. Aggressive dentigerous cyst with ectopic central incisor.

    Science.gov (United States)

    Jayam, Cheranjeevi; Mitra, Malay; Bandlapalli, Anila; Jana, Biswanath

    2014-06-09

    Dentigerous cysts form from accumulation of fluid between reduced enamel epithelium and the crown of an unerupted tooth. They cause several difficulties such as swelling, non-eruption of the involved teeth, and displacement of adjacent teeth, and thus require early detection and prompt treatment. Treatment ranges from marsupialisation to enucleation. Enucleation is rarely used in children compared with marsupialisation. This paper discusses successful use of enucleation for treating a dentigerous cyst and explains the need for such a radical procedure.

  14. Aggressive dentigerous cyst with ectopic central incisor

    OpenAIRE

    Jayam, Cheranjeevi; Mitra, Malay; Bandlapalli, Anila; Jana, Biswanath

    2014-01-01

    Dentigerous cysts form from accumulation of fluid between reduced enamel epithelium and the crown of an unerupted tooth. They cause several difficulties such as swelling, non-eruption of the involved teeth, and displacement of adjacent teeth, and thus require early detection and prompt treatment. Treatment ranges from marsupialisation to enucleation. Enucleation is rarely used in children compared with marsupialisation. This paper discusses successful use of enucleation for treating a dentige...

  15. On the Etiology of Molar-Incisor Hypomineralization.

    Science.gov (United States)

    Vieira, Alexandre R; Kup, Elaine

    Molar-incisor hypomineralization (MIH) is a condition that is defined based on its peculiar clinical presentation. Reports on the etiology of the condition and possible risk factors are inconclusive and the original suggestion that MIH is an idiopathic condition is often cited. Our group was the first to suggest MIH has a genetic component that involves genetic variation in genes expressed during dental enamel formation. In this report, we provide a rationale to explain the preferential affection of molars and incisors. We suggest that MIH is a genetic condition based on its prevalence, which varies depending on the geographic location, and the evidence that on occasion second primary molars, permanent canines, and premolars can show signs of hypomineralization of enamel when molars and incisors are affected.

  16. Removable appliance and closed of central incisors:report of 48 cases%活动矫治器+封闭式牵引术矫治上颌埋伏倒置弯曲中切牙48例报告

    Institute of Scientific and Technical Information of China (English)

    邵林琴; 张立霞; 巩若箴; 马缨卫

    2012-01-01

    PURPOSE: To evaluate the treatment effect of orthodontic traction on embedded and inverted maxillary bending central incisors. METHODS: Fifty-two embedded and inverted maxillary central incisors without-eruption ability in 48 cases were treated by combined orthodontic traction with surgical treatment after spiral CT positioning and expanding the space, the eruption situation, gingival—breaking time and teeth pulp vitality after treatment were recorded, and the treatment effect was evaluated. RESULTS: Forty—eight cases with 52 impacted upper central incisors were treated with surgical and closed orthodontic traction, successful results were achieved in 36 cases, accounting for 69.23%; 15 cases had improvement, accounting for 28.85%; 1 case failed, accounting for 1.9%. Pulp vitality tests were all normal and there was no root absorption and ankylosis. CONCLUSIONS: Selecting appropriate cases, precise positioning with spiral CT, proper space expanding and rational application of removable traction appliance are the keys to successful treatment of impacted and inverted maxillary bending central incisors of children in mixed dentition.%目的:观察上颌埋伏阻生的倒置弯曲中切牙正畸牵引治疗的效果.方法:选择48例、52颗无萌出能力的上颌埋伏阻生倒置弯曲中切牙,分别经螺旋CT定位、拓展间隙后,行手术联合正畸牵引治疗,观察治疗后的萌出状况、破龈时间、牙髓活力等,以成功、有效和失败评判疗效.结果:本组48例、52颗埋伏中切牙中,成功36颗,占69.23%;有效15颗,占28.85%;失败1颗,占1.9%.牙髓活力检测均正常;未见牙根吸收和黏连.结论:对替牙期儿童的上颌埋伏阻生倒置弯曲中切牙,选择合适的适应证、通过螺旋CT精确定位、恰当的间隙拓展以及活动牵引矫治器的合理应用,是治疗成功的关键.

  17. Mandibular incisor extraction treatment in Angle's Class I malocclusion with peg-shaped maxillary lateral incisors.

    Science.gov (United States)

    Shah, Ankit H; Shah, Darshit H

    2016-01-01

    Accurate diagnosis and treatment planning are essential for obtaining ideal treatment result in cases involving mandibular incisor extraction. This case report describes a 15-year-old female with balanced soft-tissue profile, peg-shaped maxillary lateral incisors, and moderate mandibular anterior crowding treated with a mandibular incisor extraction. Ideal overbite and overjet were achieved. "Black triangle" formation was avoided due to the bodily movement of mandibular incisors and the use of uprighting springs for ideal axial inclination of mandibular incisors. A mandibular incisor extraction can be an effective treatment option in carefully selected clinical situations.

  18. Ectopic eruption of permanent incisors after predecessor pulpectomy: five cases.

    Science.gov (United States)

    Tannure, Patricia Nivoloni; Fidalgo, Tatiana Kelly da Silva; Barcelos, Roberta; Gleiser, Rogerio; Primo, Laura Guimaraes

    2011-01-01

    Pulpectomy in primary teeth is a common technique that preserves teeth in the oral environment and maintains or recovers periapical tissues to a healthy condition. This article describes the ectopic eruption of permanent incisors whose primary predecessors underwent pulpectomy using ZOE filler paste. In a group of 135 teeth that received pulpectomy therapy due to caries, 10 primary maxillary incisors had overretention and were followed for at least 3.5 years (mean time of 4.2 years), both clinically and radiographically, until the permanent teeth erupted. The proposed treatment included extraction of the overretained primary incisors based on permanent successor eruption chronology and contralateral eruption. Seven permanent teeth erupted ectopically. Autocorrection of the permanent tooth positions was observed in five cases. It can be concluded that periodic clinical and radiographic assessments are essential to verify radicular and filling paste resorptions and to avoid overretention and any subsequent malocclusion.

  19. Impacted permanent incisors associated with compound odontoma.

    Science.gov (United States)

    Machado, Cintia de Vasconcellos; Knop, Luégya Amorin Henriques; da Rocha, Maria Celina Barreiros Siquara; Telles, Paloma Dias da Silva

    2015-01-12

    Odontomas are the most common odontogenic tumours of the maxillary bones, characterised by a slow growth and benign behaviour. They are usually small, asymptomatic and diagnosed after routine radiographic examination. The aim of this study was to report a case of a compound odontoma in the anterior maxilla of a 7-year-old girl, which was causing the impaction of the maxillary right central and lateral incisors, as well as the prolonged retention of the corresponding primary teeth. We also aimed to review the literature about these tumours, since they are not part of the dentist's day-to-day clinical practice. The clinical and radiographic features, the diagnosis and treatment of the case were discussed in this work.

  20. 成年正畸患者下中切牙间出现黑三角的病因探讨%Etiology of open gingival embrasures between two mandibullary central incisors after orthodontic treatmeat in adults

    Institute of Scientific and Technical Information of China (English)

    商燕丽; 冯剑颖; 林新平; 谷志远

    2009-01-01

    目的 评价成年固定正畸患者在治疗后下颌中切牙之间出现黑三角的病因及它们之间的联系,为临床预防出现黑三角提供理论依据.方法 实验组为100例在正畸治疗后出现黑三角的成年患者,对照组为79例在正畸治疗后未出现黑三角的成年患者,均采用直丝弓矫正技术.治疗前、后两组都分别拍摄曲面断层片进行测量分析,采用spss11.5软件包进行统计学分析.结果 治疗前下颌中切牙的旋转和重叠交错与黑三角的发生没有统计学的意义.两个下颌中切牙近中釉牙骨质界点的距离、釉牙骨质界到邻接点的距离、牙槽嵴顶到釉牙骨质界的距离、下颌中切牙邻接点到牙齿长轴的距离等与黑三角的发生有关(P<0.05),有统计学意义.女性发生黑三角比例较高(P<0.05),有统计学意义.牙周情况方面,有牙结石的患者发生黑三角的比例高(P<0.05),有统计学意义.结论 成年正畸患者发生黑三角的概率与矫治前的牙齿牙周的某些因素和矫治过程中变化程度有显著的相关性.黑三角是一个多因素发病的疾病.%Objective To evaluate the etiology of posttreatmeat open gingival embrasures in adult orthodontic patients,examine the associations and a theoretical basis for clinical prevention of open gingival embrasures. Methods A subsample of 179 patients were i-dentified for measurement and divided into 2 groups:79 patients were normal gingival embrasures and 100 patients were open gingival embrasures(56 males,123 females;18 ~ 38 years of age). Digital images of the pretreatment mandibuUary models and posttreatment panoramic radiographs were made to measure the pretreatment and posttreatment variables. The data were analyzed using SPSS 11.5 software package. Results Pretreatment mandibullary central incisor rotation and overlap were not statistically associated with postt-reatmeat open gingival embrasures. A posttreatment CEJ-CEJ distance of the two

  1. 不同咬合状态下上颌中切牙全瓷冠修复的有限元分析%Finite element analysis of maxillary central incisor all-ceramic crowns in different occlusal states

    Institute of Scientific and Technical Information of China (English)

    肖严; 熊康; 权菲菲

    2016-01-01

    BACKGROUND:The strength of al-ceramic crowns is affected by many factors. At present there are many studies concerning the neck edge shape, cutting thickness, binder and convergence angle, but little has been reported on the effects of different occlusions on al-ceramic crowns. OBJECTIVE:To explore the maxilary central incisor al-ceramic crowns in different occlusal states by finite element analysis. METHODS: Three-dimensional finite element models of the maxilary central incisor al-ceramic crowns were established. Empress II and In-Ceram Zirconia were selected. The normal overbite position and deep overbite position were applied to force a load of 230 N, with the long axis of the tooth at a 45° angle. Distribution of inner stress and edge stress was analyzed at different occlusal states. RESULTS AND CONCLUSION:(1) The stress distribution of al-ceramic crowns under different occlusion relationship was different. The stress peaks of cementum, alveolar bone and periodontium in the deep overbite were lower than those in the normal overbite. The stress peaks of al-ceramic crowns and binder were higher than in the deep overbite than the normal overbite. The stress peak of the dentin in the Empress II group was higher in the deep overbite than in the normal overbite. The stress peak of the dentin in the In-Ceram Zirconia group was lower in the deep overbite than in the normal overbite. Different al-ceramic crowns had no influence on the stress distribution, but in the deep overbite, the stress was mainly concentrated in the occlusal contact area, and in the normal overbite, the stress was mainly concentrated in the occlusal contact area and at the labial cervical margin. (2) The stress distribution of different al-ceramic crowns under the same occlusal state was different. In the normal overbite, different al-ceramic crowns had no evident influence on the stress peak, and in the deep overbite, there was a certain effect of different al-ceramic crowns on the stress peak

  2. Nonsyndromic bilateral multiple retained primary incisors in mandibular arch: Rare case report

    Directory of Open Access Journals (Sweden)

    D Deepa

    2016-01-01

    Full Text Available A disturbed eruption process creates a clinical situation that is challenging to diagnose and treat. The clinical arena of tooth eruption disorders includes both syndromic and nonsyndromic problems varying from delayed eruption to a complete failure of eruption or sometimes retained primary teeth. This paper reports a rare case of retained bilateral primary incisors on mandibular arch in a systemically healthy patient with eruption of the permanent central and lateral incisors bilaterally.

  3. Age- and gender-related incisor changes in different vertical craniofacial relationships

    Science.gov (United States)

    Linjawi, Amal I

    2016-01-01

    Objective: To investigate the age- and gender-related changes in upper and lower incisors' position and inclination in different vertical craniofacial relationships. Materials and Methods: A retrospective study on patients' records of age 8–48 years. The sample was divided based on Frankfort mandibular plane angle into three groups; normal, high, and low angle groups. It was then subdivided according to age. Upper and lower incisors' inclinations and positions were assessed from lateral cephalometric radiographs. Gender and age associations and effects size were calculated using two-way ANOVA tests. Significance level was set at P 0.05). All significant associations and effects were found in the low angle group only. A significant association was found between gender and upper incisor inclination (P < 0.05) with medium effect size (0.13 ≤ ηp2 < 0.26). An association is also found between age × gender interaction and upper incisor inclination and lower incisor position (P < 0.05) with large effect size (0.26 ≤ ηp2). Conclusion: Age- and gender-related upper and lower incisor changes were found to be significant in subjects with decreased vertical skeletal pattern only. The upper incisor inclination and the lower incisor position were the most affected variables with age and gender. PMID:27843888

  4. Dynamics-based centrality for directed networks

    Science.gov (United States)

    Masuda, Naoki; Kori, Hiroshi

    2010-11-01

    Determining the relative importance of nodes in directed networks is important in, for example, ranking websites, publications, and sports teams, and for understanding signal flows in systems biology. A prevailing centrality measure in this respect is the PageRank. In this work, we focus on another class of centrality derived from the Laplacian of the network. We extend the Laplacian-based centrality, which has mainly been applied to strongly connected networks, to the case of general directed networks such that we can quantitatively compare arbitrary nodes. Toward this end, we adopt the idea used in the PageRank to introduce global connectivity between all the pairs of nodes with a certain strength. Numerical simulations are carried out on some networks. We also offer interpretations of the Laplacian-based centrality for general directed networks in terms of various dynamical and structural properties of networks. Importantly, the Laplacian-based centrality defined as the stationary density of the continuous-time random walk with random jumps is shown to be equivalent to the absorption probability of the random walk with sinks at each node but without random jumps. Similarly, the proposed centrality represents the importance of nodes in dynamics on the original network supplied with sinks but not with random jumps.

  5. Comparison of the physiological properties of human periodontal-masseteric reflex evoked by incisor and canine stimulation

    Directory of Open Access Journals (Sweden)

    Hiroko eOhmori

    2012-06-01

    Full Text Available Introduction: The present study was designed to clarify whether the bilateral cooperation in the human periodontal-masseteric reflex (PMR differs between central incisors and canines. Methods: Surface array electrodes were placed on the bilateral masseter muscles to simultaneously record the firing activities of single motor units from both sides in 7 healthy adults. During light clenching, mechanical stimulation was applied to the right maxillary central incisor and canine to evoke the PMR. Unitary activity was plotted with respect to the background activity and firing frequency. The slope of the regression line (sRL and the correlation coefficient (CC between the central incisor and canine and the lateral differences between these values were compared. Results: There were significant differences in the sRL and CC, as well as lateral differences, between the central incisor- and canine-driven PMR. Discussion: These results suggest that the PMR differs depending on both the tooth position and laterality.

  6. DENTAL CARE FOR CHILDREN AFTER REPLANTATION OF AVULSED PERMANENT INCISORS

    Directory of Open Access Journals (Sweden)

    Rossitza Kabaktchieva

    2016-12-01

    Full Text Available The diagnosis avulsion of permanent tooth/teeth is an emergency situation which has special requirements in respect of proper storage of the avulsed tooth, the need of urgent medical/dental care, time past till replantation and splinting, the need for endodontic treatment and long term follow up period. Those clinical actions depend on three groups: parents/people who are with the child in the moment when trauma happens and give the first aid; dental specialist- surgeon who replants the tooth/teeth; dental specialist- endodontist who takes care of the endodontic treatment and the long period after treatment for follow up and observation of the replanted teeth. The aim of the paper is to present the dental postoperative care in a couple of cases of children with trauma and replanted avulsed permanent incisors. Material and methods: We present four clinical cases of children who get 6 permanent upper incisors replanted. Replantation is made by the oral surgeon. Treatment and observation after replantation are made by dental specialists of pediatric dentistry and conservative dentistry. All 4 cases get 3 years follow up period. Results: After replantation of 2 central incisors with complete root development (first clinical case the left one has developed a resorption of the root but the right one is in a stable condition. Replantation of 3 teeth with incomplete root development (second and third clinical cases where the patients refer to specialized surgical care less than 60 minutes after injury and store the teeth in different ways lead to different clinical results. In the case of avulsed upper right incisor (second case, it is stored in milk and we observe revascularization followed by partial root canal obliteration. The tooth is scheduled for endodontic treatment. In the case of upper central incisors, both kept dry till replantation in the alveolus filled up with substitute bone, we observe fast root resorption which going to lead to early

  7. Prediction of Mesiodistal Width of Unerupted Lateral Incisors, Canines and Premolars in Orthodontic Patients in Early Mixed Dentition Period

    Science.gov (United States)

    Toodehzaeim, Mohammad Hossein; Haerian, Alireza

    2016-01-01

    Objectives: Proper diagnosis and prevention of malocclusion are superior to treatment. Discrepancy between arch length and tooth size in mixed dentition period is a condition requiring timely diagnosis. Estimating the mesiodistal width of unerupted teeth according to the size of erupted ones can lead to earlier diagnosis of malocclusion. On the other hand, the best timing for serial extractions is before the eruption of lateral incisors. The aim of this study was to present prediction formulas for mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population based on the width of erupted permanent mandibular central incisors and maxillary first molars. Materials and Methods: A total of 120 dental models (60 males, 60 females) of orthodontic patients between 11–25 years were evaluated in Yazd city. The measurements were made by a digital caliper on the widest mesiodistal width of teeth at the interproximal contacts. Data were analyzed to calculate the prediction equation. Results: The prediction equation in the upper jaw was y=0.57x+10.82 for males, y=0.7x+6.37 for females and y=0.64x+8.46 for both sexes. The equation for the lower jaw was y=0.76x+2.86 for males, y=0.74x+3.53 for females and y=0.77x+2.7 for both sexes. Conclusions: The prediction equations suggested in this study can predict the mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population in early mixed dentition period without taking radiographs. PMID:28243298

  8. Moving an incisor across the midline: a treatment alternative in an adolescent patient.

    Science.gov (United States)

    Bosio, Jose A; Bradley, T Gerard; Hefti, Arthur F

    2011-04-01

    A 13-year-old sought treatment for a severely compromised maxillary left central incisor and an impacted fully developed left canine. Extraction of both teeth became necessary. As the key component of the revised comprehensive treatment plan, the right maxillary central incisor was moved into the position of the left central incisor. All other maxillary teeth were moved mesially to close any gaps. Active orthodontic treatment was completed after 34 months. Frenectomy, minor periodontal surgeries, and bonded lingual retainers were used to improve aesthetics and stabilize the tooth positions. The patient was pleased with the treatment outcome. Cone-beam computed tomography provided evidence that the tooth movement was accompanied by a deviation of the most anterior portion of the median palatine suture. This observation may make relapse more likely if long-term retention cannot be ensured. Root resorption was not observed as a consequence of the major tooth movement.

  9. Revascularization of immature permanent incisors after severe extrusive luxation injury.

    Science.gov (United States)

    Cehreli, Zafer C; Sara, Sezgi; Aksoy, Burak

    2012-07-01

    Pulp necrosis is an uncommon sequel to extrusive luxation in immature teeth with incomplete apical closure. In this report, we describe the management of severely extruded immature maxillary incisors and the outcome of revascularization to treat subsequent pulp necrosis. An 8.5-year-old boy with severe dentoalveolar trauma to the anterior maxillary region as a result of a fall was provided emergency treatment consisting of reduction of the dislodged labial cortical bone and repositioning of the central incisors, which had suffered extrusive luxation. When he presented with spontaneous pain involving the traumatized incisors a week later, the teeth were treated via a revascularization protocol using sodium hypochlorite irrigation followed by 3 weeks of intracanal calcium hydroxide, then a coronal seal of mineral trioxide aggregate and resin composite. Complete periradicular healing was observed after 3 months, followed by progressive thickening of the root walls and apical closure. Follow-up observations confirmed the efficacy of the regenerative treatment as a viable alternative to conventional apexification in endodontically involved, traumatized immature teeth.

  10. Replantation of permanent incisors in children using Emdogain.

    Science.gov (United States)

    Barrett, Edward J; Kenny, David J; Tenenbaum, Howard C; Sigal, Michael J; Johnston, Douglas H

    2005-10-01

    The aim of this study was to determine whether application of an enamel matrix protein derivative, Emdogain (Biora AB Malmo, Sweden) to the root surface of avulsed permanent incisors would improve postreplantation outcomes in a pediatric population. Between June 1999 and May 2002, 25 avulsed permanent maxillary incisors (22 centrals and three laterals) were treated with Emdogain and followed for up to 32 months, mean duration 20.6 months (range: 6.9-32.5 months). Mean patient age at the time of treatment was 12.0 years (range: 7.7-17.6 years) and mean extra-alveolar duration was 185 min (range: 100-300 min). At the end of their follow-up each of the replanted incisors demonstrated radiographic evidence of replacement root resorption and clinical evidence of ankylosis. None of the replanted teeth were affected by inflammatory root resorption and there was no evidence of infection. When compared with the control samples from Barrett and Kenny (Endod Dent Traumatol 1997;15:269-72.) and Andersson et al. (Endod Dent Traumatol 1989;5:38-47.) this sample treated with the Emdogain protocol demonstrated significantly less root resorption than either of the control samples (anova, P Emdogain protocol did not produce periodontal regeneration, it did eliminate inflammatory resorption and infection and led to significantly less root resorption compared with the two historical controls.

  11. Construction of three-dimension al finite element model of maxillary central incisor with various crown-root ratio and labial alveolar bone width%建立不同临床冠根比和唇侧牙槽嵴顶厚度的上颌中切牙三维有限元模型

    Institute of Scientific and Technical Information of China (English)

    张艺君; 廖沐莹; 张翼

    2014-01-01

    Objective:to construct a three-dimensional finite element model of maxillary central incisor with various crown-root ratio and labial alveolar bone width.Methods:after thoroughly cleaning and polished, an extracted maxillary central incisor with normal anatomic structure was scanned with micro-CT technique, and its two dimensional images were transferred into a 3-D model by using the software Mimic, reverse engineering software Geomagic, computer aid design program UG6. The 3-D parametric model of a maxillary central incisor with various crown-root ratio, periodontal membrane and alveolar bone were established in the UG software through its automated modeling.Results:The 3D parametric model with precise anatomical features were successfully established. In the Design Exploration, the clinical crown-root ratio and width of labial alveolar bone were defined as input parameters with the former ranging from 1.1 to 2.5 and the later from 0.1mm to 0.5mm. Conclusion:the 3D parametric model of model of maxillary central incisor with various crown-root ratio and labial alveolar bone width was successfully established by reverse engineering software which had precise anatomical features.%目的:建立不同临床冠根比例和唇侧牙槽嵴顶厚度的上颌中切牙三维有限元模型。方法:选择一颗解剖形态标准的离体上颌中切牙清理抛光后,在显微CT扫描下获得断层二维图像,结合有限元软件Mimics、Geomagic及UG实现三维模型的实体化。利用UG软件构建出牙周膜、松质骨及皮质骨模块,建立上颌中切牙不同临床冠根比例及唇侧牙槽嵴顶厚度的自适应模型。结果:构建了不同临床冠根比例和唇侧牙槽嵴顶厚度的三维有限元模型。将变量冠根比例的变化范围设置为1.1-2.5,变量唇侧牙槽嵴顶厚度的变化范围设置为0.1mm-0.5mm。结论:采用有限元软件建立的不同临床冠根比例和牙槽嵴顶厚度的三维有限元模型,

  12. Incisor wear and age in Yellowstone bison

    Science.gov (United States)

    Christianson, D.A.; Gogan, P.J.P.; Podruzny, K.M.; Olexa, E.M.

    2005-01-01

    Biologists commonly use tooth eruption and wear patterns or cementum annuli techniques to estimate age of ungulates. However, in some situations the accuracy or sampling procedures of either approach are undesirable. We investigated the progression of several quantitative measures of wear with age, using permanent first incisors from Yellowstone bison (Bison bison), and tested for differences between sexes and herds. We further investigated the relationship of wear and age to explore an age-estimation method. Labial-lingual width (LLW) correlated best with assigned age (r2=0.66, males; r2=0.76 females). Labial-lingual width differed between sexes, with females showing ∼0.2 mm more wear than males. Additionally, differences in rate of wear existed between bison of the northern and central Yellowstone herds (1.2 and 0.9 mm/year, respectively). We developed a regression formula to test the power of LLW as an estimator of Yellowstone bison age. Our method provided estimated ages within 1 year of the assigned age 73% and 82% of the time for female and male bison, respectively.

  13. 替牙期牵引上颌埋伏阻生中切牙对牙根发育影响的初步研究%A preliminary study of efficacy on root development of orthodontic traction for impacted maxillary central incisor in mixed dentition

    Institute of Scientific and Technical Information of China (English)

    程灿; 李小彤; 刘鹤

    2015-01-01

    目的 评价替牙期牵引上颌埋伏阻生中切牙对其牙根发育的影响.方法 选取9名8~11岁上颌中切牙埋伏阻生患者进行牵引治疗,应用CBCT进行牵引前后的牙根长度、根管壁厚度、牙根弯曲程度的测量,计算冠根比,比较阻生牙牵引前后、阻生牙与对侧对照牙牙根发育的差异.结果 9颗阻生牙经牵引均达到牵引到位标准,根管壁厚度与对照牙无显著性差异.经牵引治疗的埋伏阻生中切牙牙根继续发育,牵引后的牙根长度均长于牵引前,但短于对照牙,冠根比优于治疗前,但不及对照牙;替牙期牵引治疗可能无法改变原有的牙根弯曲,而新发育的牙根有可能在牵引过程中形成新的弯曲.结论 上颌埋伏阻生中切牙经牵引矫治能获得良好的临床效果,牙根继续发育,但需要谨慎选择替牙期牵引的适应证.%Objective To evaluate the efficacy on root development of orthodontic traction for impacted maxillary central incisor in mixed dentition.Methods 9 cases of 8 to 11 years old impacted maxillary central incisor patients were treated with traction.CBCT measurement on root length,root canal wall thickness,and degree of root bending and the ratio of crown and root of the impacted teeth were implemented,and compared with the contralateral counterpart tooth.Results 9 teeth were treated to standard place.After traction,incisor root continues development,but root length is shorter than the control teeth.Crown root ratio and root wall thickness presented no significant difference compared to control teeth.Orthodontic treatment may not be able to change the original root dilaceration,and may cause new dilaceration during traction process.Conclusions Impacted maxillary central incisor after orthodontic traction can achieve satisfied clinical results,but indications for traction during mixed dentition should be carefully evaluated.

  14. Removable orthodontic appliance with nickel-titanium spring to reposition the upper incisors in an autistic patient.

    Science.gov (United States)

    Saito, Kan; Jang, Insan; Kubota, Kazumi; Hoshino, Tomonori; Hotokezaka, Hitoshi; Yoshida, Noriaki; Fujiwara, Taku

    2013-01-01

    A newly designed removable appliance with a shape-memory wire was used for the orthodontic treatment of the anterior teeth in an 11-year-old child who had autism and intellectual disability. The device was designed to reduce the lateral incisor crossbite and the central incisors' labial rotation. The child was treated for 1 year with this removable appliance. Tooth movement was analyzed using cephalograms and surface data were derived from study models. This device proved to be very durable. The lateral incisor crossbite was corrected, and the inclination of the upper central incisors and the interincisal angle were improved. This appliance exerts light and continuous orthodontic force, without requiring any adjustments of the spring wire. The appliance also facilitated orthodontic treatment in a child with intellectual disability in whom treatment with a standard orthodontic device would be unsuitable.

  15. Clinical management of a fused mandibular lateral incisor with supernumerary tooth: A case report

    Science.gov (United States)

    Aydemir, Seda; Ozel, Emre; Arukaslan, Goze; Tekce, Neslihan

    2016-01-01

    The purpose of this report is to present a rare case of a fused mandibular lateral incisor with supernumerary tooth with a follow-up for 18-months. A 35-year-old female patient was referred to our clinic with an extraoral sinus tract in the chin. The intraoral diagnosis revealed the fusion of her mandibular lateral incisors. Vitality pulp tests were negative for mandibular right central and lateral incisors. Radiographic examinations showed a fused tooth with two separate pulp chambers, two distinct roots, and two separate root canals. There were also periapical lesion of fused teeth and mandibular right central incisor, so endodontic treatment was carried out the related teeth. Radiographic examination revealed a complete healing of the lesion postoperatively at the end of 18-months. This paper reports the successful endodontic and restorative treatment of unilateral fused incisors. Because of the abnormal morphology of the crown and the complexity of the root canal system in fused teeth, treatment protocols require special attention. PMID:26962321

  16. A radiographic analysis of external apical root resorption of maxillary incisors during active orthodontic treatment.

    Science.gov (United States)

    Mohandesan, Hooman; Ravanmehr, Hossein; Valaei, Nasser

    2007-04-01

    External apical root resorption (EARR) is an undesirable consequence of orthodontic treatment. The purpose of this study was to measure the amount of EARR and to examine its clinical significance in maxillary incisors, during a 12-month active treatment period. A further aim was to examine the contribution of gender, treatment technique, treatment duration, and extraction of maxillary first premolars to EARR. The sample comprised 151 maxillary incisor teeth in 40 patients (16 males, 24 females) aged 12-22 years, with different malocclusions. Standard periapical radiographs, using the long-cone paralleling technique, were obtained before and 6 and 12 months after the start of treatment. Quantitative measurements for 80 central and 71 lateral maxillary incisors were performed separately and corrected for image distortion. Root length reduction was calculated in millimetres and in terms of the percentage of the original root length. Resorption of more than 1 mm at 12 months of active treatment was considered to be clinically significant. On average, the degree of EARR for the maxillary central incisors was 0.77 +/- 0.42 and 1.67 +/- 0.64 mm, respectively, during the 6- and 12-month follow-up (P incisors, the degree of EARR was 0.88 +/- 0.51 and 1.79 +/- 0.66 mm, respectively (P resorption was found for 74 per cent of the centrals and 82 per cent of the laterals. No significant correlation was observed between EARR and treatment technique. EARR was found to be correlated with gender for the lateral incisors. The effect of treatment duration (P < 0.001) and premolar extraction (P < 0.001) was statistically significant for both tooth groups.

  17. Deciduous molar hypomineralization and molar incisor hypomineralization.

    Science.gov (United States)

    Elfrink, M E C; ten Cate, J M; Jaddoe, V W V; Hofman, A; Moll, H A; Veerkamp, J S J

    2012-06-01

    This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between Deciduous Molar Hypomineralization (DMH) and Molar Incisor Hypomineralization (MIH). First permanent molars develop during a period similar to that of second primary molars, with possible comparable risk factors for hypomineralization. Children with DMH have a greater risk of developing MIH. Clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6,161 children (49.8% girls; mean age 74.3 mos, SD ± 5.8). First permanent molars and second primary molars were scored with respect to DMH or MIH. The prevalence of DMH and MIH was 9.0% and 8.7% at child level, and 4.0% and 5.4% at tooth level. The Odds Ratio for MIH based on DMH was 4.4 (95% CI, 3.1-6.4). The relationship between the occurrence of DMH and MIH suggests a shared cause and indicates that, clinically, DMH can be used as a predictor for MIH.

  18. Molar incisor hypomineralization: review and recommendations for clinical management.

    Science.gov (United States)

    William, Vanessa; Messer, Louise B; Burrow, Michael F

    2006-01-01

    Molar incisor hypomineralization (MIH) describes the clinical picture of hypomineralization of systemic origin affecting one or more first permanent molars (FPMs) that are associated frequently with affected incisors. Etiological associations with systemic conditions or environmental insults during the child's first 3 years have been implicated. The complex care involved in treating affected children must address their behavior and anxiety, aiming to provide a durable restoration under pain-free conditions. The challenges include adequate anaesthesia, suitable cavity design, and choice of restorative materials. Restorations in hypomineralized molars appear to fail frequently; there is little evidence-based literature to facilitate clinical decisions on cavity design and material choice. A 6-step approach to management is described: (1) risk identification; (2) early diagnosis; (3) remineralization and desensitization; (4) prevention of caries and posteruption breakdown; (5) restorations and extractions; and (6) maintenance. The high prevalence of MIH indicates the need for research to clarify etiological factors and improve the durability of restorations in affected teeth. The purpose of this paper was to describe the diagnosis, prevalence, putative etiological factors, and features of hypomineralized enamel in molar incisor hypomineralization and to present a sequential approach to management.

  19. Finite element analysis of the maxillary central incisor with crown lengthening surgery and post-core restoration in management of crown-root fracture%上颌中切牙冠根折行冠延长术并桩核冠修复的三维有限元分析

    Institute of Scientific and Technical Information of China (English)

    甄敏; 胡文杰; 荣起国

    2015-01-01

    Objective:To construct the finite element models of maxillary central incisor and the simu-lations with crown lengthening surgery and post-core restoration in management of different crown-root fracture types, to investigate the stress intensity and distributions of these models mentioned above, and to analyze the indications of crown lengthening from the point of view of mechanics. Methods:An extrac-ted maxillary central incisor and alveolar bone plaster model were scanned by Micro-CT and dental impression scanner ( 3shape D700 ) respectively. Then the 3D finite element models of the maxillary central incisor and 9 simulations with crown lengthening surgery and post-core restoration were construc-ted by Mimics 10. 0, Geomagic studio 9. 0 and ANSYS 14. 0 software. The oblique static force (100 N) was applied to the palatal surface ( the junctional area of the incisal 1/3 and middle 1/3 ) , at 45 degrees to the longitudinal axis, then the von Mises stress of dentin, periodontal ligament, alveolar bone, post and core, as well as the periodontal ligament area, were calculated. Results:A total of 10 high-precision three-dimensional finite element models of maxillary central incisor were established. The von Mises stress of models: post >dentin >alveolar bone >core >periodontal ligament, and the von Mises stress increased linearly with the augmentation of fracture degree ( besides the core) . The periodontal ligament area of the crown lengthening was reduced by 12% to 33%. The von Mises stress of periodontal ligament of the B2L2c, B2L3c, B3L1c, B3L2c, B3L3c models exceeded their threshold limit value, respective-ly. Conclusion: The maxillary central incisors with the labial fracture greater than three-quarter crown length and the palatal fracture deeper than 1 mm below the alveolar crest are not the ideal indications of the crown lengthening surgery.%目的:构建上颌中切牙及其不同冠根折类型牙冠延长术后桩核冠修复的三维有限元模型,研究

  20. Assessment of open and incomplete bite correction by incisor overlap and optical density of polyvinyl siloxane bite registration.

    Science.gov (United States)

    Shpack, Nir; Einy, Shmuel; Beni, Lea; Vardimon, Alexander D

    2006-04-01

    Open bite (OB) is a generalized term, which could incorporate subgroups that react differently to vertical correction. The objectives of the present study were to detect vertical treatment changes in incomplete bite (IB: inter-incisor overlap with no lower incisor contact with teeth or palate) and OB (no inter-incisor overlap) groups compared with a complete bite (CB: inter-incisor overlap with full lower incisor contact with teeth or palate) control group, to evaluate treatment response of the central and lateral incisors, and to study the vertico-sagittal interaction. Dental casts were taken at three time points, pre-treatment, post-treatment, and after one year of retention, from 54 Class II patients (22 males and 32 females with a mean age of 11 years 6 months) divided into three groups: CB (n = 21), IB (n = 18) and OB (n = 15). Measurements included incisor overlap (mm) and optical density (OD/mm2) of occlusal bite registration made of polyvinl siloxane. Both CB and IB groups demonstrated post-retention bite opening. However, bite opening in the CB group was three times greater than that in the IB group (e.g. lower lateral = -1.42 mm, 118 OD/mm2 versus -0.40 mm, 107 OD/mm2). Conversely, the OB group showed a significant (P < 0.001) bite closure (e.g. lower lateral = 1.30 mm, -377 OD/mm2). Overjet changes affected OD measurements, causing diversity in OD and millimetric measurements of the lateral incisors in the IB group. In conclusion, the OB group demonstrated a significant stable vertical correction; a post-treatment non-contact inter-incisor relationship was determined by a vertico-sagittal relapse; and full compensation of an IB was not possible.

  1. Influence of anatomical barriers on maxillary incisor root resorption after orthodontic treatment with premolar extractions

    Directory of Open Access Journals (Sweden)

    Antonio Geraldo de Oliveira

    2012-04-01

    Full Text Available INTRODUCTION: Apical root resorption is a frequent and occasionally critical problem in orthodontic patients undergoing induced tooth movement. One of the factors that might influence prognosis, especially in maxillary incisors, which most frequently present resorptions, are the so-called the anatomical barriers; that is, proximity of the buccal and palatal cortical bones to the maxillary incisor roots. OBJECTIVE: The purpose of this research was to investigate whether patients with excessive vertical growth really present a small distance between the alveolar cortical bones and the maxillary incisor roots, and whether there is a correlation between this distance and the root resorption index in comparison with patients presenting horizontal growth. METHODS: The sample comprised orthodontic records of 18 patients with extraction planning of first maxillary premolars and treatment by the standard and/or preadjusted edgewise brackets. Their initial and final periapical radiographs were evaluated to determine the amount of root resorption that occurred. RESULTS: On the palatal side, patients with excessive vertical growth (Group 2 - SN-GoGn > 43º showed a narrower alveolar bone than the horizontal growth patients (Group 1 - SN-GoGn < 29º. However, the distance between the buccal cortical bone and the central incisor root apex showed no significant difference between Groups 1 and 2; CONCLUSIONS: It was concluded that there are no correlations between the proximity of buccal cortical bone, maxillary incisor roots and the root resorption index.

  2. Immediate post-traumatic upper incisor reconstruction using composite resin materials.

    Science.gov (United States)

    Panduric, Vlatko; Gabric, Dragana; Negovetic-Mandic, Visnja

    2008-02-01

    Single visit reconstruction of the fractured crown can be completed with composite resins if there is no bleeding due to the soft tissue injury. Clinical inspection revealed a complex crown fracture of the central incisor as well as a simple horizontal fracture of the lateral incisor crown of the enamel-dentin type. Vertical fracture separated the palatal enamel wall from the rest of the lateral incisor crown. After the completion of the endodontic sanitation, root canals were prepared for prefabricated composite posts and crown reconstructions were performed with the Finger Tip Technique by using composite resin materials. The advantage of this kind of reconstruction is preservation of the hard dental crown tissue removed in case of prosthetic therapy, especially in younger patients. Reconstruction can be finished in one visit, without the need for a dental technician and laboratory.

  3. Class I malocclusion treatment: influence of a missing mandibular incisor on anterior guidance.

    Science.gov (United States)

    Barros, Sérgio Estelita C; Janson, Guilherme; Torres, Fernando César; de Freitas, Marcos Roberto; de Almeida, Renato Rodrigues

    2010-07-01

    This case report describes the orthodontic treatment of a patient with a deep-overbite Angle Class I malocclusion, agenesis of a mandibular central incisor, and 2 supernumerary teeth, which caused impaction of the mandibular first premolars. The 15-year-old patient also had a convex profile, maxillary dentoalveolar protrusion, and deficiency of space for the correct alignment of teeth. Therefore, treatment consisted of fixed appliance therapy, cervical headgear, extraction of the supernumeraries and the mandibular and maxillary first premolars, and mesiodistal reduction of the maxillary incisors to solve the arch perimeter discrepancy as much as possible with interproximal stripping. This method of treatment significantly improved the patient's facial and dental esthetics and provided a good functional occlusion, despite the absence of a mandibular incisor, which generally impairs achieving adequate incisal guidance.

  4. Dental management of a talon cusp on a primary incisor.

    Science.gov (United States)

    Yoon, Richard K; Chussid, Steven

    2007-01-01

    There are many treatment options for the pediatric patient with a talon cusp (TC). The purpose of this paper was to report the case of a TC involving a primary maxillary right central incisor in a 14-month-old male causing displacement of the affected tooth. The etiology of a TC is thought to be a disturbance during the morphodifferentiation stage of tooth development. Clinical problems include: (1) occlusal interferences; (2) esthetic disturbances; (3) accidental cusp fracture; (4) tongue irritation; (5) nursing difficulty; (6) caries; and (7) displacement of the affected tooth. The TC affecting the central incisor was reduced over a period of 4 visits, followed by immediate placement of a 5% sodium fluoride varnish at the conclusion of each reduction visit. Restoration of esthetics and function was evident within 1 month following complete cusp reduction. There were no clinical signs of any problems related to the reduction, and the prognosis was considered to be guarded. The pediatric patient was placed on a 6-month oral hygiene maintenance follow-up.

  5. Resorption of Lateral Incisors during Canine Eruption: Two Clinical Cases with Focus on Root Lengths and Heredity

    Directory of Open Access Journals (Sweden)

    Mostafa Zargham

    2016-01-01

    Full Text Available Introduction: It is well-known that pressure from orthodontic appliance can provoke root resorption in dentitions with short roots. The purpose of this case report is to demonstrate two clinical cases with focus on root length in dentitions exposed due to pressure from erupting teeth. This is a pilot study aimed to improve diagnostics for avoiding the resorption of lateral maxillary incisors by pressure from erupting canines. Case Report: The first reported case is of a girl who was 11 years and 7 months old when radiographs showed severe resorption of the lateral incisors, along with malformed central incisors and short roots. The intraoral photos demonstrated light crowding in the maxilla. The orthopantomogram of the girl’s mother demonstrated several short roots. The second reported case is of a girl who was 9 years and 5 months old when radiographs demonstrated nearly complete resorption on her lateral incisor roots, extremely short roots in the central incisors, and short roots. The intraoral photos demonstrated light crowding in the maxilla. The orthopantomogram of the girl’s mother demonstrated extremely short roots in general. Conclusion: This pilot study indicates that short root length in general and abnormal incisor morphology are phenotypic traits that were characteristic for both girls who presented with severe lateral incisor resorption due to erupting canines. Furthermore, short roots were also demonstrated in the mothers. Accordingly, short root length in general could be a phenotypic trait, which should be diagnosed early for preventing severe resorption of lateral incisors during canine eruption.

  6. A measure of centrality based on modularity matrix

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper, a kind of measure of structural centrality for networks, called modularity centrality, is introduced. This centrality index is based on the eigenvector belonging to the largest magnitude eigenvalue of modularity matrix. The measure is illustrated and compared with the standard centrality measures using a classic dataset. The statistical distribution of modularity centrality is investigated by con- sidering large computer generated graphs and two networks from the real world.

  7. [Upper lateral incisor with 2 canals].

    Science.gov (United States)

    Fabra Campos, H

    1991-01-01

    Clinical case summary of the patient with an upper lateral incisor with two root canals. The suspicion that there might be an anatomic anomaly in the root that includes a complex root canal system was made when an advanced radicular groove was detected in the lingual surface or an excessively enlarged cingulum.

  8. Restoration of a fractured primary incisor.

    Science.gov (United States)

    Romero, M; Saez, M; Cabrerizo, C

    2001-01-01

    Esthetic restoration on primary teeth has been a special challenge to pediatric dentists. Composite restorations are the most often used treatment for decay and fractures of primary teeth, however, there are other possible alternatives. We present a case in which we have used an acrylic crown to treat a fractured primary incisor in a 1.8 years old child.

  9. Refining Approximating Betweenness Centrality Based on Samplings

    CERN Document Server

    Ji, Shiyu

    2016-01-01

    Betweenness Centrality (BC) is an important measure used widely in complex network analysis, such as social network, web page search, etc. Computing the exact BC values is highly time consuming. Currently the fastest exact BC determining algorithm is given by Brandes, taking $O(nm)$ time for unweighted graphs and $O(nm+n^2\\log n)$ time for weighted graphs, where $n$ is the number of vertices and $m$ is the number of edges in the graph. Due to the extreme difficulty of reducing the time complexity of exact BC determining problem, many researchers have considered the possibility of any satisfactory BC approximation algorithms, especially those based on samplings. Bader et al. give the currently best BC approximation algorithm, with a high probability to successfully estimate the BC of one vertex within a factor of $1/\\varepsilon$ using $\\varepsilon t$ samples, where $t$ is the ratio between $n^2$ and the BC value of the vertex. However, some of the algorithmic parameters in Bader's work are not yet tightly boun...

  10. 龈下残根桩核冠修复的三维有限元模型建立%Establishment of the three-dimensional finite element model of the post crown with subgingival post-core for the maxillary central incisor

    Institute of Scientific and Technical Information of China (English)

    吴张; 辛海涛; 马轩祥; 马新扬; 王卫国; 孙燕艳

    2011-01-01

    AIM : To construct a three dimensional ( 3 D) finite element ( FE) model of the post crown with subgingival post for restoration of the maxillary central incisor defected under gingival margin and crest, and to evaluaie the feasibiIJty of this newly de.signed post.METHODS: CT images of an isolated maxillary central incisor obtained through Micro-computed tomography ( Micro-CT) were used to produce a 3D solid model of an incisor by CAD software of UC coupled with Mimics10.0 and Ceomagic studio10.0.Four models of maxillary central incisor with different defect under crest restored by the newly designed post, including the periodontal ligament and the surrounding part of maxillary cortical and cancellous bone, were constructed by CAD software of UG.All models were imported into ANSYS Workbench to generate the FE model with isotropic material properties.The slidings at the bone-post interface under a lateral force of 120N was compared among different models.RUSLUTS : The FE model was successfully established.The sliding at the bone-post inte.rface of four different models were all under 50 μm and increased with the increment of the bone-post interface.CONCLUSION: According to the results of the study, the method for constructing a FE model is time-savings and efficient.It is feasible to use the newly designed post to restore teeth defected under the margin of gingiva and crest.%目的:建立不同程度缺损至牙龈下与牙槽骨内上颌中切牙残根通过龈下桩修复的桩核冠三维有限元模型,分析龈下桩修复方法的可行性.方法:使用Micro CT扫描上颌离体中切牙获得CT断层图片,通过Minics、Geomagic和UG软件生成实体结构.通过UG建市包含龈下桩核冠、牙根、牙周膜、皮质骨和松质骨不同组织的三维实体结构,并构建出4组不同程度缺损至牙龈与牙槽骨内的残根且采用龈下桩核冠修复的模型.将构建的模型导入Ansys有限元分析软件中构建有限元模型,并对

  11. Forces that fracture teeth during extraction with mandibular premolar and maxillary incisor forceps.

    Science.gov (United States)

    Ahel, V; Ćabov, T; Špalj, S; Perić, B; Jelušić, D; Dmitrašinović, M

    2015-12-01

    Our aim was to measure the forces that fracture teeth during extraction based on the effectiveness of the extraction forceps, and to compare them with data collected about forces applied to extracted teeth that did not fracture. We studied 208 patients whose teeth fractured during both the standard and our new method of extraction: maxillary incisors (n=79) extracted with forceps 1 (maxillary incisor forceps), and both maxillary (n=95) and mandibular incisors (n=34) extracted with forceps 13 (mandibular premolar forceps). Forces needed to fracture were assessed with a specially-designed instrument for measuring pressure and rotation. Mean (SD) pressure at the fracture site was significantly higher in maxillary incisors extracted with forceps 1 (1.26 (0.26) bar) then in both maxillary and mandibular incisors extracted with forceps 13 (0.96 (0.19) and 0.98 (0.16), pforces that break teeth during extractions are sometimes only slightly higher than the extraction forces, so caution is needed during extraction.

  12. Analysis of the relationship between occlusal and clinical parameters and the need for incisor reduction in confined horses - a retrospective study

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Rapp de Oliveira Pimentel

    2014-11-01

    Full Text Available The purpose of this retrospective study was to evaluate the relationship between occlusal and clinical parameters and the need for incisor shortening in horses. It was based on the retrospective analysis of the dental charts of 75 confined horses. Body condition score, shape of incisors, presence of dysmastication, excursion to molar contact (EMC distance before and after cheek teeth occlusal adjustment were evaluated. History of difficult to riding, dysmastication and digestive problems was also considered. The initial measurement of lateral excursion to molar contact (EMC revealed incisor occlusal surface abnormalities in 45 (60% horses and long incisors (EMC>15mm in five (6.6% horses. Considering clinical examination and history data the need for reduction of incisor length was significant when EMC exceeded 15mm (P<0.0001 and when based on dental shape, clinical history of dysmastication and/or digestive problems or body condition score was also significant (P<0.05. In confined horses, the decision to shorten and align the incisor teeth should be based on observation and history of dysmastication and digestive problems, body condition score, incisors shape and EMC distance. The need for incisor reduction should be determined before dental intervention and reassessed following cheek teeth oclusal adjustment

  13. Reattachment of fractured teeth fragments in mandibular incisors: a case report.

    Science.gov (United States)

    Yousef, Mohammed K

    2015-01-01

    The majority of dental trauma involves anterior teeth, especially the maxillary central incisors. A mandibular incisor fracture with or without pulp tissue involvement is considerably less common. Different approaches for treating these fractured teeth have been reported in the literature. The type of treatment rendered depends mainly on the extent of fracture, pulp involvement, radicular fracture, biologic width infringement or violation, and presence of the fractured piece. This case report illustrates reattachment of fractured fragments on two mandibular incisors without pulp exposure using a new proposed reattachment method using a combination of two different types of composite materials together with an orthodontic lingual retention wire. An 8-year-old female patient presented with fractured mandibular left incisors (Ellis class II fracture). Broken pieces were saved and brought in a closed container in water. Periapical radiographs revealed no evidence of pulpal involvement in either tooth and no periapical radiolucency was noticed. Fractured fragments and the broken teeth were prepared with circumferential bevels. Reattachment of the fractured fragments were done using two types of composite resin materials and a lingual orthodontic retention wire was also used. The patient was recalled after 8 months to follow up both teeth. Clinical examination revealed excellent composite restorations covering the fracture lines.

  14. Reattachment of fractured teeth fragments in mandibular incisors: a case report

    Directory of Open Access Journals (Sweden)

    Yousef MK

    2015-04-01

    Full Text Available Mohammed K YousefDepartment of Operative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi ArabiaAbstract: The majority of dental trauma involves anterior teeth, especially the maxillary central incisors. A mandibular incisor fracture with or without pulp tissue involvement is considerably less common. Different approaches for treating these fractured teeth have been reported in the literature. The type of treatment rendered depends mainly on the extent of fracture, pulp involvement, radicular fracture, biologic width infringement or violation, and presence of the fractured piece. This case report illustrates reattachment of fractured fragments on two mandibular incisors without pulp exposure using a new proposed reattachment method using a combination of two different types of composite materials together with an orthodontic lingual retention wire. An 8-year-old female patient presented with fractured mandibular left incisors (Ellis class II fracture. Broken pieces were saved and brought in a closed container in water. Periapical radiographs revealed no evidence of pulpal involvement in either tooth and no periapical radiolucency was noticed. Fractured fragments and the broken teeth were prepared with circumferential bevels. Reattachment of the fractured fragments were done using two types of composite resin materials and a lingual orthodontic retention wire was also used. The patient was recalled after 8 months to follow up both teeth. Clinical examination revealed excellent composite restorations covering the fracture lines.Keywords: reattachment, fractured teeth, dental trauma 

  15. Molar Incisor Hypomineralization, Prevalence, and Etiology

    OpenAIRE

    Sulaiman Mohammed Allazzam; Sumer Madani Alaki; Omar Abdel Sadek El Meligy

    2014-01-01

    Aim. To evaluate the prevalence and possible etiological factors associated with molar incisor hypomineralization (MIH) among a group of children in Jeddah, Saudi Arabia. Methods. A group of 8-12-year-old children were recruited (n = 267) from the Pediatric Dental Clinics at the Faculty of Dentistry, King Abdulaziz University. Children had at least one first permanent molar (FPM), erupted or partially erupted. Demographic information, children's medical history, and pregnancy-related data wer...

  16. MTA resorption and periradicular healing in an open-apex incisor: A case report.

    Science.gov (United States)

    Asgary, Saeed; Ehsani, Sara

    2012-01-01

    This case report describes the periradicular healing and resorption of an unintentional extrusion of mineral trioxide aggregate (MTA) in an open-apex central incisor. A 22-year old female with a symptomatic open-apex right maxillary central incisor associated with a periradicular lesion was referred for evaluation and treatment. After chemomechanical debridement, the apical third of the root canal was filled with MTA to create an apical plug. Postoperative radiographs showed the extrusion of MTA into the periradicular lesion. The tooth was then restored with a post and crown. At the 2-year follow-up, the tooth was asymptomatic and radiographs revealed complete healing of the periradicular area. At the 7-year follow-up, complete resorption of the extruded MTA was evident. The results of this case study indicate that complete resorption of extruded MTA is possible in the long term; however, the extrusion of MTA in open-apex tooth should still be avoided.

  17. Double Pyramidal Central Configurations with a Concave Quadrilateral Base

    Institute of Scientific and Technical Information of China (English)

    LIUXuefei

    2002-01-01

    As for a doudle pyramidal central configuration in 6-body problems,the case when its bese is a concave polygon is studied.By advancing several assumptions according to the definition of double pyramidal central configuration and deducing two theorems and two corollaries on this subject,the essential and sufficient conditions to form a double pyramidal central configuration with a concave quadriateral base are demonstrated.

  18. Molar incisor hypomineralization: an aesthetic conservative restorative approach

    OpenAIRE

    Silva-junior, Manoelito Ferreira; Assis,Rahyza Inácio Freire de; PAZINATTO,Flávia Bittencourt

    2016-01-01

    ABSTRACT The aim this study is to present a clinical case of conservative aesthetic restorative treatment of teeth 11 and 21 in a patient diagnosed with molar incisor hypomineralization. An 18-year-old female patient came to the Outpatient Restorative Dentistry Clinic at the Federal University of Espírito Santo, complaining mainly of not feeling comfortable with a color change in her anterior teeth. Molar incisor hypomineralization was diagnosed in molars and incisors and the negative psychos...

  19. 上切牙拔除矫治设计的临床探讨%Orthodontic treatment of malocclusions by upper incisors extraction

    Institute of Scientific and Technical Information of China (English)

    邓礼辉; 王兰; 周欣荣

    2011-01-01

    Objective To investigate the indications and orthodontic effects of upper incisors extraction in treatment of malocclusions. Methods 23 patients with dentoskeletal maxillary protrusion were treated with upper lateral incisors or central incisors(with dental or periodontal disease) extraction. When the treatment was finished, patients with upper central incisors eatraction had their upper lateral incisors restored with metal-porcelain crown to substitite for central incisors. All patients had their upper canines adjusted to imitate lateral incisors. Results All the 23 cases gained satisfactory results. All facial profile improved, teeth lined up in order and anterior teeth gained normal overbite and overjet,occlusion perfect. Conclusions Upper incisors extraction is an easy and effective choice for patients with dentoskeletal maxillary protrusion.%目的 探讨上切牙拔除矫治的适应症和矫治效果.方法 选择上前牙或上颌前突、后牙为中性、轻度远中或完全远中关系的患者23例,拔除双侧上颌侧切牙或中切牙(有牙体或牙周病变者).结果 23例患者上前牙或上颌前突畸形完全解除,前牙覆(耠)、覆盖正常,后牙呈中性或完全远中的尖窝关系,口型和面型显著改善.结论 上前牙或上颌前突拔除上切牙矫治简单(支抗易控制)、快速、有效,值得临床推广应用.

  20. Changes in root lengths of maxillary incisors during orthodontic retention period

    Directory of Open Access Journals (Sweden)

    Ravanmehr H

    2006-01-01

    Full Text Available Background and Aim: External apical root resorption is a common iatrogenic consequence of orthodontic treatment. Much controversy exists in the literature about changes in root lengths at post treatment periods. Although many practitioners believe that resorption becomes stable after active treatment, quantitative data are scarce. The purpose of this study was to determine quantitative changes in root lengths of maxillary incisors during fixed orthodontic post treatment period, and to assess if it is influenced by gender and factors related to active treatment. Materials and Methods: This was a case cross over study, performed on 80 patients (52 females and 28 males aged between 13 and 22 years. At debonding stage and beginning of retention phase of fixed orthodontic treatment, Hawley type retainer was fabricated for maxillary arch. Periapical radiographs of maxillary incisors using standard parallel technique were obtained immediately after debonding, and 3 and 7 months later. Crown and root lengths of maxillary incisors were measured using computer program. Changes in root lengths were calculated considering correction factors. Also associations between some factors and the change in root lengths during post treatment periods were assessed. These included gender, type of treatment plan (non extraction/extraction, technique (standard edgewise/straight-wire edgewise and duration of active treatment (less than 2 years/2 years and more. T-test and 4-way ANOVA were used for statistical analysis with P0.05 as the limit of significance. Results: No significant relation was found between apical root resorption of maxillary central incisors and time elapsed after treatment. Significant relation was observed between apical root resorption of maxillary lateral incisors and the length of post treatment period. No significant relation was found between root length changes of maxillary incisors during post treatment period and gender, type of treatment

  1. Central Tracking Detector Based on Scintillating Fibres

    CERN Multimedia

    2002-01-01

    Scintillating fibres form a reasonable compromise for central tracking detectors in terms of price, resolution, response time, occupancy and heat production. \\\\ \\\\ New fluorescents with large Stokes shifts have been produced, capable of working without wavelength shifters. Coherent multibundles have been developed to achieve high packing fractions. Small segments of tracker shell have been assembled and beam tests have confirmed expectations on spatial resolution. An opto-electronic delay line has been designed to delay the track patterns and enable coincidences with a first level trigger. Replacement of the conventional phosphor screen anode with a Si pixel chip is achieved. This tube is called ISPA-tube and has already been operated in beam tests with a scintillating fibres tracker. \\\\ \\\\ The aim of the proposal is to improve hit densities for small diameter fibres by increasing the fraction of trapped light, by reducing absorption and reflection losses, by reflecting light at the free fibre end, and by inc...

  2. Evaluation of the upper central incisor and first molar changes during initial leveling and alignment with hybrid sectional mechanics%应用混合片段弓丝技术排齐整平阶段上颌中切牙和第一磨牙改变的三维评价

    Institute of Scientific and Technical Information of China (English)

    李小彤; 陈贵; 张东妹; 张婕

    2015-01-01

    目的 本研究目的在于介绍混合片段弓丝技术的应用,评估利用混合片段弓丝技术初步排齐整平牙列后,上颌切牙和第一磨牙的位置改变.方法 选择9例安氏Ⅰ类中度拥挤病例,拔除第一双尖牙,用混合片段弓丝技术排齐牙列(4~8个月).治疗前和初步排齐整平时采取石膏模型,扫描,上颌腭部重叠,测量上颌中切牙和第一磨牙的线距和角度改变.结果 在应用混合片段弓丝技术初步排齐整平过程中,左右侧牙齿改变没有显著性差异(P>0.05);中切牙的矢状向改变平均为-0.99 mm,没有唇倾移动;而支抗磨牙的移动得到了较好的控制,矢状向改变平均为1.99 mm.结论 拥挤病例选择应用混合片段弓丝技术排齐牙列,能避免前牙在排齐过程中唇倾移动,有助于支抗的控制.%Objective The purpose of this study was to estimate the upper central incisor and first molar changes during initial leveling and alignment achieved by Hybrid sectional mechanics.Methods The sample consisted of 9 Class Ⅰ,first premolar extraction cases (age 11 to 19 years) with moderate crowding.The Hybrid sectional mechanics was used for leveling and alignment.Plaster cast models taken before and 4 to 8 months after treatment (initial leveling and alignment) were evaluated.The 3D maxillary casts were superimposed.Linear and angular variables were measured.Results There was no significant difference in the individual tooth movement between the right and left sides (P>0.05).The mean amount of incisor labial inclination was-0.99 mm and forward movement for the upper first molar was 1.99 mm.Conclusions The hybrid sectional mechanics was a helpful choice in avoiding anterior teeth roundtrip and reinforcing molar anchorage in patients with crowding.

  3. Compound odontoma associated with impacted maxillary incisors

    Directory of Open Access Journals (Sweden)

    S Sreedharan

    2012-01-01

    Full Text Available Odontomas are considered to be the most common odontogenic tumors of the oral cavity. Some authors consider it as malformations rather than true neoplasms. The exact etiology of odontomes is still not known. Most odontomes are asymptomatic and are discovered during routine radiographic investigations. Odontomes generally cause disturbances in the eruption of the teeth, most commonly delayed eruption or deflection. The present report describes the surgical management of a case of compound odontoma in a 10-year-old boy who presented with a complaint of swelling in the maxillary right anterior region and retained deciduous incisors. The related literature is also being reviewed in this article.

  4. Compound odontoma associated with impacted maxillary incisors.

    Science.gov (United States)

    Sreedharan, S; Krishnan, I S

    2012-01-01

    Odontomas are considered to be the most common odontogenic tumors of the oral cavity. Some authors consider it as malformations rather than true neoplasms. The exact etiology of odontomes is still not known. Most odontomes are asymptomatic and are discovered during routine radiographic investigations. Odontomes generally cause disturbances in the eruption of the teeth, most commonly delayed eruption or deflection. The present report describes the surgical management of a case of compound odontoma in a 10-year-old boy who presented with a complaint of swelling in the maxillary right anterior region and retained deciduous incisors. The related literature is also being reviewed in this article.

  5. Esthetic restoration of discolored primary incisors.

    Science.gov (United States)

    Margolis, Fred S

    2005-01-01

    Restoring primary teeth can be a strenuous task for many dentists who would like to have an esthetic, easy-to-use and relatively quick restoration for children. But, the restoration of carious, fractured or discolored primary incisors gives the dentist the satisfaction of knowing that he/she has restored the smile and self-confidence of a growing child. This article describes a technique which is relatively easy and produces a beautiful outcome in a relatively short time. The author has used the technique in hundreds of children for over twenty-five years. Modifications in the technique have been made as newer materials and techniques have evolved.

  6. Cone beam-computed topographic evaluation of a central incisor with an open apex and a failed root canal treatment using one-step apexification with Biodentine™: A case report.

    Science.gov (United States)

    Sinha, Nidhi; Singh, Bijay; Patil, Santosh

    2014-05-01

    A symptomatic endodontically treated immature tooth with periapical pathology presents multiple challenges to the clinician. Owing to incomplete root formation, gutta percha removal has to be done carefully without further damaging the periapical tissue or pushing the obturating material beyond the apex. Nonsurgical approach toward treating such a tooth would necessitate the creation of an apical barrier followed by conventional root canal treatment. Current literature suggests one-step apexification with mineral trioxide aggregate (MTA), with an apical matrix as the treatment of choice. A new calcium silicate-based cement also called as dentine substitute by the manufacturers with good handling properties has been introduced recently by the trade name Biodentine™ (Septodont, St. Maurdes Fossés, France). This case report presents management of a secondary endodontic case with an open apex treated with the concept of 'lesion sterilization and tissue repair (LSTR)' using triantibiotic paste and Biodentine™ for apical barrier formation. A 12-month follow up with cone beam-computed topography (CBCT) exhibited progressive involution of periapical radiolucency with indications of good healing of the periapical tissues and absence of clinical symptoms.

  7. Categorical attribute based centrality: E-I and G-F centrality

    OpenAIRE

    Everett, Martin G.; Stephen P. Borgatti

    2012-01-01

    In a paper examining informal networks and organizational crisis, Krackhardt and Stern (1988) proposed a measure assessing the extent to which relations in a network were internal to a group as opposed to external. They called their measure the E-I index. The measure is now in wide use and is implemented in standard network packages such as UCINET (Borgatti et al., 2002). The measure is based on a partition-based degree centrality measure and as such can be extended to other centrality measur...

  8. Molar incisor hypomineralisation: clinical management of the young patient.

    LENUS (Irish Health Repository)

    Daly, Dympna

    2009-04-01

    Molar incisor hypomineralisation (MIH) is a common developmental condition resulting in enamel defects in first permanent molars and permanent incisors. It presents at eruption of these teeth. Early diagnosis is essential since rapid breakdown of tooth structure may occur, giving rise to acute symptoms and complicated treatment. The purpose of this article is to review MIH and illustrate its clinical management in young children.

  9. Interim restorative approach for the management of congenitally missing permanent mandibular incisors: presentation of three cases.

    Science.gov (United States)

    Prakash, Prashanth; Hallur, Jayadev M; Gowda, Rachana Narse

    2011-01-01

    Congenital missing of mandibular permanent incisors with retained primary incisors may jeopardize the esthetic appearance and psychological development of children, especially during the years of transition into adolescence. The retained primary teeth are necessary for the maintenance and normal development of alveolar bone, which in turn is essential for future definitive rehabilitation. In such situations, an interim restoration may be provided before any definitive treatment is given to comfort the young patient during this transition period. Interim restorations may include resin-modified additions to the existing teeth as well as more sophisticated restorations such as resin-retained bridge and removable partial dentures. However, this restoration differs for different clinical situations based on various factors such as age and patient compliance, and also consideration has to be given for the growth changes of the child. The aim of this present paper is to discuss the esthetic management of three cases with bilateral agenesis of permanent mandibular incisors and retained primary incisors with composite interim restoration.

  10. Interim Restorative Approach for the Management of Congenitally Missing Permanent Mandibular Incisors: Presentation of Three Cases

    Directory of Open Access Journals (Sweden)

    Prashanth Prakash

    2011-01-01

    Full Text Available Congenital missing of mandibular permanent incisors with retained primary incisors may jeopardize the esthetic appearance and psychological development of children, especially during the years of transition into adolescence. The retained primary teeth are necessary for the maintenance and normal development of alveolar bone, which in turn is essential for future definitive rehabilitation. In such situations, an interim restoration may be provided before any definitive treatment is given to comfort the young patient during this transition period. Interim restorations may include resin-modified additions to the existing teeth as well as more sophisticated restorations such as resin-retained bridge and removable partial dentures. However, this restoration differs for different clinical situations based on various factors such as age and patient compliance, and also consideration has to be given for the growth changes of the child. The aim of this present paper is to discuss the esthetic management of three cases with bilateral agenesis of permanent mandibular incisors and retained primary incisors with composite interim restoration.

  11. In vivo administration of dental epithelial stem cells at the apical end of the mouse incisor

    Directory of Open Access Journals (Sweden)

    Giovanna eOrsini

    2015-04-01

    Full Text Available Cell-based tissue regeneration is an attractive approach that complements traditional surgical techniques for replacement of injured and lost tissues. The continuously growing rodent incisor provides an excellent model system for investigating cellular and molecular mechanisms that underlie tooth renewal and regeneration. An active population of dental epithelial progenitor/stem cells located at the posterior part of the incisor, commonly called cervical loop area, ensures the continuous supply of cells that are responsible for the secretion of enamel matrix. To explore the potential of these epithelial cells in therapeutic approaches dealing with enamel defects, we have developed a new method for their in vivo administration in the posterior part of the incisor. Here we provide the step-by-step protocol for the isolation of dental epithelial stem cells and their delivery at targeted areas of the jaw. This simple and yet powerful protocol, consisting in drilling a hole in the mandibular bone, in close proximity to the cervical loop area of the incisor, followed up by injection of stem cells, is feasible, reliable, and effective. This in vivo approach opens new horizons and possibilities for cellular therapies involving pathological and injured dental tissues.

  12. Apical root resorption in maxillary incisors when employing micro-implant and J-hook headgear anchorage: a 4-month radiographic study.

    Science.gov (United States)

    Wang, Qingzhu; Chen, Wenjing; Smales, Roger J; Peng, Hui; Hu, Xiaokun; Yin, Lu

    2012-10-01

    This study evaluated, over a 4-month study period, the amount of apical root resorption occurring in maxillary central incisors following their retraction when employing either micro-implant or J-hook headgear anchorage. The prospective randomised clinical trial was conducted in Orthodontic Clinic, College of Stomatology, China from 2008-2009. Subjects are patients requiring fixed appliances on waiting list (n=20). In female Han Chinese patients aged from 16-26 years, standardized periapical radiographs from 10 randomly assigned patients with maxillary protrusions comprising the micro-implant group, and from 10 similar patients comprising the J-hook headgear group, were assessed for maxillary central incisor apical root resorption. Measurements before and after orthodontic therapy were also obtained from lateral cephalometric radiographs to calculate incisor horizontal retraction and vertical intrusion distances. Estimated retraction force vectors were calculated in horizontal and vertical directions for both treatment groups. Data analysis employed t-tests and the Pearson correlation test, with α=0.05 for statistical significance. The results showed that when compared with the J-hook group, significantly more apical root resorption shortening of the maxillary central incisors was observed in the micro-implant group (1.27 mm difference, 95% CI=0.70-1.84, Presorption shortening and maxillary central incisor retraction than when intermittent J-hook retraction was employed. The employment of continuous duration orthodontic forces presents a risk for increased apical root resorption that requires careful radiographic monitoring.

  13. Eigenvector-Based Centrality Measures for Temporal Networks

    CERN Document Server

    Taylor, Dane; Clauset, Aaron; Porter, Mason A; Mucha, Peter J

    2015-01-01

    In the study of static networks, numerous "centrality" measures have been developed to quantify the importances of nodes in networks, and one can express many of these measures in terms of the leading eigenvector of a matrix. With the increasing availability of network data that changes in time, it is important to extend eigenvector-based centrality measures to time-dependent networks. In this paper, we introduce a principled generalization that is valid for any eigenvector-based centrality measure in terms of matrices of size $NT\\times NT$, where the components of the dominant eigenvector of such a matrix describes the centralities of $N$ nodes during $T$ time layers. Our approach relies on coupling centrality values between neighboring time layers with a inter-layer edge, whose weight controls the extent to which centrality trajectories change over time. By studying the limit of strong coupling between layers, we derive expressions for "time-averaged centralities," which are given by the zeroth-order terms ...

  14. Brain malformation in single median maxillary central incisor

    DEFF Research Database (Denmark)

    Kjaer, I; Wagner, Aa; Thomsen, L L

    2009-01-01

    a severe growth hormone deficiency but no other pituitary hormone deficiencies. She was treated with growth hormone and followed during a four-year period with successful gain in body height and sexual maturation. This study focuses on the developmental association between the involved structures...... and provides guidelines for early diagnostics....

  15. Management of invasive cervical resorption in a maxillary central incisor.

    Science.gov (United States)

    Kumar, S Senthil; Kumar, N S Mohan; Karunakaran, J V; Nagendran, S

    2015-08-01

    Invasive cervical resorption is often not diagnosed properly, leading to improper treatment or unnecessary loss of the tooth structure. Early diagnosis and appropriate treatment are the keys to a successful outcome of therapy. Invasive cervical resorption is often seen in the cervical area of the tooth, but because it is initiated apical to the epithelial attachment, it can present anywhere in the root. In the early stages, it may be symmetrical, but larger lesions have the tendency to be asymmetrical. It can expand apically or coronally.

  16. Management of internal resorption of central incisor using hybrid technique.

    Science.gov (United States)

    Gayathri, Prabakaran; Pandey, Ramesh Kumar; Jain, Eesha

    2014-01-28

    Internal inflammatory root resorption is characterised by progressive destruction of intraradicular dentin and dentinal tubules along the root canal wall. A number of theories have been proposed as a possible cause for internal resorption. It is usually asymptomatic and detected during routine radiographic investigations. Prompt diagnosis and early management of such defects is essential to maintain the integrity of the tooth. Non-surgical and surgical methods are the two main strategies involved in the management of internal resorption. The non-surgical method is usually preferred, but in cases of extensive resorption with external root perforation, surgical intervention has been advocated. The present case illustrates repair of perforating internal resorption by hybrid method, using mineral trioxide aggregate and gutta-percha, following surgical exposure. After a 10-month follow-up, no clinical and radiographic abnormalities were observed. Additionally, there was also marked reduction in periodontal pocket depth.

  17. Management of chronic luxated central incisor with hopeless prognosis

    Directory of Open Access Journals (Sweden)

    Gauresh Kumar Patel

    2013-01-01

    Full Text Available Traumatic injuries are the most studied yet most challenging for a dentist. Extrusive luxation injuries are usually managed by repositioning tooth in the original position and pulp sensibility is evaluated at regular periodic intervals. However, when injuries are chronic, tooth is necrotic with compromised periodontal support, treatment is a challenge. Intentional replantation utilizing growth factors in fibrin rich network of platelet rich fibrin can be a treatment modality in such patients where other restorative modalities to establish function-esthetics rehabilitation is not possible.

  18. Diagnosis and treatment of molar incisor hypomineralization.

    Science.gov (United States)

    Mathu-Muju, Kavita; Wright, J Timothy

    2006-11-01

    Molar incisor hypomineralization (MIH) is a relatively common condition that varies in clinical severity and can result in early loss of the permanent 6-year molars. The etiology of MIH remains unclear, and the diagnosis can be confused with more generalized enamel defects such as those that occur in amelogenesis imperfecta. The management of MIH depends largely on the severity of the enamel defect. Degrees of hypomineralization can range from mild enamel opacities to enamel that readily abrades from the tooth as it emerges into the oral cavity. Usually, severely affected molars are extremely hypersensitive, prone to rapid caries development, and can be difficult to manage in young patients. The purpose of this article is to review approaches to diagnosing and treating MIH.

  19. Amoxicillin may cause molar incisor hypomineralization.

    Science.gov (United States)

    Laisi, S; Ess, A; Sahlberg, C; Arvio, P; Lukinmaa, P-L; Alaluusua, S

    2009-02-01

    The etiology of molar incisor hypomineralization (MIH) is unclear. Our hypothesis was that certain antibiotics cause MIH. We examined 141 schoolchildren for MIH and, from their medical files, recorded the use of antibiotics under the age of 4 yrs. MIH was found in 16.3% of children. MIH was more common among those children who had taken, during the first year of life, amoxicillin (OR=2.06; 95% CI, 1.01-4.17) or the rarely prescribed erythromycin (OR=4.14; 95% CI, 1.05-16.4), compared with children who had not received treatment. Mouse E18 teeth were cultured for 10 days with/without amoxicillin at concentrations of 100 microg/mL-4 mg/mL. Amoxicillin increased enamel but not dentin thickness. An altered pattern of amelogenesis may have interfered with mineralization. We conclude that the early use of amoxicillin is among the causative factors of MIH.

  20. Adaptive Central Force Optimization Algorithm Based on the Stability Analysis

    Directory of Open Access Journals (Sweden)

    Weiyi Qian

    2015-01-01

    Full Text Available In order to enhance the convergence capability of the central force optimization (CFO algorithm, an adaptive central force optimization (ACFO algorithm is presented by introducing an adaptive weight and defining an adaptive gravitational constant. The adaptive weight and gravitational constant are selected based on the stability theory of discrete time-varying dynamic systems. The convergence capability of ACFO algorithm is compared with the other improved CFO algorithm and evolutionary-based algorithm using 23 unimodal and multimodal benchmark functions. Experiments results show that ACFO substantially enhances the performance of CFO in terms of global optimality and solution accuracy.

  1. Three-dimensional finite element analysis of different abutment angles and loads of the maxillary central incisor%上颌中切牙角度基台不同载荷的三维有限元优化分析

    Institute of Scientific and Technical Information of China (English)

    陈小璇; 刘国强; 徐昕

    2015-01-01

    BACKGROUND:To optimize the oral implant design in the abutment angle has an important effect on bone resorption, and meanwhile, the high bite force from patients is also crucial to rebuild bone absorption. OBJECTIVE:To optimize the model design of the maxilary anterior teeth using Ansys Workbench 13.0 software and to investigate the stress size on the cortical and cancelous bone from different angled abutments and different loads of the central incisor. METHODS:A three-dimensional finite element model of the V-shaped cylindrical threaded implants in the maxilary bone. Abutment angle was set as 0°, 5°, 10°, 15°, 20°, 25°, 30°, and the load stress was set as 90, 105, 120, 135, 150, 165, 180, 195, 210 N. Occlusion of the central incisor was simulated on the implants, and then, buccolingual mechanical loads were loaded on the center of prostheses to observe the effects of different abutment angles and loads on the Von Mises peak stress of the maxila and mandible. RESULTS AND CONCLUSION:Under the influence of a single factor, when the abutment angles acted as variables, the Von Mises peak stress of the cortical and cancelous bone was respectively increased by 60.60% and 69.30% under labial or palatal loads; when the loading stress acted as variables, the Von Mises peak stress of the cortical and cancelous bone was increased by 68.74% and 69.30% under buccolingual loads. When the loading stress was less than 150 N and the abutment angle was less than 25°, the slop of tangent for the mandible Von Mises stress response curve was-1 to 0. It seems from the mechanical analysis that the stress of cancelous bone is more susceptible to abutment angle and load stress; the optimal abutment of screwed implant should be designed to an angle less than 25° and an bite force less than 150 N.%背景:口腔种植修复中,种植体中基台角度的优化设计对骨吸收有重要影响,同时患者的高用力也对骨质的吸收重建有着重要影

  2. Early and unusual incisor resorption due to impacted maxillary canines.

    Science.gov (United States)

    Otto, Ronald L

    2003-10-01

    A very early and severe case of maxillary incisor resorption caused by impacted canines is reported. An estimated 50,000 cases of ectopic eruption and impaction of maxillary canines occur each year in the United States. Although incisor resorption due to ectopically positioned permanent maxillary canines can be swift, silent, and devastating, an effective protocol has been developed for early detection and management of this condition. Palpation and, if indicated, radiographic evaluation are combined with primary canine removal in selected cases. These strategies--particularly when used early--can prevent the vast majority of palatally impacted maxillary canines and the potentially devastating resorption of adjacent incisors.

  3. Glassfiber post: an alternative for restoring grossly decayed primary incisors.

    Science.gov (United States)

    Mehra, Manjul; Grover, Rashu

    2012-05-01

    Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. Over a 1 year period, the crowns have demonstrated good retention and esthetic results. How to cite this article: Mehra M, Grover R. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors. Int J Clin Pediatr Dent 2012;5(2):159-162.

  4. Upper incisor to Soft Tissue Plane (UI-STP): a new reference for diagnosis and planning in dentofacial deformities.

    Science.gov (United States)

    Hernandez-Alfaro, Federico

    2010-09-01

    Planning in orthognathic surgery has been and still is an open issue. We have evolved from 2D classical cephalometric hard-tissue planning to 2D soft tissue planning, and finally to 3D and hard and soft tissue evaluation. This, to our knowledge, is the first description of a new Soft Tissue Plane (STP) and its relationship with the anterior position of the upper incisor (UI). Profile photographs of 110 "attractive individuals" with lips at rest or smiling and with upper incisor shown were used. The photographs used were of 65 professional models from two international agencies and 45 individuals considered most attractive in the internet forums, which included catwalk models and actors. In 86 cases (78.18 %), the incisor was located in front of the STP (A). In 15 cases (13.63%), it was on the plane (N); and in the remaining 9 cases (8.18%), it was behind (P). Despite the limitations of this study and based on our series, we can conclude that the upper incisor is located at or in front of the Soft Tissue Plane (STP) in 91.81% of the attractive facial profiles studied. On the other hand, the relative position of the upper incisor to the soft tissue plane (UI-STP) could be a useful diagnostic and planning tool in orthodontic and surgical management of dentofacial deformities.

  5. Finite Element Analysis of Compare Stress Distribution of Maxillary Central Incisor by Three Loads after Dental Implant Prosthesis%上中切牙种植修复后3种受载应力分布的有限元分析

    Institute of Scientific and Technical Information of China (English)

    朱岩峰; 陈伟辉; 陈舟

    2015-01-01

    目的:研究上中切牙种植修复后在3种载荷时的应力分布特点。方法运用软件 Proe构建种植体、基台、基台螺丝、左正中切牙冠、松质骨、皮质骨的三维有限元模型,并在ANSYS workbench中施以不同部位静态载荷,分析其应力分布。结果应力分布云图显示:切对切咬合时应力峰值位于基台螺丝,其余2种载荷应力峰值均位于牙冠。深覆牙合时牙冠上的应力峰值远大于正常咬牙合时牙冠上的应力峰值。3种载荷骨皮质应力均明显大于骨松质。皮质骨中应力又主要集中在种植体颈部周围。载荷点及颈缘是应力集中区。结论建立上中切牙种植修复的各部件模型,并分析在3种载荷时的应力分布,情况与临床相符,为今后前牙种植修复提供参考。%Objective To use a 3‐dimensional finite element method to analyze the stress distribu‐tion of the maxillary central incisor by three loads after dental implant prosthesis . Methods Proe soft‐ware was applied to establish a 3‐dimensional solid model including the dental implant ,the upper structure and the maxillary bone ,and then ANSYS workbench was adopted to simulate static loads on various parts of the dental implant so as to analyze the stress distribution . Results The simulation showed that the maximal stress of cutting for cutting bite laid in the abutment screw while that of other two loads were in the crown . The maximal stress value of von mises of deep overbite was much higher than that of normal occlusion . The stress acting on the cortical bone ,which was centralized on the implant neck ,far excee‐ded that on the cancellous bone . T he M PS (maximal principal stress) value mainly appeared in the region submitted to the load and the proximal margin . Conclusions This modeling method met the experimen‐tal requirements for model in the establishment of the dental implant and the upper structure . T he re‐sults were

  6. [Injuries of the central base of the skull].

    Science.gov (United States)

    Fendel, K

    1976-09-01

    In different types of lesions, especially in frontobasal and laterobasal ones, the central base of the skull is injured, too (in about 20% of severe frontabasal lesions). Surgical treatment is necessary. Examination of intra- and infrabasal structures and localized intracranial operations may be performed by transthemoidal-transphenoidal or transpyramidal approaches. Main problems are the treatment of dura lesions, the control of hemorrhages, the examination of the optic nerve, and the compensation of disturbances of central regulation. The above experiences we gathered from patients in the ORL Clinic of Jena University.

  7. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors

    OpenAIRE

    Mehra, Manjul; Grover, Rashu

    2012-01-01

    ABSTRACT Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. ...

  8. ENDODONTIC MANAGEMENT OF FUSED MAXILLARY LATERAL INCISOR: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Wavdhane

    2014-11-01

    Full Text Available Fusion is a rare occurrence and its definitive diagnosis is of prime importance for successful root canal treatment. This case report discusses the endodontic and esthetic management of fused maxillary right lateral incisor. Root canal treatment was performed on the fused tooth. Nickel Chromium with ceramic crown was fabricated in the shape of lateral incisor. The patient remained asymptomatic and there was a reduction in the size of periapical radiolucency after six months.

  9. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization

    OpenAIRE

    Negre-Barber, A.; Montiel-Company, J. M.; Boronat-Catalá, M.; M. Catalá-Pizarro; Almerich-Silla, J. M.

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Ka...

  10. Replantation after extended dry storage of avulsed permanent incisors: report of a case.

    Science.gov (United States)

    Cobankara, Funda Kont; Ungor, Mete

    2007-08-01

    A 15-year-old boy lost his maxillary right and left central incisor teeth in a bicycle accident. He was referred to our clinic 1 week after the injury. The crown-root integrities of both the teeth were not damaged. Although the teeth were stored under dry conditions for 1 week, reimplantation of the teeth was planned to retain the teeth in the mouth for as long a period as possible because of the patient's age. Following the debridement and sterilization of root surfaces in 2.5% NaOCl, root canals were prepared and filled with calcium hydroxide. Then, about 2 mm of the apexes were resected to ensure that the roots easily seated in the alveolar socket and the prepared cavities in root ends were obturated with the amalgam. The teeth were placed into their respective sockets and splinted temporarily. The root canal therapy was completed 5 weeks later. Ankylosis was observed radiographically after 10 months. The patient is now 23 years old and he is still able to use both the central incisors functionally. However, there is a pink appearance on the cervical buccal surface of left central incisor because of progressive replacement resorption. In this case, the new treatment plan is to perform a permanent restoration with dental implants following the extraction of both teeth. Even though the long-term prognosis is uncertain, this treatment technique has provided an advantage for the patient in his adolescent period by maintaining the height of alveolar bone and making the provision of an aesthetically acceptable permanent restoration at a later age possible.

  11. Enamel defects in permanent first molars and incisors in individuals with cleft lip and/or palate

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    Vivian Patricia Saldias-Vargas

    2014-10-01

    Full Text Available Background. Enamel defects are common in deciduous and permanent maxillary incisors of individuals with lip and palate cleft, and their occurrence has been associated with the cleft, especially when the alveolus is affected. Objective. To compare the prevalence of enamel defects in permanent maxillary and mandibular central incisors and first molars of individuals with cleft lip and palate, cleft palate, and without clefts. Materials and methods. The study analyzed the case of 150 individuals -50 with cleft lip and palate, 50 with cleft palate and 50 without clefts-, of both genders and aged 6 to 12 years. The frequency, extent, and location of enamel alterations on the buccal aspect of teeth were evaluated by the modified DDE index. Results. There was a greater manifestation of enamel defects in maxillary incisors and molars in groups with clefts, with statistically significant difference compared with the noncleft group. Conclusions. The occurrence of enamel defects was common in permanent incisors and molars and was significantly associated with clefts.

  12. Deciduous canine and permanent lateral incisor differential root resorption.

    Science.gov (United States)

    Davies, K R; Schneider, G B; Southard, T E; Hillis, S L; Wertz, P W; Finkelstein, M; Hogan, M M

    2001-10-01

    When a permanent maxillary canine erupts apical to the permanent lateral incisor and the deciduous canine, resorption typically takes place only on the deciduous canine root. An understanding of this differential resorption could provide insight into the reasons for excessive iatrogenic root resorption during orthodontic tooth movement. The purpose of the present study was to examine the response of roots of permanent lateral incisors and deciduous canines to simulated resorption, and to acid and enzyme attack, reflecting the physiologic environment of an erupting permanent canine. Groups of maxillary permanent lateral incisor and deciduous canine roots were exposed to 5 combinations of Ten Cate demineralizing solution, Ten Cate demineralizing solution with EDTA, and a Type I collagenase solution. Sections of the roots were examined under a polarized light microscope. Analysis of variation of the resulting root lesions demonstrated that the lesion depths for deciduous canines were greater than those for permanent lateral incisors when averaged across 4 of the conditions (F(1,24) = 7.49, P =.0115). On average, deciduous canine roots demonstrated lesions 10% deeper than did permanent lateral incisor roots. We concluded that when deciduous canine and permanent lateral incisor roots are subjected to acid and enzyme attack, reflecting the physiologic environment of an erupting permanent canine, significantly deeper demineralized lesions are seen in the deciduous roots compared with the permanent roots. This finding may partially explain the differential root resorption during permanent tooth eruption.

  13. Surgical repositioning of intruded immature permanent incisor: An updated treatment concept

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    Garg S

    2008-10-01

    Full Text Available Intrusion of immature permanent anterior teeth presents a great dilemma due to variety of treatment options. The ideal treatment option is the one with least probability of developing complications like external root resorption, obliteration of pulp canal, marginal bone loss etc. This paper presents a case report with treatment strategy of repositioning, splinting, successfully attempted apexification and obturation of a completely intruded immature permanent central incisor. Excellent healing with no post-operative complications even after 10 months of follow up.

  14. Esthetic and biologic mode of reattaching incisor fracture fragment utilizing glass fiber post.

    Science.gov (United States)

    Manju, M; Shanthraj, Srinivas L; Savitha, K C; Sethi, Ntasha

    2015-01-01

    Trauma to the anterior teeth affects the esthetic and psychological well-being of the patient. Advancement in the adhesive dentistry has facilitated the restoration of the coronal tooth fractures by minimally invasive procedures when the original tooth fragment is available. Reattachment of fractured fragment offers immediate treatment with improved preponderant aesthetics and restoration of function. Here, we describe a case of complicated fracture of the maxillary left immature permanent central incisor, which was treated endodontically followed by esthetic reattachment of the fractured fragment using the glass fiber post. Functional demands and esthetic considerations of the patient were fully met with this biologic mode of fragment reattachment.

  15. Agreement in the diagnosis of dental fluorosis in central incisors performed by a standardized photographic method and clinical examination Concordância no diagnóstico da fluorose dentária em incisivos centrais realizado por um método fotográfico padronizado e pelo exame clínico

    Directory of Open Access Journals (Sweden)

    Carolina Castro Martins

    2009-05-01

    Full Text Available The aim of this study was to assess agreement in the diagnosis of dental fluorosis performed by a standardized digital photographic method and a clinical examination (gold standard. 49 children (aged 7-9 years were clinically evaluated by a trained examiner for the assessment of dental fluorosis. Central incisors were evaluated for the presence or absence of dental fluorosis and were photographed with a digital camera. Photographs were presented to three pediatric dentists, who examined the images. Data were analyzed using Cohen's kappa and validity values. Agreement in the diagnosis performed by the photographic method and clinical examination was good (0.67 and accuracy was 83.7%. The prevalence of dental fluorosis was reported to be higher in the clinical examination (49% compared with the photographic method (36.7%. The photographic method presented higher specificity (96% than sensitivity (70.8%, a positive predictive value (PPV of 94.4% and a negative predictive value (NPV of 77.4%. The diagnosis of dental fluorosis performed using the photographic method presented high specificity and PPV, which indicates that the method is reproducible and reliable for recording dental fluorosis.O objetivo do estudo foi comparar o diagnóstico de fluorose dentária realizado por um método fotográfico com o exame clínico (padrão ouro. Quarenta e nove crianças, de 7 e 9 anos, foram clinicamente examinadas por um examinador calibrado para fluorose dentária. Os incisivos foram fotografados com câmera digital e as fotografias foram apresentadas a três odontopediatras, que examinaram as imagens. A concordância por kappa entre o método fotográfico e o padrão ouro foi boa (0,67 e a acurácia foi de 83,67%. A prevalência de fluorose dentária foi levemente maior pelo método clínico (49% do que pelo fotográfico (36,7%. O método fotográfico apresentou maior especificidade (96% que sensibilidade (70,83%, valor de predição positivo (VPP de 94

  16. Prevalence of molar incisor hypomineralization in school children aged 8-12 years in Chennai

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    Savitha Deepthi Yannam

    2016-01-01

    Full Text Available Objective: To investigate the prevalence and severity of molar incisor hypomineralization (MIH. Materials and Methods: A sample of 2,864 students aged 8-12 years were selected from government and private schools in Chennai. MIH was diagnosed clinically based on the diagnostic criteria established by the European Academy of Pediatric Dentistry (EAPD 2003. Results: A total of 277 children (9.7% had MIH. There was statistically significant difference in prevalence related to age but there was no statistical difference in prevalence with respect to gender. Conclusion: Prevalence of MIH was 9.7% in the child population residing in Chennai. Males and females were equally affected. The rate of occurrence and severity of MIH are more in the right mandibular first molar. The severity of MIH is more in molars compared to incisors (P < 0.001 and is more in government schools compared to private schools (P = 0.002.

  17. Onset of molar incisor hypomineralization (MIH).

    Science.gov (United States)

    Fagrell, Tobias G; Salmon, Phil; Melin, Lisa; Norén, Jörgen G

    2013-01-01

    The etiological factors and timing of the onset of molar incisor hypomineralization (MIH) are still not clear. The aim of this study was to examine ground radial and sagittal sections from teeth diagnosed with MIH using light microscopy, polarized light microscopy and X-ray micro-computed tomography (XMCT) and to estimate the onset and timing of the MIH and to relate the hypomineralized enamel to the incremental lines. Thirteen extracted permanent first molars diagnosed MIH, were analyzed with light microscopy and XMCT. The hypomineralized areas were mainly located in the mesio-buccal cusps, starting at the enamel-dentin-junction and continuing towards the enamel surface. In a relative gray scale analysis the values decreased from the EDJ towards the enamel surface. The findings indicate that the ameloblasts in the hypomineralized enamel are capable of forming an enamel of normal thickness, but with a substantial reduction of their capacity for maturation of enamel. Chronologically, it is estimated that the timing of the disturbance is at a period during the first 6-7 months of age.

  18. Ectopic maxillary canines and root resorption of adjacent incisors. Does computed tomography (CT) influence decision-making by orthodontists?

    Science.gov (United States)

    Bjerklin, Krister; Bondemark, Lars

    2008-01-01

    The purpose of this investigation was to evaluate whether access to computed tomography (CT) influences orthodontists' decision-making about management of incisor root resorption due to ectopic maxillary canines. The study base comprised orthodontic specialists and active members of the Swedish Orthodontic Society: 182 orthodontists under 65 years of age, who had been registered specialists for at least one year and were providing specialist treatment for regular orthodontic patients. A questionnaire was sent out, comprising 8 questions about management and decision-making in cases of ectopic maxillary canines with root resorption of adjacent incisors and 7 questions about practice profile. The orthodontists were asked whether they altered their treatment decisions when CT was available as a diagnostic tool. The response rate was high, 86%. Sixty of the orthodontists had access to CT. Sixty-one percent of the 97 orthodontists without access to CT stated that, in cases with space deficiency, they seldom or never considered extraction of a lateral incisor with suspected root resorption if the resorption was not discernible on intra-oral or panoramic radiographs. It was evident that even in cases of root resorption of lateral incisors due to ectopic canines,the orthodontists' management decisions were not particularly influenced by availability of CT diagnostic data. In the extraction cases 55% of the orthodontists considered extraction of the affected incisor first when root resorption was severe, i.e. involving the pulp and 37% when the resorption reached half way to the pulp. In cases without space deficiency 82% preferred to extract these resorbed lateral incisors not until the resorption reached the pulp.

  19. Estudo da correlação do posicionamento dos incisivos superiores e inferiores com a relação ântero-posterior das bases ósseas Maxillary and mandibular incisor position and the skeletal sagital relationship: a correlation study

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Gregório Cabrera

    2005-12-01

    Full Text Available OBJETIVOS: estudou-se a correlação quanto ao comportamento das bases ósseas através da avaliação Wits e as variações aceitáveis quanto às inclinações vestíbulo-linguais dos incisivos centrais superiores por meio de métodos específicos e distintos para as avaliações cefalométricas e em modelos em gesso. METODOLOGIA: foram utilizadas telerradiografias em norma lateral e modelos em gesso de 57 jovens brasileiros, sendo 26 do gênero masculino e 31 do feminino, com idades de 12 anos e 9 meses a 20 anos e 11 meses, tratados ortodonticamente através de aparelhos Straight Wire - padrão, apresentando as seis chaves para a oclusão perfeita preconizada por Andrews. RESULTADOS: para a avaliação Wits, quanto ao relacionamento entre as bases ósseas, o valor normativo encontrado foi de -2,26mm e desvio padrão de 1,83mm, sem dimorfismo sexual. Para as aferições cefalométricas, os valores das inclinações dos incisivos superiores apresentaram média de +13,35º e os inferiores de +5,14º. Nas aferições em modelos, o valor padrão médio encontrado para as inclinações dos incisivos centrais superiores foi de +7,96º e para os inferiores de +5,03º. CONCLUSÃO: na análise dos resultados foi possível constatar haver uma correlação significante entre o comportamento da variação das bases ósseas e as inclinações dos incisivos centrais superiores e inferiores.AIM: it was studied the behavior of the dentoskeletal relationship through the Wits appraisal and the acceptable variations of the maxillary and mandibular incisor buccolingual inclinations through different methods using teleradiographies and plaster models. METHODS: the sample was comprised by teleradiographs in lateral norm and plasters models from fifty seven brazilian youths, divided in 26 male and 31 females. The age ranged from 15 years and 5 month old for the females and 16 years and 6 month old for the males, orthodontically treated by the Straight

  20. Establishment of crown-root domain borders in mouse incisor.

    Science.gov (United States)

    Juuri, Emma; Saito, Kan; Lefebvre, Sylvie; Michon, Frederic

    2013-10-01

    Teeth are composed of two domains, the enamel-covered crown and the enamel-free root. The understanding of the initiation and regulation of crown and root domain formation is important for the development of bioengineered teeth. In most teeth the crown develops before the root, and erupts to the oral cavity whereas the root anchors the tooth to the jawbone. However, in the continuously growing mouse incisor the crown and root domains form simultaneously, the crown domain forming the labial and the root domain the lingual part of the tooth. While the crown-root border on the incisor distal side supports the distal enamel extent, reflecting an evolutionary diet adaptation, on the incisor mesial side the root-like surface is necessary for the attachment of the interdental ligament between the two incisors. Therefore, the mouse incisor exhibits a functional distal-mesial asymmetry. Here, we used the mouse incisor as a model to understand the mechanisms involved in the crown-root border formation. We analyzed the cellular origins and gene expression patterns leading to the development of the mesial and distal crown-root borders. We discovered that Barx2, En1, Wnt11, and Runx3 were exclusively expressed on the mesial crown-root border. In addition, the distal border of the crown-root domain might be established by cells from a different origin and by an early Follistatin expression, factor known to be involved in the root domain formation. The use of different mechanisms to establish domain borders gives indications of the incisor functional asymmetry.

  1. Mandibular lateral incisor-canine transposition, concomitant dental anomalies, and genetic control.

    Science.gov (United States)

    Peck, S; Peck, L; Kataja, M

    1998-10-01

    Mandibular lateral incisor-canine (Mn.I2.C) transposition is a rare developmental disturbance of tooth order characterized by positional interchange of the two teeth. In children with Mn.I2.C anomaly, the mandibular lateral incisor shows distal ectopic eruption and the adjacent canine subsequently erupts mesial to it. A sample of 60 orthodontic patients with Mn.I2.C transposition was studied using roentgenograms taken at the time of diagnosis. Two age-related phenotypes of the anomaly were identified: early-stage (median age, 9 years) and mature-stage (median age, 12 years). Mn.I2.C transposition occurred bilaterally in 10 subjects (17%) and favored female expression (sex ratio, M1:F3) and right-side occurrence (68% of unilateral cases). Statistically significant associations were found between Mn.I2.C transposition and increased frequency of tooth agenesis (M3, p position probably caused by genetic influences. The Mn.I2.C anomaly likely results from genetic mechanisms similar to those responsible for occurrences of its associated dental anomalies, such as tooth agenesis and peg-shaped maxillary lateral incisors. In an appendix, clinical orthodontic management of Mn.I2.C transposition is discussed, based on treatment data derived from the study sample.

  2. Scaling and adaptations of incisors and cheek teeth in caviomorph rodents (Rodentia, Hystricognathi).

    Science.gov (United States)

    Becerra, Federico; Vassallo, Aldo I; Echeverría, Alejandra I; Casinos, Adrià

    2012-10-01

    The South American hystricognath rodents are one of the most diverse mammalian clades considering their occupied habitats, locomotor modes and body sizes. This might have been partly evolved by diversification of their masticatory apparatus' structure and its ecological commitment, for example, chisel-tooth digging. In this phylogeny-based comparative study, we test the relationship between ecological behavior and mechanical features of their incisors and molariforms. In 33 species of nine families of caviomorph rodents, we analyze incisor attributes related to structural stress resistance and molar features related with grinding capacity, for example, second moment of inertia and enamel index (EI) (enamel band length/occlusal surface area), respectively. Most of these variables scaled isometrically to body mass, with a strong phylogenetic effect. A principal component analysis discrimination on the EI clustered the species according to their geographic distribution. We presume that selective pressures in Andean-Patagonian regions, on particular feeding habits and chisel-tooth digging behaviors, have modeled the morphological characteristics of the teeth. Subterranean/burrower ctenomyids, coruros, and plains viscachas showed the highest bending/torsion strength and anchorage values for incisors; a simplified enamel pattern in molariforms would be associated with a better grinding of the more abrasive vegetation present in more open and drier biomes.

  3. Radiologically determined orthodontically induced external apical root resorption in incisors after non-surgical orthodontic treatment of class II division 1 malocclusion: a systematic review.

    Science.gov (United States)

    Tieu, Long D; Saltaji, Humam; Normando, David; Flores-Mir, Carlos

    2014-07-23

    This study aims to critically evaluate orthodontically induced external apical root resorption (OIEARR) in incisors of patients undergoing non-surgical orthodontic treatment of class II division 1 malocclusion by a systematic review of the published data. An electronic search of two databases was performed; the bibliographies of relevant articles were also reviewed. Studies were included if they examined the amount of OIEARR in incisors produced during non-surgical orthodontic treatment of individuals with class II division I malocclusion in the permanent dentition. Individuals had no previous history of OIEARR, syndromes, pathologies, or general diseases. Study selections, risk of bias assessment, and data extraction were performed in duplicate. Eight studies of moderate methodological quality were finally included. An increased prevalence (65.6% to 98.1%) and mild to moderate severity of OIEARR (resorption was found. For the maxillary incisors, there was no evidence that either the central or lateral incisor was more susceptible to OIEARR. A weak to moderate positive correlation between treatment duration and root resorption, and anteroposterior apical displacement and root resorption was found. Current limited evidence suggests that non-surgical comprehensive orthodontic treatment to correct class II division 1 malocclusions causes increased prevalence and severity of OIEARR the more the incisor roots are displaced and the longer this movement takes.

  4. 不同冠延长术式处理上中切牙冠根折并桩核冠修复的三维有限元比较%Finite element analysis of the maxillary central incisor with traditional and modified crown lengthening surgery and post-core restoration in management of crown-root fracture

    Institute of Scientific and Technical Information of China (English)

    甄敏; 危伊萍; 胡文杰; 荣起国; 张豪

    2016-01-01

    traditional method.The maxillary central incisors with labial fracture at gingival margin level and with palatal fracture at or below the alveolar crest level are not the indication of the crown lengthening surgery.%目的 构建上中切牙不同冠根折类型行改良冠延长术后桩核冠修复的三维有限元模型,研究术后牙齿应力大小和分布情况,从力学角度对比分析常规和改良牙冠延长术的适应证.方法 采用显微CT扫描技术和三维激光扫描技术、DICOM数据直接建模法、逆向工程技术和有限元法,构建9种上中切牙冠根折类型行改良冠延长术后桩核冠修复的三维有限元模型(简称不同改良冠延长术模型),分析牙体、牙周和修复体各结构(牙本质、牙周膜、牙槽骨、桩、核)的等效应力(von Mises stress)峰值及其分布位置、牙周膜面积、牙周膜极限阈值,并与本课题组既往研究中常规冠延长术模型的相关结果进行比较.结果 不同改良牙冠延长术模型中不同结构的等效应力大小:牙本质>桩>核>牙槽骨>牙周膜;牙本质的应力峰值(44.37~ 80.58 MPa)出现在舌侧中央肩台处;改良冠延长术术后牙周膜面积减少了6%~28%,在相同折裂条件下,改良冠延长术模型保留的牙周膜面积大于常规冠延长术模型;改良冠延长术模型中仅B3L1m、B3L2m、B3L3m模型的牙周膜应力超过了牙周膜的极限阈值,而常规冠延长术模型中的B2L2c、B2L3c、B3Llc、B3L2c、B3L3c模型的牙周膜应力均超过了牙周膜的极限阈值.结论 改良冠延长术较常规法保留了相对多的牙周支持组织,有利于术牙的远期疗效;改良冠延长术的适应证范围大于常规冠延长术;唇侧折裂平齐龈缘且舌侧折裂至牙槽嵴顶及其根方的上前牙冠根折不是改良冠延长术的适应证.

  5. Molar incisor hypomineralization in HIV-infected children and adolescents.

    Science.gov (United States)

    Andrade, Natália Silva; Pontes, Alessandra Silva; de Sousa Paz, Hélvis Enri; de Moura, Marcoeli Silva; Moura, Lúcia de Fátima Almeida de Deus; Lima, Marina de Deus Mourade

    2017-01-01

    The objective was to determine the prevalence of molar incisor hypomineralization (MIH) among individuals between 7 and 15 years old infected or noninfected with human immunodeficiency virus (HIV). The study was conducted with 33 HIV-infected individuals (study group; SG) and 66 non-HIV-infected schoolchildren (control group; CG), paired by gender and age. Data collection was based on medical records (SG), a questionnaire for caregivers and oral examination for diagnosis of MIH (European Academy of Pediatric Dentistry criteria) and caries (DMFT index and ICDAS). Data were analyzed with Mann-Whitney, chi-square, and Fisher's exact tests and logistic regression. In SG, MIH (45.5%) and caries (87.9%) had higher prevalence. MIH was associated with use of protease inhibitors in SG (OR: 2.14; 95% CI: 1.21 to 3.77) and incubator need in CG (OR: 2.80; 95% CI: 1.71 to 9.10). HIV-infected patients had a higher prevalence of MIH and dental caries in the permanent dentition.

  6. Orthodontic Treatment of a Mandibular Incisor Extraction Case with Invisalign

    Directory of Open Access Journals (Sweden)

    Khalid H. Zawawi

    2014-01-01

    Full Text Available Mandibular incisor extraction for orthodontic treatment is considered an unusual treatment option because of the limited number of patients that meet the criteria for such treatment. Accurate diagnosis and treatment planning is essential to achieve the desired results. Adult orthodontic patients are increasingly motivated by esthetic considerations and reject the idea of conventional fixed appliances. In recent years, Invisalign appliances have gained tremendous attention for orthodontic treatment of adult patients to meet their esthetic demands. In this case report, a case of Class I malocclusion was treated with mandibular incisor extraction using the Invisalign appliance system. Successful tooth alignment of both arches was achieved. The use of Invisalign appliance is an effective treatment option in adult patients with Class I malocclusion that requires incisor extraction due to moderate to severe mandibular anterior crowding.

  7. Orthodontic Treatment of a Mandibular Incisor Extraction Case with Invisalign

    Science.gov (United States)

    Zawawi, Khalid H.

    2014-01-01

    Mandibular incisor extraction for orthodontic treatment is considered an unusual treatment option because of the limited number of patients that meet the criteria for such treatment. Accurate diagnosis and treatment planning is essential to achieve the desired results. Adult orthodontic patients are increasingly motivated by esthetic considerations and reject the idea of conventional fixed appliances. In recent years, Invisalign appliances have gained tremendous attention for orthodontic treatment of adult patients to meet their esthetic demands. In this case report, a case of Class I malocclusion was treated with mandibular incisor extraction using the Invisalign appliance system. Successful tooth alignment of both arches was achieved. The use of Invisalign appliance is an effective treatment option in adult patients with Class I malocclusion that requires incisor extraction due to moderate to severe mandibular anterior crowding. PMID:25024852

  8. Mandibular incisor extraction: indications and long-term evaluation.

    Science.gov (United States)

    Canut, J A

    1996-10-01

    The extraction of a lower incisor constitutes a therapeutic alternative limited to certain occlusal situations, i.e. supernumerary incisors, tooth size anomalies (peg-shaped upper laterals), ectopic eruption and anterior crossbites. The effect of the extraction of a single incisor on the out of retention alignment of lower anterior teeth was studied in 26 treated cases. Initial (T1), final (T2) and 5-8 years out of retention (T3) dental casts were measured. Mean crowding at the start of treatment (T1 = 3.86 mm) relapsed out of retention (T3 = 1.49 mm), with a net mean improvement of 2.37 mm. Little's irregularity index at the start of treatment (T1 = 6.44) relapsed out of retention (T3 = 2.53), with a net mean improvement of T1-T3 = 3.91. Alignment stability seems to be better than that achieved in cases subjected to premolar extraction.

  9. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors

    Science.gov (United States)

    Grover, Rashu

    2012-01-01

    ABSTRACT Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. Over a 1 year period, the crowns have demonstrated good retention and esthetic results. How to cite this article: Mehra M, Grover R. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors. Int J Clin Pediatr Dent 2012;5(2):159-162. PMID:25206160

  10. Orthodontic treatment of a mandibular incisor extraction case with invisalign.

    Science.gov (United States)

    Zawawi, Khalid H

    2014-01-01

    Mandibular incisor extraction for orthodontic treatment is considered an unusual treatment option because of the limited number of patients that meet the criteria for such treatment. Accurate diagnosis and treatment planning is essential to achieve the desired results. Adult orthodontic patients are increasingly motivated by esthetic considerations and reject the idea of conventional fixed appliances. In recent years, Invisalign appliances have gained tremendous attention for orthodontic treatment of adult patients to meet their esthetic demands. In this case report, a case of Class I malocclusion was treated with mandibular incisor extraction using the Invisalign appliance system. Successful tooth alignment of both arches was achieved. The use of Invisalign appliance is an effective treatment option in adult patients with Class I malocclusion that requires incisor extraction due to moderate to severe mandibular anterior crowding.

  11. A new approach to incisor retention--the lingual spur retainer.

    LENUS (Irish Health Repository)

    McNamara, T G

    1996-08-01

    Late lower incisor crowding and incisor rotations remain a problem in orthodontics. We describe a new fixed retainer which is simple to use, allows physiological tooth movement, but prevents rotational and labio-lingual relapse.

  12. Treatment of severely mutilated incisors: a challenge to the pedodontist.

    Science.gov (United States)

    Usha, M; Deepak, V; Venkat, S; Gargi, M

    2007-01-01

    Dental caries is the single most common chronic childhood disease. In early childhood caries, there is early carious involvement and gross destruction of the maxillary anterior teeth. This leads to difficulty in speech, decreased masticatory efficiency, development of abnormal tongue habits and subsequent malocclusion and psychological problems if esthetics are compromised. The restoration of severely decayed primary incisors is often a difficult procedure that presents a special challenge to pediatric dentists. This case report documents the restoration of severely mutilated lateral incisors in a patient with early childhood caries.

  13. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Nanekrungsan, Kamonporn [Dept. of Dentistry, Overbrook Hospital, Chiang Rai (Thailand); Patanaporn, Virush; Janhom, Apirum; Korwanich, Narumanus [Dept. of Chiang Mai University, Chiang Mai (Thailand)

    2012-09-15

    This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. The periapical radiographs of 564 teeth showed that the average root resorption was 1.39{+-}1.27 (8.24{+-}7.22%) and 1.69{+-}1.14 mm (10.16{+-}6.78%) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

  14. Diagnosis of ankylosis in permanent incisors by expert ratings, Periotest and digital sound wave analysis.

    Science.gov (United States)

    Campbell, Karen M; Casas, Michael J; Kenny, David J; Chau, Tom

    2005-08-01

    The objectives of this investigation were to: (i) assess the reliability of expert raters to detect ankylosis from recordings of percussion sounds, (ii) measure differences in Periotest values (PTV) between ankylosed and non-ankylosed incisors and (iii) identify characteristic differences in recorded percussion sounds from ankylosed and non-ankylosed incisors using digital sound wave analysis. A convenience sample of healthy children (age range 7-18 years) was invited to participate. Ankylosis group children had one or more documented ankylosed maxillary incisors. Control group children had intact, non-ankylosed incisors. Digital recordings of percussion sounds and PTV were acquired for each incisor of interest. Four experienced pediatric dentists rated the randomized percussion sound pairs for the presence of ankylosis. Percussion sounds were also subjected to digital sound wave analysis. Overall agreement for the expert raters was substantial (kappa = 0.7). Intra-rater agreement was substantial to almost perfect (kappa = 0.6-0.9). Diagnosis of ankylosis demonstrated sensitivity of 76-92% and specificity of 74-100%. PTV from ankylosed incisors were statistically lower than PTV from non-ankylosed incisors. Ankylosed incisor digital sound wave signals exhibited significantly more energy in high-frequency bands than non-ankylosed incisors. This investigation demonstrated that: (i) experienced pediatric dentists reliably detected ankylosis by percussion sound alone; (ii) PTV for ankylosed incisors were statistically lower than PTV from non-ankylosed incisors; and (iii) ankylosed incisors exhibited a higher proportion of their signal energy in high-frequency bands.

  15. Transverse forces exerted on the maxillary incisors during laryngoscopy

    NARCIS (Netherlands)

    M.J.L. Bucx (Martin); M.H. van der Vegt (Marinus); C.J. Snijders (Chris); Th. Stijnen (Theo); P.R. Wesselink

    1996-01-01

    textabstractPurpose: In this study the effect of level of experience of the intubator on the forces applied by the Macintosh laryngoscope on the maxillary incisors in both the axial and transverse direction were investigated. Methods: Five groups of different levels of experience (15 per group), sta

  16. Factors associated with molar incisor hypomineralization in Thai children.

    Science.gov (United States)

    Pitiphat, Waranuch; Luangchaichaweng, Sarunporn; Pungchanchaikul, Patimaporn; Angwaravong, Onauma; Chansamak, Nusara

    2014-08-01

    Molar incisor hypomineralization (MIH) is a qualitative developmental enamel defect that affects one to four permanent first molars, with or without involvement of permanent incisors. Its etiology is of systemic origin, but is not well understood. Therefore, we conducted this cross-sectional study to examine pre-, peri-, and postnatal risk factors for MIH among children, 7-8 yr of age, in urban areas of Khon Kaen, Thailand. Molar incisor hypomineralization defects were diagnosed using the European Academy of Pediatric Dentistry criteria. Mothers or primary caregivers were interviewed on maternal medical history and habits during pregnancy, pregnancy and delivery complications, and the child's medical history. Molar incisor hypomineralization defects were observed in 78 (27.7%) of 282 children. Multiple logistic regression analysis showed a statistically significant association between the development of MIH and Cesarean section (adjusted OR = 2.0, 95% CI = 1.1-3.7), complications during vaginal delivery (adjusted OR = 4.5, 95% CI = 1.9-11.0), and severe/chronic illness when under 3 yr of age (adjusted OR = 2.9, 95% CI = 1.6-5.0). There was no association of preterm birth and low birth weight with MIH. The results suggest that Cesarean section, complications during vaginal delivery, and poor health during the first 3 yr of life are independent risk factors for MIH.

  17. Repair of perforating inflammatory root resorption in a previously traumatized incisor: 36-month follow-up.

    Science.gov (United States)

    Cehreli, Zafer C; Guzeler, Irem; Uysal, Serdar

    2012-01-01

    Inflammatory root resorption is a serious complication of dental trauma, which leads to progressive loss of the root structure. The purpose of this report was to present a case of perforating inflammatory root resorption in a previously traumatized young incisor tooth with incomplete root development. A 12-year-old girl, who had suffered a traumatic dental injury 4 years earlier, was referred with symptoms of pain and swelling in a permanent maxillary central incisor. The tooth had been root-filled and had thin dentinal walls and a wide open apex. During retreatment, a perforating resorption site was observed on the root's distal aspect. Because the entire root canal filling could not be removed, the resorption site was repaired with white mineral trioxide aggregate in the presence of the remaining gutta-percha. Clinical and radiographic follow-up was conducted for 36 months, demonstrating arrest of the resorptive process, regeneration of the periradicular tissues, and re-establishment of the periodontal space.

  18. Existence and uniqueness for a class of double pyramidal central configurations with a concave pentagonal base

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with a concave pentagonal base in 7-body problems are proved and the range of the ratio between radius and half-height is obtained, within which the 7 bodies involved form a central configuration or form uniquely a central configuration.

  19. The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha.

    Science.gov (United States)

    Mothé, Dimila; Ferretti, Marco P; Avilla, Leonardo S

    2016-01-01

    The incisors of proboscideans (tusks and tushes) are one of the most important feature in conservation, ecology and evolutionary history of these mammals. Although the absence of upper incisors is rare in proboscideans (occurring only in deinotheres), the independent losses of lower incisors are recognized for most of its lineages (dibelodont condition). The presence of lower incisors in the Pan-American gomphothere Cuvieronius hyodon was reported a few times in literature, but it was neglected in systematic studies. We analyzed several specimens of Cuvieronius hyodon from the Americas and recognized that immature individuals had lower incisors during very early post-natal developmental stages. Subsequently, these are lost and lower incisors alveoli close during later developmental stages, before maturity. Moreover, for the first time in a formal cladistic analysis of non-amebelodontine trilophodont gomphotheres, Rhynchotherium and Cuvieronius were recovered as sister-taxa. Among several non-ambiguous synapomorphies, the presence of lower incisors diagnoses this clade. We recognize that the presence of lower incisors in Cuvieronius and Rhynchotherium is an unique case of taxic atavism among the Elephantimorpha, since these structures are lost at the origin of the ingroup. The rediscovery of the lower incisors in Cuvieronius hyodon, their ontogenetic interpretation and the inclusion of this feature in a revised phylogenetic analysis of trilophodont gomphotheres brought a better understanding for the evolutionary history of these proboscideans.

  20. The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha.

    Directory of Open Access Journals (Sweden)

    Dimila Mothé

    Full Text Available The incisors of proboscideans (tusks and tushes are one of the most important feature in conservation, ecology and evolutionary history of these mammals. Although the absence of upper incisors is rare in proboscideans (occurring only in deinotheres, the independent losses of lower incisors are recognized for most of its lineages (dibelodont condition. The presence of lower incisors in the Pan-American gomphothere Cuvieronius hyodon was reported a few times in literature, but it was neglected in systematic studies. We analyzed several specimens of Cuvieronius hyodon from the Americas and recognized that immature individuals had lower incisors during very early post-natal developmental stages. Subsequently, these are lost and lower incisors alveoli close during later developmental stages, before maturity. Moreover, for the first time in a formal cladistic analysis of non-amebelodontine trilophodont gomphotheres, Rhynchotherium and Cuvieronius were recovered as sister-taxa. Among several non-ambiguous synapomorphies, the presence of lower incisors diagnoses this clade. We recognize that the presence of lower incisors in Cuvieronius and Rhynchotherium is an unique case of taxic atavism among the Elephantimorpha, since these structures are lost at the origin of the ingroup. The rediscovery of the lower incisors in Cuvieronius hyodon, their ontogenetic interpretation and the inclusion of this feature in a revised phylogenetic analysis of trilophodont gomphotheres brought a better understanding for the evolutionary history of these proboscideans.

  1. The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha

    Science.gov (United States)

    2016-01-01

    The incisors of proboscideans (tusks and tushes) are one of the most important feature in conservation, ecology and evolutionary history of these mammals. Although the absence of upper incisors is rare in proboscideans (occurring only in deinotheres), the independent losses of lower incisors are recognized for most of its lineages (dibelodont condition). The presence of lower incisors in the Pan-American gomphothere Cuvieronius hyodon was reported a few times in literature, but it was neglected in systematic studies. We analyzed several specimens of Cuvieronius hyodon from the Americas and recognized that immature individuals had lower incisors during very early post-natal developmental stages. Subsequently, these are lost and lower incisors alveoli close during later developmental stages, before maturity. Moreover, for the first time in a formal cladistic analysis of non-amebelodontine trilophodont gomphotheres, Rhynchotherium and Cuvieronius were recovered as sister-taxa. Among several non-ambiguous synapomorphies, the presence of lower incisors diagnoses this clade. We recognize that the presence of lower incisors in Cuvieronius and Rhynchotherium is an unique case of taxic atavism among the Elephantimorpha, since these structures are lost at the origin of the ingroup. The rediscovery of the lower incisors in Cuvieronius hyodon, their ontogenetic interpretation and the inclusion of this feature in a revised phylogenetic analysis of trilophodont gomphotheres brought a better understanding for the evolutionary history of these proboscideans. PMID:26756209

  2. Sex determination using the mesio-distal dimension of permanent maxillary incisors and canines in a modern Chilean population.

    Science.gov (United States)

    Peckmann, Tanya R; Logar, Ciara; Garrido-Varas, Claudia E; Meek, Susan; Pinto, Ximena Toledo

    2016-03-01

    The pelvis and skull have been shown to be the most accurate skeletal elements for the determination of sex. Incomplete or fragmentary bones are frequently found at forensic sites however teeth are often recovered in forensic cases due to their postmortem longevity. The goal of the present research was to investigate sexual dimorphism between the mesio-distal dimension of the permanent maxillary incisors and canines for the determination of sex in a contemporary Chilean population. Three hundred and three dental models (126 males and 177 females) from individuals ranging in age from 13 years to 37 years old were used from the School of Dentistry, University of Chile. The statistical analyses showed that only the central incisors and canines were sexually dimorphic. Discriminant function score equations were generated for use in sex determination. The average accuracy of sex classification ranged from 59.7% to 65.0% for the univariate analysis and 60.1% to 66.7% for the multivariate analysis. Comparisons to other populations were made. Overall, the accuracies ranged from 54.4% to 63.3% with males most often identified correctly and females most often misidentified. The determination of sex from the mesio-distal width of incisors and canines in Chilean populations does not adhere to the Mohan and Daubert criteria and therefore would not be presented as evidence in court.

  3. Molar-incisor hypomineralization: Prevalence, severity and clinical characteristics in 8- to 13-year-old children of Udaipur, India

    Directory of Open Access Journals (Sweden)

    Shubha Arehalli Bhaskar

    2014-01-01

    Full Text Available Background: The last couple of decades has seen an increasing interest in molar-incisor hypomineralization (MIH. Although the reported prevalence of MIH ranges from 2.4% to 40.2% worldwide, very little data is available from India. Objective: To assess the prevalence, clinical characteristics, distribution, severity and association with caries of MIH defects in children aged 8-13 years of Udaipur, Rajasthan. Study design: This cross-sectional descriptive study consisted of 1173 children aged 8-13 years selected by random sampling procedure. The European Academy of Pediatric Dentistry criteria were followed for MIH diagnosis. The presence of dental caries and treatment need for MIH-affected teeth were recorded as per the WHO criteria. Results: The prevalence of MIH in the children examined was 9.46%. Severity of the defects increased with the age of the children. Involvement of incisors increased when more First permanent molars (FPMs were affected. An average of 3.65 teeth was involved per MIH-affected individual. Significantly larger numbers of mandibular FPMs and maxillary central incisors were diagnosed with MIH. The association of dental caries was significantly higher with MIH-affected FPMs. Primary molars and permanent canines and premolars were also showed MIH like lesions in some of the MIH-affected children. Conclusion: MIH was observed in about 10% of the children examined. MIH-affected FPMs appear to be more vulnerable to early caries and subsequent pulp involvement with need for extensive dental treatment.

  4. Finite element analysis of equine incisor teeth. Part 2: investigation of stresses and strain energy densities in the periodontal ligament and surrounding bone during tooth movement.

    Science.gov (United States)

    Schrock, P; Lüpke, M; Seifert, H; Staszyk, C

    2013-12-01

    This study investigated the hypothetical contribution of biomechanical loading to the onset of equine odontoclastic tooth resorption and hypercementosis (EOTRH) and to elucidate the physiological age-related positional changes of the equine incisors. Based on high resolution micro-computed tomography (μCT) datasets, 3-dimensional models of entire incisor arcades and the canine teeth were constructed representing a young and an old incisor dentition. Special attention was paid to constructing an anatomically correct model of the periodontal ligament (PDL). Using previously determined Young's moduli for the equine incisor PDL, finite element (FE) analysis was performed. Resulting strains, stresses and strain energy densities (SEDs), as well as the resulting regions of tension and compression within the PDL and the surrounding bone were investigated during occlusion. The results showed a distinct distribution pattern of high stresses and corresponding SEDs in the PDL and bone. Due to the tooth movement, peaks of SEDs were obtained in the PDL as well as in the bone on the labial and palatal/lingual sides of the alveolar crest. At the root, highest SEDs were detected in the PDL on the palatal/lingual side slightly occlusal of the root tip. This distribution pattern of high SEDs within the PDL coincides with the position of initial resorptive lesions in EOTRH affected teeth. The position of high SEDs in the bone can explain the typical age-related alteration of shape and angulation of equine incisors.

  5. Comparison of the effect of labiolingual inclination and anteroposterior position of maxillary incisors on esthetic profile in three different facial patterns

    Science.gov (United States)

    Chirivella, Praveen; Singaraju, Gowri Sankar; Mandava, Prasad; Reddy, V Karunakar; Neravati, Jeevan Kumar; George, Suja Ani

    2017-01-01

    Objective: To test the null hypothesis that there is no effect of esthetic perception of smiling profile in three different facial types by a change in the maxillary incisor inclination and position. Materials and Methods: A smiling profile photograph with Class I skeletal and dental pattern, normal profile were taken in each of the three facial types dolichofacial, mesofacial, and brachyfacial. Based on the original digital image, 15 smiling profiles in each of the facial types were created using the FACAD software by altering the labiolingual inclination and anteroposterior position of the maxillary incisors. These photographs were rated on a visual analog scale by three panels of examiners consisting of orthodontists, dentists, and nonprofessionals with twenty members in each group. The responses were assessed by analysis of variance (ANOVA) test followed by post hoc Scheffe. Results: Significant differences (P < 0.001) were detected when ratings of each photograph in each of the individual facial type was compared. In dolichofacial and mesofacial pattern, the position of the maxillary incisor must be limited to 2 mm from the goal anterior limit line. In brachyfacial pattern, any movement of facial axis point of maxillary incisors away from GALL is worsens the facial esthetics. The result of the ANOVA showed differences among the three groups for certain facial profiles. Conclusion: The hypothesis was rejected. The esthetic perception of labiolingual inclination and anteroposterior of maxillary incisors differ in different facial types, and this may effect in formulating treatment plans for different facial types. PMID:28197396

  6. Structural and Morphometric Comparison of Lower Incisors in PACAP-Deficient and Wild-Type Mice.

    Science.gov (United States)

    Sandor, B; Fintor, K; Reglodi, D; Fulop, D B; Helyes, Z; Szanto, I; Nagy, P; Hashimoto, H; Tamas, A

    2016-06-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread distribution. PACAP plays an important role in the development of the nervous system, it has a trophic and protective effect, and it is also implicated in the regulation of various physiological functions. Teeth are originated from the mesenchyme of the neural crest and the ectoderm of the first branchial arch, suggesting similarities with the development of the nervous system. Earlier PACAP-immunoreactive fibers have been found in the odontoblastic and subodontoblastic layers of the dental pulp. Our previous examinations have shown that PACAP deficiency causes alterations in the morphology and structure of the developing molars of 7-day-old mice. In our present study, morphometric and structural comparison was performed on the incisors of 1-year-old wild-type and PACAP-deficient mice. Hard tissue density measurements and morphometric comparison were carried out on the mandibles and the lower incisors with micro-CT. For structural examination, Raman microscopy was applied on frontal thin sections of the mandible. With micro-CT morphometrical measurements, the size of the incisors and the relative volume of the pulp to dentin were significantly smaller in the PACAP-deficient group compared to the wild-type animals. The density of calcium hydroxyapatite in the dentin was reduced in the PACAP-deficient mice. No structural differences could be observed in the enamel with Raman microscopy. Significant differences were found in the dentin of PACAP-deficient mice with Raman microscopy, where increased carbonate/phosphate ratio indicates higher intracrystalline disordering. The evaluation of amide III bands in the dentin revealed higher structural diversity in wild-type mice. Based upon our present and previous results, it is obvious that PACAP plays an important role in tooth development with the regulation of morphogenesis, dentin, and enamel mineralization. Further studies are

  7. Central poststroke pain: a population-based study.

    Science.gov (United States)

    Klit, Henriette; Finnerup, Nanna Brix; Andersen, Grethe; Jensen, Troels Staehelin

    2011-04-01

    Central poststroke pain (CPSP) is a specific pain condition arising as a direct consequence of a cerebrovascular lesion. There is limited knowledge about the epidemiology and clinical characteristics of this often neglected but important consequence of stroke. In this population-based study, a questionnaire was sent out to all (n=964) stroke patients identified through the Danish National Indicator Project Stroke Database in Aarhus County, Denmark, between March 2004 and February 2005. All surviving patients who fulfilled 4 questionnaire criteria for possible CPSP (n=51) were selected for further clinical examination, and their pain was classified by using stringent and well-defined criteria and a detailed, standardized clinical examination. The minimum prevalence of definite or probable CPSP in this population is 7.3% and the prevalence of CPSP-like dysesthesia or pain is 8.6%. Pinprick hyperalgesia was present in 57%, cold allodynia in 40%, and brush-evoked dysesthesia in 51% of patients with CPSP. Because of its negative impact on quality of life and rehabilitation, pain is an important symptom to assess in stroke survivors.

  8. The relationship between sports activities and permanent incisor crown fractures in a group of school children aged 7-9 and 11-13 in Ankara, Turkey.

    Science.gov (United States)

    Cetinbaş, Tuğba; Yildirim, Gözde; Sönmez, Hayriye

    2008-10-01

    The objective of the study was to determine the distribution, aetiology of the crown fractures of permanent anterior teeth in children aged 7-9 and 11-13 years and to identify the role of participation in sports associated with crown fractures. The study population comprised 2570 students from 10 primary schools randomly selected from five municipalities in Ankara, Turkey. Two paediatric dentists examined all permanent maxillary and mandibular incisors for evidence of fracture and completed a standardized examination form to obtain information on the age, gender, severity of incisor injury and frequency and type of sports participation for each child, as well as whether or not children used mouthguards during sports activities. Chi-square and z-tests were used to determine differences. A total of 191 (7.43%) of the 2570 subjects examined were affected by dental trauma. The proportion of fractured incisors was significantly higher in males than in females among older children (P < 0.01). Out of a total of 222 fractured teeth, 84% involved the maxillary central incisors. Bicycling caused significantly higher rates of crown fractures than other types of sports (P < 0.05). The percentage of incisal fractures caused by sports-related accidents was 14.14%. The number of children interested in sports is high, and the sports chosen are generally contact sports. The high rate (14.14%) of crown injuries caused by sports activities supports these findings.

  9. Molar incisor hypomineralization (MIH): clinical presentation, aetiology and management.

    Science.gov (United States)

    Weerheijm, K L

    2004-01-01

    In this paper, the current knowledge about Molar Incisor Hypomineralization (MIH) is presented. MIH is defined as hypomineralization of systemic origin of one to four permanent first molars frequently associated with affected incisors and these molars are related to major clinical problems in severe cases. At the moment, only limited data are available to describe the magnitude of the phenomenon. The prevalence of MIH in the different studies ranges from 3.6-25% and seems to differ in certain regions and birth cohorts. Several aetiological factors (for example, frequent childhood diseases) are mentioned as the cause of the defect. Children at risk should be monitored very carefully during the period of eruption of their first permanent molars. Treatment planning should consider the long-term prognosis of these teeth.

  10. The effect of epidermal growth factor on neonatal incisor differentiation in the mouse.

    Science.gov (United States)

    Topham, R T; Chiego, D J; Gattone, V H; Hinton, D A; Klein, R M

    1987-12-01

    The effect of epidermal growth factor (EGF) on cellular differentiation of the neonatal mouse mandibular incisor was examined autoradiographically using tritiated thymidine ([3H]TDR) and tritiated proline ([3H]PRO). On days 0 (day of birth), 1, and 2, EGF was administered (3 micrograms/g body wt) sc to neonates. Mice were killed on Days 1, 4, 7, 10, and 13 after birth and were injected with either [3H]TDR or [3H]PRO 1 hr before death. [3H]TDR was used to analyze cell proliferation in eight cell types in the developing mouse incisor including upper (lingual) and lower (buccal) pulpal fibroblasts, preodontoblasts, inner and outer enamel epithelial cells (IEE and OEE), stratum intermedium (SI), stellate reticulum (SR), and periodontal ligament (PDL) fibroblasts. [3H]PRO was used to analyze protein synthesis in ameloblasts, and their secretion products (enamel and dentin), as well as PDL fibroblasts. The selected EGF injection scheme elicited acceleration of incisor eruption with minimal growth retardation. At Day 1, the upper and lower pulp, preodontoblasts, SI, and SR showed a significant decrease in labeling index (LI) 24 hr after a single EGF injection. After multiple injections (Days 0, 1, 2), two LI patterns were observed. In lower pulp, preodontoblasts, IEE, SI, SR, and OEE, a posteruptive change in LI was observed. In contrast, the upper pulp and PDL regions demonstrated a direct temporal relationship with eruption. Autoradiographic analysis with [3H]PRO indicated that EGF treatment caused significant increases in grain counts per unit area in ameloblast, odontoblast, and PDL regions studied. Significant differences were found in all four regions studied (ameloblasts, enamel, odontoblasts, dentin) at the 45-microns-tall ameloblast level as well as ameloblasts and odontoblasts at the 30-microns level at 13 days of age. The PDL demonstrated significant differences at all locations studied (base, 30 microns, 45 microns,) in 4-, 7-, and 13-day-old mice

  11. Non-invasive management of fused upper incisors

    OpenAIRE

    Pouran Samimi; Mohammad-Reza Shirban; Farahnaz Arbabzadeh-Zavareh

    2012-01-01

    The union of two different dental sprouts which can happen in any phase of dental development is commonly called fusion. This developmental anomaly may cause clinical problems including esthetic impairment, which are mainly treated by endodontic and surgical treatments. There are a few reports of conservative not invasive treatment of fused incisors teeth through restorative or prosthetic techniques. They are rarely reported in mandibular posterior teeth. This paper presents an unusual case o...

  12. Angle Class I malocclusion and agenesis of lateral incisors

    OpenAIRE

    2011-01-01

    p. 137-147 Orthodontic planning for patients with agenesis of lateral incisors should include extremely relevant esthetic and functional considerations so that a satisfactory clinical result is achieved. Both space closure and space opening or maintenance have advantages and disadvantages that should be evaluated according to the patient's individual characteristics. Some of the important factors that affect planning are the skeletal pattern, the type of malocclusion and the color and shap...

  13. Bonded composite resin crowns for primary incisors: technique update.

    Science.gov (United States)

    Croll, T P

    1990-02-01

    A technique for restoration of carious primary maxillary incisors with a hybrid visible light-curing composite resin and a dentinal bonding agent is described. Careful use of this technique and the new materials can provide a restoration that is esthetic and resistant to fracture and displacement. The technique requires careful preparation of the operative field and precise handling of the restorative materials. The method is illustrated by the placement of bonded composite resin crowns in a 3-year-old boy.

  14. Restoration of congenitally missing maxillary lateral incisors using mini implants.

    Science.gov (United States)

    Collins, Ron

    2013-11-01

    In this author's opinion, the advent of mini implants, or small diameter implants (SDIs) as they are more frequently being called, is becoming in many situations a viable alternative to the more traditional root form implants. They offer advantages of less cost, a more simplified placement technique, usually faster healing times, and generally less post-operative complications. A case presentation is given to demonstrate their usage for a narrow ridge application to restore congenitally missing maxillary lateral incisors.

  15. Differential expression of syndecan isoforms during mouse incisor amelogenesis.

    Science.gov (United States)

    Muto, Taro; Miyoshi, Keiko; Munesue, Seiichi; Nakada, Hiroshi; Okayama, Minoru; Matsuo, Takashi; Noma, Takafumi

    2007-08-01

    Syndecans are transmembranous heparan sulfate proteoglycans (HSPGs) with covalently attached glycosaminoglycan side-chains located on the cell surface. The mammalian syndecan family is composed of four types of syndecans (syndecan-1 to -4). Syndecans interact with the intracellular cytoskeleton through the cytoplasmic domains of their core proteins and membrane proteins, extracellular enzymes, growth factors, and matrix components, through their heparan-sulfate chains, to regulate developmental processes.Here, as a first step to assess the possible roles of syndecan proteins in amelogenesis, we examined the expression patterns of all syndecan isoforms in continuously growing mouse incisors, in which we can overview major differentiation stages of amelogenesis at a glance. Understanding the expression domain of each syndecan isoform during specific developmental stages seems useful for investigating their physiological roles in amelogenesis. Immunohistochemical analysis of syndecan core proteins in the lower incisors from postnatal day 1 mice revealed spatially and temporally specific expression patterns, with syndecan-1 expressed in undifferentiated epithelial and mesenchymal cells, and syndecan-2, -3, and -4 in more differentiated cells. These findings suggest that each syndecan isoform functions distinctly during the amelogenesis of the incisors of mice.

  16. Risk factors in the occurrence of molar-incisor hypomineralization amongst a group of Iraqi children.

    Science.gov (United States)

    Ghanim, Aghareed; Manton, David; Bailey, Denise; Mariño, Rodrigo; Morgan, Michael

    2013-05-01

    BACKGROUND.  Despite the worldwide increasing interest in the prevalence studies of molar-incisor hypomineralization (MIH), there is still insufficient evidence to verify the aetiological factors of this condition. AIMS.  To investigate risk factors involved in the development of MIH in a group of school-aged Iraqi children. DESIGN.  Seven- to nine-year-old school children (823 of 1000 eligible, response rate of 82.3%) had their first permanent molars and incisors evaluated using the European Academy of Paediatric Dentistry evaluation criteria for MIH. Mothers completed a medical history questionnaire-based interview performed in the schools by a trained examiner. RESULTS.  For children with MIH, 6% reported no relevant medical history; the remaining 94% reported various medical conditions putatively associated with MIH compared with 70% for the non-affected group. Post-natal medical conditions (33.3%) were most frequently reported. When data were split into the possible risk effect groups, maternal psychological stress (OR, 3.24), frequent exposure to ultrasonic scans during the last gestational trimester (OR, 2.51) and birth order as a fourth sibling or later (OR, 3.17 and 5.73, respectively) were previously unreported significant risk factors and postulated as contributing to, or causing the defect. CONCLUSIONS.  Children with MIH had experienced a greater number of medical conditions than their unaffected peers with no single health event identified as a risk factor.

  17. Three-dimensional evaluation of upper anterior alveolar bone dehiscence after incisor retraction and intrusion in adult patients with bimaxillary protrusion malocclusion

    Institute of Scientific and Technical Information of China (English)

    Qing-yuan GUO; Shi-jie ZHANG; Hong LIU; Chun-ling WANG; Fu-lan WEI; Tao LV; Na-na WANG; Dong-xu LIU

    2011-01-01

    Objective: The purpose of this study was to evaluate three-dimensional (3D) dehiscence of upper anterior alveolar bone during incisor retraction and intrusion in adult patients with maximum anchorage.Methods: Twenty adult patients with bimaxillary dentoalveolar protrusion had the four first premolars extracted.Miniscrews were placed to provide maximum anchorage for upper incisor retraction and intrusion.A computed tomography (CT) scan was performed after placement of the miniscrews and treatment.The 3D reconstructions of pre- and post-CT data were used to assess the dehiscence of upper anterior alveolar bone.Results: The amounts of upper incisor retraction at the edge and apex were (7.64±1.68) and (3.91±2.10) mm,respectively,and (1.34±0.74) mm of upper central incisor intrusion.Upper alveolar bone height losses at labial alveolar ridge crest (LAC) and palatal alveolar ridge crest (PAC) were 0.543 and 2.612 mm,respectively,and the percentages were (6.49±3.54)% and (27.42±9.77)%,respectively.The shape deformations of LAC-labial cortex bending point (LBP) and PAC-palatal cortex bending point (PBP) were (15.37±5.20)° and (6.43±3.27)°,respectively.Conclusions: Thus,for adult patients with bimaxillary protrusion,mechanobiological response of anterior alveolus should be taken into account during incisor retraction and intrusion.Pursuit of maximum anchorage might lead to upper anterior alveolar bone loss.

  18. BCL11B regulates epithelial proliferation and asymmetric development of the mouse mandibular incisor.

    Directory of Open Access Journals (Sweden)

    Kateryna Kyrylkova

    Full Text Available Mouse incisors grow continuously throughout life with enamel deposition uniquely on the outer, or labial, side of the tooth. Asymmetric enamel deposition is due to the presence of enamel-secreting ameloblasts exclusively within the labial epithelium of the incisor. We have previously shown that mice lacking the transcription factor BCL11B/CTIP2 (BCL11B hereafter exhibit severely disrupted ameloblast formation in the developing incisor. We now report that BCL11B is a key factor controlling epithelial proliferation and overall developmental asymmetry of the mouse incisor: BCL11B is necessary for proliferation of the labial epithelium and development of the epithelial stem cell niche, which gives rise to ameloblasts; conversely, BCL11B suppresses epithelial proliferation, and development of stem cells and ameloblasts on the inner, or lingual, side of the incisor. This bidirectional action of BCL11B in the incisor epithelia appears responsible for the asymmetry of ameloblast localization in developing incisor. Underlying these spatio-specific functions of BCL11B in incisor development is the regulation of a large gene network comprised of genes encoding several members of the FGF and TGFβ superfamilies, Sprouty proteins, and Sonic hedgehog. Our data integrate BCL11B into these pathways during incisor development and reveal the molecular mechanisms that underlie phenotypes of both Bcl11b(-/- and Sprouty mutant mice.

  19. Treatment of a Class I malocclusion with a carious mandibular incisor and no Bolton discrepancy.

    Science.gov (United States)

    Kokich, V O

    2000-07-01

    Occasionally orthodontists must plan treatment for a patient with extensive caries or a traumatic injury to one mandibular incisor. If the patient has a Bolton discrepancy, one treatment option could involve extraction of the affected mandibular incisor. However, if the patient does not have a Bolton discrepancy and a mandibular incisor is extracted, the treatment becomes more complicated. This case report will present and discuss the ramifications of extracting one mandibular incisor in a patient without an anterior tooth-size discrepancy. The CDABO Student Case Selection Committee chose this case for publication.

  20. Distribution and characteristics of molar-incisor hypomineralization

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    Janković Svjetlana

    2014-01-01

    Full Text Available Background/Aim. Developmental disorders of teeth are the problems that are becoming more present in pediatric dentistry, especially on first permanent molars and incisors. Molar Incisor Hypomineralization (MIH is proposed term for this phenomenon. The aim of this study was to establish the MIH prevalence in children living in the Foča municipality (Bosnia and Herzegovina as well as to assess characteristics and expression of hypomineralization within the tested population. Methods. A total of 141 children from the Foča municipality, 8 years of age, were included in this study. Criteria according to Weerhejm have been used for diagnosis of hypomineralization: demarcated opacity (DO, post-eruptive breakdown (PEB, atypical restoration (AR, extracted molars due to MIH (E-MIH and unerupted tooth (UT. Level and the prominence of color changes have been determined for patients with DO, PEB and AR. Results. MIH in this area was present in 12.8% of children. The prevalence of MIH changes expressed in percentages was as follows: DO was at 9.2%, PEB in 3.5%, AR in 5.6%, while E-MIH was 5.6%. A total of 9.9% of the examinees had mild, 5.6% moderate, and 7.8% severe form of MIH. White form of MIH defects was found in 9.9% of the examinees, white-yellow one in 5.6% and yellow-brown color in 3.5% of the examined children. These changes were more often present in the lower jaw (60.3%. In total, 6.4% of children had these changes present only on molars, while 6.4% of them both on molars and incisors simultaneously. Conclusion. A total of 12.8% of the examinees with MIH is not to be disregarded. With timely diagnosis, prevention and therapy complications could be avoided or mitigated.

  1. Central Pattern Generator Based Omnidirectional Locomotion for Quadrupedal Robotics

    Science.gov (United States)

    2014-09-01

    revolute joint is controlled with a 90W Maxon brushless DC motor with an 86:1 ceramic planetary gearhead and is sensed directly at the motor with a 1000...many animals use central pattern generators (CPGs) for generating joint trajectories and regulation through sensory feedback. However, CPG models ...notable exceptions [7], [8]), the bulk of research has focused on design of steady state forward gaits. The majority of CPG models , when they do specify a

  2. Weighting links based on edge centrality for community detection

    Science.gov (United States)

    Sun, Peng Gang

    2014-01-01

    Link weights have the equally important position as links in complex networks, and they are closely associated with each other for the emergence of communities. How to assign link weights to make a clear distinction between internal links of communities and external links connecting communities is of vital importance for community detection. Edge centralities provide a powerful approach for distinguishing internal links from external ones. Here, we first use edge centralities such as betweenness, information centrality and edge clustering coefficient to weight links of networks respectively to transform unweighted networks into weighted ones, and then a weighted function that both considers links and link weights is adopted on the weighted networks for community detection. We evaluate the performance of our approach on random networks as well as real-world networks. Better results are achieved on weighted networks with stronger weights of internal links of communities, and the results on unweighted networks outperform that of weighted networks with weaker weights of internal links of communities. The availability of our findings is also well-supported by the study of Granovetter that the weak links maintain the global integrity of the network while the strong links maintain the communities. Especially in the Karate club network, all the nodes are correctly classified when we weight links by edge betweenness. The results also give us a more comprehensive understanding on the correlation between links and link weights for community detection.

  3. The permeability of dentine from bovine incisors in vitro.

    Science.gov (United States)

    Tagami, J; Tao, L; Pashley, D H; Horner, J A

    1989-01-01

    The permeability of coronal dentine was investigated by measuring the hydraulic conductance of dentine discs. Reductions in dentine thickness from the enamel side of disc resulted in a greater increase in permeability than reductions from the pulpal side. Scanning electron microscopy revealed fewer dentinal tubules with smaller diameters in superficial dentine than in deep dentine. The permeability of coronal incisor bovine dentine is six to eight times less than that of unerupted coronal human third molar dentine but similar to that of human root dentine.

  4. Lower incisor extraction treatment with the Invisalign® technique: three case reports.

    Science.gov (United States)

    Giancotti, Aldo; Garino, Francesco; Mampieri, Gianluca

    2015-03-01

    The extraction of a lower incisor can lead to satisfactory orthodontic results for patients with moderate to severe lower incisor crowding. Invisalign(®) is a treatment modality for such treatments, moving teeth with precision and reducing inconvenience for the patient. Three case reports are presented in this article supporting the above statements.

  5. The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

    NARCIS (Netherlands)

    Wu, MK; de Schwartz, FBC; van der Sluis, LWM; Wesselink, PR

    2001-01-01

    Aim The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. Methodology Roots of 40 mandibular incisors. 12 mm in length. were divided into two groups and instrumented using a balanced force techni

  6. Preformed resin-veneered stainless steel crowns for restoration of primary incisors.

    Science.gov (United States)

    Croll, T P; Helpin, M L

    1996-05-01

    Stainless steel crown forms with bonded resin veneers for primary incisors are commercially available to dentists. This type of preveneered crown was developed to serve as a convenient, durable, reliable, and esthetic solution to the difficult challenge of restoring severely carious primary incisors. This article describes preveneered crowns, reviews their advantages and disadvantages, and details a technique for placement of such restorations.

  7. Variations in the shape of permanent maxillary lateral incisors in Sundanese.

    Science.gov (United States)

    Schlegel, D; Satravaha, S

    1984-01-01

    During a survey in Java we found unusual shaped upper lateral incisors. A total of 110 school children shows 3 cases with pegging, approximately 20% with canine-like shape. In all cases the lateral incisor was present. Compared with other publication the incidence of pegging is low, the canine-like variation never described as far as we know.

  8. Analysis of crown widths in subjects with congenitally missing maxillary lateral incisors.

    Science.gov (United States)

    Mirabella, A Davide; Kokich, Vincent G; Rosa, Marco

    2012-12-01

    The aim of the study was to test the hypothesis that the gene defect causing congenital absence of maxillary lateral incisors also causes narrowing of the dentition. A total of 81 patients with one or two congenitally missing lateral incisors were retrieved; 52 (64.2 per cent) patients presented bilateral agenesis, whereas 29 (35.8 per cent) had unilateral agenesis. The control group consisted of 90 consecutively treated patients. The largest mesiodistal crown dimension for all teeth, except for the maxillary second and third molars, was measured on plaster casts using a digital caliper to the nearest 10th of a millimetre. Statistical testing was performed using the analysis of variance model (P < 0.05) to test for differences in the mesiodistal dimension between the sample and the control group. Significance has been assessed using a P-value threshold level of 5 per cent. Agenesis of maxillary lateral incisors was found to be a significant predictor of tooth size. Patients who were missing maxillary lateral incisors had smaller teeth compared to control subjects, except for the maxillary right and left first molars. This finding was true for both unilateral and bilateral lateral incisor agenesis. Interaction between maxillary lateral incisor agenesis and gender was not significant. Patients with congenitally missing lateral incisors have narrower teeth than patients without any dental anomalies, except for maxillary first molars. A higher prevalence of microdontic contralateral incisors was found in patients with unilateral agenesis with respect to the control group.

  9. Orthodontic Management of Congenitally Missing Maxillary Lateral Incisors: A Case Report

    Directory of Open Access Journals (Sweden)

    Sergio Paduano

    2014-01-01

    Full Text Available This case report describes the orthodontic treatment of a woman, aged 15 years, with permanent dentition, brachyfacial typology, with congenitally missing maxillary lateral incisors. Multibracket straightwire fixed appliance was used to open the space for dental implant placement, and treat the impaired occlusion. The missing lateral incisors were substituted with oral implants.

  10. Fracture resistance of composite resin restorations and porcelain veneers in relation to residual tooth structure in fractured incisors.

    Science.gov (United States)

    Batalocco, Guido; Lee, Heeje; Ercoli, Carlo; Feng, Changyong; Malmstrom, Hans

    2012-02-01

    The aim of the present study was to investigate whether there is a direct correlation between the amount of residual tooth structure in a fractured maxillary incisor and the fracture resistance of composite resin restorations or porcelain veneers after cyclic loading. Sixty human-extracted maxillary central and lateral incisors were mounted in an acrylic block with the coronal aspect of the tooth protruding from the block surface. The teeth were assigned to two groups: 2-mm incisal fracture and 4-mm incisal fracture. Then, the teeth were further divided into two different restoration subgroups, porcelain laminate veneer and composite resin restoration, therefore obtaining four groups for the study (n=15). The specimens were subjected to 1000 cycles of thermocycling and were mechanically tested with a custom-designed cyclic loading apparatus for 2×106 cycles or until they failed. The specimens that survived the cyclic loading were loaded on the incisal edge along the long axis of the tooth with a flat stainless steel applicator until they fractured using a universal testing machine to measure the failure load. Two-way anova was used to assess the significance of restoration, amount of fracture, and interaction effect (α=0.05). During the cyclic loading, for the composite resin group, two specimens with 2-mm fracture and three specimens with 4-mm fracture failed. For the porcelain veneer group, two specimens with 2-mm fracture and one specimen with 4-mm fracture failed. The 2-way anova did not show statistical significance for restoration (P=0.584), amount of fracture (P=0.357), or interaction effect (P=0.212). A composite resin restoration and a porcelain veneer could perform similarly for replacing a fractured incisor edge up to 4mm. Other factors such as esthetic and/or cost would be considerations to indicate one treatment over the other.

  11. 儿童前牙外伤原因及伤后对儿童心理的影响%ANALYSIS OF THE CAUSES OF TRAUMATIZED PERMANENT INCISORS AND SUBSEQUENT PSYCHO-LOGICAL CHANGES IN CHILDREN

    Institute of Scientific and Technical Information of China (English)

    赵锦辉; 陈晖

    2014-01-01

    Objective To investigate the factors associated with the traumatized permanent incisors ,and the psychological changes post-trauma in children .Methods A retrospective analysis was performed based on the data from 85 patients with 106 traumatized permanent incisors .The cause ,age ,gender ,location and the time when trauma occurred were collected ,and the psychological changes were analyzed by a ques-tionnaire survey .Results The main cause for dental trauma in children was their nature of active ,fall off when riding bike was another common reason .Most cases happened in children aged 8 -10 years .The maxillary central incisor was most vulnerable to injury ,mostly represented as crown fractures .Prevalence was relatively high with more boys affected than girls .Most dental trauma occurred in July ,August and September .On the psychological changes :Children with traumatized permanent incisors were reluctant to communicate with others and in avoid of opening mouth .The confidence and self -respect of the children with dental trauma were declined when compared with these before trauma .Conclusions There are many factors associated with traumatized permanent incisors in children ,and the dental trauma leads to the de-clined confidence and self -respect .%目的:探讨儿童恒前牙外伤发生的因素以及伤后儿童心理变化。方法回顾85例儿童106颗外伤恒前牙相关资料并且采取问卷调查分析伤后患儿心理变化情况。对儿童恒前牙外伤发生的原因、年龄、性别、具体牙位、发生时间等情况进行分析并且采取问卷调查恒前牙伤后儿童心理变化情况得到的结果加以分析。结果①儿童恒前牙外伤的好发原因多与儿童跑跳嬉闹的天性有关,儿童骑自行车摔倒也是比较常见原因;②最易受伤的年龄主要发生在8~10岁;③最易受伤的牙齿上颌中切牙,受伤方式冠折多见;④男孩受伤发生率明显高于女孩;⑤好发期

  12. Geminated Maxillary Lateral Incisor with Two Root Canals

    Science.gov (United States)

    Romano, Nayara; Souza-Flamini, Luis Eduardo; Mendonça, Isabela Lima; Silva, Ricardo Gariba

    2016-01-01

    This paper reports a case of gemination in a maxillary lateral incisor with two root canals and crown-root dilaceration. A 16-year-old male patient was referred for endodontic treatment of the maxillary left lateral incisor and evaluation of esthetic and functional complaints in the anterior region. The patient reported trauma to the anterior primary teeth. There was no spontaneous pain, but the tooth responded positively to the vertical percussion test and negatively to the pulp vitality test. Clinical examination showed esthetic and functional alterations and normal periodontal tissues. CBCT imaging confirmed the suspicion of gemination and crown-root dilaceration and also revealed the presence of two root canals and periapical bone rarefaction. The root canals were instrumented with Reciproc R40 and 1% NaOCl irrigation and were filled by lateral condensation of gutta-percha and AH Plus sealer. The tooth was definitely restored with composite resin to recover esthetics. Continued follow-up over 6 months has shown absence of pain or clinical alterations as well as radiographic image suggestive of apical repair. PMID:28119787

  13. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization.

    Science.gov (United States)

    Negre-Barber, A; Montiel-Company, J M; Boronat-Catalá, M; Catalá-Pizarro, M; Almerich-Silla, J M

    2016-08-25

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Co-occurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9-86.6) and the negative predictive value 84.7% (80.6-88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9-17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47-0.68). The odds ratio was 18.2 (9.39-35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH.

  14. When is a central bank governor replaced? Evidence based on a new data set

    NARCIS (Netherlands)

    Dreher, Axel; Sturm, Jan-Egbert; de Haan, Jakob

    2010-01-01

    Using new data on the term in office of central bank governors for a large set of countries for 1970-2005, we estimate a model for the probability that a central bank governor is replaced before the end of his legal term in office. We formulate hypotheses based on the literature on the determinants

  15. [Multi-bed & multi-parameter central monitoring system based on TCP/IP protocol].

    Science.gov (United States)

    Lian, S J; Hu, D K; Zhao, M H; Tang, L H

    2000-02-01

    Communication is one of the key problems to a central monitoring system. In this paper we put forward a central monitoring system using TCP/IP as the network protocol, Windows NT4.0 as the platform, forming a Intranet in a hospital. We also discussed the communication problem between the bed-side monitoring station and the central monitoring station in detail and then put forward a new protocol--Hospital Central Monitor Protocol (HCMP) based on TCP/IP to transfer monitoring data. It is easy to achieve tele-monitoring through the current communication subsystem.

  16. Ground-based Fourier transform infrared spectroscopy in central Mexico

    Science.gov (United States)

    Plaza, Eddy; Stremme, Wolfgang; Bezanilla, Alejandro; Baylon, Jorge; Grutter, Michel; Blumenstock, Thomas; Hase, Frank

    2014-05-01

    Altzomoni is a high altitude station in central Mexico (19.12 N, 98.65 W, 4000 m a.s.l.) for continuous measurements of various atmospheric parameters. It is located within the Izta-Popo National Park and is operated remotely from the UNAM campus. Since May 2012, high resolution solar absorption spectra have been recorded from this site using a FTIR from Bruker (HR120/5) equipped with MCT, InSb and InGaAs detectors and various optical filters. In this contribution we present a detailed description of the measurement site and the instrumental set-up including a record of the instrumental line-shapes (modulation efficiency and phase error) obtained from cell measurements and analyzed with the LINEFIT code. A preliminary analysis of almost two years of spectra recorded at the Altzomoni site resulting in profile retrievals of four NDACC gases O3, CO, HF and HCl is presented. The retrieval code PROFFIT is used and the Averaging Kernels and an error analysis are used to describe the quality of the measurements. The annual cycles in the time series of O3 and CO are presented and discussed, as well as some examples of anomalies due to volcanic gas emissions of HF and HCl are shown. The presented work is part of an effort to certify this station as part of the NDACC international network.

  17. A super base station based centralized network architecture for 5G mobile communication systems

    Directory of Open Access Journals (Sweden)

    Manli Qian

    2015-04-01

    Full Text Available To meet the ever increasing mobile data traffic demand, the mobile operators are deploying a heterogeneous network with multiple access technologies and more and more base stations to increase the network coverage and capacity. However, the base stations are isolated from each other, so different types of radio resources and hardware resources cannot be shared and allocated within the overall network in a cooperative way. The mobile operators are thus facing increasing network operational expenses and a high system power consumption. In this paper, a centralized radio access network architecture, referred to as the super base station (super BS, is proposed, as a possible solution for an energy-efficient fifth-generation (5G mobile system. The super base station decouples the logical functions and physical entities of traditional base stations, so different types of system resources can be horizontally shared and statistically multiplexed among all the virtual base stations throughout the entire system. The system framework and main functionalities of the super BS are described. Some key technologies for system implementation, i.e., the resource pooling, real-time virtualization, adaptive hardware resource allocation are also highlighted.

  18. Enamel-free teeth: Tbx1 deletion affects amelogenesis in rodent incisors.

    Science.gov (United States)

    Catón, Javier; Luder, Hans-Ulrich; Zoupa, Maria; Bradman, Matthew; Bluteau, Gilles; Tucker, Abigail S; Klein, Ophir; Mitsiadis, Thimios A

    2009-04-15

    TBX1 is a principal candidate gene for DiGeorge syndrome, a developmental anomaly that affects the heart, thymus, parathyroid, face, and teeth. A mouse model carrying a deletion in a functional region of the Tbx1 gene has been extensively used to study anomalies related to this syndrome. We have used the Tbx1 null mouse to understand the tooth phenotype reported in patients afflicted by DiGeorge syndrome. Because of the early lethality of the Tbx1-/- mice, we used long-term culture techniques that allow the unharmed growth of incisors until their full maturity. All cultured incisors of Tbx1-/- mice were hypoplastic and lacked enamel, while thorough histological examinations demonstrated the complete absence of ameloblasts. The absence of enamel is preceded by a decrease in proliferation of the ameloblast precursor cells and a reduction in amelogenin gene expression. The cervical loop area of the incisor, which contains the niche for the epithelial stem cells, was either severely reduced or completely missing in mutant incisors. In contrast, ectopic expression of Tbx1 was observed in incisors from mice with upregulated Fibroblast Growth Factor signalling and was closely linked to ectopic enamel formation and deposition in these incisors. These results demonstrate that Tbx1 is essential for the maintenance of ameloblast progenitor cells in rodent incisors and that its deletion results in the absence of enamel formation.

  19. Angle Class I malocclusion treated with lower incisor extraction

    Directory of Open Access Journals (Sweden)

    Vanessa Leal Tavares Barbosa

    2013-06-01

    Full Text Available In planning orthodontic cases that include extractions as an alternative to solve the problem of negative space discrepancy, the critical decision is to determine which teeth will be extracted. Several aspects must be considered, such as periodontal health, orthodontic mechanics, functional and esthetic alterations, and treatment stability. Despite controversies, extraction of teeth to solve dental crowding is a therapy that has been used for decades. Premolar extractions are the most common, but there are situations in which atypical extractions facilitate mechanics, preserve periodontal health and favor maintenance of the facial profile, which tends to unfavorably change due to facial changes with age. The extraction of a lower incisor, in selected cases, is an effective approach, and literature describes greater post-treatment stability when compared with premolar extractions. This article reports the clinical case of a patient with Angle Class I malocclusion and upper and lower anterior crowding, a balanced face and harmonious facial profile. The presence of gingival and bone recession limited large orthodontic movements. The molars and premolars were well occluded, and the discrepancy was mainly concentrated in the anterior region of the lower dental arch. The extraction of a lower incisor in the most ectopic position and with compromised periodontium, associated with interproximal stripping in the upper and lower arches, was the alternative of choice for this treatment, which restored function, providing improved periodontal health, maintained facial esthetics and allowed finishing with a stable and balanced occlusion. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO, as part of the requirements for obtaining the BBO Diplomate title.

  20. Angle Class I malocclusion treated with lower incisor extraction.

    Science.gov (United States)

    Barbosa, Vanessa Leal Tavares

    2013-01-01

    In planning orthodontic cases that include extractions as an alternative to solve the problem of negative space discrepancy, the critical decision is to determine which teeth will be extracted. Several aspects must be considered, such as periodontal health, orthodontic mechanics, functional and esthetic alterations, and treatment stability. Despite controversies, extraction of teeth to solve dental crowding is a therapy that has been used for decades. Premolar extractions are the most common, but there are situations in which atypical extractions facilitate mechanics, preserve periodontal health and favor maintenance of the facial profile, which tends to unfavorably change due to facial changes with age. The extraction of a lower incisor, in selected cases, is an effective approach, and literature describes greater post-treatment stability when compared with premolar extractions. This article reports the clinical case of a patient with Angle Class I malocclusion and upper and lower anterior crowding, a balanced face and harmonious facial profile. The presence of gingival and bone recession limited large orthodontic movements. The molars and premolars were well occluded, and the discrepancy was mainly concentrated in the anterior region of the lower dental arch. The extraction of a lower incisor in the most ectopic position and with compromised periodontium, associated with interproximal stripping in the upper and lower arches, was the alternative of choice for this treatment, which restored function, providing improved periodontal health, maintained facial esthetics and allowed finishing with a stable and balanced occlusion. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), as part of the requirements for obtaining the BBO Diplomate title.

  1. [Molar incisor hypomineralization (MIH)--a literature review].

    Science.gov (United States)

    Gotler, M; Ratson, T

    2010-04-01

    MIH was defined by Weerheijm (2001) as "hypomineralisation of systemic origin of 1-4 permanent first molars, frequently associated with affected incisors". The prevalence of MIH varies between 2.8% and 25%, dependent upon the study. At their sixth congress in 2003, The European Association of pediatric dentistry defined criteria for diagnosis of the phenomena. It included the presence of demarcated opacity, posteruptive enamel breakdown, atypical restoration, extracted molar due to MIH and unerupted teeth. According to the teeth involved and to the time of the crown formation, researches focused on environmental and systemic conditions as possible reasons for MIH.The etiologies were divided into five groups: Exposure to environmental contaminants, pre/peri and neonatal problems, exposure to fluoride, common childhood illnesses and medically compromised children. The clinical implications include highly sensitive teeth, difficulty to achieve adequate anesthesia, behavioral problems and anxiety, rapid progression of caries and the esthetic implications. A six step approach to management was described suggested: risk identification, early diagnosis, remineralization and desensitization, prevention of caries and posteruption breakdown, restorations and extractions and finally maintenance. Restoring an affected molar can vary from adhesive intra coronal restorations (resin composite is the material of choice) to extra coronal restorations (e.g. preformed metal crown). Esthetic solutions to affected incisors may include microabrasion (that shows little improvement) and resin composite or porcelain veneer. The key for a successful treatment is early diagnosis, intense follow up and usage of remineralizating agents as soon as the teeth erupt. There is still need for further research to clarify the etiological factors and improve the durability of restoration in affected teeth.

  2. Sequential Shh expression in the development of the mouse upper functional incisor.

    Science.gov (United States)

    Hovorakova, Maria; Smrckova, Lucie; Lesot, Herve; Lochovska, Katerina; Peterka, Miroslav; Peterkova, Renata

    2013-11-01

    The mouse incisor is a frequently used model in studies of the molecular control of organ development. The appropriate interpretation of data on normogenesis is essential for understanding the data obtained in mutant mice. For this reason, we performed a very detailed investigation of the development of the upper incisor in wild-type mice from embryonic day (ED) 11.5 till 14.5. A combination of histology, whole mount in situ hybridization, computer-aided three-dimensional reconstructions, and fluorescent microscopy, has been used. Several sonic hedgehog (Shh) expression domains have been detected in the upper incisor region during early prenatal development. At ED11.5-13.5, there was a single Shh positive domain present in the anterior part of left or right upper jaw arches, corresponding to the epithelial thickening. More posteriorly, a new Shh expression domain appeared in the incisor bud in the developmentally more advanced ED13.5 embryos. At ED14.5, only this posterior Shh expression in the incisor germ remained detectable. This study brings new insights into the early development of the upper incisor in mice and completes the data on normal mouse incisor development. The temporal-spatial pattern of Shh expression reflects the development of two tooth generations, being detectable in two successive, antero-posteriorly located areas in the prospective incisor region in the upper jaw. The first, anterior and superficial Shh expression domain reflects the rudimentary tooth development suppressed during evolution. Only the subsequent, posterior and deeper Shh expression region, appearing at ED13.5, correlates with the prospective upper functional incisor in wild-type mice.

  3. Comparison of the changes of alveolar bone thickness in maxillary incisor area in extraction and non-extraction cases: computerized tomography evaluation

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Barroso Picanço

    2013-10-01

    Full Text Available OBJECTIVE: To compare, through computed tomography, alveolar bone thickness changes at the maxillary incisors area during orthodontic treatment with and without tooth extraction. METHODS: Twelve patients were evaluated. They were divided into 2 groups: G1 - 6 patients treated with extraction of right and left maxillary first premolars, with mean initial age of 15.83 years and mean treatment length of 2.53 years; G2 - 6 patients treated without extraction, with mean initial age of 18.26 years and mean treatment length of 2.39 years. Computed tomographies, lateral cephalograms and periapical radiographs were used at the beginning of the treatment (T1 and 18 months after the treatment had started (T2. Extraction space closure occurred in the extraction cases. Intragroup and intergroup comparisons were performed by dependent and independent t test, respectively. RESULTS: In G1, the central incisor was retracted and uprighted, while in G2 this tooth showed vestibularization. Additionally, G1 presented a higher increase of labial alveolar bone thickness at the cervical third in comparison with G2. The incidence of root resorption did not present significant differences between groups. CONCLUSION: There were no changes in alveolar bone thickness when extraction and nonextraction cases were compared, except for the labial alveolar bone thickness at the cervical third of maxillary incisors.

  4. Stability of Spatial Structure of Urban Agglomeration in China Based on Central Place Theory

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper brings forward the concept of stability of the spatial structure of urban agglomeration (UA) based on Central Place Theory by introducing centrality index and fractal theory. Before assessment, K=4 is selected as parameter to calculate centrality index and fractal dimension (K represents the quantitive relationship between city and the counties in Central Place Theory), and then found the number of nodes, the type of spatial structure, the spatial allocation of nodes with different hierarchy affecting the stability of spatial structure. According to spatial contact direction and the level of stability, UAs in China are classified into five types. Finally, it is posed as a further question that how to use hierarchical relation K=6 and K=7 in central place system to coordinate with the assessment of stability of spatial structure is brought forward.

  5. Multidisciplinary approach for the aesthetic treatment of maxillary lateral incisors agenesis: thinking about implants?

    Science.gov (United States)

    de Avila, Érica Dorigatti; de Molon, Rafael Scaf; de Assis Mollo, Francisco; de Barros, Luiz Antonio Borelli; Capelozza Filho, Leopoldino; de Almeida Cardoso, Mauricio; Cirelli, Joni Augusto

    2012-11-01

    Missing maxillary lateral incisors create an esthetic problem with specific orthodontic and prosthetic considerations. Implants are commonly used to replace congenitally missing lateral incisors in adolescent orthodontic patients. However, an interdisciplinary approach should be observed during the diagnosis, prognosis, and treatment plan to provide a result with good predictability and meet the esthetic and functional expectations of the patient. The present study describes a case of a young patient with tooth agenesis of maxillary lateral incisors, which was conducted with an integrated planning. After 5-year follow-up of 2 fixed implant-supported prostheses, clinical and radiographic examination showed the treatment to be successful.

  6. Dracula tooth: A very rare case report of peg-shaped mandibular incisors

    Directory of Open Access Journals (Sweden)

    Ashwin Devasya

    2016-01-01

    Full Text Available Microdontia is a term used to describe teeth which are smaller than normal. Peg-shaped teeth are type of microdontia, a developmental disturbances of teeth mainly due to congenital reasons. Most commonly affecting single teeth, that is maxillary lateral incisors. Incidence of peg shaped tooth in maxillary laterals are usually seen and reported. But in mandibular arch it is very rare. Present case, it affected all the incisors of mandibular arch and also the laterals of maxillary arch which is rarest of condition. This case report presents a non syndromic, peg shaped mandibular incisors in a 11 year old male patient.

  7. Dracula tooth: A very rare case report of peg-shaped mandibular incisors.

    Science.gov (United States)

    Devasya, Ashwin; Sarpangala, Mythri

    2016-01-01

    Microdontia is a term used to describe teeth which are smaller than normal. Peg-shaped teeth are type of microdontia, a developmental disturbances of teeth mainly due to congenital reasons. Most commonly affecting single teeth, that is maxillary lateral incisors. Incidence of peg shaped tooth in maxillary laterals are usually seen and reported. But in mandibular arch it is very rare. Present case, it affected all the incisors of mandibular arch and also the laterals of maxillary arch which is rarest of condition. This case report presents a non syndromic, peg shaped mandibular incisors in a 11 year old male patient.

  8. A new understanding of oral and dental disorders of the equine incisor and canine teeth.

    Science.gov (United States)

    Earley, Edward; Rawlinson, Jennifer T

    2013-08-01

    This article discusses the classification systems for dental fractures and how the assessment affects treatment options. Diagonal incisor malocclusion is discussed in relation to skull asymmetry and how this commonly relates to premolar and molar occlusion. Oral and radiographic assessment of incisive bone fracture and incisor avulsion is reviewed for determining treatment options. A summary of incisor and canine resorption and hypercementosis is presented. Clinical presentations, staging, and classifications of tooth resorption as well as canine odontoplasty are discussed. Excessive plaque and calculus formation on lower canines leading to periodontal disease and abscess is examined.

  9. Advances in the treatment of diseased equine incisor and canine teeth.

    Science.gov (United States)

    Rawlinson, Jennifer T; Earley, Edward

    2013-08-01

    Dental therapies for equid incisor and canine teeth have modernized significantly over the last 2 decades. Basic principles in incisor reduction have become more conservative, and extraction procedures more exacting. Periodontal and endodontic treatments are described to save teeth that would have succumbed to extraction in the past. Pathologic impacts on treatment decisions for equine odontoclastic tooth resorption and hypercementosis are significant, and veterinarians and owners need to be aware of treatment options and outcomes. Easy access to equid incisor and canine teeth offers a variety of therapeutic options, and this article reviews some of the practical procedures available.

  10. Notching and anterior beveling on fossil horse incisors: Indicators of domestication?

    Science.gov (United States)

    Rogers, Richard A.; Rogers, Laurine A.

    1988-01-01

    One of the lines of evidence cited for possible late Pleistocene human control of horses has been the presence of notching and anterior beveling on horse incisor teeth recovered from upper and middle Paleolithic sites in Europe. Similar forms of wear have been found on the incisor teeth of wild horses from early and middle Pleistocene deposits in North America. Notching appears partly due to malocclusion and chipping. The causes of beveling are less certain but may involve the eating of bark. Therefore, the presence of notching and anterior beveling on horse incisor teeth may not be a reliable indicator of human control.

  11. Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations

    Directory of Open Access Journals (Sweden)

    Yehoshua Shapira

    2016-01-01

    Full Text Available Bilateral mandibular tooth transposition is a relatively rare dental anomaly caused by distal migration of the mandibular lateral incisors and can be detected in the early mixed dentition by radiographic examination. Early diagnosis and interceptive intervention may reduce the risk of possible transposition between the mandibular canine and lateral incisor. This report illustrates the orthodontic management of bilateral mandibular canine-lateral incisor transposition. Correct positioning of the affected teeth was achieved on the left side while teeth on the right side were aligned in their transposed position. It demonstrates the outcome of good alignment of the teeth in the dental arch.

  12. Dracula tooth: A very rare case report of peg-shaped mandibular incisors

    Science.gov (United States)

    Devasya, Ashwin; Sarpangala, Mythri

    2016-01-01

    Microdontia is a term used to describe teeth which are smaller than normal. Peg-shaped teeth are type of microdontia, a developmental disturbances of teeth mainly due to congenital reasons. Most commonly affecting single teeth, that is maxillary lateral incisors. Incidence of peg shaped tooth in maxillary laterals are usually seen and reported. But in mandibular arch it is very rare. Present case, it affected all the incisors of mandibular arch and also the laterals of maxillary arch which is rarest of condition. This case report presents a non syndromic, peg shaped mandibular incisors in a 11 year old male patient. PMID:28123271

  13. THE INDEPENDENCE OF CENTRAL BANKS IN CENTRAL AND EASTERN EUROPE-A MONETARY POLICY STRATEGY BASED APPROACH

    OpenAIRE

    Popescu Iulian Vasile

    2013-01-01

    The present paper aims to examine the trends of the last decade and a half of central banks independence (CBI) in Central and Eastern European countries on the road to the euro adoption and to compare the results with those identified in the case of the European Central Bank (ECB). We approached CBI from the perspective of monetary policy strategies central banks (CBs) use. The main results show increasing independence during the selected time frame for all monetary authorities subject to ana...

  14. Research on central heating system control strategy based on genetic algorithm

    Science.gov (United States)

    Ding, Sa; Yang, Jianhua; Lu, Wei; Duan, Zhipeng

    2017-03-01

    The central heating is a major way of warming in northeast China in winter, however, the traditional heating method is inefficient, intensifying the energy consumption. How to improve the heating efficiency and reduce energy waste attracts more and more attentions in our country. In this paper, the mathematical model of heat transfer station temperature control system was established based on the structure of central heating system. The feedforward-feedback control strategy was used to overcome temperature fluctuations caused by the pressurized heating exchange system. The genetic algorithm was used to optimize the parameters of PID controller and simulation results demonstrated that central heating temperature achieved well control effect and meet stabilization requirements.

  15. Delayed orthodontic extrusion of a traumatically intruded immature upper permanent incisor - a case report.

    Science.gov (United States)

    Umesan, Uday Kumar; Chua, Kui Lay; Kok, Ei Chuen

    2014-10-01

    Dental injuries are probably the most common orofacial injuries sustained during sports and play. Intrusion or intrusive luxations occur when the teeth are driven into the alveolus by an axially directed impact. This article describes the clinical case of an 8-year-old patient who suffered complete intrusive luxation of an immature permanent central incisor following an accident. An attempt at spontaneous re-eruption failed to facilitate re-emergence of the tooth beyond 2 mm. The recommended wait-and-see strategy in anticipation of spontaneous re-eruption should cease to be an option when no further elongation can be observed. Orthodontic extrusion or surgical re-positioning is a valid treatment alternative when the former fails. In this case, although the recommended time period for effecting orthodontic extrusion had elapsed, this procedure was undertaken successfully presumably owing to the application of controlled, biologically optimal forces. A review of the extruded tooth a year later revealed no clinical or radiographic signs of loss of vitality. This was confirmed radiographically by the completion of root development, an intact lamina dura and no evident signs of resorption.

  16. Traumatic impact loading on human maxillary incisor: A Dynamic finite element analysis

    Directory of Open Access Journals (Sweden)

    K Jayasudha

    2015-01-01

    Full Text Available Background: The most vulnerable tooth is the maxillary incisor, which sustains 80% of dental injuries. Dynamic Finite element analysis is used to understand the biomechanics of fracture of maxillary incisor under traumatic impact loading. Aim: The aim was to investigate the stress patterns of an upper incisor in a three-dimensional (3D model under traumatic impact loading in various directions. Materials and Methods: A 3D finite element model of the upper incisor and surrounding tissues was established. A sinusoidal force of 800N was applied over a period of 4 ms. Results: Software performs a series of calculations and mathematical equations and yields the simulation results. During the horizontal impact (F1, stresses were concentrated in the cervical area of the crown, reaching peak stress of 125 MPa at 2 ms. Conclusion: A horizontal force exerted on the labial surface of the tooth tends to cause cervical crown fractures, oblique crown root fractures, and oblique root fractures.

  17. Light wire auxiliaries with pre-adjusted edgewise appliance to control individual incisor torque

    Directory of Open Access Journals (Sweden)

    Sharanya Sabrish

    2015-01-01

    The use of light wire auxiliaries have definite advantages and hence should be a part of our armamentarium to handle such cases. Light wire auxiliaries offer us a biomechanically superior and economical alternative to apply torque forces on incisors.

  18. Caribbean and Central American Women's Feminist Inquiry through Theater-Based Action Research

    Science.gov (United States)

    Sánchez Ares, Rocío

    2015-01-01

    Feminist action research interrogates gendered dynamics in the development of a collective consciousness. A group of immigrant Latina women (Latinas) from the Caribbean and Central America employed community-based theater as an instrument to mobilize diverse audiences against discriminatory practices and policies. Based on their theater work, I…

  19. Treatment of Two Canals in All Mandibular Incisor Teeth in the Same Patient

    Directory of Open Access Journals (Sweden)

    Vandana B. Kokane

    2014-01-01

    Full Text Available The main reason for unfavourable outcome in endodontic treatment of mandibular incisor is the inability to detect the presence of second canal. Pain even after extirpation of complete pulp tissue from root canal of vital teeth is the main indication of hidden canals. The present case report is also on pain because of another neglected canal in all mandibular incisors in the same patient.

  20. Conservative treatment of shovel-shaped upper incisors and dens invaginatus: a case study

    OpenAIRE

    Maisa Oliveira Caliani Corral Morales; Luiz Evaristo Ricci Volpato; Fabio Luis Miranda Pedro; Cyntia Rodrigues de Araújo Estrela; Álvaro Henrique Borges

    2012-01-01

    The purpose of this paper was to describe the conservative treatment adopted in one nonsyndromic patient presenting with shovel-shaped upper incisors and dens invaginatus. A 13-yearold female patient sought treatment reporting pain in response to cold stimuli in the upper anterior teeth. Four upper incisors with shovel-shaped anatomical alterations in the palatal side of the crown were detected during intra-oral clinical examination; in addition, imaging exams revealed a type I dens invaginat...

  1. Class II, Division 1 Angle malocclusion with severe proclination of maxillary incisors

    Directory of Open Access Journals (Sweden)

    Kátia Montanha

    2016-02-01

    Full Text Available Protrusion of maxillary incisors is a common complaint among patients seeking orthodontic treatment. This report addresses the correction of Class II Angle malocclusion with excessively bucally proclined maxillary incisors, in an adolescent female patient, through the use of extraoral and fixed appliances. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO as part of the requirements for obtaining the title of certified by the BBO.

  2. Influence of anatomical barriers on maxillary incisor root resorption after orthodontic treatment with premolar extractions

    OpenAIRE

    2012-01-01

    INTRODUCTION: Apical root resorption is a frequent and occasionally critical problem in orthodontic patients undergoing induced tooth movement. One of the factors that might influence prognosis, especially in maxillary incisors, which most frequently present resorptions, are the so-called the anatomical barriers; that is, proximity of the buccal and palatal cortical bones to the maxillary incisor roots. OBJECTIVE: The purpose of this research was to investigate whether patients with excessive...

  3. A Simplified Method for the Restoration of Severely Decayed Primary Incisors

    OpenAIRE

    Maryam Talebi; Iman Parisay; Fatemeh Khorakian; Elham Nik

    2015-01-01

    Objectives: Caries and dental trauma are common reasons for primary anterior teeth restorations in children. This non-control clinical trial was designed to eva- luate crown restorations reinforced with a sectioned file post for the restoration of severely damaged primary maxillary incisors.Materials and Methods: Thirty-eight primary maxillary incisors of 12 children (3-5 years old) with early childhood caries (ECC) received composite restorations with a custom made post. The restorations wer...

  4. Interim Restorative Approach for the Management of Congenitally Missing Permanent Mandibular Incisors: Presentation of Three Cases

    OpenAIRE

    Prashanth Prakash; Jayadev M. Hallur; Rachana Narse Gowda

    2011-01-01

    Congenital missing of mandibular permanent incisors with retained primary incisors may jeopardize the esthetic appearance and psychological development of children, especially during the years of transition into adolescence. The retained primary teeth are necessary for the maintenance and normal development of alveolar bone, which in turn is essential for future definitive rehabilitation. In such situations, an interim restoration may be provided before any definitive treatment is given to co...

  5. Perivascular Stem Cells at the Tip of Mouse Incisors Regulate Tissue Regeneration.

    Science.gov (United States)

    Pang, Yvonne Wy; Feng, Jifan; Daltoe, Felipe; Fatscher, Robert; Gentleman, Eileen; Gentleman, Molly M; Sharpe, Paul T

    2016-03-01

    Cells with in vitro properties similar to those of bone marrow stromal stem cells are present in tooth pulp as quiescent cells that are mobilized by damage. These dental pulp stem cells (DPSCs) respond to damage by stimulating proliferation and differentiation into odontoblast-like cells that form dentine to repair the damage. In continuously growing mouse incisors, tissue at the incisor tips is continuously being damaged by the shearing action between the upper and lower teeth acting to self-sharpen the tips. We investigated mouse incisor tips as a model for the role of DPSCs in a continuous natural repair/regeneration process. We show that the pulp at the incisor tip is composed of a disorganized mass of mineralized tissue produced by odontoblast-like cells. These cells become embedded into the mineralized tissue that is rapidly formed and then lost during feeding. Tetracycline labeling not only revealed the expected incorporation into newly synthesized dentine formation of the incisor but also a zone covering the pulp cavity at the tips of the incisors that is mineralized very rapidly. This tissue was dentine-like but had a significantly lower mineral content than dentine as determined by Raman spectroscopy. The mineral was more crystalline than dentine, indicative of small, defect-free mineral particles. To identify the origin of cells responsible for deposition of this mineralized tissue, we genetically labeled perivascular cells by crossing NG2(ERT2) Cre and Nestin Cre mice with reporter mice. A large number of pericyte-derived cells were visible in the pulp of incisor tips with some having elongated, odontoblast-like shapes. These results show that in mouse incisors, rapid, continuous mineralization occurs at the tip to seal off the pulp tissue from the external environment. The mineral is formed by perivascular-derived cells that differentiate into cells expressing dentin sialo-phosphoprotein (DSPP) and produce a dentine-like material in a process that

  6. Molar Incisor Hypomineralization: An Epidemiological Study with Prevalence and Etiological Factors in Indian Pediatric Population

    OpenAIRE

    Mishra, Apurva; Pandey, Ramesh K.

    2016-01-01

    ABSTRACT Aims: To determine the prevalence of molar incisor hypomineralization (MIH) in Indian children and to analyze the possible etiological factors. Materials and methods: First permanent molars and all permanent incisors were examined in 1,369 children aged 8 to 12 years. Examinations were performed by two calibrated observers. The subjects were evaluated using judgment criteria proposed by Weerheijm et al in 2003. The parents accompanying children were given a questionnaire regarding pr...

  7. Current View on the Diagnosis and Treatment of Molar Incisor Hypomineralization

    OpenAIRE

    Güner, Şirin; Salcıoğlu, Dilara

    2016-01-01

    Molar incisor hypomineralization (MIH) is defined as the hypomineralization of one or more first permanent molars with or without the involvement of the maxillary and mandibular permanent incisors. Although the etiology of MIH remains unclear, several etiological factors, such as the genetic and environmental factors and systemic disturbance during pre-, peri-, and postnatal period, can cause enamel defects and their occurrence. The prevalence of MIH is reported to be between 2.4% and 25% in ...

  8. Maxillary dentoalveolar assessment following retraction of maxillary incisors: a preliminary study

    Science.gov (United States)

    Oliveira, Tiago Maia Fernandes; Claudino, Lígia Vieira; Mattos, Cláudia Trindade; Sant'Anna, Eduardo Franzotti

    2016-01-01

    ABSTRACT Objective: The aim of this preliminary study was to assess changes in tooth length and alveolar thickness following retraction of maxillary incisors. Methods: A total of 11 patients presenting severe maxillary dentoalveolar protrusion revealed by initial (T1) cone-beam computed tomography (CBCT), and whose treatment plan included extraction of maxillary first premolars and retraction of maxillary incisors, were selected and submitted to CBCT examination one month after the end of incisors retraction (T2). The premaxilla was assessed through seven axial slices by means of Dolphin ImagingTM software. In each of these slices, five measurements of the distance from the buccal cortical bone to the palatal cortical bone were performed. Tooth length of maxillary incisors (n = 44) was also measured in sagittal slices. Measurements were repeated after a two-week interval, and intraclass correlation coefficient (ICC) was used to test examiner calibration. Wilcoxon test was used to detect differences in measurements performed at the two time intervals. Results: The ICC was satisfactory for tooth length (0.890) and for premaxilla alveolar thickness measurements (0.980). Analysis of data showed no statistically significant differences (p > 0.05) in tooth length or alveolar thickness between the two-time intervals assessed. Conclusion: The force used in retraction of maxillary incisors in this research did not promote significant changes in tooth length of maxillary incisors or in premaxilla alveolar thickness. PMID:27901233

  9. Maxillary dentoalveolar assessment following retraction of maxillary incisors: a preliminary study

    Directory of Open Access Journals (Sweden)

    Tiago Maia Fernandes Oliveira

    Full Text Available ABSTRACT Objective: The aim of this preliminary study was to assess changes in tooth length and alveolar thickness following retraction of maxillary incisors. Methods: A total of 11 patients presenting severe maxillary dentoalveolar protrusion revealed by initial (T1 cone-beam computed tomography (CBCT, and whose treatment plan included extraction of maxillary first premolars and retraction of maxillary incisors, were selected and submitted to CBCT examination one month after the end of incisors retraction (T2. The premaxilla was assessed through seven axial slices by means of Dolphin ImagingTM software. In each of these slices, five measurements of the distance from the buccal cortical bone to the palatal cortical bone were performed. Tooth length of maxillary incisors (n = 44 was also measured in sagittal slices. Measurements were repeated after a two-week interval, and intraclass correlation coefficient (ICC was used to test examiner calibration. Wilcoxon test was used to detect differences in measurements performed at the two time intervals. Results: The ICC was satisfactory for tooth length (0.890 and for premaxilla alveolar thickness measurements (0.980. Analysis of data showed no statistically significant differences (p > 0.05 in tooth length or alveolar thickness between the two-time intervals assessed. Conclusion: The force used in retraction of maxillary incisors in this research did not promote significant changes in tooth length of maxillary incisors or in premaxilla alveolar thickness.

  10. Maxillary incisor root resorption after rapid palatal expansion in Felis catus.

    Science.gov (United States)

    Vardimon, Alexander D; Levy, Thierry; Weinreb, Miron

    2005-02-01

    Root resorption after rapid palatal expansion (RPE) treatment was found in anchored teeth but has not been studied on non-anchored incisors. This study evaluated root resorption, root tipping, and root proximity of maxillary incisors after RPE treatment. Fourteen cats were divided into treated (n = 10) and untreated (n = 4) groups. The RPE treatment consisted of active, retention, and relapse phases, lasting 25, 60 and 60 d, respectively. Standardized occlusal radiographs were taken to measure tipping and root proximity before and after each treatment phase. Maxillary incisors were analysed histologically by fluorescent microscopy for root resorption. Data was analysed statistically with anova with repeated measures, t-test and Pearson's coefficient of correlation. Root resorption was confined to the first incisors and was 750-fold greater in the treated vs. the control group. Root tipping and root proximity were significantly greater (2.5- and 17-fold, respectively) in the first than in the second maxillary incisor and highly correlated with root resorption (r = -0.927 and 0.723, respectively). This suggests a cause (tipping and root proximity) and effect (root resorption) relationship. Data suggest that first maxillary incisor susceptibility to root resorption during RPE is associated with severe tipping and root proximity.

  11. Root development of permanent lateral incisor in cleft lip and palate children: A radiographic study

    Directory of Open Access Journals (Sweden)

    Amarlal Deepti

    2007-01-01

    Full Text Available Objective: The objective of this study was to compare the root development of lateral incisor on the cleft side with the root development of its contralateral tooth in cleft lip and palate children. Setting: Cleft lip and palate wing, Meenakshi Ammal Dental College and Hospital, Chennai, South India. Materials and Methods: A sample of 96 orthopantamograms of patients with unilateral or bilateral cleft lip and/or cleft palate was selected, regardless of sex and race. Main Outcome Measure: Orthopantamograms were analyzed for root development of lateral incisor on the cleft and noncleft side. Associated anomalies like hypodontia, supernumerary teeth, malformed lateral incisors and root development of canine, if present, were recorded. Findings and Conclusions: Root development of permanent lateral incisor was delayed on the cleft side compared to the noncleft side. There was a statistically significant relationship between levels of root development of lateral incisors on the cleft side within the different study groups ( P < 0.05. Incidence of hypodontia increased in proportion to cleft severity. Frequency of missing second premolars, supernumerary teeth and malformed lateral incisors increased in cleft lip and palate patients. Root development of canine showed a slight delay on the cleft side when compared to the canine on the noncleft side.

  12. Non-invasive management of fused upper incisors

    Directory of Open Access Journals (Sweden)

    Pouran Samimi

    2012-01-01

    Full Text Available The union of two different dental sprouts which can happen in any phase of dental development is commonly called fusion. This developmental anomaly may cause clinical problems including esthetic impairment, which are mainly treated by endodontic and surgical treatments. There are a few reports of conservative not invasive treatment of fused incisors teeth through restorative or prosthetic techniques. They are rarely reported in mandibular posterior teeth. This paper presents an unusual case of fusion of 7 and 8, and also 9 and 10 teeth which was treated with a nonendodontic and nonsurgical conservative approach. Patient was a healthy18-year-old female with chief complaint of bad-looking teeth that in intraoral examination revealed the fusion of 7 and 8, and also 9 and 10 teeth. The space between the mesial of the 6 and 11 teeth was reconstructed. Diastema between the fused teeth was closed. A new lateral tooth was replaced between the fused teeth (7 and 8 and 6 tooth with direct fiber-reinforced composite. The space between the fused teeth (9 and 10 and also tooth 11 was partially closed. Gingival papillas were reconstructed using pink composite. The mandibular anterior missing teeth were replaced with rochett bridge. At the end of treatment the esthetic of the patient was improved. As the treatment was not invasive, major complications are not expected; however, there is potential for eventual long-term periodontal problems due to poor oral hygiene. Debonding of the rochett bridge may happen as well.

  13. Non-invasive management of fused upper incisors.

    Science.gov (United States)

    Samimi, Pouran; Shirban, Mohammad-Reza; Arbabzadeh-Zavareh, Farahnaz

    2012-01-01

    The union of two different dental sprouts which can happen in any phase of dental development is commonly called fusion. This developmental anomaly may cause clinical problems including esthetic impairment, which are mainly treated by endodontic and surgical treatments. There are a few reports of conservative not invasive treatment of fused incisors teeth through restorative or prosthetic techniques. They are rarely reported in mandibular posterior teeth. This paper presents an unusual case of fusion of 7 and 8, and also 9 and 10 teeth which was treated with a nonendodontic and nonsurgical conservative approach. Patient was a healthy18-year-old female with chief complaint of bad-looking teeth that in intraoral examination revealed the fusion of 7 and 8, and also 9 and 10 teeth. The space between the mesial of the 6 and 11 teeth was reconstructed. Diastema between the fused teeth was closed. A new lateral tooth was replaced between the fused teeth (7 and 8) and 6 tooth with direct fiber-reinforced composite. The space between the fused teeth (9 and 10) and also tooth 11 was partially closed. Gingival papillas were reconstructed using pink composite. The mandibular anterior missing teeth were replaced with rochett bridge. At the end of treatment the esthetic of the patient was improved. As the treatment was not invasive, major complications are not expected; however, there is potential for eventual long-term periodontal problems due to poor oral hygiene. Debonding of the rochett bridge may happen as well.

  14. CentiServer: A Comprehensive Resource, Web-Based Application and R Package for Centrality Analysis.

    Directory of Open Access Journals (Sweden)

    Mahdi Jalili

    Full Text Available Various disciplines are trying to solve one of the most noteworthy queries and broadly used concepts in biology, essentiality. Centrality is a primary index and a promising method for identifying essential nodes, particularly in biological networks. The newly created CentiServer is a comprehensive online resource that provides over 110 definitions of different centrality indices, their computational methods, and algorithms in the form of an encyclopedia. In addition, CentiServer allows users to calculate 55 centralities with the help of an interactive web-based application tool and provides a numerical result as a comma separated value (csv file format or a mapped graphical format as a graph modeling language (GML file. The standalone version of this application has been developed in the form of an R package. The web-based application (CentiServer and R package (centiserve are freely available at http://www.centiserver.org/.

  15. 成人安氏Ⅰ类双颌前突患者的上颌切牙区牙槽骨体积%Alveolar bone volume around upper incisors in adult patients with Class Ⅰ bimaxillary protrusion

    Institute of Scientific and Technical Information of China (English)

    刘璐; 李荣荣; 刘梦臖; 张琰; 刘东旭

    2015-01-01

    Objective To investigate the alveolar bone volume around upper incisors in adult patients with Class Ⅰbimaxillary protrusion and provide a reference for orthodontic diagnosis and treatment planning.Methods Twenty-two cases with Class Ⅰ bimaxillary protrusion (bimaxillary protrusion group)and Eighteen cases with individual normal occlusion (control group)were recruited.Lateral cephalograms and cone beam computed tomography(CBCT)scan-nings were taken respectively and the alveolar bone volume around four upper incisors in each subject were measured by Mimics 16.0.Results In bimaxillary protrusion group,alveolar bone volume around upper incisors decreased com-pared to the control group (P <0.05),apart from labial root apex zone of central incisors,labial root apex and palatal crest zone of the lateral incisors.Besides,alveolar crest zone,middle root zone,palatal alveolar bone,total alveolar bone of the central incisors,labial alveolar bone,palatal alveolar bone,total alveolar bone of the lateral incisors and total alveolar bone volume of four upper incisors in bimaxillary protrusion group were decreased compared to the control group (P <0.001).Conclusion The alveolar bone volume around upper incisors in adult patients with Class Ⅰ bima-xillary protrusion is fewer than that in the subjects with normal occlusion.It should be more cautious in the process of treatment planning,especially retraction or intrusion of the upper incisors.%目的:研究成人安氏Ⅰ类双颌前突患者上颌切牙区牙槽骨体积,为正畸诊断及治疗计划制定提供参考。方法选择安氏Ⅰ类双颌前突患者22例(双颌前突组)及个别正常牙合志愿者18例(对照组),分别拍摄头颅侧位片及锥体束计算机断层扫描(CBCT),利用 Mimics 16.0测量上颌4颗切牙牙槽骨体积。结果双颌前突组上颌切牙区牙槽骨体积除中切牙唇侧根尖区、侧切牙唇侧根尖区及腭侧牙槽嵴顶区外,

  16. Goat-based aid programme in Central Java: An effective intervention for the poor and vulnerable?

    NARCIS (Netherlands)

    Budisatria, I.G.S.; Udo, H.M.J.

    2013-01-01

    This study evaluated a goat-based aid programme developed to facilitate the recovery of vulnerable people in an earthquake affected area in Central Java, Indonesia. Farmers, organised in farmers’ groups, received a package of one male and four female goats. In total, 72 farmers from 6 farmers’ group

  17. Nitrogen phosphoric fertilizer production technology on the base of Central Kyzylkum phosphorites and ammonium nitrate melt

    Directory of Open Access Journals (Sweden)

    Shavkat Namazov

    2012-11-01

    Full Text Available The process of obtaining nitrogen phosphoric fertilizer by introduction Central Kyzylkum phosphates and ammonium nitrate melt is studied. On the base of these results production technology diagram for nitrogen phosphoric fertilizer is offered. The given technology was approved and developed at the functioning devices of OJSC “NAVOIAZOT” ammonium nitrate shop.

  18. Lyapunov-Based Control Scheme for Single-Phase Grid-Connected PV Central Inverters

    NARCIS (Netherlands)

    Meza, C.; Biel, D.; Jeltsema, D.; Scherpen, J. M. A.

    2012-01-01

    A Lyapunov-based control scheme for single-phase single-stage grid-connected photovoltaic central inverters is presented. Besides rendering the closed-loop system globally stable, the designed controller is able to deal with the system uncertainty that depends on the solar irradiance. A laboratory p

  19. Understanding Urban Spatial Structure of Shanghai Central City Based on Mobile Phone Data

    Institute of Scientific and Technical Information of China (English)

    Niu; Xinyi; Ding; Liang; Song; Xiaodong; Zhang; Qingfei

    2015-01-01

    Taking Shanghai Central City as its case study, this paper presents an approach to exploring the urban spatial structure through mobile phone positioning data. Firstly, based on base station location data and mobile phone signaling data, the paper analyses the number of users connecting to each base station, and further generates the maps of mobile phone user density through kernel density analysis. We move on to calculate the multi-day average user density based on a time frame of 10:00 and 23:00 at workdays and 15:00 and 23:00 at weekends for Shanghai Central City. Then, through spatial aggregation and density classifi cation on the density maps of 10:00 at workdays and 15:00 at weekends, we identify the ranks and functions of public centers within Shanghai Central City. Lastly, we identify residential areas, business off ice areas, and leisure areas in Shanghai Central City and measure the degree of functional mix by comparing the ratio of day and night user density as well as the user density at nighttime of workdays and weekends.

  20. Comparison of the outcomes of the lower incisor extraction, premolar extraction and non-extraction treatments.

    Science.gov (United States)

    Ileri, Zehra; Basciftci, Faruk Ayhan; Malkoc, Siddik; Ramoglu, Sabri Ilhan

    2012-12-01

    The aim of this retrospective study was to evaluate the treatment outcome of lower incisor extraction and to compare it with premolar extraction and non-extraction treatment. The sample consisted of 60 subjects with Class I malocclusion and moderate crowding. The sample was separated into three groups: extraction of a lower incisor group, extraction of a four first premolar group and a non-extraction group. All groups involved 13 girls and 7 boys with a total of 20 patients. The Peer assessment rating (PAR) index was applied to a patient's pre-treatment (T1) and post-treatment (T2) dental casts. T1 dental casts were also used for determining Bolton discrepancy. One-way analysis of variance and post hoc Tukey HSD tests were used for statistical analysis. For the mean percentage PAR score reduction for each group, there was one significant difference seen between the lower incisor extraction group and the non-extraction group (P = 0.047). For the mean anterior ratios, there were significant differences among premolar extraction group versus non-extraction group (P = 0.042) and non-extraction group versus lower incisor extraction group (P = 0.000). For the mean overall ratios, there were significant differences among the premolar extraction group versus lower incisor extraction group (P = 0.048) and the non-extraction group versus lower incisor extraction group (P = 0.001). Orthodontic treatment without extraction has a better treatment outcome than the four-first premolar extraction and single lower incisor extraction protocols in Class I cases with moderate to severe mandibular anterior crowding.

  1. Contemporary approaches to reducing the risks of central counterparties based on the use of marginal contributions

    Directory of Open Access Journals (Sweden)

    Utkin Viktor Sergeyevich

    2012-07-01

    Full Text Available To protect their own interests central counterparties has developed a number of procedures, including payment of guarantee margin by trading members as a means to ensure their positions. This article discusses a number of approaches, which attempt to simulate the risks of the Central Committee, as well as calculating the amount of margin and other resources in the event of insolvency. These approaches are based on the simulation of the three main types: (a statistical modeling; (b optimization modeling, and (c model of option pricing. The author incorporates the basic provisions of models.

  2. Prevalence assessment of root dilaceration in permanent incisors

    Directory of Open Access Journals (Sweden)

    Beatriz Feitosa da Silva

    2012-12-01

    Full Text Available INTRODUCTION: Root dilaceration is a dental anomaly characterized by an abnormal curvature of the dental root, which can cause problems during eruption and complications in the orthodontic and endodontic treatment or extraction. OBJECTIVE: The aim of this study was to determine the prevalence of root dilaceration in permanent incisors in an oral radiology clinic in the city of João Pessoa / PB, Brazil. METHODS: The sample consisted of 548 patients who allowed assessments of their dental radiographs, a total of 3,948 examined teeth. Each tooth was examined according to the occurrence of root dilaceration, regarding type (mild, moderate or severe, root third that it was in and direction of the root. The angle formed by the root deviation in relation to the long tooth axis was obtained by means of a diagram printed on transparent acetate, placed over the radiograph. RESULTS: The results were analyzed with SPSS software (Statistical Package for Social Sciences version 13.0, performing an exploratory data analysis. The prevalence of root dilaceration in the studied sample was 1.03% (41 cases, with higher incidence in males (65.8%, being the superior lateral incisor the most affected teeth (78%. The most prevalent type of root dilaceration was the mild one (73.1%, occurring more in the apical third (90.2% and with distal direction of the root (95.1%. CONCLUSION: Considering these results, it is emphasized the importance of performing a diagnostic radiographic examination prior to planning a treatment in permanent anterior teeth.INTRODUÇÃO: a dilaceração radicular é uma anomalia dentária caracterizada por uma curvatura anormal na raiz do dente que pode causar problemas na erupção e complicações durante movimentação ortodôntica, tratamento endodôntico ou exodontia. OBJETIVO: o objetivo do presente trabalho foi verificar a prevalência da dilaceração radicular em incisivos permanentes, em uma clínica de radiologia odontológica da

  3. A Traffic Reduction Method for Centralized RSSI-Based Location Estimation in Wireless Sensor Networks

    Science.gov (United States)

    Zemek, Radim; Hara, Shinsuke; Yanagihara, Kentaro; Kitayama, Ken-Ichi

    In a centralized localization scenario, the limited throughput of the central node constrains the possible number of target node locations that can be estimated simultaneously. To overcome this limitation, we propose a method which effectively decreases the traffic load associated with target node localization, and therefore increases the possible number of target node locations that can estimated simultaneously in a localization system based on received signal strength indicator (RSSI) and maximum likelihood estimation. Our proposed method utilizes a threshold which limits the amount of forwarded RSSI data to the central node. As the threshold is crucial to the method, we further propose a method to theoretically determine its value. We experimentally verified the proposed method in various environments and the experimental results revealed that the method can reduce the load by 32-64% without significantly affecting the estimation accuracy.

  4. An approach to maintain orthodontic alignment of lower incisors without the use of retainers.

    Science.gov (United States)

    Aasen, Tore Odd; Espeland, Lisen

    2005-06-01

    The purpose of this investigation was to examine the long-term stability of orthodontic alignment of lower incisors without the use of retainers. The study sample comprised 56 patients treated according to a protocol that included over-correction of rotated teeth at an early stage of treatment and systematic enamel reduction (stripping) of the approximal surfaces in the mandibular anterior region, both during treatment and follow-up. Care was also taken to maintain dental arch form and to avoid lateral expansion of the lower dental arch and proclination of the incisors. Dental study casts were obtained pre-treatment, at the end of treatment, and 3 years post-treatment. Alignment of the mandibular incisors was recorded using Little's irregularity index. The inter-canine distance and the sum of the mesio-distal widths of the mandibular incisors and canines were also measured. The total amount of enamel removed from the approximal surfaces of the lower anterior teeth ranged from 0.3 to 5.0 mm (mean 1.9 mm). The mean increase in irregularity index score of 0.6 from post-treatment to 3 years follow-up indicated good stability. In 45 per cent of the patients the change in score during this period was less than 0.5, indicating that the treatment approach presented may be considered an alternative strategy to placement of lower retainers to safeguard the stability of alignment of mandibular incisors.

  5. Inhibition of Notch Signaling During Mouse Incisor Renewal Leads to Enamel Defects.

    Science.gov (United States)

    Jheon, Andrew H; Prochazkova, Michaela; Meng, Bo; Wen, Timothy; Lim, Young-Jun; Naveau, Adrien; Espinoza, Ruben; Cox, Timothy C; Sone, Eli D; Ganss, Bernhard; Siebel, Christian W; Klein, Ophir D

    2016-01-01

    The continuously growing rodent incisor is an emerging model for the study of renewal of mineralized tissues by adult stem cells. Although the Bmp, Fgf, Shh, and Wnt pathways have been studied in this organ previously, relatively little is known about the role of Notch signaling during incisor renewal. Notch signaling components are expressed in enamel-forming ameloblasts and the underlying stratum intermedium (SI), which suggested distinct roles in incisor renewal and enamel mineralization. Here, we injected adult mice with inhibitory antibodies against several components of the Notch pathway. This blockade led to defects in the interaction between ameloblasts and the SI cells, which ultimately affected enamel formation. Furthermore, Notch signaling inhibition led to the downregulation of desmosome-specific proteins such as PERP and desmoplakin, consistent with the importance of desmosomes in the integrity of ameloblast-SI attachment and enamel formation. Together, our data demonstrate that Notch signaling is critical for proper enamel formation during incisor renewal, in part by regulating desmosome-specific components, and that the mouse incisor provides a model system to dissect Jag-Notch signaling mechanisms in the context of mineralized tissue renewal.

  6. Biologic restoration of a traumatized maxillary central incisor in a toddler: A case report

    OpenAIRE

    Sheen Ann John; Anandaraj, S; Sageena George

    2014-01-01

    Trauma to the anterior teeth is relatively common in young children and teenagers. Traumatized anterior teeth require quick functional and aesthetic repair, and poses a challenge to the dental practitioner owing to the lack of co-operation ceded and the longer time invested. Reattachment of tooth fragment should be the first choice to restoring teeth when a usable fragment is available, since it gives a psychological and aesthetic advantage over the conventional technique. With the vast impro...

  7. Assessment of the size of the radiographic image of permanent upper central incisors dental follicle

    OpenAIRE

    Isabela Capparelli Cardioli

    2012-01-01

    Ao entender o desenvolvimento do folículo dental, conhecemos a normalidade, diagnosticamos possíveis alterações, e realizamos o tratamento adequado. Os objetivos foram avaliar: o tamanho e comportamento da imagem radiográfica do folículo do germe de incisivos centrais superiores permanentes e estimar os valores máximos da distância e da área para cada idade; a associação entre trauma nos incisivos centrais superiores decíduos e expansão do folículo dos sucessores permanentes; os fatores assoc...

  8. CenLP: A centrality-based label propagation algorithm for community detection in networks

    Science.gov (United States)

    Sun, Heli; Liu, Jiao; Huang, Jianbin; Wang, Guangtao; Yang, Zhou; Song, Qinbao; Jia, Xiaolin

    2015-10-01

    Community detection is an important work for discovering the structure and features of complex networks. Many existing methods are sensitive to critical user-dependent parameters or time-consuming in practice. In this paper, we propose a novel label propagation algorithm, called CenLP (Centrality-based Label Propagation). The algorithm introduces a new function to measure the centrality of nodes quantitatively without any user interaction by calculating the local density and the similarity with higher density neighbors for each node. Based on the centrality of nodes, we present a new label propagation algorithm with specific update order and node preference to uncover communities in large-scale networks automatically without imposing any prior restriction. Experiments on both real-world and synthetic networks manifest our algorithm retains the simplicity, effectiveness, and scalability of the original label propagation algorithm and becomes more robust and accurate. Extensive experiments demonstrate the superior performance of our algorithm over the baseline methods. Moreover, our detailed experimental evaluation on real-world networks indicates that our algorithm can effectively measure the centrality of nodes in social networks.

  9. Root resorption of the maxillary lateral incisor caused by impacted canine: a literature review.

    Science.gov (United States)

    Alqerban, A; Jacobs, R; Lambrechts, P; Loozen, G; Willems, G

    2009-09-01

    Root resorption of maxillary lateral incisors caused by erupting canines is well known and a relatively common phenomenon. However, much debate and conflicting evidence exists with regard to the actual resorption trigger and potential etiological factors involved. Consequently, there are no obvious clinical clues concerning prevention and diagnosis as well as subsequent treatment decisions. The introduction of cone beam computer tomography has recently allowed drawing a new and much more documented light on the diagnostic and therapeutic strategies. However, no investigations have determined that this new information may result in another and better diagnostic approach and an improved treatment outcome. Therefore, the present review will attempt to summarize the existing evidence on two- and three-dimensional images and try to link the radiological observations to any further preventive, diagnostic, and/or therapeutic measures. Detection thresholds, accuracy, and reliability of impacted canine localization and neighboring root resorption risks will also be considered. This review demonstrates how adding a third-dimension to the radiographic information may notably alter the prevalence of root resorptions and descriptions of this prevalence. In any case, further investigation is needed to determine resorption detection thresholds in various two-dimensional and three-dimensional imaging techniques, as well as to determine therapeutic thresholds and criteria for strategic tooth extraction based on radiographic manifest and not manageable resorption lesions.

  10. Sequelae of trauma to primary maxillary incisors. I. Complications in the primary dentition.

    Science.gov (United States)

    Borum, M K; Andreasen, J O

    1998-02-01

    Two hundred and eighty-seven children with a total of 545 traumatized primary upper incisors were followed using standardized procedures until the age of 10. Extraction was the only treatment offered when intervention was necessary. The immediate as well as the long-term consequences of trauma were studied on the basis of this material. Consequences in the primary dentition comprised: color changes (53%), pulp necrosis (25%), pulp canal obliteration (36%), gingival retraction (6%), permanent displacement after luxation (5-22%), pathological root resorption (1-10%) as well as disturbances in physiological root resorption (4%) and, lastly, premature tooth loss (46%). In a multivariate analysis of the development of pulp necross in primary teeth after trauma, the following decisive factors were found: age of the patient at the time of injury, degree of displacement of the tooth as well as the degree of loosening and presence of crown fracture. The factors found to influence development of pulp canal obliteration were: displacement of the tooth at time of injury as well as detectable physiologic root resorption at time of trauma. The presence of crown fracture seemed to decrease the risk of obliteration. The need for scientifically based treatment strategies for managing and reducting complications after trauma in the primary dentition is stressed.

  11. The effect of the monetary base on money supply – Does the quantity of central bank money carry any information?

    OpenAIRE

    2007-01-01

    In discussing the transmission mechanism, basic macroeconomics textbooks focus on changes in money supply, which the central bank can control by manipulating the monetary base. Modern central banks, however, take a considerably more complex view of the transmission mechanism, and the operational target of most central banks is to set a short-term interest rate. Under such circumstances, the direction of the mutual effect of the monetary base and money supply is rather the reverse in today’s p...

  12. THE INDEPENDENCE OF CENTRAL BANKS IN CENTRAL AND EASTERN EUROPE-A MONETARY POLICY STRATEGY BASED APPROACH

    Directory of Open Access Journals (Sweden)

    Popescu Iulian Vasile

    2013-06-01

    Full Text Available The present paper aims to examine the trends of the last decade and a half of central banks independence (CBI in Central and Eastern European countries on the road to the euro adoption and to compare the results with those identified in the case of the European Central Bank (ECB. We approached CBI from the perspective of monetary policy strategies central banks (CBs use. The main results show increasing independence during the selected time frame for all monetary authorities subject to analysis, regardless of the applied monetary policy strategy; superior average levels of CBI in CEE countries oriented to inflation targeting compared to those using the exchange rate as nominal anchor; higher degree of independence of ECB in relation to monetary authorities that use an inflation targeting strategy; the simultaneous presence of a significant level of independence, low inflation and stronger economic development in CEE members where CB is geared towards inflation targeting compared to CBs that implement a strategy of exchange rate targeting.

  13. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor.

    Science.gov (United States)

    Achary, Ravindranath C; Ravi, G R

    2016-01-01

    Dilaceration of the permanent tooth usually is a consequence of traumatic injuries to the primary teeth. Although it may appear anywhere in the long axis of the tooth, i.e., crown, cementoenamel junction, or root, most often the root is involved. However, crown dilaceration is a rare condition representing 3% of the total injuries. Maxillary incisors are more susceptible to such injury and affected tooth may either erupt buccally or lingually or remain impacted. Hitherto, the treatment options also differ as per the clinical scenario. This article proposes a novel technique of restoring esthetic function of the affected permanent maxillary lateral incisor with crown-root dilaceration while preserving the vitality of tooth. How to cite this article: Achary RC, Ravi GR. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2016;9(2):152-155.

  14. Premature loss of the maxillary primary incisors: effect on speech production.

    Science.gov (United States)

    Gable, T O; Kummer, A W; Lee, L; Creaghead, N A; Moore, L J

    1995-01-01

    The residual effect of premature loss due to extraction of the four maxillary primary incisors on speech production was studied. The articulation of twenty-six subjects who had their teeth extracted before the age of five years was evaluated at eight, nine, or ten years old and compared with the articulation of an age-matched comparison group with normal exfoliation of their incisors. T-tests for related measures revealed no statistically significant differences between the group with premature loss and the comparison group. These results suggest that loss of maxillary incisors in children younger than five years is not likely to result in defective articulation while the teeth are missing or when the permanent dentition is acquired.

  15. Sex determination using mesiodistal dimension of permanent maxillary incisors and canines

    Directory of Open Access Journals (Sweden)

    Rajbir Kaur Khangura

    2011-01-01

    Full Text Available Background: Sexual dimorphism refers to the differences in size, shape, etc., between males and females. The dentition′s use in sex assessment has been explored and advocated owing to its strength and resistance to peri- and post-mortem insults. Objectives: The study evaluated permanent maxillary incisors and canines for sexual dimorphism and estimated the level of accuracy with which they could be used for sex determination. Materials and Methods: The study was conducted on 100 subjects (50 males, 50 females. The mesiodistal dimension of permanent maxillary incisors and canines was measured and the data were subjected to statistical analysis. Result: Univariate analysis revealed that all permanent maxillary incisors and canines exhibited larger mean values of mesiodistal dimension in males compared to females but only canines were found to be statistically significant for sexual dimorphism. Conclusion: The study showed maxillary canines exhibiting significant sexual dimorphism and can be used for sex determination along with other procedures.

  16. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor

    Science.gov (United States)

    Ravi, GR

    2016-01-01

    ABSTRACT Dilaceration of the permanent tooth usually is a consequence of traumatic injuries to the primary teeth. Although it may appear anywhere in the long axis of the tooth, i.e., crown, cementoenamel junction, or root, most often the root is involved. However, crown dilaceration is a rare condition representing 3% of the total injuries. Maxillary incisors are more susceptible to such injury and affected tooth may either erupt buccally or lingually or remain impacted. Hitherto, the treatment options also differ as per the clinical scenario. This article proposes a novel technique of restoring esthetic function of the affected permanent maxillary lateral incisor with crown-root dilaceration while preserving the vitality of tooth. How to cite this article: Achary RC, Ravi GR. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2016;9(2):152-155. PMID:27365939

  17. Managing congenitally missing lateral incisors. Part II: tooth-supported restorations.

    Science.gov (United States)

    Kinzer, Greggory A; Kokich, Vincent O

    2005-01-01

    Three treatment options exist for the replacement of congenitally missing lateral incisors: canine substitution, a tooth-supported restoration, or a single-tooth implant. Selecting the appropriate treatment option depends on the malocclusion, the anterior relationship, specific space requirements, and the condition of the adjacent teeth. The ideal treatment is the most conservative alternative that satisfies individual esthetic and functional requirements. This article closely examines the three options when replacing a missing lateral incisor with a tooth-supported restoration. These options are a resin-bonded fixed partial denture, a cantilevered fixed partial denture, and a conventional full-coverage fixed partial denture. The specific criteria that must be evaluated for each option is addressed to illustrate the importance of interdisciplinary treatment planning to achieve optimal esthetics and long-term predictability. This article is the second of a three-part series discussing the three treatment alternatives for replacing congenitally missing lateral incisors.

  18. Dental anomalies in an orthodontic patient population with maxillary lateral incisor agenesis

    Science.gov (United States)

    Citak, Mehmet; Cakici, Elif Bahar; Benkli, Yasin Atakan; Cakici, Fatih; Bektas, Bircan; Buyuk, Suleyman Kutalmış

    2016-01-01

    ABSTRACT Introduction: The purpose of this study was to evaluate the prevalence of dental anomalies in a subpopulation of orthodontic patients with agenesis of maxillary lateral incisors (MLI). Methods: The material of the present study included the records of the 1964 orthodontic patients. Panoramic radiographs and dental casts were used to analyze other associated eight dental anomalies, including agenesis of other teeth, dens invaginatus, dens evaginatus, peg shaped MLI, taurodontism, pulp stone, root dilaceration and maxillary canine impaction. Results: Out of the 1964 patients examined, 90 were found to have agenesis of MLI, representing a prevalence of 4.6%. The most commonly found associated-anomalies were agenesis of other teeth (23.3%), peg-shaped MLIs (15.6%), taurodontism (42.2%), and dilacerated teeth (18.9%). Conclusion: Permanent tooth agenesis, taurodontism, peg-shaped maxillary lateral incisor, and root dilacerations are frequently associated with maxillary lateral incisor agenesis. PMID:28125145

  19. Dental anomalies in an orthodontic patient population with maxillary lateral incisor agenesis

    Directory of Open Access Journals (Sweden)

    Mehmet Citak

    Full Text Available ABSTRACT Introduction: The purpose of this study was to evaluate the prevalence of dental anomalies in a subpopulation of orthodontic patients with agenesis of maxillary lateral incisors (MLI. Methods: The material of the present study included the records of the 1964 orthodontic patients. Panoramic radiographs and dental casts were used to analyze other associated eight dental anomalies, including agenesis of other teeth, dens invaginatus, dens evaginatus, peg shaped MLI, taurodontism, pulp stone, root dilaceration and maxillary canine impaction. Results: Out of the 1964 patients examined, 90 were found to have agenesis of MLI, representing a prevalence of 4.6%. The most commonly found associated-anomalies were agenesis of other teeth (23.3%, peg-shaped MLIs (15.6%, taurodontism (42.2%, and dilacerated teeth (18.9%. Conclusion: Permanent tooth agenesis, taurodontism, peg-shaped maxillary lateral incisor, and root dilacerations are frequently associated with maxillary lateral incisor agenesis.

  20. Simple method of designing centralized PI controllers for multivariable systems based on SSGM.

    Science.gov (United States)

    Dhanya Ram, V; Chidambaram, M

    2015-05-01

    A method is given to design multivariable PI/PID controllers for stable and unstable multivariable systems. The method needs only the steady state gain matrix (SSGM). The method is based on the static decoupler design followed by SISO PI/PID controllers design and combining the resulted decoupler and the diagonal PI(D) controllers as the centralized controllers. The result of the present method is shown to be equivalent to the empirical method proposed by Davison EJ. Multivariable tuning regulators: the feed-forward and robust control of general servo-mechanism problem. IEEE Trans Autom Control 1976;21:35-41. Three simulation examples are given. The performance of the controllers is compared with that of the reported centralized controller based on the multivariable transfer function matrix.

  1. Central Nervous System Based Computing Models for Shelf Life Prediction of Soft Mouth Melting Milk Cakes

    Directory of Open Access Journals (Sweden)

    Gyanendra Kumar Goyal

    2012-04-01

    Full Text Available This paper presents the latency and potential of central nervous system based system intelligent computer engineering system for detecting shelf life of soft mouth melting milk cakes stored at 10o C. Soft mouth melting milk cakes are exquisite sweetmeat cuisine made out of heat and acid thickened solidified sweetened milk. In today’s highly competitive market consumers look for good quality food products. Shelf life is a good and accurate indicator to the food quality and safety. To achieve good quality of food products, detection of shelf life is important. Central nervous system based intelligent computing model was developed which detected 19.82 days shelf life, as against 21 days experimental shelf life.

  2. Differences between dentitions with palatally and labially located maxillary canines observed in incisor width, dental morphology and space conditions

    DEFF Research Database (Denmark)

    Artmann, L; Larsen, H J; Sørensen, H B;

    2010-01-01

    To analyze the interrelationship between incisor width, deviations in the dentition and available space in the dental arch in palatally and labially located maxillary ectopic canine cases.......To analyze the interrelationship between incisor width, deviations in the dentition and available space in the dental arch in palatally and labially located maxillary ectopic canine cases....

  3. Treating dental crowding with mandibular incisor extraction in an Angle Class I patient

    Directory of Open Access Journals (Sweden)

    Gislana Braga Machado

    2015-06-01

    Full Text Available Mandibular dental crowding often encourages patients to seek orthodontic treatment. The orthodontist should decide between protrusion of incisors or decrease in dental volume so as to achieve proper alignment and leveling. The present study reports the treatment of an Angle Class I malocclusion adolescent female brachyfacial patient with severe mandibular dental crowding, increased curve of Spee and deep overbite. The patient was treated with extraction of a mandibular incisor. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO as a requirement for the title of certified by the BBO.

  4. Maxillary lateral incisors with two canals and two separate curved roots

    Directory of Open Access Journals (Sweden)

    Ajit George Mohan

    2012-01-01

    Full Text Available Variation in the roots and root canal anatomy seems to be the norm rather than an exception. For a successful endodontic treatment, a clinician should have a thorough knowledge of the internal and external dental anatomy and its variations. Maxillary lateral incisors usually exhibit single canal with a single root. In this case, clinical examination and radiographs clearly demonstrates the presence of two root canals with two separate curved roots. This case report emphasizes the need for attention during endodontic management of maxillary lateral incisors.

  5. Simulating certain aspects of hypogravity: Effects on the mandibular incisors of suspended rats (PULEH model)

    Science.gov (United States)

    Simmons, D. J.; Winter, F.; Morey-Holton, E. R.

    1984-01-01

    The effect of a hypogravity simulating model on the rate of mandibular incisor formation, dentinogenesis and, amelogenesis in laboratory rats was studied. The model is the partial unloading by elevating the hindquarters. In this system, rat hindquarters are elevated 30 to 40 deg from the cage floors to completely unload the hindlimbs, but the animals are free to move about using their forelimbs. This model replicates the fluid sift changes which occur during the weightlessness of spaceflight and produces an osteopenia in the weight bearing skeletons. The histogenesis and/or mineralization rates of the mandibular incisor during the first 19d of PULEH in young growing rats are recorded.

  6. Rehabilitation of molar-incisor hypomineralization (MIH) complicated with localized tooth surface loss: a case report.

    Science.gov (United States)

    Lam, Walter Y H; Ho, Edward H T; Pow, Edmond H N

    2014-05-01

    Molar-incisor hypomineralization (MIH) is a developmental enamel hypomineralized condition characteristically involving the first permanent molars and sometimes also the incisors. The affected teeth are predisposed to tooth surface loss (TSL) which may not only compromise the esthetics and function but also endanger the pulp and longevity of the teeth. This report describes the management of a patient with MIH complicated with localized TSL and lack of occlusal clearance due to dentoalveolar compensation. The atypical TSL pattern involved all anterior teeth and required the placement of Dahl appliances on both arches.

  7. Development of a Physiologically-Based Pharmacokinetic Model of the Rat Central Nervous System

    Directory of Open Access Journals (Sweden)

    Raj K. Singh Badhan

    2014-03-01

    Full Text Available Central nervous system (CNS drug disposition is dictated by a drug’s physicochemical properties and its ability to permeate physiological barriers. The blood–brain barrier (BBB, blood-cerebrospinal fluid barrier and centrally located drug transporter proteins influence drug disposition within the central nervous system. Attainment of adequate brain-to-plasma and cerebrospinal fluid-to-plasma partitioning is important in determining the efficacy of centrally acting therapeutics. We have developed a physiologically-based pharmacokinetic model of the rat CNS which incorporates brain interstitial fluid (ISF, choroidal epithelial and total cerebrospinal fluid (CSF compartments and accurately predicts CNS pharmacokinetics. The model yielded reasonable predictions of unbound brain-to-plasma partition ratio (Kpuu,brain and CSF:plasma ratio (CSF:Plasmau using a series of in vitro permeability and unbound fraction parameters. When using in vitro permeability data obtained from L-mdr1a cells to estimate rat in vivo permeability, the model successfully predicted, to within 4-fold, Kpuu,brain and CSF:Plasmau for 81.5% of compounds simulated. The model presented allows for simultaneous simulation and analysis of both brain biophase and CSF to accurately predict CNS pharmacokinetics from preclinical drug parameters routinely available during discovery and development pathways.

  8. Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    R. Ebru Tirali

    2013-01-01

    Full Text Available Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly.

  9. Road network selection for small-scale maps using an improved centrality-based algorithm

    Directory of Open Access Journals (Sweden)

    Roy Weiss

    2014-12-01

    Full Text Available The road network is one of the key feature classes in topographic maps and databases. In the task of deriving road networks for products at smaller scales, road network selection forms a prerequisite for all other generalization operators, and is thus a fundamental operation in the overall process of topographic map and database production. The objective of this work was to develop an algorithm for automated road network selection from a large-scale (1:10,000 to a small-scale database (1:200,000. The project was pursued in collaboration with swisstopo, the national mapping agency of Switzerland, with generic mapping requirements in mind. Preliminary experiments suggested that a selection algorithm based on betweenness centrality performed best for this purpose, yet also exposed problems. The main contribution of this paper thus consists of four extensions that address deficiencies of the basic centrality-based algorithm and lead to a significant improvement of the results. The first two extensions improve the formation of strokes concatenating the road segments, which is crucial since strokes provide the foundation upon which the network centrality measure is computed. Thus, the first extension ensures that roundabouts are detected and collapsed, thus avoiding interruptions of strokes by roundabouts, while the second introduces additional semantics in the process of stroke formation, allowing longer and more plausible strokes to built. The third extension detects areas of high road density (i.e., urban areas using density-based clustering and then locally increases the threshold of the centrality measure used to select road segments, such that more thinning takes place in those areas. Finally, since the basic algorithm tends to create dead-ends—which however are not tolerated in small-scale maps—the fourth extension reconnects these dead-ends to the main network, searching for the best path in the main heading of the dead-end.

  10. Root resorption and factors analysis of the maxillary incisors before retraction in patients with protrusion%前突患者上切牙内收前的牙根吸收状况及因素分析

    Institute of Scientific and Technical Information of China (English)

    马宁; 李巍然

    2013-01-01

    目的 调查前突患者上切牙内收前的牙根吸收状况,并且对该阶段牙根吸收的影响因素进行初步的探索.方法 选择上颌需要拔除双侧第一前磨牙且需要强支抗的前突患者50名,分别于正畸治疗前(T1)和上切牙内收前(T2)拍摄上颌切牙的平行投照根尖片和头颅侧位片,通过测量和评价,得到每颗切牙的牙根吸收量、治疗前牙根形态及上中切牙的角度位置及变化量,并记录其他诊断和治疗因素.对牙根吸收量作描述性统计,对各因素作多因素分析.结果 ①前突患者上切牙内收前,中切牙的牙根吸收平均为(0.73±0.53)mm,侧切牙为(0.84±0.70)mm.②有3%的中切牙和6%的侧切牙牙根吸收大于2mm.③多元线性回归表明T1期牙根形态异常、内收前疗程长、上中切牙根尖距唇侧骨皮质的距离减小量大、T1期U1/PP角小、上颌前部拥挤为中切牙牙根吸收的危险因素.T1期牙根形态异常、上颌前部拥挤、内收前疗程长、T1期牙齿长度长为侧切牙牙根吸收的危险因素.结论 前突患者上切牙内收前有一定量的牙根吸收,个别高危患者其牙根吸收状况较严重.我们的研究因素中存在此阶段与上切牙牙根吸收相关的因素,但这些因素对于牙根吸收的解释仅为30%左右.%Objective To investigate root resorption of the maxillary incisors before retraction in patients with protrusion and to explore the possible risk factors.Methods 50 patients with protrusion malocclusion treated with bilateral maxillary first premolars extractions and high anchorage were selected.The periapical radiographs of the maxillary incisors using paralleling technique and cephalograms were obtained before treatment(T1) and before retraction(T2).Root resorption values of each incisor were measured and root forms at T1 were diagnosed.The inclination angle,the position and the changes of the maxillary central incisors were measured.Other diagnosis

  11. The efficacy of centralized flow rate control in 802.11-based wireless mesh networks

    KAUST Repository

    Jamshaid, K.

    2013-06-13

    Commodity WiFi-based wireless mesh networks (WMNs) can be used to provide last mile Internet access. These networks exhibit extreme unfairness with backlogged traffic sources. Current solutions propose distributed source-rate control algorithms requiring link-layer or transport-layer changes on all mesh nodes. This is often infeasible in large practical deployments. In wireline networks, router-assisted rate control techniques have been proposed for use alongside end-to-end mechanisms. We wish to evaluate the feasibility of establishing similar centralized control via gateways in WMNs. In this paper, we focus on the efficacy of this control rather than the specifics of the controller design mechanism. We answer the question: Given sources that react predictably to congestion notification, can we enforce a desired rate allocation through a single centralized controller? The answer is not obvious because flows experience varying contention levels, and transmissions are scheduled by a node using imperfect local knowledge. We find that common router-assisted flow control schemes used in wired networks fail in WMNs because they assume that (1) links are independent, and (2) router queue buildups are sufficient for detecting congestion. We show that non-work-conserving, rate-based centralized scheduling can effectively enforce rate allocation. It can achieve results comparable to source rate limiting, without requiring any modifications to mesh routers or client devices. 2013 Jamshaid et al.; licensee Springer.

  12. Central-force decomposition of spline-based modified embedded atom method potential

    Science.gov (United States)

    Winczewski, S.; Dziedzic, J.; Rybicki, J.

    2016-10-01

    Central-force decompositions are fundamental to the calculation of stress fields in atomic systems by means of Hardy stress. We derive expressions for a central-force decomposition of the spline-based modified embedded atom method (s-MEAM) potential. The expressions are subsequently simplified to a form that can be readily used in molecular-dynamics simulations, enabling the calculation of the spatial distribution of stress in systems treated with this novel class of empirical potentials. We briefly discuss the properties of the obtained decomposition and highlight further computational techniques that can be expected to benefit from the results of this work. To demonstrate the practicability of the derived expressions, we apply them to calculate stress fields due to an edge dislocation in bcc Mo, comparing their predictions to those of linear elasticity theory.

  13. What do central counterparties default funds really cover? A network-based stress test answer

    CERN Document Server

    Poce, Giulia; Gabrielli, Andrea; Zaccaria, Andrea; Baldacci, Giuditta; Polito, Marco; Rizzo, Mariangela; Sabatini, Silvia

    2016-01-01

    In the last years, increasing efforts have been put into the development of effective stress tests to quantify the resilience of financial institutions. Here we propose a stress test methodology for central counterparties based on a network characterization of clearing members, whose links correspond to direct credits and debits. This network constitutes the ground for the propagation of financial distress: equity losses caused by an initial shock with both exogenous and endogenous components reverberate within the network and are amplified through credit and liquidity contagion channels. At the end of the dynamics, we determine the vulnerability of each clearing member, which represents its potential equity loss. We apply the proposed framework to the Fixed Income asset class of CC&G, the central counterparty operating in Italy whose main cleared securities are Italian Government Bonds. We consider two different scenarios: a distributed, plausible initial shock, as well as a shock corresponding to the co...

  14. Evidence-based measures to prevent central line-associated bloodstream infections: a systematic review

    Directory of Open Access Journals (Sweden)

    Daniele Cristina Perin

    Full Text Available ABSTRACT Objective: to identify evidence-based care to prevent CLABSI among adult patients hospitalized in ICUs. Method: systematic review conducted in the following databases: PubMed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf and Cochrane Studies addressing care and maintenance of central venous catheters, published from January 2011 to July 2014 were searched. The 34 studies identified were organized in an instrument and assessed by using the classification provided by the Joanna Briggs Institute. Results: the studies presented care bundles including elements such as hand hygiene and maximal barrier precautions; multidimensional programs and strategies such as impregnated catheters and bandages and the involvement of facilities in and commitment of staff to preventing infections. Conclusions: care bundles coupled with education and the commitment of both staff and institutions is a strategy that can contribute to decreased rates of central line-associated bloodstream infections among adult patients hospitalized in intensive care units.

  15. Botulinum neurotoxin type A in the masseter muscle: Effects on incisor eruption in rabbits

    Science.gov (United States)

    Navarrete, Alfonso L.; Rafferty, Katherine L.; Liu, Zi Jun; Ye, Wenmin; Greenlee, Geoffrey M.; Herring, Susan W.

    2015-01-01

    Introduction Botulinum neurotoxins are responsible for the paralytic food poisoning, botulism. Commercial formulations such as botulinum neurotoxin type A are increasingly used for various conditions, including cosmetic recontouring of the lower face by injection of the large masseter muscles. The paralysis of a major muscle of mastication lowers occlusal force and thus might affect tooth eruption. The purpose of this study was to investigate the effects of unilateral masseter muscle injection of botulinum neurotoxin type A on the rate of eruption of incisors in a rabbit model. We hypothesized that the teeth would overerupt in an underloaded environment. Methods Forty rabbits were injected with either botulinum neurotoxin type A or saline solution in 1 masseter muscle. Mastication and muscle force production were monitored, and incisor eruption rate was assessed by caliper measurement of grooved teeth. Results The injection of saline solution had no effect. The masseter muscle injected with botulinum neurotoxin type A showed a dramatic loss of force 3 weeks after injection despite apparently normal mastication. Incisor eruption rate was significantly decreased for the botulinum neurotoxin type A group, an effect attributed to decreased attrition. Conclusions This study has implications for orthodontics. Although findings from ever-growing rabbit incisors cannot be extrapolated to human teeth, it is clear that botulinum neurotoxin type A caused a decrease in bite force that could influence dental eruption. PMID:23561411

  16. Mandibular incisor alignment and dental arch changes 1 year after extraction of deciduous canines.

    Science.gov (United States)

    Sjögren, Anders; Arnrup, Kristina; Lennartsson, Bertil; Huggare, Jan

    2012-10-01

    This study investigated the early effects on mandibular incisor irregularity and rotation together with dental arch dimensions of the extraction of four deciduous canines. Children, during early mixed dentition, were randomized into one extraction (n = 32) and one control (n = 41) group. Dental casts from baseline (T0) and 1 year follow-up (T1) were used to evaluate changes in the irregularity index and in mandibular incisor rotation, dental arch dimensions, overjet, and overbite. Median mandibular incisor irregularity decreased over time, significantly more in the extraction than the control group (1.2 versus 0.7 mm; P extraction group (42 versus 20 per cent; P extraction group versus 34 per cent in the control group (P extraction group (1.3, 1.1 mm and 2.4, 2.0 mm, respectively; P extraction of the deciduous canines, small improvements in mandibular incisor alignment were seen, together with reduced arch dimensions. Little's index underestimated malalignment related to tooth rotation.

  17. ASSESSMENT OF ROOT RESORPTION DEGREE OF INCISORS AFTER ORTHODONTIC TREATMENT IN ADULTS

    Directory of Open Access Journals (Sweden)

    I. Luchian

    2012-03-01

    Full Text Available The main iatrogenic effects associated with orthodontic treatment refer to: influence of orthodontic rings on the periodontal tissue; gum retractions; the effect of the orthodontic treatment on dental root (root resorption; the effect of the orthodontic treatment on alveolar bone height; mobility and pain associated with orthodontic treatment. AIM of the study: To assess the degree of root resorption of incisors, after orthodontic treatment, on a group of 48 adults with dental-maxillary abnormalities. Materials and method: The study included 48 young adult patients, 35 women and 13 men aged 18 to 30 years, who had received fixed orthodontic treatment. To assess the degree of root resorption (changes at root level and apical contour length, apical radiographies were taken in the maxillary incisors and jaw both at the beginning and end of the orthodontic treatment. Results: Out of the 239 incisors examined at the beginning of orthodontic treatment, 163 showed code 0, meaning 88.1%, and 50 showed a slight squash apex (code 1, respectively 10.9%. Only 1% of all incisors assessed presented mild and severe root resorption. Conclusions: The results of the study show that, generally, an adult orthodontic treatment, applied for functional and aesthetic objectives, may have clinically acceptable iatrogenic effects.

  18. A study of the management of 55 traumatically intruded permanent incisor teeth in children.

    LENUS (Irish Health Repository)

    Stewart, C

    2009-01-01

    These were to examine the main presenting, treatment and outcome factors for intruded permanent incisors in children, the effect of apical development and degree of intrusion on decisions on repositioning, the effect of apical development status on the maintenance of pulp vitality and the time of pulp extirpation and to compare the decisions made to the advice given in existing clinical guidelines.

  19. Measurement of Incisor Overjet and Physiological Diastemata Parameters in Quarter Horse Foals.

    Science.gov (United States)

    Omura, Carla Michel; Drumond, Bianca; Rossi, João Luiz Júnior; Coelho, Clarisse Simões; Gioso, Marco Antônio

    2015-01-01

    Cephalometric studies are important to quantify abnormalities of jaw length and positioning. In this study, 4 to 7-month-old Quarter horse foals (n = 51) were examined to determine overjet (horizontal overlap) prevalence and measure the size of the physiological diastemata. Results were analyzed in relation to age, sex, and lineage. Another aim of this study was to develop a simple field technique for measuring incisor malocclusion and physiological diastemata dimensions that could be used to monitor the growth of the rostral components of maxilla, incisive bone, and mandible. The overall prevalence of overjet lesions in these foals was 51%. Females were overrepresented (61.5%). Overjet occurred more commonly in show foals (50% prevalence) than other working (7.7%) and race (42.3%) lineage foals. Significant differences were found between maxillary and mandibular physiological diastemata lengths in foals of all ages and, as expected, there was a positive statistical correlation between age and maxillary and mandibular physiological diastemata measurements. Incisor overjet was present in 44.4% of 4-month-old foals, 45.5% of 5-month-old foals, 58.3% of 6-month-old foals, and 60% of 7-month-old foals. There was a weak positive correlation between age and the presence of incisor overjet. It was concluded that incisor overiet was common among Quarter horse foals, especially those from show and race lineages. The field technique for physiological diastema measurements was considered effective.

  20. A Teething Problem: Artefactual X-Ray Appearances of Odontoid Fracture due to Superimposed Incisor

    Directory of Open Access Journals (Sweden)

    Matthew Crocker

    2012-01-01

    Full Text Available We report a case of artefactual C2 fracture caused by a superimposed incisor tooth in a seven-year-old boy. CT refuted the diagnosis. Trauma clinicians should be aware of this entity to guide correct interpretation of trauma X-rays.

  1. Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population

    NARCIS (Netherlands)

    Delli, Konstantina; Livas, Christos; Bornstein, Michael M

    2013-01-01

    OBJECTIVE: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. MATERIALS AND METHODS: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Arme

  2. An evolutionarily conserved enhancer regulates Bmp4 expression in developing incisor and limb bud.

    Directory of Open Access Journals (Sweden)

    Dolrudee Jumlongras

    Full Text Available To elucidate the transcriptional regulation of Bmp4 expression during organogenesis, we used phylogenetic footprinting and transgenic reporter analyses to identify Bmp4 cis-regulatory modules (CRMs. These analyses identified a regulatory region located ∼46 kb upstream of the mouse Bmp4 transcription start site that had previously been shown to direct expression in lateral plate mesoderm. We refined this regulatory region to a 396-bp minimal enhancer, and show that it recapitulates features of endogenous Bmp4 expression in developing mandibular arch ectoderm and incisor epithelium during the initiation-stage of tooth development. In addition, this enhancer directs expression in the apical ectodermal ridge (AER of the developing limb and in anterior and posterior limb mesenchyme. Transcript profiling of E11.5 mouse incisor dental lamina, together with protein binding microarray (PBM analyses, allowed identification of a conserved DNA binding motif in the Bmp4 enhancer for Pitx homeoproteins, which are also expressed in the developing mandibular and incisor epithelium. In vitro electrophoretic mobility shift assays (EMSA and in vivo transgenic reporter mutational analyses revealed that this site supports Pitx binding and that the site is necessary to recapitulate aspects of endogenous Bmp4 expression in developing craniofacial and limb tissues. Finally, Pitx2 chromatin immunoprecipitation (ChIP demonstrated direct binding of Pitx2 to this Bmp4 enhancer site in a dental epithelial cell line. These results establish a direct molecular regulatory link between Pitx family members and Bmp4 gene expression in developing incisor epithelium.

  3. The effect of fluoride on enamel and dentin formation in the uremic rat incisor

    NARCIS (Netherlands)

    Lyaruu, Donacian; Bronckers, Antonius; Santos, Fernando; Mathias, Robert; Besten, Pamela Den

    2008-01-01

    Renal impairment in children is associated with tooth defects that include enamel pitting and hypoplasia. However, the specific effects of uremia on tooth formation are not known. In this study, we used rat mandibular incisors, which continuously erupt and contain all stages of tooth formation, to c

  4. Gingival recessions and the change of inclination of mandibular incisors during orthodontic treatment

    NARCIS (Netherlands)

    Renkema, Anne Marie; Fudalej, Piotr S.; Renkema, Alianne; Bronkhorst, Ewald; Katsaros, Christos

    2013-01-01

    A recent systematic review demonstrated that, overall, orthodontic treatment might result in a small worsening of periodontal status. The aim of this retrospective study was to test the hypothesis that a change of mandibular incisor inclination promotes development of labial gingival recessions. One

  5. Comparison of the Fracture Resistance of 3 Different Posts in Restoring Extensively Damaged Primary Maxillary Incisors

    Directory of Open Access Journals (Sweden)

    F. Mojarad

    2013-10-01

    Full Text Available Introduction & Objective: The management of mutilated primary incisors in early childhood caries is a clinical challenge. This study's purpose was to compare the resistance strength of 3 different types of posts in restoring broken primary incisors: (1 composite posts, (2 ortho-dontic wire posts and (3 quartz fiber posts. Materials & Methods: This semi experimental in vitro study was performed on 27 extracted human primary maxillary incisors. The coronal portion of specimens was sectioned 1-mm above the cementoenamel junction. Complete pulpectomy was performed for all specimens. The post space was created using a straight fissure bur approximately 3 mm. Samples were randomly divided into 3 groups. Group 1(composite posts and composite core, group 2(quartz fiber posts and composite core and group 3 (orthodontic ? wire posts and composite core. Mounted specimens were subjected for fracture strength on an instron testing ma-chine at 45 angles. Results: Mean fracture strength value for group 1 was 248.9± 72.36 N, group 2 was 446.7±116.4 N and group 3 was 365.6± 31.3. This result showed significant differences among the three groups. Conclusion: Quartz fiber posts showed greater fracture strength for extensively damaged primary incisors than composite posts and orthodontic wire posts. (Sci J Hamadan Univ Med Sci 2013; 20 (3:240-246

  6. 安氏I类错(牙合)儿童上颌切牙唇腭侧齿槽厚度的CBCT研究%Maxillary incisors' dento-alveolar analysis of class I children using cone-beam CT

    Institute of Scientific and Technical Information of China (English)

    韩剑丽; 刘进; 葛元输; 彭兆伟

    2012-01-01

    Objective: The aim of this study was to evaluate the thickness of labial and palatal alveolar bone and labial bony curvature in maxillary anterior teeth of children using CBCT images. Method: Twenty-five patients (9 males,16 females),with mean age of 12.5 years were included in this study. Three-dimensional (3D) images were reformatted through CBCT. The incisor labio-palatal inclination,the thickness of labial and palatal alveolar bone,the labial bony curvature angle below root apex and the distance from root apex to the deepest point of labial bony curvature were measured using New Tom NNT programme. Paired t test was performed using SPSS 13.0 software package for Windows. Result: Mean thickness of labial plate 2 mm below CEJ was (0.96±0.32)mm at central incisor,(0.78±0.32)mm at lateral incisor. Mean thickness of palatal plate 2 mm below CEJ was (1.53±0.40)mm of central incisor,(1.12±0.48)mm of lateral incisor. Labio-palatal inclination was 114.59±5.25 of central incisor,111.75 ±5.98 of lateral incisor. Labial bony curvature angle was 145.70°± 11.09° and 156.92°±8.33°,respectively. Distance between root apex and the deepest point of labial bony curvature of central incisor was (2.88±1.49)mm,(2.69±0.99)mm of lateral incisor. Conclusion:The central incisor is more labial inclination than the lateral incisor. The thickness of maxillary anterior labial plate was very thin and the palatal plate was relatively thick. The maxillary incisor root apex was closer to the labial cortical bone than to the palatal cortical bone.%目的:采用CBCT影像测量安氏I类错(牙合)患儿上颌前牙唇倾度及前牙唇腭侧齿槽骨的厚度,探讨上颌切牙与其支持骨的空间位置关系.方法:选取深圳市儿童医院口腔正畸科2010.1~2012.1年间就诊的正畸患儿25名,年龄11~14岁,平均12.5岁,男9例,女16例.Angle I类轻度错(牙合)畸形.上前牙排列良好,无严重拥挤.所有病例均拍摄CBCT影像,在重建后的图像下

  7. SOTER-based soil parameter estimates for Central Africa - DR of Congo, Burundi and Rwanda (ver. 1.0)

    NARCIS (Netherlands)

    Batjes, N.H.

    2014-01-01

    This harmonized set of soil parameter estimates for Central Africa, comprising Burundi, the Democratic Republic of the Congo and Rwanda, was derived from the Soil and Terrain Database for Central Africa (SOTERCAF ver. 1.0) and the ISRIC-WISE soil profile database, using standardized taxonomy-based p

  8. Cluster-based centralized data fusion for tracking maneuvering targets using interacting multiple model algorithm

    Indian Academy of Sciences (India)

    V Vaidehi; K Kalavidya; S Indira Gandhi

    2004-04-01

    The interacting multiple model (IMM) algorithm has proved to be useful in tracking maneuvering targets. Tracking accuracy can be further improved using data fusion. Tracking of multiple targets using multiple sensors and fusing them at a central site using centralized architecture involves communication of large volumes of measurements to a common site. This results in heavy processing requirement at the central site. Moreover, track updates have to be obtained in the fusion centre before the next measurement arrives. For solving this computational complexity, a cluster-based parallel processing solution is presented in this paper. In this scheme, measurements are sent to the data fusion centre where the measurements are partitioned and given to the slave processors in the cluster. The slave processors use the IMM algorithm to get accurate updates of the tracks. The master processor collects the updated tracks and performs data fusion using ‘weight decision approach’. The improvement in the computation time using clusters in the data fusion centre is presented in this paper.

  9. High-order central Hermite WENO schemes: Dimension-by-dimension moment-based reconstructions

    Science.gov (United States)

    Tao, Zhanjing; Li, Fengyan; Qiu, Jianxian

    2016-08-01

    In this paper, a class of high-order central finite volume schemes is proposed for solving one- and two-dimensional hyperbolic conservation laws. Formulated on staggered meshes, the methods involve Hermite WENO (HWENO) spatial reconstructions, and Lax-Wendroff type discretizations or the natural continuous extension of Runge-Kutta methods in time. Differently from the central Hermite WENO methods we developed previously in Tao et al. (2015) [34], the spatial reconstructions, a core ingredient of the methods, are based on the zeroth-order and the first-order moments of the solution, and are implemented through a dimension-by-dimension strategy when the spatial dimension is higher than one. This leads to much simpler implementation of the methods in higher dimension and better cost efficiency. Meanwhile, the proposed methods have the attractive features of the general central Hermite WENO methods such as being compact in reconstruction and requiring neither flux splitting nor numerical fluxes, while being accurate and essentially non-oscillatory. A collection of one- and two-dimensional numerical examples is presented to demonstrate high resolution and robustness of the methods in capturing smooth and non-smooth solutions.

  10. Electric protections based in microprocessors in power plants; Protecciones electricas basadas en microprocesadores en centrales generadoras

    Energy Technology Data Exchange (ETDEWEB)

    Libreros, Domitilo; Castanon Jimenez, Jose Ismael [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    This article is centered around the substitution of the conventional electric protections of a power plant in connection type unit for protections based in microprocessors. A general model of conventional protection of a power plant is described and the number of analogic and digital signals that intervene in that model are quantified. A model is setup for power plant protection with microprocessors, analyzing each one of the modules that would form it. Finally, the algorithms to carry on such protection are presented. [Espanol] Este articulo se centra en torno a la sustitucion de las protecciones electricas convencionales de una central generadora en conexion tipo unidad por protecciones basadas en microprocesadores. Se describe el modelo general de proteccion convencional de una central generadora y se cuantifica el numero de senales analogicas y digitales que interviene en dicho modelo. Se propone un modelo para proteccion de centrales generadoras mediante microprocesadores, analizandose cada uno de los modulos que lo conformarian. Finalmente, se presentan los algoritmos para realizar dicha proteccion.

  11. Palaeocology of coal-bearing Eocene sediments in central Anatolia (Turkey) based on quantitative palynological data

    Energy Technology Data Exchange (ETDEWEB)

    Akkiraz, M.S.; Kayseri, M.S.; Akgun, F. [Dokuz Eylul University, Izmir (Turkey). Dept. of Geological Engineering

    2008-04-15

    In this study, the lignite-bearing Yoncali formation between Yozgat and Sorgun, in central Anatolia has been palynologically examined. Based on 37 outcrop samples, quantitative palynological studies recognized 64 genera and 136 palynoflora species in the palynological assemblage, which indicated a Middle-Late Eocene age. This paper also presents a quantitative palaeovegetation and palaeoclimate reconstruction for the Middle-Upper Eocene coal occurrences of Central Anatolia on the basis of palynomorph assemblages. The diversified floral and ecological characteristics of the pollen taxa indicates that the Middle-Upper Eocene formations in central Anatolia were characterized by the presence of a complex mangrove swamp with contributions by Nypa, Pelliciera, Avicennia, Diporites tszkaszentgydrgyi and dinoflagellate cysts which reflect warm climatic conditions. Lowland-riparian and montane elements are characterized by the dominance of Myricaceae, Symplocaceae, Icacinaceae, Quercus, Pinus and Castanea. Swamp-freshwater elements are represented by Sparganjaceae, Nymphaceae, Taxodjaceae, Cupressaceae and Nyssa as well as fern spores such as Osmundaceae and Gleicheniaceae. The calculations were performed with the help of the 'Coexistence Approach' method to climatically evaluate palynoflora from the Yozgat-Sorgun area. The obtained results have been compared to data derived from the application of the Coexistence Approach to other, already published Central Anatolian palynofloras of the same age. The results of the climatic inferences suggest that the palaeoclimatic conditions were in the megathermal zone, megatherm/mesotherm intermediate zone whereas mesothermic conditions prevailed in the montane region. Likewise, the results of mean annual range of temperatures indicate the influence of the Indian ocean, which enabled the development of the mangroves.

  12. Chemical and structural composition of Atlantic Canadian moose (Alces alces) incisors with patterns of high breakage.

    Science.gov (United States)

    MacKenzie, Cynthia S Kendall; Clough, Michael J; Broders, Hugh G; Tubrett, Mike

    2011-11-15

    Analysis of mammalian teeth can provide information regarding local environmental conditions. For example, a high incidence of breakage and wear within a population may indicate poor food quality. Individuals consuming a diet causing high mechanical stress on their teeth, and/or lacking the appropriate minerals for proper development, could experience degradation of tooth condition. Previously, we documented a high rate of incisor tooth breakage, with age, in two genetically distinct moose populations in Atlantic Canada. In this study, multi-element (11B, 63Cu, 64Zn, 75As, 85Rb, 88Sr, 111Cd, 118Sn, 137Ba, 208Pb, 232Th, and 238U) analyses using laser ablation ICP-MS were performed on moose incisors from multiple North American regions. The purpose was to determine whether the elemental composition of moose incisors varies among regions, and whether that variation is related to tooth degradation among Atlantic Canadian populations. A principal components analysis revealed that nearly 50% of the elemental variation in the inner enamel matrix of moose teeth was explained by three groupings of elements. The element groupings revealed differences among geographic regions, but did not explain the variation between incisors that were broken and those that were not. Regression models indicate that the elemental group which includes Cu, Pb, and Zn is related to decreases in incisal integrity. It is likely that other environmental factors contribute to the occurrence of increased incisor breakage in affected populations. The relationship between food resource quantity and quality, as a function of moose density, is hypothesized to explain loss of tooth integrity.

  13. One Odontogenic Cell-Population Contributes to the Development of the Mouse Incisors and of the Oral Vestibule

    Science.gov (United States)

    Hovorakova, Maria; Lochovska, Katerina; Zahradnicek, Oldrich; Domonkosova Tibenska, Kristina; Dornhoferova, Michaela; Horakova-Smrckova, Lucie; Bodorikova, Silvia

    2016-01-01

    The area of the oral vestibule is often a place where pathologies appear (e.g., peripheral odontomas). The origin of these pathologies is not fully understood. In the present study, we traced a cell population expressing Sonic hedgehog (Shh) from the beginning of tooth development using Cre-LoxP system in the lower jaw of wild-type (WT) mice. We focused on Shh expression in the area of the early appearing rudimentary incisor germs located anteriorly to the prospective incisors. The localization of the labelled cells in the incisor germs and also in the inner epithelial layer of the vestibular anlage showed that the first very early developmental events in the lower incisor area are common to the vestibulum oris and the prospective incisor primordia in mice. Scanning electron microscopic analysis of human historical tooth-like structures found in the vestibular area of jaws confirmed their relation to teeth and thus the capability of the vestibular tissue to form teeth. The location of labelled cells descendant of the early appearing Shh expression domain related to the rudimentary incisor anlage not only in the rudimentary and functional incisor germs but also in the externally located anlage of the oral vestibule documented the odontogenic potential of the vestibular epithelium. This potential can be awakened under pathological conditions and become a source of pathologies in the vestibular area. PMID:27611193

  14. Light and electron microscopic analysis of the somata and parent axons innervating the rat upper molar and lower incisor pulp.

    Science.gov (United States)

    Paik, S K; Park, K P; Lee, S K; Ma, S K; Cho, Y S; Kim, Y K; Rhyu, I J; Ahn, D K; Yoshida, A; Bae, Y C

    2009-09-15

    The morphology of intradental nerve fibers of permanent teeth and of continuously growing rodent incisors has been studied in detail but little information is available on the parent axons that give rise to these fibers. Here we examined the axons and somata of trigeminal neurons that innervate the rat upper molar and lower incisor pulp using tracing with horseradish peroxidase and light and electron microscopic analysis. The majority (approximately 80%) of the parent axons in the proximal root of the trigeminal ganglion that innervated either molar or incisor pulp were small myelinated fibers (fibers were almost exclusively large myelinated for the molar pulp and unmyelinated for the incisor pulp. The majority of neuronal somata in the trigeminal ganglion that innervated either molar (48%) or incisor pulp (62%) were medium in size (300-600 microm(2) cross-sectional area). Large somata (>600 microm(2)) constituted 34% and 20% of the trigeminal neurons innervating molar and incisor pulp, respectively, while small somata (fiber function may be carried out differently in the molar and incisor pulp in the rat.

  15. IMPLEMENTATION OF CENTRAL QUEUE BASED REALTIME SCHEDULER FOR MULTIPLE SOURCE DATA STREAMING

    Directory of Open Access Journals (Sweden)

    V. Kaviha

    2014-01-01

    Full Text Available Real-time data packet sources are required to remain robust against different security threats. This study proposes a real-time secure scheduling strategy for data transmission to enhance the communication throughput and reduce the overheads. The proposed system combines real-time scheduling with security service enhancement, error detection and realtime scheduler based on EDF algorithm using uc/os-II real time operating system, implemented on cortex M3 processor. The scheduling unit uses central queue management model and the security enhancement scheme adopts a blowfish encryption mechanism.

  16. Central FPGA-based destination and load control in the LHCb MHz event readout

    Science.gov (United States)

    Jacobsson, R.

    2012-10-01

    The readout strategy of the LHCb experiment is based on complete event readout at 1 MHz. A set of 320 sub-detector readout boards transmit event fragments at total rate of 24.6 MHz at a bandwidth usage of up to 70 GB/s over a commercial switching network based on Gigabit Ethernet to a distributed event building and high-level trigger processing farm with 1470 individual multi-core computer nodes. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. An FPGA-based central master module, partly operating at the LHC bunch clock frequency of 40.08 MHz and partly at a double clock speed, is in charge of the entire trigger and readout control from the front-end electronics up to the high-level trigger farm. One FPGA is dedicated to controlling the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load control and trigger rate regulation as a function of the global farm load. It also allows the vital task of fast central monitoring and automatic recovery in-flight of failing nodes while maintaining dead-time and event loss at a minimum. This paper demonstrates the strength and suitability of implementing this real-time task for a very large distributed system in an FPGA where no random delays are introduced, and where extreme reliability and accurate event accounting are fundamental requirements. It was in use during the entire commissioning phase of LHCb and has been in faultless operation during the first two years of physics luminosity data taking.

  17. Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.

    Science.gov (United States)

    Love, R M

    1996-12-01

    One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The

  18. A comparison of a centralized versus de-centralized recruitment schema in two community-based participatory research studies for cancer prevention.

    Science.gov (United States)

    Adams, Swann Arp; Heiney, Sue P; Brandt, Heather M; Wirth, Michael D; Khan, Samira; Johnson, Hiluv; Davis, Lisa; Wineglass, Cassandra M; Warren-Jones, Tatiana Y; Felder, Tisha M; Drayton, Ruby F; Davis, Briana; Farr, Deeonna E; Hébert, James R

    2015-04-01

    Use of community-based participatory research (CBPR) approaches is increasing with the goal of making more meaningful and impactful advances in eliminating cancer-related health disparities. While many reports have espoused its advantages, few investigations have focused on comparing CBPR-oriented recruitment and retention. Consequently, the purpose of this analysis was to report and compare two different CBPR approaches in two cancer prevention studies. We utilized frequencies and Chi-squared tests to compare and contrast subject recruitment and retention for two studies that incorporated a randomized, controlled intervention design of a dietary and physical activity intervention among African Americans (AA). One study utilized a de-centralized approach to recruitment in which primary responsibility for recruitment was assigned to the general AA community of various church partners whereas the other incorporated a centralized approach to recruitment in which a single lay community individual was hired as research personnel to lead recruitment and intervention delivery. Both studies performed equally well for both recruitment and retention (75 and 88 % recruitment rates and 71 and 66 % retention rates) far exceeding those rates traditionally cited for cancer clinical trials (~5 %). The de-centralized approach to retention appeared to result in statistically greater retention for the control participants compared to the centralized approach (77 vs. 51 %, p < 0.01). Consequently, both CBPR approaches appeared to greatly enhance recruitment and retention rates of AA populations. We further note lessons learned and challenges to consider for future research opportunities.

  19. An application-layer based centralized information access control for VPN

    Institute of Scientific and Technical Information of China (English)

    OUYANG Kai; ZHOU Jing-li; XIA Tao; YU Sheng-sheng

    2006-01-01

    With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the internal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that ifone vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem.To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC-the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC's constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper.

  20. A PEG Construction of LDPC Codes Based on the Betweenness Centrality Metric

    Directory of Open Access Journals (Sweden)

    BHURTAH-SEEWOOSUNGKUR, I.

    2016-05-01

    Full Text Available Progressive Edge Growth (PEG constructions are usually based on optimizing the distance metric by using various methods. In this work however, the distance metric is replaced by a different one, namely the betweenness centrality metric, which was shown to enhance routing performance in wireless mesh networks. A new type of PEG construction for Low-Density Parity-Check (LDPC codes is introduced based on the betweenness centrality metric borrowed from social networks terminology given that the bipartite graph describing the LDPC is analogous to a network of nodes. The algorithm is very efficient in filling edges on the bipartite graph by adding its connections in an edge-by-edge manner. The smallest graph size the new code could construct surpasses those obtained from a modified PEG algorithm - the RandPEG algorithm. To the best of the authors' knowledge, this paper produces the best regular LDPC column-weight two graphs. In addition, the technique proves to be competitive in terms of error-correcting performance. When compared to MacKay, PEG and other recent modified-PEG codes, the algorithm gives better performance over high SNR due to its particular edge and local graph properties.

  1. A Centralized Energy Efficient Distance Based Routing Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Rohit D. Gawade

    2016-01-01

    Full Text Available Wireless sensor network (WSN typically consists of a large number of low cost wireless sensor nodes which collect and send various messages to a base station (BS. WSN nodes are small battery powered devices having limited energy resources. Replacement of such energy resources is not easy for thousands of nodes as they are inaccessible to users after their deployment. This generates a requirement of energy efficient routing protocol for increasing network lifetime while minimizing energy consumption. Low Energy Adaptive Clustering Hierarchy (LEACH is a widely used classic clustering algorithm in WSNs. In this paper, we propose a Centralized Energy Efficient Distance (CEED based routing protocol to evenly distribute energy dissipation among all sensor nodes. We calculate optimum number of cluster heads based on LEACH’s energy dissipation model. We propose a distributed cluster head selection algorithm based on dissipated energy of a node and its distance to BS. Moreover, we extend our protocol by multihop routing scheme to reduce energy dissipated by nodes located far away from base station. The performance of CEED is compared with other protocols such as LEACH and LEACH with Distance Based Thresholds (LEACH-DT. Simulation results show that CEED is more energy efficient as compared to other protocols. Also it improves the network lifetime and stability period over the other protocols.

  2. NPP-VIIRS DNB-based reallocating subpopulations to mercury in Urumqi city cluster, central Asia

    Science.gov (United States)

    Zhou, X.; Feng, X. B.; Dai, W.; Li, P.; Ju, C. Y.; Bao, Z. D.; Han, Y. L.

    2017-02-01

    Accurate and update assignment of population-related environmental matters onto fine grid cells in oasis cities of arid areas remains challenging. We present the approach based on Suomi National Polar-orbiting Partnership (S-NPP) -Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) to reallocate population onto a regular finer surface. The number of potential population to the mercury were reallocated onto 0.1x0.1 km reference grid in Urumqi city cluster of China’s Xinjiang, central Asia. The result of Monte Carlo modelling indicated that the range of 0.5 to 2.4 million people was reliable. The study highlights that the NPP-VIIRS DNB-based multi-layered, dasymetric, spatial method enhances our abilities to remotely estimate the distribution and size of target population at the street-level scale and has the potential to transform control strategies for epidemiology, public policy and other socioeconomic fields.

  3. Accurate stress analysis on rigid central buckle of Ions-span suspension bridges based on submodel method

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; LI AiQun; GUO Tong; MA Shuang

    2009-01-01

    Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is introduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the accurate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working behavior and mechanical characteristics of the central buckle of the RSB under vehicle loads were analyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.

  4. Accurate stress analysis on rigid central buckle of long-span suspension bridges based on submodel method

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is in- troduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the ac- curate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working be- havior and mechanical characteristics of the central buckle of the RSB under vehicle loads were ana- lyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.

  5. Mobile devices for community-based REDD+ monitoring: a case study for Central Vietnam.

    Science.gov (United States)

    Pratihast, Arun Kumar; Herold, Martin; Avitabile, Valerio; de Bruin, Sytze; Bartholomeus, Harm; Souza, Carlos M; Ribbe, Lars

    2012-12-20

    Monitoring tropical deforestation and forest degradation is one of the central elements for the Reduced Emissions from Deforestation and Forest Degradation in developing countries (REDD+) scheme. Current arrangements for monitoring are based on remote sensing and field measurements. Since monitoring is the periodic process of assessing forest stands properties with respect to reference data, adopting the current REDD+ requirements for implementing monitoring at national levels is a challenging task. Recently, the advancement in Information and Communications Technologies (ICT) and mobile devices has enabled local communities to monitor their forest in a basic resource setting such as no or slow internet connection link, limited power supply, etc. Despite the potential, the use of mobile device system for community based monitoring (CBM) is still exceptional and faces implementation challenges. This paper presents an integrated data collection system based on mobile devices that streamlines the community-based forest monitoring data collection, transmission and visualization process. This paper also assesses the accuracy and reliability of CBM data and proposes a way to fit them into national REDD+ Monitoring, Reporting and Verification (MRV) scheme. The system performance is evaluated at Tra Bui commune, Quang Nam province, Central Vietnam, where forest carbon and change activities were tracked. The results show that the local community is able to provide data with accuracy comparable to expert measurements (index of agreement greater than 0.88), but against lower costs. Furthermore, the results confirm that communities are more effective to monitor small scale forest degradation due to subsistence fuel wood collection and selective logging, than high resolution remote sensing SPOT imagery.

  6. Central FPGA-based Destination and Load Control in the LHCb MHz Event Readout

    CERN Document Server

    Jacobsson, Richard

    2012-01-01

    The readout strategy of the LHCb experiment [1] is based on complete event readout at 1 MHz [2]. Over 300 sub-detector readout boards transmit event fragments at 1 MHz over a commercial 70 Gigabyte/s switching network to a distributed event building and trigger processing farm with 1470 individual multi-core computer nodes [3]. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a powerful non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. A high-speed FPGA-based central master module controls the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load balancing and trigger rate regulation as a function of the global farm load. It also ...

  7. Essentiality of early diagnosis of molar incisor hypomineralization in children and review of its clinical presentation, etiology and management.

    Science.gov (United States)

    Garg, Nishita; Jain, Abhay Kumar; Saha, Sonali; Singh, Jaspal

    2012-09-01

    Molar incisor hypomineralization (MIH) is a common developmental condition resulting in enamel defects in first permanent molars and permanent incisors. It presents at eruption of these teeth. One to four molars, and often also the incisors, could be affected. Since first recognized, the condition has been puzzling and interpreted as a distinct phenomenon unlike other enamel disturbances. Early diagnosis is essential since, rapid breakdown of tooth structure may occur, giving rise to acute symptoms and complicated treatment. The purpose of this article is to review MIH and illustrate its diagnosis and clinical management in young children. How to cite this article: Garg N, Jain AK, Saha S, Singh J. Essentiality of Early Diagnosis of Molar Incisor Hypomineralization in Children and Review of its Clinical Presentation, Etiology and Management. Int J Clin Pediatr Dent 2012;5(3):190-196.

  8. Branch-based centralized data collection for smart grids using wireless sensor networks.

    Science.gov (United States)

    Kim, Kwangsoo; Jin, Seong-il

    2015-05-21

    A smart grid is one of the most important applications in smart cities. In a smart grid, a smart meter acts as a sensor node in a sensor network, and a central device collects power usage from every smart meter. This paper focuses on a centralized data collection problem of how to collect every power usage from every meter without collisions in an environment in which the time synchronization among smart meters is not guaranteed. To solve the problem, we divide a tree that a sensor network constructs into several branches. A conflict-free query schedule is generated based on the branches. Each power usage is collected according to the schedule. The proposed method has important features: shortening query processing time and avoiding collisions between a query and query responses. We evaluate this method using the ns-2 simulator. The experimental results show that this method can achieve both collision avoidance and fast query processing at the same time. The success rate of data collection at a sink node executing this method is 100%. Its running time is about 35 percent faster than that of the round-robin method, and its memory size is reduced to about 10% of that of the depth-first search method.

  9. Quantitative study on pollen-based reconstructions of vegetation history from central Canada

    Institute of Scientific and Technical Information of China (English)

    YU Ge; HART Catherina; VETTER Mary; SAUCHYN David

    2008-01-01

    Based on high-resolution pollen records from lake cores in central Canada, the present study instructed pollen taxa assignations in ecosystem groups and modern analogue technique, reported major results of quantitative reconstructions of vegetation history during the last 1000 years, and discussed the validation of simulated vegetation. The results showed that in central America (115°-95°W,40°-60°N), best analogue of the modern vegetation is 81% for boreal forest, 72% for parkland, and 94% for grassland-parkland, which are consistent with vegetation distributions of the North American Ecosystem Ⅱ. Simulations of the past vegetation from the sedimentary pollen showed climate changes during the past 1000 years: it was warm and dry in the Medieval Warm period, cold and wet in the earlier period and cold and dry in the later period of the Little Ice Age. It became obviously increasing warm and drought in the 20th century. The present studies would provide us scientific basis to understand vegetation and climate changes during the last 1000 years in a characteristic region and in 10-100 year time scales.

  10. Branch-Based Centralized Data Collection for Smart Grids Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Kwangsoo Kim

    2015-05-01

    Full Text Available A smart grid is one of the most important applications in smart cities. In a smart grid, a smart meter acts as a sensor node in a sensor network, and a central device collects power usage from every smart meter. This paper focuses on a centralized data collection problem of how to collect every power usage from every meter without collisions in an environment in which the time synchronization among smart meters is not guaranteed. To solve the problem, we divide a tree that a sensor network constructs into several branches. A conflict-free query schedule is generated based on the branches. Each power usage is collected according to the schedule. The proposed method has important features: shortening query processing time and avoiding collisions between a query and query responses. We evaluate this method using the ns-2 simulator. The experimental results show that this method can achieve both collision avoidance and fast query processing at the same time. The success rate of data collection at a sink node executing this method is 100%. Its running time is about 35 percent faster than that of the round-robin method, and its memory size is reduced to about 10% of that of the depth-first search method.

  11. Quantitative study on pollen-based reconstructions of vegetation history from central Canada

    Institute of Scientific and Technical Information of China (English)

    HART; Catherina; VETTER; Mary; SAUCHYN; David

    2008-01-01

    Based on high-resolution pollen records from lake cores in central Canada, the present study instructed pollen taxa assignations in ecosystem groups and modern analogue technique, reported major results of quantitative reconstructions of vegetation history during the last 1000 years, and discussed the validation of simulated vegetation. The results showed that in central America (115°-95°W, 40°-60°N), best analogue of the modern vegetation is 81% for boreal forest, 72% for parkland, and 94% for grassland-parkland, which are consistent with vegetation distributions of the North American Ecosystem II. Simulations of the past vegetation from the sedimentary pollen showed climate changes during the past 1000 years: it was warm and dry in the Medieval Warm period, cold and wet in the earlier period and cold and dry in the later period of the Little Ice Age. It became obviously increasing warm and drought in the 20th century. The present studies would provide us scientific basis to understand vegetation and climate changes during the last 1000 years in a characteristic region and in 10-100 year time scales.

  12. 拔除上颌中切牙的正畸治疗分析%Orthodontic treatment with maxillary incisor extraction

    Institute of Scientific and Technical Information of China (English)

    韦溅萍; 马佳君

    2015-01-01

    目的:探讨拔除上颌中切牙进行矫治的疗效和治疗特点。方法:选择拔除上颌中切牙进行矫治的患者9例,男4例、女5例,开始治疗年龄平均17.2岁。拔除双侧上颌中切牙和下颌2颗第一前磨牙者5例;拔除单侧上颌中切牙及对侧第一前磨牙和下颌2颗第一前磨牙者4例。进行治疗前后 Bolton 指数、X 线头影测量和临床疗效分析。结果:所有患者均取得了良好的疗效。治疗前预测 Bolton 指数前牙比和全牙比分别为80.14%和91.31%;治疗后分别为78.68%和90.28%。X 线头影测量分析治疗前后 U1-NA(mm)、U1-NA、L1-NB(mm)、L1-NB、U1-SN、L1-MP、UL-E、LL-E 的值减小(P <0.05)。结论:根据 Bo-lton 指数分析,进行个体化设计,拔除双侧上颌中切牙或单侧上颌中切牙及对侧第一前磨牙和下颌2颗第一前磨牙进行正畸治疗,可以获得良好的疗效。%Objective:To evaluate the effectiveness and treatment feature of maxillary incisor extraction in orthodontics.Methods:9 patients underwent orthodontic treatment with maxillary incisor extraction,5 female and 4 male,with an average age of 1 7.2 years at the start,were included.5 patients were treated by extraction of both upper incisors and lower first premolars,4 by extraction of the abnor-mal incisor and the first premolars in the other three quadrants.Cephalometric and Bolton index analysis were carried out.Results:Sat-isfactory treatment results were observed in all patients.Before treatment the predicted Bolton index of the patients of the anterior ratio and the overall ratio were 80.1 4% and 91 .3%,after orthodontic treatment 78.68% and 90.28%,respectively.Cephalometric analysis showed that U1 -NA(mm),U1 -NA,L1 -NB(mm),L1 -NB,U1 -SN,L1 -MP,UL-E and LL-E were decreased(P <0.05).Conclu-sion:Individual treatment plan based on Bolton index analysis and the corresponding techniques and methods,the patients with abnor

  13. Efficient crop type mapping based on remote sensing in the Central Valley, California

    Science.gov (United States)

    Zhong, Liheng

    Most agricultural systems in California's Central Valley are purposely flexible and intentionally designed to meet the demands of dynamic markets. Agricultural land use is also impacted by climate change and urban development. As a result, crops change annually and semiannually, which makes estimating agricultural water use difficult, especially given the existing method by which agricultural land use is identified and mapped. A minor portion of agricultural land is surveyed annually for land-use type, and every 5 to 8 years the entire valley is completely evaluated. So far no effort has been made to effectively and efficiently identify specific crop types on an annual basis in this area. The potential of satellite imagery to map agricultural land cover and estimate water usage in the Central Valley is explored. Efforts are made to minimize the cost and reduce the time of production during the mapping process. The land use change analysis shows that a remote sensing based mapping method is the only means to map the frequent change of major crop types. The traditional maximum likelihood classification approach is first utilized to map crop types to test the classification capacity of existing algorithms. High accuracy is achieved with sufficient ground truth data for training, and crop maps of moderate quality can be timely produced to facilitate a near-real-time water use estimate. However, the large set of ground truth data required by this method results in high costs in data collection. It is difficult to reduce the cost because a trained classification algorithm is not transferable between different years or different regions. A phenology based classification (PBC) approach is developed which extracts phenological metrics from annual vegetation index profiles and identifies crop types based on these metrics using decision trees. According to the comparison with traditional maximum likelihood classification, this phenology-based approach shows great advantages

  14. External apical root resorption in maxillary root-filled incisors after orthodontic treatment: A split-mouth design study

    OpenAIRE

    2011-01-01

    Introduction: The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps. Methodology: The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken befor...

  15. LexRank: Graph-based Lexical Centrality as Salience in Text Summarization

    CERN Document Server

    Erkan, G; 10.1613/jair.1523

    2011-01-01

    We introduce a stochastic graph-based method for computing relative importance of textual units for Natural Language Processing. We test the technique on the problem of Text Summarization (TS). Extractive TS relies on the concept of sentence salience to identify the most important sentences in a document or set of documents. Salience is typically defined in terms of the presence of particular important words or in terms of similarity to a centroid pseudo-sentence. We consider a new approach, LexRank, for computing sentence importance based on the concept of eigenvector centrality in a graph representation of sentences. In this model, a connectivity matrix based on intra-sentence cosine similarity is used as the adjacency matrix of the graph representation of sentences. Our system, based on LexRank ranked in first place in more than one task in the recent DUC 2004 evaluation. In this paper we present a detailed analysis of our approach and apply it to a larger data set including data from earlier DUC evaluatio...

  16. Distortion-Invariant Binary Image Recognition Based on Central Projection Correlation

    Institute of Scientific and Technical Information of China (English)

    WU Yaming; XIAO Yanping; SUN Fanghong; FANG Nian

    2001-01-01

    A method of central projection correlation which is invariant to distortion of shift, scale and rotation of the binary target image is proposed. A 2-D binary image is transformed into an 1-D central projection referring to the centroid of the binary image. The distortion-invariant central projection correlation is successfully performed by computer simulations and its optical implementation is presented.

  17. Treatment of severe inflammatory root resorption in a young permanent incisor with mineral trioxide aggregate.

    Science.gov (United States)

    Guzeler, Irem; Uysal, Serdar; Cehreli, Zafer C

    2011-01-01

    Inflammatory root resorption is a pathologic condition caused by several etiologic factors including traumatic dental injury. In this case report, we describe treatment of a maxillary lateral incisor affected by severe, perforating inflammatory root resorption. An 11-year-old patient presented with a previously traumatized, root-filled maxillary lateral incisor associated with pain, mobility and a sinus tract. Radiographic examination revealed a large periradicular lesion involving pathologic resorption of the apical region of the root. After removal of the root canal filling, the tooth was treated with intracanal calcium hydroxide for 2 weeks. The calcium hydroxide dressing was then removed and the entire root canal was filled with mineral trioxide aggregate. The endodontic access cavity was restored with composite resin. After 1 year, advanced osseous healing of the periradicular region had occurred and no clinical symptoms were apparent.

  18. Unilateral Fusion of Maxillary Lateral Incisor: Diagnosis Using Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Iury Oliveira Castro

    2014-01-01

    Full Text Available Objective. The objective of this paper is to report a dental fusion case focusing on clinical and radiographic features for the diagnosis. Method. To report a case of right maxillary lateral incisor fusion and a supernumerary tooth, the anatomy of the root canal and dental united portion were assessed by cone beam computed tomography (CBCT. Results. The clinical examination showed dental juxtaposition with the absence of interdental papilla and esthetic impairment in the right maxillary lateral incisor region. The periapical radiography did not provide enough information for the differential diagnosis due to the inherent limitations of this technique. CBCT confirmed the presence of tooth fusion. Conclusion. CBCT examination supports the diagnosis and provides both the identification of changes in tooth development and the visualization of their extent and limits.

  19. Organic and inorganic content of fluorotic rat incisors measured by FTIR spectroscopy

    Science.gov (United States)

    Porto, Isabel Maria; Saiani, Regina Aparecida; Chan, K. L. Andrew; Kazarian, Sergei G.; Gerlach, Raquel Fernanda; Bachmann, Luciano

    2010-09-01

    Details on how fluoride interferes in enamel mineralization are still controversial. Therefore, this study aimed at analyzing the organic contents of fluorosis-affected teeth using Fourier Transformation Infrared spectroscopy. To this end, 10 male Wistar rats were divided into two groups: one received 45 ppm fluoride in distilled water for 60 days; the other received distilled water only. Then, the lower incisors were removed and prepared for analysis by two FTIR techniques namely, transmission and micro-ATR. For the first technique, the enamel was powdered, whereas in the second case one fluorotic incisor was cut longitudinally for micro-ATR. Using transmission and powdered samples, FTIR showed a higher C-H content in the fluorotic enamel compared with control enamel ( p amelogenesis. Further studies along this line may definitely answer some questions regarding protein content in fluorotic enamel as well as their origin.

  20. Molar incisor hypomineralization: considerations about treatment in a controlled longitudinal case.

    Science.gov (United States)

    de Oliveira, Daniela Cristina; Favretto, Carla Oliveira; Cunha, Robson Frederico

    2015-01-01

    Molar incisor hypomineralization (MIH) is a defect in the tooth enamel of systemic origin and may affect one or all four first permanent molars frequently associated with the permanent incisors. This case reports a 7-year-old child with severe MIH in the permanent molars associated with tooth decay and intense pain. In the first stage of treatment, therapy was performed with fluoride varnish and restoration with glass ionomer cement (GIC). After 6 years of clinical and radiographic follow-up, the restorations presented wear and fractures on the margins, indicating their replacement with composite resin. Severe cases of MIH in the early permanent molars can be treated with varnish and GIC to restore the patient's comfort and strengthen the hypomineralized dental structures. The clinical and radiographic monitoring frequently indicated when the restoration with composite resin should be performed.

  1. Molar incisor hypomineralization: Considerations about treatment in a controlled longitudinal case

    Directory of Open Access Journals (Sweden)

    Daniela Cristina de Oliveira

    2015-01-01

    Full Text Available Molar incisor hypomineralization (MIH is a defect in the tooth enamel of systemic origin and may affect one or all four first permanent molars frequently associated with the permanent incisors. This case reports a 7-year-old child with severe MIH in the permanent molars associated with tooth decay and intense pain. In the first stage of treatment, therapy was performed with fluoride varnish and restoration with glass ionomer cement (GIC. After 6 years of clinical and radiographic follow-up, the restorations presented wear and fractures on the margins, indicating their replacement with composite resin. Severe cases of MIH in the early permanent molars can be treated with varnish and GIC to restore the patient′s comfort and strengthen the hypomineralized dental structures. The clinical and radiographic monitoring frequently indicated when the restoration with composite resin should be performed.

  2. Phylogenetic analysis of Persian Gazella, Gazella subgutturosa (Artiodactyla: Bovidae based on cytochrome b in central Iran

    Directory of Open Access Journals (Sweden)

    Davoud Fadakar

    2013-12-01

    Full Text Available Persian gazelle, Gazella subgutturosa, exists throughout arid and semiarid regions of Iran and has a key role in these frail ecosystems. Habitat degradation and population decline has placed it on the list of vulnerable species in 2008. The phylogenetic relationships of three Persian gazelle populations in the central part of Iran (i.e. Ghamishlou National Park and Wildlife Refuge, Mouteh Wildlife Refuge in Isfahan province and Kalmand-Bahadoran Protected Area in Yazd province were investigated using parts and short fragments of mitochondrial cytochrome b gene (425 base pairs. A maximum likelihood phylogenetic tree separated the populations of Yazd and Isfahan provinces, but populations within the Isfahan province shared the same clade. All populations were classified as Persian gazelle. The studied populations are facing threats because of road construction, industrial development and urbanization. Accordingly urgent conservation plans are needed to preserve their genetic diversity and prevent them from falling into extinction.

  3. Mathematical Modeling of a developed Central Receiver Based on Evacuated Solar Tubes

    Directory of Open Access Journals (Sweden)

    Ali Basil. H.

    2016-01-01

    Full Text Available Solar central receiver plays a considerable role in the plant output power; it is one of the most important synthesis in the solar power tower plants. Its performance directly affects the efficiency of the entire solar power generation system. In this study, a new designed receiver model based on evacuated solar tube was proposed, and the dynamic characteristics of the developed receiver were investigated. In order to optimise and evaluate the dynamic characteristics of solar power plant components, the model investigates the solar radiation heat conversion process through the developed receiver, where the energy and mass conservation equations are used to determine the working fluid temperature and state through the receiver parts, beside the calculation and analysis of the thermal losses.

  4. Village-based primary health care in the Central Highlands of Vietnam.

    Science.gov (United States)

    Barrett, B; Ladinsky, J; Volk, N

    2001-02-01

    This paper describes the first year of an ongoing village health care and economic development project in the Krong Buk district of Dak Lak province in Vietnam's Central Highlands. The project serves 21 villages with a total population of just over 15,000. Most belong to ethnic minority groups. Physicians from the province capital of Boun Me Thuot were trained by a multi-disciplinary team of American health care workers to be trainers and supervisors of 21 village health care workers (VHWs). Two months later, a VHW from each village was trained in primary and preventive health care by the physician-supervisors. Since this initial training, each VHW has been provided with materials, medicines and monthly supervision by the physician-supervisors. The health care component has been complemented by an economic development project based on a system of small loans. Data from the first year of monthly reports and from a baseline survey are presented in this paper.

  5. Satellite-based detection of volcanic sulphur dioxide from recent eruptions in Central and South America

    Directory of Open Access Journals (Sweden)

    D. Loyola

    2008-01-01

    Full Text Available Volcanic eruptions can emit large amounts of rock fragments and fine particles (ash into the atmosphere, as well as several gases, including sulphur dioxide (SO2. These ejecta and emissions are a major natural hazard, not only to the local population, but also to the infrastructure in the vicinity of volcanoes and to aviation. Here, we describe a methodology to retrieve quantitative information about volcanic SO2 plumes from satellite-borne measurements in the UV/Visible spectral range. The combination of a satellite-based SO2 detection scheme and a state-of-the-art 3D trajectory model enables us to confirm the volcanic origin of trace gas signals and to estimate the plume height and the effective emission height. This is demonstrated by case-studies for four selected volcanic eruptions in South and Central America, using the GOME, SCIAMACHY and GOME-2 instruments.

  6. Presurgical orthodontic decompensation alters alveolar bone condition around mandibular incisors in adults with skeletal Class III malocclusion.

    Science.gov (United States)

    Sun, Boyang; Tang, Jun; Xiao, Ping; Ding, Ying

    2015-01-01

    This study is to use cone beam computed tomography (CBCT) to acquire accurate radiographic images for alveolar bone in lower incisors and the change after presurgical orthodontic treatment. Seventeen patients with skeletal Class III malocclusion, ten normal occlusion subjects, and fifteen patients treated with orthodontic treatment and orthognathic surgery were included. CBCT images were obtained. The labial and lingual inclinations of mandibular incisors, the thickness of alveolar bone, the vertical alveolar height and root length were measured. Alveolar bone thickness at the apex in patients with skeletal Class III malocclusion was thinner than normal subjects. The vertical alveolar bone heights at labial and lingual sides in patients with skeletal Class III malocclusion were both reduced compared with normal subjects, especially at the labial side. There were statistically significant correlations between lower incisor inclination and alveolar bone morphology. After orthodontics, the incisors root apex was closer to the lingual side of alveolar bone. The alveolar bone thickness at apex was not statistically changed. The vertical alveolar bone heights at the labial and lingual sides were both significantly reduced especially the lingual side after presurgical orthodontic treatment. The root length was not significantly changed. In conclusion, the alveolar bone thickness at apex is thinner and the vertical alveolar height is reduced at the labial side. Forward movement of lower incisors during presurgical orthodontic treatment can render the lower incisors root apex closer to the lingual side and the vertical alveolar height is reduced.

  7. Measuring long-term impact based on network centrality: unraveling cinematic citations.

    Directory of Open Access Journals (Sweden)

    Andreas Spitz

    Full Text Available Traditional measures of success for film, such as box-office revenue and critical acclaim, lack the ability to quantify long-lasting impact and depend on factors that are largely external to the craft itself. With the growing number of films that are being created and large-scale data becoming available through crowd-sourced online platforms, an endogenous measure of success that is not reliant on manual appraisal is of increasing importance. In this article we propose such a ranking method based on a combination of centrality indices. We apply the method to a network that contains several types of citations between more than 40,000 international feature films. From this network we derive a list of milestone films, which can be considered to constitute the foundations of cinema. In a comparison to various existing lists of 'greatest' films, such as personal favourite lists, voting lists, lists of individual experts, and lists deduced from expert polls, the selection of milestone films is more diverse in terms of genres, actors, and main creators. Our results shed light on the potential of a systematic quantitative investigation based on cinematic influences in identifying the most inspiring creations in world cinema. In a broader perspective, we introduce a novel research question to large-scale citation analysis, one of the most intriguing topics that have been at the forefront of scientific enquiries for the past fifty years and have led to the development of various network analytic methods. In doing so, we transfer widely studied approaches from citation analysis to the the newly emerging field of quantification efforts in the arts. The specific contribution of this paper consists in modelling the multidimensional cinematic references as a growing multiplex network and in developing a methodology for the identification of central films in this network.

  8. Measuring long-term impact based on network centrality: unraveling cinematic citations.

    Science.gov (United States)

    Spitz, Andreas; Horvát, Emőke-Ágnes

    2014-01-01

    Traditional measures of success for film, such as box-office revenue and critical acclaim, lack the ability to quantify long-lasting impact and depend on factors that are largely external to the craft itself. With the growing number of films that are being created and large-scale data becoming available through crowd-sourced online platforms, an endogenous measure of success that is not reliant on manual appraisal is of increasing importance. In this article we propose such a ranking method based on a combination of centrality indices. We apply the method to a network that contains several types of citations between more than 40,000 international feature films. From this network we derive a list of milestone films, which can be considered to constitute the foundations of cinema. In a comparison to various existing lists of 'greatest' films, such as personal favourite lists, voting lists, lists of individual experts, and lists deduced from expert polls, the selection of milestone films is more diverse in terms of genres, actors, and main creators. Our results shed light on the potential of a systematic quantitative investigation based on cinematic influences in identifying the most inspiring creations in world cinema. In a broader perspective, we introduce a novel research question to large-scale citation analysis, one of the most intriguing topics that have been at the forefront of scientific enquiries for the past fifty years and have led to the development of various network analytic methods. In doing so, we transfer widely studied approaches from citation analysis to the the newly emerging field of quantification efforts in the arts. The specific contribution of this paper consists in modelling the multidimensional cinematic references as a growing multiplex network and in developing a methodology for the identification of central films in this network.

  9. Influence of maxillary incisor edge asymmetries on the perception of smile esthetics among orthodontists and laypersons

    OpenAIRE

    Machado, Andre Wilson Lima; Moon, Won; Gandini Júnior, Luiz Gonzaga [UNESP

    2013-01-01

    Texto completo. Acesso restrito. p. 658–664 Introduction: Our objective was to determine the perception of smile esthetics among orthodontists and laypeople with respect to asymmetries on the maxillary incisor edges in a frontal smile analysis. Methods: Two frontal close-up smile photos of 2 women, 1 white and 1 Afro-Brazilian, were selected for this study. Both smiles displayed healthy maxillary anterior dentitions. The images were digitally altered to create tooth wear on the...

  10. Complications of untreated molar-incisor hypomineralization in a 12-year-old boy

    OpenAIRE

    Shubha Arehalli Bhaskar; Sapna Hegde

    2012-01-01

    Complications arising because of untreated molar-incisor hypomineralization (MIH) have received little mention in the dental literature. However, this can be an area of concern, with severe consequences in rare cases. Hence, early recognition and prompt management of MIH is essential for long-term oral health of affected individuals. This paper describes an untreated case of severe MIH that resulted in infection of facial spaces.

  11. Complications of untreated molar-incisor hypomineralization in a 12-year-old boy

    Directory of Open Access Journals (Sweden)

    Shubha Arehalli Bhaskar

    2012-11-01

    Full Text Available Complications arising because of untreated molar-incisor hypomineralization (MIH have received little mention in the dental literature. However, this can be an area of concern, with severe consequences in rare cases. Hence, early recognition and prompt management of MIH is essential for long-term oral health of affected individuals. This paper describes an untreated case of severe MIH that resulted in infection of facial spaces.

  12. Influence of deciduous molar hypomineralization on the development of molar-incisor hypomineralizarion

    OpenAIRE

    Costa-Silva C.M.; Paula J.S.; Ambrosano G.M.B.; Mialhe F.L.

    2013-01-01

    Defects similar to Molar-Incisor Hypomineralization (MIH) in second primary molars can be found in the literature, being recently named Deciduous Molar Hypomineralization (DMH). Researchers have stated that the presence of DMH in primary dentition represents a risk for MIH in permanent teeth. The explanation for this association is probably related to the etiological factors. Aim: To investigate prospectively the association between DMH and MIH and the etiologic factors involved in both defec...

  13. Complications of untreated molar-incisor hypomineralization in a 12-year-old boy.

    Science.gov (United States)

    Bhaskar, Shubha Arehalli; Hegde, Sapna

    2012-10-12

    Complications arising because of untreated molar-incisor hypomineralization (MIH) have received little mention in the dental literature. However, this can be an area of concern, with severe consequences in rare cases. Hence, early recognition and prompt management of MIH is essential for long-term oral health of affected individuals. This paper describes an untreated case of severe MIH that resulted in infection of facial spaces.

  14. Interproximal wear versus incisors extraction to solve anterior lower crowding: A systematic review

    Directory of Open Access Journals (Sweden)

    Natália Valli de Almeida

    2015-02-01

    Full Text Available OBJECTIVE: To determine by means of a systematic review the best treatment, whether interproximal wear or incisor extraction, to correct anterior lower crowding in Class I patients in permanent dentition. METHODS: A literature review was conducted using MEDLINE, Scopus and Web of Science to retrieve studies published between January 1950 and October 2013. In selecting the sample, the following inclusion criteria were applied: studies involving interproximal wear and/or extraction of mandibular incisors, as well as Class I cases with anterior lower crowding in permanent dentition. RESULTS: Out of a total of 943 articles found after excluding duplicates, 925 were excluded after abstract analysis. After full articles were read, 13 were excluded by the eligibility criteria and one due to methodological quality; therefore, only fours articles remained: two retrospective and two randomized prospective studies. Data were collected, analyzed and organized in tables. CONCLUSION: Both interproximal wear and mandibular incisor extraction are effective in treating Class I malocclusion in permanent dentition with moderate anterior lower crowding and pleasant facial profile. There is scant evidence to determine the best treatment option for each case. Clinical decision should be made on an individual basis by taking into account dental characteristics, crowding, dental and oral health, patient's expectations and the use of set-up models.

  15. Mandibular incisor extractions in orthodontics: pitfalls and triumphs: a report of three cases.

    Science.gov (United States)

    Hegde, Chatura; Hegde, Manjunath

    2014-01-01

    Mandibular incisor extraction therapy has been used as a treatment option since the early 1900s to relieve tooth size-arch length discrepancies in the anterior segment of the mandible. The advantages of this therapy include potential reduction in treatment time, possibility of achieving better long-term stability in the mandibular anterior segment since inter canine width is not increased and maintenance of the soft-tissue profile because retraction of the mandibular incisors is less compared with mandibular premolar extractions These advantages are counterbalanced, however, by some potential disadvantages. The most significant of these is the possibility of the space reopening in the long term, an occlusal result less than ideal because of a significant tooth-mass reduction in the anterior mandibular region, development of an open gingival embrasure and the need for permanent or long term retention. We present three cases with three different indications for mandibular incisor extraction where the patient was benefited despite this atypical extraction pattern.

  16. The inorganic components of cementum- and enamel-related dentin in the rat incisor.

    Science.gov (United States)

    Steinfort, J; Deblauwe, B M; Beertsen, W

    1990-06-01

    Recently, we have shown that, in rodent incisors, the crown- and root-analogue dentin (enamel- and cementum-related dentin) show differences in mineralization rates (Beertsen and Niehof, 1986) and composition of the organic matrices (Steinfort et al., 1989). It was the aim of the present study to determine whether these differences were accompanied by differences in the inorganic components. Rat incisors were analyzed by means of hardness measurements, microradiography, and the determination of Ca, Mg, and PO4 content. The outer circumpulpal dentin layer of the enamel-related dentin (ERD) was considerably harder and denser than the comparable layer of the cementum-related dentin (CRD). Concomitantly, a higher Ca and PO4 content was found for the ERD than for the CRD, while the reverse occurred with respect to Mg. From the apical end of the incisor toward the incisal edge, the Ca/PO4 ratio tended to decrease for both ERD and CRD, while the Mg/PO4 ratio increased. All differences appeared to be statistically significant. It is concluded that differences in the non-collagenous organic matrix were accompanied by differences in the inorganic components. More specifically, a relatively high content of highly phosphorylated phosphoproteins (ERD) was associated with a higher Ca and a lower Mg content.

  17. On the cutting edge of organ renewal: Identification, regulation, and evolution of incisor stem cells.

    Science.gov (United States)

    Kuang-Hsien Hu, Jimmy; Mushegyan, Vagan; Klein, Ophir D

    2014-02-01

    The rodent incisor is one of a number of organs that grow continuously throughout the life of an animal. Continuous growth of the incisor arose as an evolutionary adaptation to compensate for abrasion at the distal end of the tooth. The sustained turnover of cells that deposit the mineralized dental tissues is made possible by epithelial and mesenchymal stem cells residing at the proximal end of the incisor. A complex network of signaling pathways and transcription factors regulates the formation, maintenance, and differentiation of these stem cells during development and throughout adulthood. Research over the past 15 years has led to significant progress in our understanding of this network, which includes FGF, BMP, Notch, and Hh signaling, as well as cell adhesion molecules and micro-RNAs. This review surveys key historical experiments that laid the foundation of the field and discusses more recent findings that definitively identified the stem cell population, elucidated the regulatory network, and demonstrated possible genetic mechanisms for the evolution of continuously growing teeth.

  18. Clinical treatment approach of a child with molar incisor hypomineralization (MIH combined with malocclusion.

    Directory of Open Access Journals (Sweden)

    Rossitza Kabaktchieva

    2012-04-01

    Full Text Available Introduction. Molar incisor hypomineralization (MIH was defined as "hypomineralisation of systemic origin of permanent first molars, frequently associated with affected incisors". MIH includes the presence of demarcated opacity, post eruptive enamel breakdown, atypical restoration. Тhe approach to management suggested: risk identification, early diagnosis, remineralization for prevention of caries and post eruption breakdown, restorations. The clinicians very seldom notice that children with MIH usually have both- hypomineralisation and malocclusions, and they do not discuss combine treatment plan.Aim. To present our interdisciplinary approach to a patient with MIH, combined with malocclusion.Material and methods. We are presenting 9 year old child with contusio and fractura coronae dentis noncomplicata, distal occlusion, overjet, overbite and retrusion. Two consecutive stages were defined: First stage:- Professional oral hygiene and local remineralisation therapy- Vital pulp therapy of tooth 21 - Space gaining for restoration of the lost height of the molars by the means of posterior bite-plane removable appliance- Restoration of the molars with metal inlays- Lingual tipping of the lower incisorsSecond stage:- Class II correction- Growth control Results.First phase: - The tooth 21 was restored with aesthetic composite material;- Occlusion was raised with occlusal restorations (inleys and orthodontic appliance. Second phase:Medialisation of mandible and holding maxillary growth with functional appliance and occipital EOA until class one occlusal relations.Conclusion. Children with MIH should be examined and treated complex in collaboration with orthodontist and if necessary by other specialists too.

  19. The Multidisciplinary Management of Fused Maxillary Lateral Incisor with a Supernumerary Tooth in Cleft Lip Adolescence

    Directory of Open Access Journals (Sweden)

    Ahmet Yagci

    2014-01-01

    Full Text Available Fusion, an uncommon anomaly of the hard dental tissues, is potentially the cause of clinical problems related to esthetics, tooth spacing, and other periodontal complications. This paper describes a multidisciplinary approach involving surgical, endodontic, restorative, and orthodontic attention for the successful, functional, and esthetic rehabilitation of a maxillary left lateral incisor fused with a supernumerary tooth in unilateral cleft lip adolescence in contralateral side. After clinical and radiographic examinations, a fusion between the left maxillary lateral incisor and a supernumerary tooth was diagnosed in the patient, and a small connection was detected between the pulp systems of the two root canals. The case reported in this paper presents the successful resolution of a fused maxillary lateral incisor with a supernumerary tooth, using endodontic, surgical, restorative, and orthodontic management. The decision made in extracting or retaining the fused tooth depends on the arch discrepancy and esthetic needs. Future studies, with long-term followup, will be helpful in evaluating the long-term efficacy of the different treatment options.

  20. Delayed diagnosis of central skull-base osteomyelitis with abscess: case report and learning points.

    Science.gov (United States)

    Chawdhary, G; Hussain, S; Corbridge, R

    2017-01-01

    Central skull-base osteomyelitis (CSBO) is a rare life-threatening infection, usually resulting from medial spread of necrotising otitis externa. Here, we describe a case with no identifiable source of infection, causing a delay in diagnosis. An 80-year-old man with Crohn's disease treated with mesalazine presented with collapse and tonic-clonic seizure. Computed tomography and magnetic resonance imaging showed a nasopharyngeal mass that was initially thought to be a neoplasm. Awaiting formal biopsy, he represented with collapse and repeat imaging showed features of abscess formation. Review of previous scans revealed skull-base erosion and the diagnosis was revised to skull-base osteomyelitis. This is the first reported case of CSBO associated with mesalazine use, an aminosalicylate used in Crohn's disease. It is only the second reported case with abscess formation. We discuss the learning points in making a timely diagnosis and examine the potential association of factors such as mesalazine use and abscess formation in this case.

  1. Port central venous catheters-associated bloodstream infection during outpatient-based chemotherapy.

    Science.gov (United States)

    Mauri, Davide; Roumbkou, Sofia; Michalopoulou, Stella; Tsali, Lamprini; Spiliopoulou, Anastasia; Panou, Charalampos; Valachis, Antonis; Panagopoulos, Angelos; Polyzos, Nikolaos P

    2010-12-01

    Central venous catheters (CVCs) are commonly used for the administration of intravenous chemotherapy in outpatient setting. Nevertheless, outbreaks of catheter-associated bloodstream infections had been reported from oncology centers. We describe a large outbreak of CVCs-associated Klebsiella oxytoca bloodstream infection, occurring in an oncology chemotherapy outpatient unit of northern Greece between October 2006 and May 2007. The outbreak involved approximately 10% of the patients with CVCs who were receiving home-based chemotherapy, and it represents the second larger outbreak of CVCs-associated BSIs due to Klebsiella oxytoca in oncology outpatient centers. We retrospectively analyzed the chain of investigations and prophylactic/diagnostic measures taken to eradicate the infection: (1) patients' chart audit, (2) estimation of the infection among asymptomatic patients, (3) implementation of the level of awareness of medical and paramedical personnel, (4) collection of samples from environment, medications and infusion materials, (5) critical appraisal of chemotherapeutical schemes and (6) cooperation with peripheral institutions. The isolation of Klebsiella oxytoca in a chemotherapy solution (infusional 5-FU in dextrose 5% solution within a 48 h pump) from a peripheral General Hospital and the prompt transmission of the data to the chemotherapy center played a key role for the management of the infection cluster. This is the first report that evidenced the detection of Klebsiella oxytoca within a chemotherapeutical preparation. Data transmission from peripheral hospitals to the central institution resulted in an important feedback that allowed a better estimation of the infection cluster and more tailored actions for the eradication of the infection.

  2. New insight into genes in association with asthma: literature-based mining and network centrality analysis

    Institute of Scientific and Technical Information of China (English)

    LIANG Rui; WANG Lei; WANG Gang

    2013-01-01

    Background Asthma is a heterogeneous disease for which a strong genetic basis has been firmly established.Until now no studies have been undertaken to systemically explore the network of asthma-related genes using an internally developed literature-based discovery approach.This study was to explore asthma-related genes by using literaturebased mining and network centrality analysis.Methods Literature involving asthma-related genes were searched in PubMed from 2001 to 2011.Integration of natural language processing with network centrality analysis was used to identify asthma susceptibility genes and their interaction network.Asthma susceptibility genes were classified into three functional groups by gene ontology (GO) analysis and the key genes were confirmed by establishing asthma-related networks and pathways.Results Three hundred and twenty-six genes related with asthma such as IGHE (IgE),interleukin (IL)-4,5,6,10,13,17A,and tumor necrosis factor (TNF)-alpha were identified.GO analysis indicated some biological processes (developmental processes,signal transduction,death,etc.),cellular components (non-structural extracellular,plasma membrane and extracellular matrix),and molecular functions (signal transduction activity) that were involved in asthma.Furthermore,22 asthma-related pathways such as the Toll-like receptor signaling pathway,hematopoietic cell lineage,JAK-STAT signaling pathway,chemokine signaling pathway,and cytokine-cytokine receptor interaction,and 17 hub genes,such as JAK3,CCR1-3,CCR5-7,CCR8,were found.Conclusions Our study provides a remarkably detailed and comprehensive picture of asthma susceptibility genes and their interacting network.Further identification of these genes and molecular pathways may play a prominent role in establishing rational therapeutic approaches for asthma.

  3. Population-based study of central post-stroke pain in Rimini district, Italy

    Directory of Open Access Journals (Sweden)

    Raffaeli W

    2013-09-01

    Full Text Available William Raffaeli,1 Cristina E Minella,2 Francesco Magnani,3 Donatella Sarti3 1ISAL Foundation, Institute for Research on Pain, Torre Pedrera, Rimini, Italy 2Pain Therapy Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy 3Department of Pain Therapy and Palliative Care, Infermi Hospital, Rimini, Italy Abstract: Central post-stroke pain (CPSP is still an underestimated complication of stroke, resulting in impaired quality of life and, in addition to the functional and cognitive consequences of stroke, the presence of CPSP may be associated with mood disorders, such as depression, anxiety, and sleep disturbances. This type of pain may also impair activities of daily living and further worsen quality of life, negatively influencing the rehabilitation process. The prevalence of CSPS in the literature is highly variable (1%–12% according to different studies, and this variability could be influenced by selection criteria and the different ethnic populations being investigated. With this scenario in mind, we performed a population-based study to assess the prevalence of CPSP and its main features in a homogeneous health district (Rimini, Italy, including five hospitals for a total population of 329,970 inhabitants. From 2008 to 2010, we selected 1,494 post-stroke patients and were able to interview 660 patients, 66 (11% of whom reported pain with related tactile and thermal hyperesthesia, accompanied by needle puncture, tingling, swelling, and pressure sensations. Patients reported motor impairment and disability, which influenced their working ability, rehabilitation, and social life. Despite this severe pain state, there was a high percentage of patients who did not receive adequate treatment for pain. Keywords: stroke, central post-stroke pain, disability

  4. The PCR-Based Diagnosis of Central Nervous System Tuberculosis: Up to Date

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    Teruyuki Takahashi

    2012-01-01

    Full Text Available Central nervous system (CNS tuberculosis, particularly tuberculous meningitis (TBM, is the severest form of Mycobacterium tuberculosis (M.Tb infection, causing death or severe neurological defects in more than half of those affected, in spite of recent advancements in available anti-tuberculosis treatment. The definitive diagnosis of CNS tuberculosis depends upon the detection of M.Tb bacilli in the cerebrospinal fluid (CSF. At present, the diagnosis of CNS tuberculosis remains a complex issue because the most widely used conventional “gold standard” based on bacteriological detection methods, such as direct smear and culture identification, cannot rapidly detect M.Tb in CSF specimens with sufficient sensitivity in the acute phase of TBM. Recently, instead of the conventional “gold standard”, the various molecular-based methods including nucleic acid amplification (NAA assay technique, particularly polymerase chain reaction (PCR assay, has emerged as a promising new method for the diagnosis of CNS tuberculosis because of its rapidity, sensitivity and specificity. In addition, the innovation of nested PCR assay technique is worthy of note given its contribution to improve the diagnosis of CNS tuberculosis. In this review, an overview of recent progress of the NAA methods, mainly highlighting the PCR assay technique, was presented.

  5. Central retinal vein occlusion: A review of current Evidence-based treatment options

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    Amy Patel

    2016-01-01

    Full Text Available A central retinal vein occlusion (CRVO can induce an ischemic and hypoxic state with resulting sequelae of macular edema and neovascularization. Many treatment options have been studied. Our review aims to investigate the safety and efficacy of the multiple treatment options of CRVO. A PubMed and Cochrane literature search was performed. Well-controlled randomized clinical trials that demonstrated strong level 1 evidence-based on the rating scale developed by the British Centre for Evidence-Based Medicine were included. Seven clinical trials met inclusion criteria to be included in this review. These included studies that investigated the safety and efficacy of retinal photocoagulation (1 study, intravitreal steroid treatment (2 studies, and antivascular endothelial growth factor treatment (4 studies for the treatment of CRVO. In addition, studies evaluating surgical treatment options for CRVO were also included. Many treatment modalities have been demonstrated to be safe and efficacious in the treatment of CRVO. These treatment options offer therapeutic benefits for patients and clinically superior visual acuity and perhaps the quality of life after suffering from a CRVO.

  6. Parameters inversion of high central core rockfill dams based on a novel genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wei; LI ShaoLin; MA Gang; CHANG XiaoLin; MA Xing; ZHANG Chao

    2016-01-01

    Parameters identification of rockfill materials is a crucial issue for high rockfill dams.Because of the scale effect,random sampling and sample disturbance,it is difficult to obtain the actual mechanical properties of rockfill from laboratory tests.Parameters inversion based on in situ monitoring data has been proven to be an efficient method for identifying the exact parameters of the rockfill.In this paper,we propose a modified genetic algorithm to solve the high-dimension multimodal and nonlinear optimal parameters inversion problem.A novel crossover operator based on the sum of differences in gene fragments (SoDX) is proposed,inspired by the cloning of superior genes in genetic engineering.The crossover points are selected according to the difference in the gene fragments,defining the adaptive length.The crossover operator increases the speed and accuracy of algorithm convergence by reducing the inbreeding and enhancing the global search capability of the genetic algorithm.This algorithm is compared with two existing crossover operators.The modified genetic algorithm is then used in combination with radial basis function neural networks (RBFNN) to perform the parameters back analysis of a high central earth core rockfill dam.The settlements simulated using the identified parameters show good agreement with the monitoring data,illustrating that the back analysis is reasonable and accurate.The proposed genetic algorithm has considerable superiority for nonlinear multimodal parameter identification problems.

  7. Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland.

    Science.gov (United States)

    Żądzińska, Elżbieta; Lorkiewicz, Wiesław; Kurek, Marta; Borowska-Strugińska, Beata

    2015-07-01

    Physiological disruptions resulting from an impoverished environment during the first years of life are of key importance for the health and biological status of individuals and populations. Studies of growth processes in archaeological populations point to the fact that the main causes of childhood mortality in the past are to be sought among extrinsic factors. Based on this assumption, one would expect random mortality of children, with the deceased individuals representing the entire subadult population. The purpose of this study is to explore whether differences in early childhood survival are reflected in differences in deciduous tooth enamel, which can provide an insight into the development of an individual during prenatal and perinatal ontogeny. Deciduous incisors were taken from 83 individuals aged 2.0-6.5 years from a medieval inhumation cemetery dated AD 1300-1600. Prenatal and postnatal enamel formation time, neonatal line width, and the number of accentuated lines were measured using an optical microscope. The significantly wider neonatal line and the higher frequency of accentuated lines in the enamel of the incisors of children who died at the age of 2-3 years suggest the occurrence of stronger or more frequent stress events in this group. These results indicate that in skeletal populations mortality was not exclusively determined by random external factors. Individuals predisposed by an unfavorable course of prenatal and perinatal growth were more likely to die in early childhood.

  8. Comparison of shear bond strength of reattached incisor fragment using Er,Cr:YSGG laser etching and conventional acid etching: An in vitro study

    Science.gov (United States)

    Kumar, Gyanendra; Goswami, Mridula; Dhillon, Jatinder Kaur

    2016-01-01

    Aim: The aim of this invitro study is to evaluate the shear bond strength of reattached fractured incisor fragments using Er,Cr:YSGG laser and conventional acid etching without additional tooth preparation. Materials and methods: Forty extracted human teeth were divided in two groups of 20 each (Groups A and B). In Group A, fractured surface was treated by an Er, Cr: YSGG laser system (Waterlase MD, Biolase Technology Inc., San Clemente, CA, USA) operating at a wavelength of 2,780 nm and frequency of 20 Hz. In Group B, fractured surface was etched using 37% phosphoric acid (Scotchbond, 3M). In both the groups, further subdivision with 10 sample each was made based on horizontal and oblique fracture. After laser or acid etching, all the samples were reattached using flowable composite resin and light cured. The samples were tested for shear bond strength. Results: Mean shear bond strength for Group A (94.70±39.158) was lower as compared to Group B (121.25±49.937), although the difference was not statistically significant(p value=0.121). Similarly no statistical significant difference was observed amongst the subgroups. (p>0.05) Conclusion: Er,Cr:YSGG laser etching in reattachment of fractured incisor fragment is a good alternative to conventional acid etching. Er,Cr:YSGG showed comparable efficiency in rebonding of fractured teeth fragment as acid etching. PMID:27721563

  9. An Innovative Approach to Treat Incisors Hypomineralization (MIH: A Combined Use of Casein Phosphopeptide-Amorphous Calcium Phosphate and Hydrogen Peroxide—A Case Report

    Directory of Open Access Journals (Sweden)

    Stefano Mastroberardino

    2012-01-01

    Full Text Available Molar Incisor Hypomineralization (MIH is characterized by a developmentally derived deficiency in mineral enamel. Affected teeth present demarcated enamel opacities, ranging from white to brown; also hypoplasia can be associated. Patient frequently claims aesthetic discomfort if anterior teeth are involved. This problem leads patients to request a bleaching treatment to improve aestheticconditions.Nevertheless, hydrogen peroxide can produce serious side-effects, resulting from further mineral loss. Microabrasion and/or a composite restoration are the treatments of choice in teeth with mild/moderate MIH, but they also need enamel loss. Recently, a new remineralizing agent based on Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP has been proposed to be effective in hypomineralized enamel, improving also aesthetic conditions. The present paper presents a case report of a young man with white opacities on incisors treated with a combined use of CPP-ACP mousse and hydrogen peroxide gel to correct the aesthetic defect. The patient was instructed to use CPP-ACP for two hours per day for three months in order to obtain enamel remineralization followed by a combined use of CPP-ACP and bleaching agent for further two months. At the end of this five-month treatment, a noticeable aesthetic improvement of the opacities was observed.

  10. An Innovative Approach to Treat Incisors Hypomineralization (MIH): A Combined Use of Casein Phosphopeptide-Amorphous Calcium Phosphate and Hydrogen Peroxide-A Case Report.

    Science.gov (United States)

    Mastroberardino, Stefano; Campus, Guglielmo; Strohmenger, Laura; Villa, Alessandro; Cagetti, Maria Grazia

    2012-01-01

    Molar Incisor Hypomineralization (MIH) is characterized by a developmentally derived deficiency in mineral enamel. Affected teeth present demarcated enamel opacities, ranging from white to brown; also hypoplasia can be associated. Patient frequently claims aesthetic discomfort if anterior teeth are involved. This problem leads patients to request a bleaching treatment to improve aestheticconditions.Nevertheless, hydrogen peroxide can produce serious side-effects, resulting from further mineral loss. Microabrasion and/or a composite restoration are the treatments of choice in teeth with mild/moderate MIH, but they also need enamel loss. Recently, a new remineralizing agent based on Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) has been proposed to be effective in hypomineralized enamel, improving also aesthetic conditions. The present paper presents a case report of a young man with white opacities on incisors treated with a combined use of CPP-ACP mousse and hydrogen peroxide gel to correct the aesthetic defect. The patient was instructed to use CPP-ACP for two hours per day for three months in order to obtain enamel remineralization followed by a combined use of CPP-ACP and bleaching agent for further two months. At the end of this five-month treatment, a noticeable aesthetic improvement of the opacities was observed.

  11. Characteristics and Composition of Atmospheric Aerosols in Phimai, Central Thailand During BASE-ASIA

    Science.gov (United States)

    Li, Can; Tsay, Si-Chee; Hsu, N. Christina; Kim, Jin Young; Howell, Steven G.; Huebert, Barry J.; Ji, Qiang; Jeong, Myeong-Jae; Wang, Sheng-Hsiang; Hansell, Richard A.; Bell, Shaun W.

    2012-01-01

    Popular summary: Atmospheric aerosols play an important role in the Earth's climate system, and can also have adverse effects on air quality and human health. The environmental impacts of aerosols, on the other hand, are highly regional, since their temporal/spatial distribution is inhomogeneous and highly depends on the regional emission sources. To better understand the effects of aerosols, intensive field experiments are necessary to characterize the chemical and physical properties on a region-by-region basis. From late February to early May in 2006, NASA/GSFC's SMARTLabs facility was deployed at a rural site in central Thailand, Southeast Asia, to conduct a field experiment dubbed BASE-ASIA (Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment). The group was joined by scientists from the University of Hawaii and other regional institutes. Comprehensive measurements were made during the experiment, including aerosol chemical composition, optical and microphysical properties, as well as surface energetics and local . meteorology. This study analyzes part of the data from the BASE-ASIA experiment. It was found that, even for the relatively remote rural site, the aerosol loading was still substantial. Besides agricultural burning in the area, industrial pollution near the Bangkok metropolitan area, about 200 km southeast of the site, and even long-range transport from China, also contribute to the area's aerosol loading. The results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow. Abstract: Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.l83 N, 102.565 E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 +/- 64 Mm(exp -1); absorption: 15

  12. Status and future transition of rapid urbanizing landscape in central Western Ghats - CA based approach

    Science.gov (United States)

    Bharath, S..; Rajan, K. S.; Ramachandra, T. V.

    2014-11-01

    The land use changes in forested landscape are highly complex and dynamic, affected by the natural, socio-economic, cultural, political and other factors. The remote sensing (RS) and geographical information system (GIS) techniques coupled with multi-criteria evaluation functions such as Markov-cellular automata (CA-Markov) model helps in analysing intensity, extent and future forecasting of human activities affecting the terrestrial biosphere. Karwar taluk of Central Western Ghats in Karnataka state, India has seen rapid transitions in its forest cover due to various anthropogenic activities, primarily driven by major industrial activities. A study based on Landsat and IRS derived data along with CA-Markov method has helped in characterizing the patterns and trends of land use changes over a period of 2004-2013, expected transitions was predicted for a set of scenarios through 2013-2022. The analysis reveals the loss of pristine forest cover from 75.51% to 67.36% (1973 to 2013) and increase in agriculture land as well as built-up area of 8.65% (2013), causing impact on local flora and fauna. The other factors driving these changes are the aggregated level of demand for land, local and regional effects of land use activities such as deforestation, improper practices in expansion of agriculture and infrastructure development, deteriorating natural resources availability. The spatio temporal models helped in visualizing on-going changes apart from prediction of likely changes. The CA-Markov based analysis provides us insights into the localized changes impacting these regions and can be useful in developing appropriate mitigation management approaches based on the modelled future impacts. This necessitates immediate measures for minimizing the future impacts.

  13. Centrality measures in networks based on nodes attributes, long-range interactions and group influence

    CERN Document Server

    Aleskerov, F; Shvydun, S

    2016-01-01

    We propose a new method for assessing agents influence in network structures, which takes into consideration nodes attributes, individual and group influences of nodes, and the intensity of interactions. This approach helps us to identify both explicit and hidden central elements which cannot be detected by classical centrality measures or other indices.

  14. Comparison of two treatment method for maxillary incisors intrusion%2种上颌前牙压低方法的疗效比较

    Institute of Scientific and Technical Information of China (English)

    马丹; 王旭霞; 靳淑梅; 董瑞; 刘宛鑫; 李静; 张君

    2013-01-01

    PURPOSE: To compare the clinical effects of miniscrews and conventional utility arch in the maxillary incisors intrusion. METHODS: Twenty adult patients with HI degree deep bite were chosen and divided into two groups randomly. The cephalometric films, intraoral periapical radiographies with metal guide bars, and periodontium parameters were taken before and after intrusion. The major measurement items included alteration of the maxillary first molar in vertical dimension, torque and length of maxillary central incisors, overbite, clinical crown of maxillary central incisors, probing depth (PD), gingival index (GI), plaque index (PI) and etc. PASW statistics 18.0 was used for statistical analysis. RESULTS: In the miniscrew group, there was no change of U1-SN, U6-PP distance, U6-SN (P>0.05), but significant reductions in overbite and U1 -Stm distance (P0.05). CONCLUSIONS: Compared with the conventional utility arch, minisrew has advantages on intruding upper incisors, and improving lip-tooth relationships. Less treatment period is needed in the minisrew group, and the impact on periodontal supporting tissue is similar. Supported by Science and Technology Development Plan of Shangdong Province(2010GWZ20255) and Special Project for Educational Science of Shandong Province(2050205).%目的:比较微螺钉种植体支抗与多用途弓在压低上颌前牙时的临床疗效.方法:选择牙列排齐后仍表现为前牙Ⅲ°深覆(猞)的成年患者20例,随机分为微螺钉种植体支抗组和多用途弓组进行上颌前牙压低治疗.治疗前、后分别拍摄头颅定位侧位片,并进行上颌前牙区牙周组织检查,测量项目包括上颌第一磨牙和上颌中切牙的矢状向和垂直向变化、前牙覆(耠)改变、上颌中切牙临床冠改变、上颌切牙菌斑指数、牙周探诊深度变化等.利用PASW statistics18软件包对测量数据进行统计学分析.结果:微螺钉种植体支抗组治疗前、后U1-SN、U6-SN和U6-PP

  15. CO2 Total Column Variability From Ground-Based FTIR Measurements Over Central Mexico

    Science.gov (United States)

    Baylon, J. L.; Stremme, W.; Plaza, E.; Bezanilla, A.; Grutter, M.; Hase, F.; Blumenstock, T.

    2014-12-01

    There are now several space missions dedicated to measure greenhouse gases in order to improve the understanding of the carbon cycle. Ground based measurement sites are of great value in the validation process, however there are only a few stations in tropical latitudes. We present measurements of solar-absorption infrared spectra recorded on two locations over Central Mexico: the High-Altitude Station Altzomoni (19.12 N, 98.65 W), located in the Izta-Popo National Park outside of Mexico City; and the UNAM's Atmospheric Observatory (19.32 N, 99.17 W) in Mexico City. These measurements were performed using a high resolution Fourier transform infrared spectrometer FTIR (Bruker, HR 120/5) at Altzomoni and a moderate resolution FTIR (Bruker, Vertex 80) within the city. In this work, we present the first results for total vertical columns of CO2 derived from near-infrared spectra recorded at both locations using the retrieval code PROFFIT. We present the seasonal cycle and variability from the measurements, as well as the full diagnostics of the retrieval in order assess its quality and discuss the differences of both instruments and locations (altitudes, urban vs remote). This work aims to contribute to generate high quality datasets for satellite validation.

  16. Incidence and mechanism of central pontine myelinolysis based on analysis of MRI images and risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Masato [Akita Univ. (Japan). School of Medicine

    2000-02-01

    In this study, the incidence of central pontine myelinolysis (CPM)-like lesions on MRI images was studied in 1917 subjects, 1,500 of which were psychiatric patients and 417 were patients attending a brain health examination. The CPM-like lesions were first classified into four groups based on the characteristics of their MRI images: group 1 showed symmetrical lesions on both T1 low and T2 high images and were considered to be typical CPM; group 2 showed symmetrical high intensity lesions only on T2 images; group 3 had asymmetrical lesions only on T2 images; and group 4 had asymmetrical lesions on both T1 low and T2 high images. Furthermore, the relationships of each group with particular risk factors, such as alcoholism, hypertension, hyperlipidemia were statistically analysed. The cause of CPM-like features in the MRI images were discussed. Among our subjects, the incidence of CPM-like lesions was 3.8%, and that of group 1 was 1.2%. Significant correlations between group 1 and alcoholism, and group 3 and 4 with brain ischemic lesions were observed. A previous hypothesis that group 2 may be a premature state of CPM is not supported by our results. (author)

  17. The Contribution of a Central Pattern Generator in a Reflex-Based Neuromuscular Model

    Directory of Open Access Journals (Sweden)

    Florin eDzeladini

    2014-06-01

    Full Text Available Although the concept of central pattern generators (CPGs controlling locomotion in vertebrates is widely accepted, the presence of specialized CPGs in human locomotion is still a matter of debate. An interesting numerical model developed in the 90s' demonstrated the important role CPGs could play in human locomotion, both in terms of stability against perturbations, and in terms of speed control. Recently, a reflex-based neuro-musculo-skeletal model has been proposed, showing a level of stability to perturbations similar to the previous model, without any CPG components. Although exhibiting striking similarities with human gaits, the lack of CPG makes the control of speed/step length in the model difficult. In this paper, we hypothesize that a CPG component will offer a meaningful way of controlling the locomotion speed. After introducing the CPG component in the reflex model, and taking advantage of the resulting properties, a simple model for gait modulation is presented.The results highlight the advantages that a feedforward component can have in terms of gait modulation.

  18. Characteristics and composition of atmospheric aerosols in Phimai, central Thailand during BASE-ASIA

    Science.gov (United States)

    Li, Can; Tsay, Si-Chee; Hsu, N. Christina; Kim, Jin Young; Howell, Steven G.; Huebert, Barry J.; Ji, Qiang; Jeong, Myeong-Jae; Wang, Sheng-Hsiang; Hansell, Richard A.; Bell, Shaun W.

    2013-10-01

    Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.183°N, 102.565°E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 ± 64 Mm-1; absorption: 15 ± 8 Mm-1; PM10 concentration: 33 ± 17 μg m-3), and dominated by submicron particles. Major aerosol compounds included carbonaceous (OC: 9.5 ± 3.6 μg m-3; EC: 2.0 ± 2.3 μg m-3) and secondary species (SO42-: 6.4 ± 3.7 μg m-3, NH4+: 2.2 ± 1.3 μg m-3). While the site was seldom under the direct influence of large forest fires to its north, agricultural fires were ubiquitous during the experiment, as suggested by the substantial concentration of K+ (0.56 ± 0.33 μg m-3). Besides biomass burning, aerosols in Phimai during the experiment were also strongly influenced by industrial and vehicular emissions from the Bangkok metropolitan region and long-range transport from southern China. High humidity played an important role in determining the aerosol composition and properties in the region. Sulfate was primarily formed via aqueous phase reactions, and hygroscopic growth could enhance the aerosol light scattering by up to 60%, at the typical morning RH level of 85%. The aerosol single scattering albedo demonstrated distinct diurnal variation, ranging from 0.86 ± 0.04 in the evening to 0.92 ± 0.02 in the morning. This experiment marks the first time such comprehensive characterization of aerosols was made for rural central Thailand. Our results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow.

  19. A multidisciplinary treatment of congenitally missing maxillary lateral incisors: a 14-year follow-up case report

    Directory of Open Access Journals (Sweden)

    Renato Rodrigues de ALMEIDA

    2014-10-01

    Full Text Available Absence of the maxillary lateral incisor creates an aesthetic problem which can be managed in various ways. The condition requires careful treatment planning and consideration of the options and outcomes following either space closure or prosthetic replacement. Recent developments in restorative dentistry have warranted a re-evaluation of the approach to this clinical situation. Factors relating both to the patient and the teeth, including the presentation of malocclusion and the effect on the occlusion must be considered. The objective of this study was to describe the etiology, prevalence and alternative treatment modalities for dental agenesis and to present a clinical case of agenesis of the maxillary lateral incisors treated by the closure of excessive spaces and canine re-anatomization. A clinical case is presented to illustrate the interdisciplinary approach between orthodontics and restorative dentistry for improved esthetic results. In this report, the treatment of a girl with a Class II malocclusion of molars and canines with missing maxillary lateral incisors and convex facial profile is shown. Treatment was successfully achieved and included the space closure of the areas corresponding to the missing upper lateral incisors, through movement of the canines and the posterior teeth to mesial by fixed appliances as well as the canines transformation in the maxillary lateral incisors. This is a 14-year follow-up case report involving orthodontics and restorative dentistry in which pretreatment, posttreatment, and long-term follow-up records for the patient are presented.

  20. Comparative studies between mice molars and incisors are required to draw an overview of enamel structural complexity

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    MICHEL eGOLDBERG

    2014-09-01

    Full Text Available In the field of dentistry, the murine incisor has long been considered as an outstanding model to study amelogenesis. However, it clearly appears that enamel from wild type mouse incisors and molars presents several structural differences. In incisor, exclusively radial enamel is observed. In molars, enamel displays a high level of complexity since the inner part is lamellar whereas the outer enamel shows radial and tangential structures. Recently, the serotonin 2B receptor (5-HT2BR was shown to be involved in ameloblast function and enamel mineralization. The incisors from 5HT2BR knockout (KO mice exhibit mineralization defects mostly in the outer maturation zone and porous matrix network in the inner zone. In the molars, the mutation affects both secretory and maturation stages of amelogenesis since pronounced alterations concern overall enamel structures. Molars from 5HT2BR KO mice display reduction in enamel thickness, alterations of inner enamel architecture including defects in Hunter-Schreger Bands arrangements, and altered maturation of the outer radial enamel. Differences of enamel structure were also observed between incisor and molar from other KO mice depleted for genes encoding enamel extracellular matrix proteins.

  1. Prevalence of molar incisor hypomineralization in the city of Buenos Aires.

    Science.gov (United States)

    Biondi, Ana M; Cortese, Silvina G; Martínez, Karina; Ortolani, Andrea M; Sebelli, Patricia M F; Ienco, Melisa; Paván, Verónica H; Mendel, Nancy; Bertolino, Mariana; Hecht, Pedro

    2011-01-01

    The prevalence of Molar Incisor Hypomineralization (MIH) still remains unknown in Argentina. The objectives of this work were to: estimate prevalence of MIH in a group of children seeking dental care in the city of Buenos Aires, analyze distribution according to year of birth and compare prevalence and severity of MIH in children with different access to health care services. A prospective, observational, transversal, descriptive study was designed, to be conducted on children seeking attention at Department of Comprehensive Children's Dentistry at the School of Dentistry of Buenos Aires University and at 3 pediatric dentistry offices attended by members of the team, located in Buenos Aires city (Kappa 0.933 0.911-0.952), from April to August 2010. The study included all children born between 1993 and 2003, whose 4 first molars and 8 permanent incisors had erupted. After prophylaxis and drying, the teeth were clinically evaluated and specially designed charts were used to record sex, year of birth, type of access to dental care, presence of MIH, number of affected incisors and molars, and maximum degree of severity for each tooth. The data obtained were analyzed using percentages, Fisher's Exact Test and Linear regression. 1098 children, mean age 11.3 years (11.08-11.39) were evaluated. Prevalence of MIH in this study was 15.9% (13.8-18.2). A highly significant positive correlation was obtained between MIH and year of birth (pmolars, 37% (32.2-42) in A and 13.7% (6.7-23.8) in B had grade 3 lesions, with loss of enamel (p<0.0001). In this study, MIH was a frequent pathology (15.9%) and a significant increase was found according to year of birth during the study period. Patients with better access to health care had greater prevalence and degree of severity of MIH.

  2. Eruptive malpositioning of the mandibular permanent lateral incisors: three case reports.

    Science.gov (United States)

    Bradley, E J; Bell, R A

    1990-01-01

    Ectopic eruption of the mandibular permanent lateral incisors involving the loss of the adjacent primary canines is not uncommon, yet the extreme distalization and transposition of such teeth (partial or true) has been reported infrequently. Three cases that illustrate various anomalous eruption-exfoliation patterns are presented. Theories that attempt to explain the etiology of anomalous eruption positions are discussed. However, the multifactorial process of growth and development makes it difficult to identify specific primary etiological factors. Treatment options also are discussed and illustrated, with emphasis on early orthodontic intervention for optimal results.

  3. Esthetic rehabilitation of severely decayed primary incisors using glass fiber reinforced composite: a case report.

    Science.gov (United States)

    Metha, Deepak; Gulati, Akanksha; Basappa, N; Raju, O S

    2012-01-01

    Restoration of primary maxillary incisors severely damaged by caries or trauma is a clinical challenge in pediatric dental clinics. Early childhood caries is observed in approximately half the child population. In the past, the only treatment option would have been to extract the affected teeth and replace them with prosthetic substitutes. With the introduction of new adhesive systems and restorative materials, alternative approaches in treating these teeth have been proposed. The purpose of this paper was to describe the rehabilitation of primary anterior teeth in a 5-year-old patient using glass fiber reinforced composite resin as an intracanal post.

  4. Minimally invasive Approach to Restore with Porcelain Laminate Veneer on Maxillary Lateral Incisors

    Directory of Open Access Journals (Sweden)

    Luiz Guilherme Freitas de Paula

    2014-01-01

    Full Text Available The enhancement of indirect restorations along the advancement of adhesive systems made possible the preservation of tooth structure through the completion of minimal wear. The laminates ceramics veneers type "contact lens" are presented as a great option when compared to other restorations and excellent results can be noted in a conservative approach. The indication and proper planning are critical to the success of treatment. The present case aims to show the restoration of height and shape of lateral incisors combining the wishes of the patient to the possibilities that dentistry has to offer.

  5. Skeletal class III camouflage by mandibular incisor extraction: A case report

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    Janardhanan Kumaresan

    2014-01-01

    Full Text Available Treatment planning in orthodontics plays a key role in determining the successful treatment of any kind of malocclusion. Skeletal class III malocclusions are generally difficult to treat because of the complex nature of the skeletal and dental manifestations they produce. Mild to moderate skeletal class III malocclusions sometimes have an acceptable facial profile where orthodontic camouflage is possible. In this case report, camouflage of a mild skeletal class III is done by the extraction of a single mandibular incisor, which helped in maintaining the profile of the patient and also in the correction of crowding in the mandibular anterior region.

  6. Immunocytochemical localization of claudin 1 in the maturation ameloblasts of rat incisors

    Directory of Open Access Journals (Sweden)

    Sumio eNishikawa

    2010-11-01

    Full Text Available Claudin 1 is a tight junction transmembrane protein. Its localization in the maturation ameloblasts of rat incisors was examined by immunofluorescence microscopy. Distal junction area of ruffle-ended ameloblasts (RA and the Golgi apparatus of a sub-population of smooth-ended ameloblasts (SA and RAs stained positive with anti-claudin 1 antibodies. Since it has been shown that ameloblasts repeatedly alternate between an SA and an RA morphology during enamel maturation, the presence of claudin 1 in the Golgi cisterns may indicate the presence of tight junction precursors before transportation to the junctional area.

  7. Environmental Drivers of NDVI-Based Vegetation Phenology in Central Asia

    Directory of Open Access Journals (Sweden)

    Jahan Kariyeva

    2011-02-01

    Full Text Available Through the application and use of geospatial data, this study aimed to detect and characterize some of the key environmental drivers contributing to landscape-scale vegetation response patterns in Central Asia. The objectives of the study were to identify the variables driving the year-to-year vegetation dynamics in three regional landscapes (desert, steppe, and mountainous; and to determine if the identified environmental drivers can be used to explain the spatial-temporal variability of these spatio-temporal dynamics over time. It was posed that patterns of change in terrestrial phenology, derived from the 8 km bi-weekly time series of Normalized Difference Vegetation Index (NDVI data acquired by the Advanced Very High Resolution Radiometer (AVHRR satellites (1981–2008, can be explained through a multi-scale analysis of a suite of environmental drivers. Multiple linear stepwise regression analyses were used to test the hypotheses and address the objectives of the study. The annually computed phenological response variables or pheno-metricstime (season start, season length, and an NDVI-based productivity metric were modeled as a function of ten environmental factors relating to soil, topography, and climate. Each of the three studied regional landscapes was shown to be governed by a distinctive suite of environmental drivers. The phenological responses of the steppe landscapes were affected by the year-to-year variation in temperature regimes. The phenology of the mountainous landscapes was influenced primarily by the elevation gradient. The phenological responses of desert landscapes were demonstrated to have the greatest variability over time and seemed to be affected by soil carbon content and year-to-year variation of both temperature regimes and winter precipitation patterns. Amounts and scales of observed phenological variability over time (measured through coefficient of variation for each pheno-metrictime in each of the regional

  8. Implementation of Central Dogma Based Cryptographic Algorithm in Data Warehouse Architecture for Performance Enhancement

    Directory of Open Access Journals (Sweden)

    Rajdeep Chowdhury

    2015-11-01

    Full Text Available Data warehouse is a set of integrated databases deliberated to expand decision-making and problem solving, espousing exceedingly condensed data. Data warehouse happens to be progressively more accepted theme for contemporary researchers with respect to contemporary inclination towards industry and executive purview. The crucial tip of the proposed work is integrated on delivering an enhanced and an exclusive innovative model based on the intention of enhancing security measures, which at times have been found wanting and also ensuring improved accessibility using Hashing modus operandi. An unsullied algorithm was engendered using the concept of protein synthesis, prevalently studied in Genetics, that is, in the field of Biotechnology, wherein three steps are observed, namely; DNA Replication, Translation and Transcription. In the proposed algorithm, the two latter steps, that is, Translation and Transcription have been taken into account and the concept have been used for competent encryption and proficient decryption of data. Central Dogma Model is the name of the explicit model that accounts for and elucidates the course of action for Protein Synthesis using the Codons which compose the RNA and the DNA and are implicated in numerous bio–chemical processes in living organisms. It could be observed that subsequently a dual stratum of encryption and decryption mechanism has been employed for optimal security. The formulation of the immaculate Hashing modus operandi ensure that there would be considerable diminution of access time, keeping in mind the apt retrieval of all indispensable data from the data vaults. The pertinent appliance of the proposed model with enhanced security might be in its significant service in a variety of organizations where accrual of protected data is of extreme magnitude. The variety of organizations might include educational organizations, corporate houses, medical establishments, private establishments and so on

  9. Building a wide coverage multilingual lexical knowledge base: Multilingual Central Repository

    Directory of Open Access Journals (Sweden)

    Aitor Gonzalez-Agirre

    2013-07-01

    Full Text Available The use of wide coverage and general domain semantic resources has become a common practice and often necesary by existing systems Natural Language Processing (NLP. WordNet is by far the most widely used semantic resource in NLP. Following the success of WordNet, the EuroWordNet project has designed a multilingual semantic infrastructure to develop wordnets for a set of European languages. In EuroWordNet, these wordnets are interconnected with links stored in the Inter-Lingual Index (ILI. Following the EuroWordNet architecture, the MEANING project has developed the first versions of Multilingual Central Repository (MCR using WordNet 1.6 as ILI. Thus, maintaining the compatibility between wordnets of different languages ​​and versions. This version of the MCR integrates six different versions of the English WordNet (1.6 to 3.0 and wordnets in Spanish, Catalan, Basque and Italian, along with more than a million semantic relationships between concepts and semantic properties different ontologies. We recently developed a new version of MCR using WordNet 3.0 as ILI. This new version of the MCR integrates wordnets of five different languages: English, Spanish, Catalan, Basque and Galician. The current version of MCR, like the previous one, systematically integrates thousands of semantic relations between concepts. In addition, the MCR is enriched with about 460,000 semantic and ontological properties including Base Level Concepts, Top Ontology, WordNet Domains and AdimenSUMO, providing all ontological consistency the integrated semantic wordnets and resources on it.

  10. Remote Sensing Based Biophysical Characterization of Tropical Deciduous Forest in Central India

    Science.gov (United States)

    Singh, R. P.; Goroshi, S.; Sharma, N. K.; Bairagi, G. D.; Sharma, R.; Jalil, P.; Jain, A.; Sonakia, A.; Parihar, J. S.

    2011-09-01

    The paper reports the measurements of biophysical parameters using field and satellite data over a tropical deciduous forest Kanha National Park (KNP), central India. Field measurement (GBH, LAI, litter, soil moisture) was carried out over ten quadrates of 0.1ha in KNP for characterization of biophysical parameters with specified measurement protocol and sampling. Satellite based remote sensing analysis (LAI, Phenology, and NPP) was carried out using multi date observations of IRS-LISS-III, IMS-1MX, SPOT-VEGETATION and EOS-MODIS instruments. Rank correlation analysis using field data collected in the selected quadrates at KNP showed Sal (Shorea robusta) is dominant forest species followed by Lendia, Jamun (Syzygium cumini), Saja, Harra and Dhawda etc. Field measurement of Sal showed GBH range from 20 cm to 170 cm. Different forest classes such as Sal; Sal mixed with Jamun, Bamboo (Dendrocalamus strictus) etc, including grasslands/scrubland were classified with overall accuracy of 85.56 percent using March, May and October multi spectral data. Sal has distinct growth characteristics (low vegetation growth/ leaf fall in March instead of May) as compared to other vegetation species. As per the Leaf Area Index (LAI) measurement using hemispherical photographs, Sal showed the highest LAI (6.95 m2/m2) during September and lowest LAI (2.63 m2/m2) during March. Overall good agreement (r= 0.79) was found between the LAI generated from LISS-III and MODIS data product. It was observed from SPOT-VEGETATION analysis that NPP varied from 8.4 tC/ha/year (dry deciduous forest) to 14.25 tC/ha/year (Moist deciduous forest) in KNP.

  11. Indicator minerals as guides to base metal sulphide mineralisation in Betul Belt, central India

    Indian Academy of Sciences (India)

    Biswajit Ghosh; M N Praveen

    2008-08-01

    Zn-bearing minerals that act as indicator minerals for base metal sulphide mineralization from the Proterozoic Betul Belt,central India with special emphasis on their genetic significance have been discussed.Sulphide mineralisation is hosted by the felsic volcanic rocks and has similarities with volcanic-hosted massive sulphide deposits in other parts of the world.Synvolcanic hydrothermal alteration is crudely zoned with an inner high Mg-Ca core and an outer wider envelop of Al-Fe rich mineral assemblage.Most of the prospects have strata bound,moderately to steeply dipping, multiple,sub-parallel sheet like ore bodies composed of disseminated and semi-massive to massive ores.Zn-bearing spinel,staurolite,biotite and ilmenite typically occur within the foot-wall altera- tion zones in close proximity to the sulphide mineralization.Zincian spinel is ubiquitous irrespective of the nature of alteration zone.Zincian staurolite is nearly absent in Mg-Ca alteration zones but commonly present in Al-Fe alteration zone along with zincian ilmenite.Zn-bearing biotite in intimate association with zincian spinel is generally found in Mg-Ca alteration zone and in the transition to Al-Fe alteration zone.Most of these indicator minerals can be considered as products of desulphidation of sphalerite during metamorphism.Mechanisms other than desulphidation like formation of gahnite by overstepping of the zinc saturation limit of biotite during retrogression to chlorite and formation of zincian staurolite at the expense of gahnite is also recorded.Field presence of these minerals has immense significance in exploration in Betul Belt as they occur in close spatial relationship with the sulphide rich zones and therefore act as direct vectors to ore.

  12. Measurement of incisor root resorption by CBCT in treatment of gummy smile using implant anchorage%种植支抗治疗露龈笑过程中切牙牙根吸收的CBCT检测

    Institute of Scientific and Technical Information of China (English)

    吴碧蓉; 骆英; 王晖

    2014-01-01

    目的:通过 CBCT技术精确测量种植支抗治疗露龈笑过程中所导致的上颌切牙牙根吸收的情况。方法11例患者全部采用直丝弓矫治技术,在上颌两侧侧切牙和中切牙之间的牙槽骨上,各植入1枚微螺钉,每侧约0.98 N 压低上前牙。当龈缘距与微笑线基本平齐时,治疗停止,进入保持阶段。治疗前后拍摄 CBCT,在矢状位图像选取牙根长度最长的轴面进行长度测量。结果所有患者露龈笑均有明显改善,平均减小(2.47±0.64)mm,切牙压入量为(2.81±0.62)mm。CBCT显示,治疗前后切牙牙根有一定程度的吸收,其中中切牙的吸收量大于侧切牙,但没有统计学意义。结论采用种植支抗治疗露龈笑会导致上颌切牙出现牙根吸收,CBCT能够定量测量根吸收的情况。%Objective To measurethe incisor root resorptionquantitatively by CBCT in the treatment of gummy smile by using implant anchorage.Methods The straight wire appliance technology was used for 1 1 cases.Mini -screw implants were inserted between the central and lateral incisors.100 g force was used for the intrusion of incisors.Treatment stopped and maintainence began when the gingi-val margin flushed with smile line.CBCT images of all patients were taken immediately before and after intrusion.The measurement of the root length was from the longest axis on the saggital plane.Results Significant improvement of gummy smile was found in all ca-ses,and the average decrease was (2.47 ±0.64)mm.The intrusion of incisors was (2.81 ±0.62)mm.CBCT showed that the resorp-tion was more in central incisors than that in lateral incisors.Conclusions Root resorption occurred in the treatment of gummy smile by using implant anchorage,and CBCT can measure root resorption quantitatively.

  13. GEODATA: Information System Based on Geospatial for Early Warning Tracking and Analysis Agricultural Plant Diseases in Central Java

    Science.gov (United States)

    Prasetyo, S. Y. J.; Agus, Y. H.; Dewi, C.; Simanjuntak, B. H.; Hartomo, K. D.

    2017-03-01

    The Government of Indonesia is currently faced with the problems of food, especially rice. It needs in large numbers that have to import from neighboring countries. Actually, the Indonesian government has the ability to produce rice to meet national needs but is still faced with the problem of pest attack rice annually increasing extent. One of the factors is that geographically Indonesia located on the migration path of world rice insect pests (called BPH or Brown Planthoppers) (Nilaparvata lugens Stal.) It leads endemic status annually. One proposed strategy to be applied is to use an early warning system based on a specific region of the main pest population. The proposed information system called GEODATA. GEODATA is Geospatial Outbreak of Disease Tracking and Analysis. The system works using a library ESSA (Exponential Smoothing - Spatial Autocorrelation) developed in previous studies in Satya Wacana Christian University. GEODATA built to meet the qualifications required surveillance device by BMKG (Indonesian Agency of Meteorology, Climatology and Geophysics’ Central Java Provinces), BPTPH (Indonesian Agency of Plant Protection and Horticulture) Central Java Provinces, BKP-KP District Boyolali, Central Java, (Indonesian Agency of Food Security and Agriculture Field Supervisor, District Boyolali, Central Java Provinces) and farmer groups. GIS GEODATA meets the needs of surveillance devices that include: (1) mapping of the disease, (2) analysis of the dynamics of the disease, and (3) prediction of attacks / disease outbreaks in a particular region. GIS GEODATA is currently under implementation in the laboratory field observations of plant pest in Central Java province, Indonesia.

  14. Retreatment of a Maxillary Lateral Incisor With Two Separate Root Canals Confirmed With Cone Beam Computed Tomography

    Science.gov (United States)

    Aydemir, Seda; Helvacioglu-Yigit, Dilek; Sinanoglu, Alper; Ozel, Emre

    2015-01-01

    The purpose of this report is to present a rare case of a maxillary lateral incisor exhibiting two separate root canals confirmed by cone-beam computed tomography (CBCT). A 65-year-old female patient with an esthetic complaint regarding her maxillary left lateral incisor was referred to our clinic. During a radiographical examination, an endodontically treated root canal and an extra root canal with an apical lesion were observed. The retreatment was performed. CBCT findings confirmed the root canal mophology of the maxillary left lateral with two distinct canals. We conclude that the CBCT imaging is an adjunctive tool for better assessment of complex root canal systems. PMID:26015823

  15. Theoretical Study of the Effect of Enamel Parameters on Laser-Induced Surface Acoustic Waves in Human Incisor

    Science.gov (United States)

    Yuan, Ling; Sun, Kaihua; Shen, Zhonghua; Ni, Xiaowu; Lu, Jian

    2015-06-01

    The laser ultrasound technique has great potential for clinical diagnosis of teeth because of its many advantages. To study laser surface acoustic wave (LSAW) propagation in human teeth, two theoretical methods, the finite element method (FEM) and Laguerre polynomial extension method (LPEM), are presented. The full field temperature values and SAW displacements in an incisor can be obtained by the FEM. The SAW phase velocity in a healthy incisor and dental caries is obtained by the LPEM. The methods and results of this work can provide a theoretical basis for nondestructive evaluation of human teeth with LSAWs.

  16. A device for continuous monitoring of true central fixation based on foveal birefringence.

    Science.gov (United States)

    Gramatikov, Boris; Irsch, Kristina; Müllenbroich, Marie; Frindt, Nicole; Qu, Yinhong; Gutmark, Ron; Wu, Yi-Kai; Guyton, David

    2013-09-01

    A device for continuous monitoring of central fixation utilizes birefringence, the property of the Henle fibers surrounding the human fovea, to change the polarization state of light. A circular scan of retinal birefringence, where the scanning circle encompasses the fovea, allows identification of true central fixation-an assessment much needed in various applications in ophthalmology, psychology, and psychiatry. The device allows continuous monitoring for central fixation over an extended period of time in the presence of fixation targets and distracting stimuli, which may be helpful in detecting attention deficit hyperactivity disorder, autism spectrum disorders, and other disorders characterized by changes in the subject's ability to maintain fixation. A proof-of-concept has been obtained in a small study of ADHD patients and normal control subjects.

  17. Post-Fontan care based on hemodynamic characteristics, with special reference to the central venous pressure.

    Directory of Open Access Journals (Sweden)

    Nawa,Sugato

    1989-08-01

    Full Text Available Changes in the hemodynamics of six patients having received Fontan-like operations were closely observed during the first 48 h after the operation. Catheterization studies and simultaneous angiocardiography were also performed before and after the operation. Hemodynamic derangement was particularly severe during the first 24 h postoperatively as indicated by a low cardiac output of less than 2.01/min/m2, which persisted in spite of very high central venous pressure. Furthermore, the central venous pressure needed to re-establish the circulation soon after the Fontan procedure significantly correlated with the angiocardiographically assessed preoperative size of distal pulmonary arteries. Accordingly, the preoperative evaluation of the distal pulmonary arterial size is very important, that provides a good guide-line for the degree of circulatory volume expansion necessary to elevate the central venous pressure and to sustain the circulation in the early postoperative period.

  18. Effects of denervation on 3H-fucose incorporation by odontoblasts in the mouse incisor.

    Science.gov (United States)

    Chiego, D J; Fisher, M A; Avery, J K; Klein, R M

    1983-01-01

    The present study was designed to determine the effects of denervation on glycoprotein synthesis in the predentinal matrix of the mouse incisor. The inferior alveolar nerve (IAN), superior cervical ganglion (SCG) or both (IAN + SCG) were unilaterally resected in adult mice with the contralateral side remaining intact as a control. Fourteen days after surgery and 4 h prior to killing, 0.2 mCi of 3H-fucose was injected intravenously and mandibles were processed for standard histological and autoradiographic techniques. Silver halide grains were counted over the predentin matrix for 2000 micrometers per tooth. The results showed that the IAN and SCG resection affected 3H-fucose incorporation into the predentinal matrix; however, the highest absolute mean grain counts occurred after IAN + SCG resection. SCG resection increased the amount of 3H-fucose incorporated into the predentinal matrix by 48%, that of IAN by 24% and that of IAN + SCG by 14% as compared to contralateral controls. These data indicate a regulatory role for the nervous system and a possible interaction of neural components in the control of glycoprotein synthesis by odontoblasts in the mouse incisor.

  19. A Simplified Method for the Restoration of Severely Decayed Primary Incisors

    Directory of Open Access Journals (Sweden)

    Maryam Talebi

    2015-10-01

    Full Text Available Objectives: Caries and dental trauma are common reasons for primary anterior teeth restorations in children. This non-control clinical trial was designed to eva- luate crown restorations reinforced with a sectioned file post for the restoration of severely damaged primary maxillary incisors.Materials and Methods: Thirty-eight primary maxillary incisors of 12 children (3-5 years old with early childhood caries (ECC received composite restorations with a custom made post. The restorations were evaluated using the modified United State Public Health Service (USPHS criteria. The results were statistically analyzed by descriptive –analytical tests.Results: In this trial, the quality of marginal adaptation decreased after three and 12 months intervals. Recurrent carious lesions were observed during intervals. In terms of restoration retention, only one patient lost both the post and the restora- tion at the 12-month follow up.Conclusion: The sectioned file post technique showed good retention and aesthet- ics for restoring severely damaged primary maxillary anterior teeth.

  20. Maxillary sinusitis as a complication of infected dens invaginatus in maxillary lateral incisor: A case report

    Directory of Open Access Journals (Sweden)

    Paras Mull Gehlot

    2015-01-01

    Full Text Available Introduction: Maxillary sinusitis can have various origins, including odontogenic origin. Case Report: We describe a case of maxillary sinusitis in a 25-year-old female patient who experienced pain and swelling in the right maxillary region as a complication of infected maxillary lateral incisor. Clinical and radiographic examinations revealed dens invaginatus (DI; Oehler′s type III associated with apical pathosis in the maxillary right lateral incisor, with a large periapical lesion involving the adjacent four teeth. Nonsurgical root canal treatment using calcium hydroxide medicament was carried out for all five teeth, which resulted in gradual diminution of sinusitis, and the patient remained asymptomatic. Discussion: This paper emphasizes the following: (i the challenges posed by DI for root canal treatment because of its anatomical complexity; (ii a nonsurgical approach in the management of a large periapical lesion, using calcium hydroxide medicament; and (iii the interdisciplinary management of conditions of common clinical concern for medical and dental practitioners, for successful outcome.

  1. Position and stability of the mandibular incisors after rapid maxillary expansion

    Directory of Open Access Journals (Sweden)

    Darcy Flávio Nouer

    Full Text Available Objective: To make a cephalometric evaluation of the position and stability of the mandibular incisors immediately after rapid maxillaryexpansion and after a containment period of five months. Methods: The sample consisted of 21 schoolchildren, aged between 6 years and 11 months and 11 years, with mixed dentition, posterior reverse articulation (posterior cross bite, and erupted permanent first molars. The children were randomly divided into two groups: Group1 (composed of eleven children, in whom the encapsulated rapid maxilla expander was used, and Group 2 (composed of ten children, inwhom the conventional Hyrax expander was used. Three lateral teleradiographs of each individual were taken: before treatment, after rapid maxillary expansion, and after a containment period of five months. The cephalometric measurements used for analyzing the incisors were: /1.NB, /1-NB, /1-Line I, IMPA and /1-Jr. The data were submitted to the Dalhberg test, to calculate the error of repeatability, and to ANOVA (p<0.05. Results: The result showed significant difference between the adopted mechanics, but showed no difference between the initial measures, those after rapid expansion of the maxilla and final measures for all the distances, except for /1-Jr. Conclusion: Rapid maxillary expansion, using the encapsulated appliance or Hyrax, caused no significant alteration in the distances: /1.NB, /1-NB, /1-Line I, IMPA; before, after rapid maxillary expansion and after containment.

  2. Orthodontic Treatment of Maxillary Incisors with Severe Root Resorption Caused by Bilateral Canine Impaction in a Class II Division 1 Patient.

    Science.gov (United States)

    Chang, Na-Young; Park, Jae Hyun; Lee, Mi-Young; Cho, Jin-Woo; Cho, Jin-Hyoung; An, Ki-Yong; Chae, Jong-Moon

    2016-01-01

    This case report shows the successful alignment of bilateral impacted maxillary canines. A 12-year-old male with the chief complaint of the protrusion of his maxillary anterior teeth happened to have bilateral maxillary canine impaction on the labial side of his maxillary incisors. Four maxillary incisors showed severe root resorption because of the impacted canines. The patient was diagnosed as skeletal Class II malocclusion with proclined maxillary incisors. The impacted canine was carefully retracted using sectional buccal arch wires to avoid further root resorption of the maxillary incisors. To distalize the maxillary dentition, two palatal miniscrews were used. After 25 months of treatment, the maxillary canines were well aligned without any additional root resorption of the maxillary incisors.

  3. Geodiversity of the Umbria region (central Italy): a GIS-based quantitative index

    Science.gov (United States)

    Melelli, Laura; Pica, Alessia; Del Monte, Maurizio

    2014-05-01

    The measure of natural range related to geological bedrock, landforms and geomorphological processes is the necessary starting point to geodiversity evaluation. Geodiversity plays a strategic role in landscape management. Whereas geotourism and geosites are identified as a driving power for the scientific and economic promotion of an area, the geodiversity knowledge is required for a complete and accurate research. For example, high values of this abiotic parameter identify and support the foundation of geoparks. According to this perspective, the geodiversity is the unifying factor for these areas of interest. While a subjective and qualitative approach may be adequate for geosites definition, identification and cultural promotion, the geodiversity concept needs a different evaluation method. A quantitative procedure allows achieving an objective and repeatable process exportable in different geographic units. Geographical Information Systems and spatial analysis techniques are the base to quantitative evaluation involving topographic, geological and geomorphological data. Therefore, the assessment of a numerical index derived from the overlay of spatial parameters can be conveniently computed in GIS environment. In this study, a geodiversity index is proposed where geological, geomorphological and landcover factors deriving mainly from maps and field survey; topographic ones are employed from DEM and remote sensed data. Each abiotic parameter is modelled in a grid format; focal functions do provide neighbourhood analysis and computing variety statistics. A particular extent is dedicated to topographic information and terrain roughness, that are strictly related to efficiency of geomorphological processes and generally corresponding to the abiotic components variability. The study area is located in central Italy and is characterized by a well known natural heritage. Thirty-seven geosites are detected in the Umbria region, where seven regional and one natural

  4. Comparing the Gibraltar and Calabrian subduction zones (central western Mediterranean) based on seismic tomography

    Science.gov (United States)

    Argnani, Andrea; Battista Cimini, Giovanni; Frugoni, Francesco; Monna, Stephen; Montuori, Caterina

    2016-04-01

    The Central Western Mediterranean (CWM) was shaped by a complex tectonic and geodynamic evolution. Deep seismicity and tomographic studies point to the existence, under the Alboran and Tyrrhenian Seas, of lithospheric slabs extending down to the bottom of the mantle transition zone, at 660 km depth. Two narrow arcs correspond to the two slabs, the Gibraltar and Calabrian Arcs (e.g., Monna et al., 2013; Montuori et al., 2007). Similarities in the tectonic and mantle structure of the two areas have been explained by a common subduction and roll-back mechanism for the opening of the CWM, in which the two arcs are symmetrical end products. In spite of this unifying model, a wide amount of literature from different disciplines shows that many aspects of the two areas are still controversial. We present a new 3-D tomographic model at mantle scale for the Calabrian Arc and compare it with a recently published 3-D tomographic model for the Gibraltar Arc by Monna et al (2013). The two models are based on non-linear inversion of teleseismic phase arrivals, and have scale and parametrization that allow for a direct comparison. Unlike previous studies the tomographic models here presented include Ocean Bottom Seismometer broadband data, which improved the resolution of the mantle structures in the marine areas surrounding the arcs. We focus on key features of the two models that constrain reconstructions of the geodynamic evolution of the CWM (e.g., Monna et al., 2015). At Tortonian time the opening of the Tyrrhenian basin was in its initial stage, and the Calabrian arc formed subsequently; on the contrary, the Gibraltar arc was almost completely defined. We hypothesize that the complexity of the continental margin approaching the subduction zone played a key role during the final stages of the arc formation. References Monna, S., G. B. Cimini, C. Montuori, L. Matias, W. H. Geissler, and P. Favali (2013), New insights from seismic tomography on the complex geodynamic evolution

  5. Ecological and economic impacts of gorilla-based tourism in Dzanga-Sangha, Central African Republic

    NARCIS (Netherlands)

    Blom, A.

    2001-01-01

    This thesis investigates the potential role of tourism in the funding of protected area management in the Congo Basin. An assessment of the protected areas and gazetted forests of the Central African Republic (CAR) showed that only about one third of the protected areas is more or less effectively m

  6. Constructing Market-based Economies in Central Asia: A Natural Experiment?

    Directory of Open Access Journals (Sweden)

    Pomfret, Richard

    2010-12-01

    Full Text Available This paper reviews the experience of the five Central Asian countries in the two decades since independence. In the 1990s the five countries looked like a natural experiment. They had similar initial conditions, but different transition strategies. Today that does not appear to have been a useful research agenda, which raises some broader questions for comparative economic studies.

  7. A simulation-based "just in time" and "just in place" central venous catheter education program.

    Science.gov (United States)

    Lengetti, Evelyn; Monachino, Anne Marie; Scholtz, Amy

    2011-01-01

    The authors describe the Central Venous Catheter Dress Rehearsal simulation program. Teaching is conducted at the bedside, which is efficient and cost effective and allows nurses to practice in a safe environment with no harm to the patient. The educators' challenges and remediation strategies are shared. This simulation program has demonstrated improved consistency of practice and knowledge among pediatric nurses.

  8. The Design and Implementation of the Remote Centralized-Monitoring System of Well-Control Equipment Based on RFID Technique

    Directory of Open Access Journals (Sweden)

    Luo Bin

    2017-01-01

    Full Text Available At present, in domestic for the management of well control equipment continue to the traditional way of nameplates identifies and paper-based registration, there are many issues like the separation of data information of device, easy lose, difficult query, confused management and many other problems, which will make the problem device into the well field, and then resulting in well control runaway drilling accident. To solve the above problems, this paper put forward to the integrated remote centralized-monitoring management mode of the well-control equipment. Taking the advantages of IOT technology, adopting the RFID technology, and combining with the remote transmission, this paper designs the remote centralized-monitoring system of well-control equipment based on RFID, which realizes the intelligent management of well-control equipment and meets the actual demand of the well-control equipment safe use and timely scheduling, and it has the ability of field application.

  9. Mineral Deposit Data for Epigenetic Base- and Precious-metal and Uranium-thorium Deposits in South-central and Southwestern Montana and Southern and Central Idaho

    Science.gov (United States)

    Klein, T.L.

    2004-01-01

    Metal deposits spatially associated with the Cretaceous Boulder and Idaho batholiths of southwestern Montana and southern and central Idaho have been exploited since the early 1860s. Au was first discovered in placer deposits; exploitation of vein deposits in bedrock soon followed. In 1865, high-grade Ag vein deposits were discovered and remained economically important until the 1890s. Early high-grade deposits of Au, Ag and Pb were found in the weathered portions of the veins systems. As mining progressed to deeper levels, Ag and Pb grades diminished. Exploration for and development of these vein deposits in this area have continued until the present. A majority of these base- and precious-metal vein deposits are classified as polymetallic veins (PMV) and polymetallic carbonate-replacement (PMR) deposits in this compilation. Porphyry Cu and Mo, epithermal (Au, Ag, Hg and Sb), base- and precious-metal and W skarn, W vein, and U and Th vein deposits are also common in this area. The world-class Butte Cu porphyry and the Butte high-sulfidation Cu vein deposits are in this study area. PMV and PMR deposits are the most numerous in the region and constitute about 85% of the deposit records compiled. Several types of syngenetic/diagenetic sulfide mineral deposits in rocks of the Belt Supergroup or their equivalents are common in the region and they have been the source of a substantial metal production over the last century. These syngenetic deposits and their metamorphosed/structurally remobilized equivalents were not included in this database; therefore, deposits in the Idaho portion of the Coeur d'Alene district and the Idaho Cobalt belt, for example, have not been included because many of them are believed to be of this type.

  10. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare.

    Science.gov (United States)

    Grier-Lowe, Candace K; Anthony, James

    2015-08-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described.

  11. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare

    OpenAIRE

    2015-01-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described.

  12. Hyperlipidemia induced by high-fat diet enhances dentin formation and delays dentin mineralization in mouse incisor.

    Science.gov (United States)

    Ye, Xin; Zhang, Jin; Yang, Pishan

    2016-10-01

    Dyslipidemia has become a serious health problem in children and adolescents worldwide for its high prevalence. Since hard tissues of permanent teeth form mainly during this period and lipids are actively involved in tooth development, the effects of hyperlipidemia on dental tissue formation and mineralization need to be illustrated. In this study, hyperlipidemia model was established in mice fed with high-fat diet (HFD). Micro-CT and histomorphological analyses were performed on the mandibular bones to assess the morphological changes of the mandibular incisor and first molar. After 4 weeks of HFD feeding, mice had significantly elevated serum lipid levels compared with mice fed with control diet. After 8 weeks, the mandibular incisor presented significantly increased dentin thickness and decreased diameter of pulp cavity in HFD-fed mice compared with control diet-fed mice, while its gross morphology and enamel thickness were not altered. In the mandibular first molar, dentin thickness of root did not show difference between the two groups. Histological section showed that mandibular incisor of HFD-fed mice manifested a wider predentin region and a lower mineral apposition rate compared with that of the control mice. In conclusion, hyperlipidemia induced by HFD feeding enhances dentin formation and delays dentin mineralization in the developing mouse incisor.

  13. Does experience influence the forces exerted on maxillary incisors during laryngoscopy? A manikin study using the Macintosh laryngoscope

    NARCIS (Netherlands)

    M.J.L. Bucx (Martin); R.T.M. van Geel (R. T M); J.T. Wegener (J.); C. Robers (C.); Th. Stijnen (Theo)

    1995-01-01

    textabstractThe influence of the level of experience of the laryngoscopist on the duration of laryngoscopy, the forces exerted on the tongue and on the maxillary incisors during laryngoscopy, were investigated. Five groups (anaesthetists, residents in anaesthesia, nurse anaesthetists, surgeons and m

  14. Orthodontic Space Closure Versus Prosthetic Replacement of Missing Upper Lateral Incisors in Patients With Bilateral Cleft Lip and Palate

    NARCIS (Netherlands)

    Oosterkamp, Barbara C. M.; Dijkstra, Pieter U.; Remmelink, Hendrik J.; van Oort, Robert P.; Sandham, John

    2010-01-01

    Objective To compare dental aesthetics and function of orthodontic space closure versus prosthetic replacement of upper lateral incisors in patients with bilateral cleft lip and palate The predominant mode of prosthetic replacement was resin-bonded bridges Patients and Methods The retrospective stud

  15. Teachers' professional development in a community: A study of the central actors, their networks and web-based learning

    Directory of Open Access Journals (Sweden)

    Jiri Lallimo

    2008-07-01

    Full Text Available The goal of this article was to study teachers' professional development related to web-based learning in the context of the teacher community. The object was to learn in what kind of networks teachers share the knowledge of web-based learning and what are the factors in the community that support or challenge teachers professional development of web-based learning. The findings of the study revealed that there are teachers who are especially active, called the central actors in this study, in the teacher community who collaborate and share knowledge of web-based learning. These central actors share both technical and pedagogical knowledge of web-based learning in networks that include both internal and external relations in the community and involve people, artefacts and a variety of media. Furthermore, the central actors appear to bridge different fields of teaching expertise in their community.According to the central actors' experiences the important factors that support teachers' professional development of web-based learning in the community are; the possibility to learn from colleagues and from everyday working practices, an emotionally safe atmosphere, the leader's personal support and community-level commitment. Also, the flexibility in work planning, challenging pupils, shared lessons with colleagues, training events in an authentic work environment and colleagues' professionalism are considered meaningful for professional development. As challenges, the knowledge sharing of web-based learning in the community needs mutual interests, transactive memory, time and facilities, peer support, a safe atmosphere and meaningful pedagogical practices.On the basis of the findings of the study it is suggested that by intensive collaboration related to web-based learning it may be possible to break the boundaries of individual teachership and create such sociocultural activities which support collaborative professional development in the teacher

  16. [Central hemodynamic changes in children reoperated on for congenital spinal cord hernia using balanced anesthesia based on midasolam and propofol].

    Science.gov (United States)

    Diordiev, A V; Kontakevich, M M; Il'in, A V; Kusakin, V V; Ostreĭkov, I F

    2005-01-01

    The central hemodynamics was studied and analyzed in 51 patients reoperated on for congenital spinal cord hernia under balanced anesthesia based on midasolam and proforol. The procedure for anesthesiological provision of replastic repair of operated spinal hernia, which is based on propofol of bolus administration of midasolam with a hypnotic appliance, was found to cause no negative hemodynamic effects. When the benzodiazepine antagonist flumazenyl is used, the interval between the end of surgery and tracheal extubation is virtually identical in the propofol and midasolam groups since the intravenous injection of flumazenyl induces a drastic awakening effect.

  17. New neonatal classification of unilateral cleft lip and palate part 2: to predict permanent lateral incisor agenesis and maxillary growth.

    Science.gov (United States)

    Doucet, Jean-Charles; Delestan, Christian; Montoya, Pedro; Matei, Lucia; Bigorre, Michèle; Herlin, Christian; Baümler, Caroline; Daures, Jean-Pierre; Captier, Guillaume

    2014-09-01

    Objectives : To bring a neonatal classification system of unilateral cleft lip and palate and to correlate this classification with the distribution of the permanent lateral incisor and maxillary growth. Design : Retrospective with longitudinal follow-up. Setting : Tertiary. Patients : A total of 112 individuals with treated unilateral cleft lip and palate and 30 controls. Main Outcome Measures : Unilateral cleft lip and palate neonatal casts were classified anatomically in four categories, in which Class 1 corresponds to a maxillary arch with a narrow alveolar cleft; Class 2 corresponds to a balanced form; Class 3 corresponds to a wide cleft and short maxilla; and Class 4 corresponds to a wide cleft and long maxilla. The classification was correlated with the distribution of the permanent lateral incisor. Maxillary growth was evaluated using a cephalometric analysis after the age of 10 years. Results : Clinical classification of unilateral cleft lip and palate found 10 cases of Class 1 (8.9%), 34 cases of Class 2 (30.4%), 46 cases of Class 3 (41.1%), and 22 cases of Class 4 (19.6%). The permanent lateral incisor was most often present in narrower clefts (Classes 1 and 2); whereas, large clefts (Classes 3 and 4) were relatively more frequently associated with an agenesis of the permanent lateral incisor (P = .019). Maxillary growth impairment was most severe in Class 3, with a mean sella-nasion-A point angle at 71.9° ± 4.6° (P cleft width, arch form, and shape of the nasal septum, unilateral cleft lip and palate can be classified into four different classes at birth, which can all give information about permanent lateral incisor agenesis and maxillary growth.

  18. Evaluation of the lower incisor inclination during alignment and leveling using superelastic NiTi archwires: a laboratory study

    Directory of Open Access Journals (Sweden)

    Carolina Baratieri

    2012-06-01

    Full Text Available OBJECTIVE: The aim of this laboratory study is to evaluate the influence of the shape and the length limitation of superelastic nickel-titanium (NiTi archwires on lower incisors inclination during alignment and leveling. METHODS: Metal teeth mounted on a typodont articulator device were used to simulate a malocclusion of the mandibular arch (-3.5 mm model discrepancy. Three different shapes (Standard, Accuform and Ideal of superelastic NiTi archwires (Sentalloy, GAC, USA were tested. Specimens were divided in two groups: Group I, with no limitation of the archwire length; and Group II, with distal limitation. Each group had thirty specimens divided into three subgroups differentiated by the archwire shape. All groups used round wires with diameters of 0.014-in, 0.016-in, 0.018-in and 0.020-in. The recording of all intervals was accomplished using standardized digital photographs with orthogonal norm in relation to median sagittal plane. The buccolingual inclination of the incisor was registered using photographs and software CorelDraw. RESULTS: The results were obtained using ANOVA and Tukey's test at a significant level of 5%. The inclination of the lower incisor increased in both groups and subgroups. The shape of the archwire had statistically significant influence only in Group I - Standard (11.76º, Ideal (5.88º and Accuform (1.93º. Analyzing the influence of the length limitation, despite the mean incisor tipping in Group II (3.91º had been smaller than Group I (6.52º, no statistically significant difference was found, except for Standard, 3.89º with limitation and 11.76º without limitation. The greatest incisor tipping occurred with the 0.014-in archwires.

  19. Establishment of rat retention model in incisors%大鼠前牙扭转移动后保持期动物模型的建立

    Institute of Scientific and Technical Information of China (English)

    崔淑霞; 朱凤节

    2011-01-01

    目的 建立大鼠实验性正畸前牙扭转移动后保持期的动物模型并分析保持时间与复发距离的关系.方法 采用36只雌性SD大鼠,在上颌两个中切牙间施加20 g的力量,建立牙根扭转的动物模型.10d后进行固定保持,分为1、4、7、14、21d保持组(实验组),并设不予保持的对照组.测量加力结束后、保持结束时和拆除保持器后7d两中切牙之间的距离变化.计算每组大鼠拆除保持器7d后的复发距离(M).复发距离(M)=保持结束后两切牙之间的距离(M1)一复发7d后两切牙中间的距离(M2).结果 各实验组复发距离分别为(1.95±0.30)、(0.84±0.06)、(0.69±0.03)、(0.32±0.10)、(0.09±0.04)mm,明显小于对照组(2.57±0.08)mm,差异有统计学意义(P<0.05).结论 正畸用直径0.25 mm结扎丝可以用作固定保持器来建立大鼠前牙扭转移动后保持期的动物模型.%Objective To establish an experimental orthodontic movement of anterior teeth in rats and analyze the relationship between retention duration and relapse distance. Methods Totally 36 female SD rats were provided for the experiment and divided into 6 groups with 6 rats in each. Maxillary central incisors were anchored to each other and a continuous force of 20 g was applied for 10 days so as to rotate the root of both the maxillary incisors in the animal models. After the rotation was completed, orthodontic ligation wire of a diameter of 0.25 mm was used to retain the tooth in rotated position. Rats in each group were maintained to continue retention for 1, 4, 7, 14 and 21 days respectively and the retention wire was removed, but in the control group no retention was done. The distance between the two maxillary central incisors was measured after 7 days of removal of appliances. The effectiveness of devices for retention was studied by the relationship between duration of maintaining retention appliance and the relapse of tooth movement distance and calculated as the

  20. Immunolocalization of CSF-1, RANKL and OPG in the enamel-related periodontium of the rat incisor and their implications for alveolar bone remodeling.

    Science.gov (United States)

    Neves, J S; Salmon, C R; Omar, N F; Narvaes, E A O; Gomes, J R; Novaes, P D

    2009-07-01

    The enamel-related periodontium (ERP) in rat incisors is related to bone resorption. In these teeth the face of the socket related to the enamel is continuously removed at the inner side and newly formed at the outer side. CSF-1, RANKL and OPG are regulatory molecules essential for osteoclastogenesis. To verify the effects of impeded eruption on bone remodeling, the tooth eruption was prevented by immobilization of lower rat incisor and CSF-1, RANKL and OPG distribution in the ERP was analyzed after 18 days of immobilization and in normal eruption. The region of the alveolar crest of the rat incisor was used. Immunohistochemistry and tartrate-resistant acid phosphatase (TRAP) were performed. The immunostaining of the dental follicle was quantified using Leica QWin software. Positive-TRAP osteoclasts were counted, and both groups were compared. In the normal incisor, the number of osteoclasts was significantly greater than in the immobilized tooth. In the dental follicle, there was no significant difference in the immunostaining intensity for CSF-1 and OPG between the groups (p > 0.05), but for RANKL the immobilized incisor group showed immunostaining intensity smaller than the normal incisor group (p incisor, modify the RANKL/OPG ratio, in the presence of CSF-1, altering the metabolism of cells that participate in the bone remodeling.