Semicircular canals in Anolis lizards: ecomorphological convergence and ecomorph affinities of fossil species

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Dickson, Blake V.; Sherratt, Emma; Losos, Jonathan B.; Pierce, Stephanie E.

2017-10-01

Anolis lizards are a model system for the study of adaptive radiation and convergent evolution. Greater Antillean anoles have repeatedly evolved six similar forms or ecomorphs: crown-giant, grass-bush, twig, trunk, trunk-crown and trunk-ground. Members of each ecomorph category possess a specific set of morphological, ecological and behavioural characteristics which have been acquired convergently. Here we test whether the semicircular canal system-the organ of balance during movement-is also convergent among ecomorphs, reflecting the shared sensory requirements of their ecological niches. As semicircular canal shape has been shown to reflect different locomotor strategies, we hypothesized that each Anolis ecomorph would have a unique canal morphology. Using three-dimensional semilandmarks and geometric morphometrics, semicircular canal shape was characterized in 41 Anolis species from the Greater Antilles and the relationship between canal shape and ecomorph grouping, phylogenetic history, size, head dimensions, and perch characteristics was assessed. Further, canal morphology of modern species was used to predict the ecomorph affinity of five fossil anoles from the Miocene of the Dominican Republic. Of the covariates tested, our study recovered ecomorph as the single-most important covariate of canal morphology in modern taxa; although phylogenetic history, size, and head dimensions also showed a small, yet significant correlation with shape. Surprisingly, perch characteristics were not found to be significant covariates of canal shape, even though they are important habitat variables. Using posterior probabilities, we found that the fossil anoles have different semicircular canals shapes to modern ecomorph groupings implying extinct anoles may have been interacting with their Miocene environment in different ways to modern Anolis species.

Semicircular canals in Anolis lizards: ecomorphological convergence and ecomorph affinities of fossil species.

Science.gov (United States)

Dickson, Blake V; Sherratt, Emma; Losos, Jonathan B; Pierce, Stephanie E

2017-10-01

Anoli s lizards are a model system for the study of adaptive radiation and convergent evolution. Greater Antillean anoles have repeatedly evolved six similar forms or ecomorphs: crown-giant, grass-bush, twig, trunk, trunk-crown and trunk-ground. Members of each ecomorph category possess a specific set of morphological, ecological and behavioural characteristics which have been acquired convergently. Here we test whether the semicircular canal system-the organ of balance during movement-is also convergent among ecomorphs, reflecting the shared sensory requirements of their ecological niches. As semicircular canal shape has been shown to reflect different locomotor strategies, we hypothesized that each Anolis ecomorph would have a unique canal morphology. Using three-dimensional semilandmarks and geometric morphometrics, semicircular canal shape was characterized in 41 Anolis species from the Greater Antilles and the relationship between canal shape and ecomorph grouping, phylogenetic history, size, head dimensions, and perch characteristics was assessed. Further, canal morphology of modern species was used to predict the ecomorph affinity of five fossil anoles from the Miocene of the Dominican Republic. Of the covariates tested, our study recovered ecomorph as the single-most important covariate of canal morphology in modern taxa; although phylogenetic history, size, and head dimensions also showed a small, yet significant correlation with shape. Surprisingly, perch characteristics were not found to be significant covariates of canal shape, even though they are important habitat variables. Using posterior probabilities, we found that the fossil anoles have different semicircular canals shapes to modern ecomorph groupings implying extinct anoles may have been interacting with their Miocene environment in different ways to modern Anolis species.

Association between type 1 diabetes mellitus and deposits in the semicircular canals.

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Yoda, Shigetoshi; Cureoglu, Sebahattin; Yildirim-Baylan, Muzeyyen; Morita, Norimasa; Fukushima, Hisaki; Harada, Tamotsu; Paparella, Michael M

2011-09-01

To compare the prevalence of cupular and free-floating deposits in the semicircular canals between temporal bones of type 1 diabetes mellitus patients and normal controls. Case-control histopathologic human temporal bone study. Otopathology laboratory in a tertiary academic medical center. Twenty-eight temporal bones from 14 patients with type 1 diabetes mellitus and 56 normal temporal bones from 28 age-matched individuals were histopathologically examined. The cupula and lumina of the semicircular canals were examined for evidence of deposits. The prevalence of cupular and free-floating deposits in the lateral and posterior semicircular canals was significantly higher in type 1 diabetes mellitus patients compared with normal temporal bones (lateral, cupular deposits, odds ratio [OR], 5.47; 95% confidence interval [CI], 1.43 to 21.02; free-floating deposits, OR, 8.25; 95% CI, 2.42 to 27.85; posterior, cupular deposits, OR, 41.73; 95% CI, 5.96 to 275.50; free-floating deposits, OR, 7.44; 95% CI, 1.91 to 28.53). The prevalence of these deposits was associated with the duration of disease rather than with aging. The findings suggest that type 1 diabetes mellitus is associated with cupular and free-floating deposits in the semicircular canals. The patients with type 1 diabetes mellitus with a longer duration of disease have an increased probability of suffering from benign paroxysmal positional vertigo.

Congenital aplasia of the semicircular canals.

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Satar, Bulent; Mukherji, Suresh K; Telian, Steven A

2003-05-01

To describe the underrecognized inner ear malformation characterized by complete aplasia of the labyrinthine semicircular canals associated with a relatively well-formed cochlea, to investigate its relationship with known syndromic forms of hearing loss, and to hypothesize regarding the potential embryopathogenesis of this anomaly. A retrospective case review consisting of cases of sensorineural hearing loss with radiographic evidence demonstrating agenesis of the semicircular canals associated with a cochlea that was either morphologically normal or sufficiently well developed to accommodate the full insertion of a cochlear implant electrode. Cases were identified by computerized tomography findings that identified the anomaly under study. Departments of otolaryngology and radiology in a tertiary referral center, with a large cochlear implant program serving over 800 patients, more than half of whom are children. Fifteen patients with the anomaly under study were identified. Each patient underwent a complete otologic examination, audiometric studies, and high resolution computerized tomography of the temporal bone in axial and coronal planes. The bony morphology of the cochlea, round and oval windows, vestibule, semicircular canals, and vestibular aqueduct, and the course of the facial nerve were examined. Auditory findings and otologic treatment are presented. Of the 15 identified patients, 4 were nonsyndromic, 9 had CHARGE association (Coloboma of the eye, congenital Heart defects, choanal Atresia, mental and/or growth Retardation, Genital hypoplasia, and Ear anomalies and/or deafness), 1 met criteria for Noonan's syndrome, and one had features of both these syndromes. Although the cochlea was present in all cases, the cochlear morphology was usually abnormal in the CHARGE association patients. Of the 20 ears in the CHARGE subjects, only 3 ears (15%) were seen to have completely normal development of the cochlea in both the basal and upper turns. The others

Vestibular Dysfunction in Wernicke’s Encephalopathy: Predominant Impairment of the Horizontal Semicircular Canals

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Seung-Han Lee

2018-03-01

Full Text Available BackgroundWernicke’s encephalopathy (WE, a metabolic disorder due to thiamine deficiency, manifests with various neurological symptoms and signs. It has been known as a cause of vestibular dysfunction. Preliminary reports have proposed predominant involvement of the horizontal semicircular canals (HSCs.ObjectiveTo better characterize the pattern of vestibular impairment in patients with WE using quantitative video head-impulse testing and to review the literature regarding this topic.MethodFrom January 2014 to December 2016, we retrospectively enrolled five cases of WE that received quantitative video-head-impulse testing (vHIT. We retrieved the clinical features from the medical records and reviewed quantitative head-impulse testing (qHIT and caloric irrigation. Based on the gain and the number of corrective saccades, the function (normal vs. impaired of each semicircular canal was rated. In addition, we conducted a MEDLINE and EMBASE search to identify other published cases of WE that had received qHIT. Neuro-otologic and neuro-ophthalmologic findings and vestibular testing results were extracted.ResultsA total of 17 patients (own series = 5; published cases = 12 aged 54.6 ± 11 years were included. Key neurologic findings were ataxia of stance and gait (13/13, 100%, spontaneous nystagmus (7/14, 50%, gaze-evoked nystagmus (GEN (17/17, 100%, positive bedside head-impulse testing for the horizontal canals (16/17, 94%, and memory impairment and mental changes (6/11, 54.5%. Regarding vestibular testing, qHIT (either video based or search-coil based documented selective bilateral horizontal canal dysfunction with normal or minimal vertical canal impairment (14/14, 100%. On caloric irrigation, bilateral horizontal canal paresis was noted in most cases (10/11, 91%.ConclusionIn WE, signs of both peripheral and central vestibular dysfunction (i.e., GEN, ataxia of stance and gait, abnormal head-impulse testing were common. Selective or

Mondini-like malformation mimicking otosclerosis and superior semicircular canal dehiscence.

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Karlberg, M; Annertz, M; Magnusson, M

2006-05-01

In 2003, it was reported that superior semicircular canal dehiscence can mimic otosclerosis because of low-frequency bone conduction hearing gain and dissipation of air-conducted acoustic energy through the dehiscence. We report the case of a 17-year-old girl with left-sided combined hearing loss thought to be due to otosclerosis. Bone conduction thresholds were -10 dB at 250 and 500 Hz and she had a 40 dB air-bone gap at 250 Hz. When a tuning fork was placed at her ankle she heard it in her left ear. Acoustic reflexes and vestibular evoked myogenic potentials could be elicited bilaterally. Imaging of the temporal bones showed no otosclerosis, superior semicircular canal dehiscence or large vestibular aqueduct, but a left-sided, Mondini-like dysplasia of the cochlea with a modiolar deficiency could be seen. Mondini-like cochlear dysplasia should be added to the causes of inner-ear conductive hearing loss.

Persistent positional nystagmus: a case of superior semicircular canal benign paroxysmal positional vertigo?

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Heidenreich, Katherine D; Kerber, Kevin A; Carender, Wendy J; Basura, Gregory J; Telian, Steven A

2011-08-01

Involvement of the superior semicircular canal (SSC) in benign paroxysmal positional vertigo (BPPV) is rare. SSC BPPV is distinguished from the more common posterior semicircular canal (PSC) variant by the pattern of nystagmus triggered by the Dix-Hallpike position: down-beating torsional nystagmus in SSC BPPV versus up-beating torsional nystagmus in PSC BPPV. SSC BPPV may be readily treated at the bedside, which is a key component in excluding central causes of down-beating nystagmus. We present an unusual video case report believed to represent refractory SSC BPPV based on the pattern of nystagmus and the absence of any other central signs. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

CT and MR Imagings of Semicircular Canal Aplasia

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Shin, Chung Hee; Hong, Hyun Sook; Yi, Beom Ha; Cha, Jang Gyu; Park, Seong Jin; Kim, Dae Ho; Lee, Hae Kyung; Kim, Shi Chan [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

2009-07-15

To evaluate the clinical, CT and MR imaging findings of semicircular canal (SCC) aplasia and to evaluate if a correlation exists between these findings and the associated anomalies or syndromes. This study retrospectively reviewed the CT and MRI findings of five patients with SCC aplasia. The CT and MR findings were analyzed for SCC, direction of facial nerve canal, cochlea, vestibule, oval or round window, middle ear ossicles, and internal auditory canal (IAC). The subjects included three boys and two girls ranging in age from one to 120 months (mean age; 51 months). Four of the subjects had the CHARGE syndrome, and one had the Goldenhar syndrome. Moreover, four subjects had sensorineural hearing loss and one had combined hearing loss. The course of the facial nerve canal was abnormal in all five cases. Moreover, trapped cochlea and dysplastic modiolus were each observed in one case. Four subjects had atresia of the oval window; whereas ankylosis of the ossicles was present in three subjects. IAC stenosis was present in one patient with the CHARGE syndrome. The aberrant course of the facial nerve canal, atresia of the oval window, and abnormal ossicles were frequently associated in patients with SCC aplasia. In addition, the Goldenhar and CHARGE syndromes were also commonly associated syndromes.

A Comparison of Surgical Treatments for Superior Semicircular Canal Dehiscence: A Systematic Review

NARCIS (Netherlands)

Ziylan, F.; Kinaci, A.; Beynon, A.J.; Kunst, H.P.M.

2017-01-01

OBJECTIVE: We investigate the postoperative subjective and objective outcomes of different surgical treatments for superior semicircular canal dehiscence (SSCD): vestibular signs, auditory signs, vestibular evoked myogenic potential test, pure tone audiogram, speech audiogram, or

Changes of ampulla pressure in the semicircular canal of pigeons by caloric stimulation

Science.gov (United States)

Wada, Yoshiro; Suzuki, Hiroyuki; Watanabe, Satoru

Still now several hypotheses about the mechanisms of the caloric nystagmus have been in conclusive. In this study we confirmed the convection effect and the volume change effect of the endolymph in horizontal semicircular canal following the caloric stimulation using pigeons ( Columba livia). Although the direction of the caloric nystagmus depended on the head position and the stimulus site of calorization, the caloric nystagmus disappeared after plugging of horizontal semicircular canal. On the other hand, the ampulla pressure increased by cold calorization and decreased by hot calorization and these pressure changes had no relation to the head position. These results show that the main role of the mechanisms of the caloric nystagmus under 1G is the convection effect but the volume change effect may act on the caloric nystagmus not only under 1G but also under microgravity.

Gyroscopic stimulation of the semicircular canals during sensory deprivation.

Science.gov (United States)

Newsom, B. D.; Brady, J. F.; Stumm, J. E.

1971-01-01

A static object revolving at a constant velocity is stationary with respect to that environment. When the object is rotated outside the plane of spin, a gyroscopic or cross-coupled acceleration is produced orthogonal to the two planes of rotation. In this situation, a man feels himself moving in a direction other than that which his visual or proprioceptive sensors perceive. The conflict in spatial orientation is the cross-coupled acceleration imposed on the semicircular canals. This perceptual conflict and the thresholds involved were studied by partial isolation of the physiological stimuli through sensory deprivation. Subjects weighted to neutral buoyancy were submerged in 94 F water in the dark. The subjects were then rotated while being revolved about a displaced axis. Thresholds for detection of angular acceleration were higher than those reported in the literature for detection of acceleration of a single plane. This discrepancy may be attributable to the length of time the stimuli are imposed to each of the canals and the cupular response periods.

The Human Semicircular Canals Orientation Is More Similar to the Bonobos than to the Chimpanzees

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El Khoury, Marwan; Braga, José; Dumoncel, Jean; Nancy, Javotte; Esclassan, Remi; Vaysse, Frederic

2014-01-01

For some traits, the human genome is more closely related to either the bonobo or the chimpanzee genome than they are to each other. Therefore, it becomes crucial to understand whether and how morphostructural differences between humans, chimpanzees and bonobos reflect the well known phylogeny. Here we comparatively investigated intra and extra labyrinthine semicircular canals orientation using 260 computed tomography scans of extant humans (Homo sapiens), bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). Humans and bonobos proved more similarities between themselves than with chimpanzees. This finding did not fit with the well established chimpanzee – bonobo monophyly. One hypothesis was convergent evolution in which bonobos and humans produce independently similar phenotypes possibly in response to similar selective pressures that may be associated with postural adaptations. Another possibility was convergence following a “random walk” (Brownian motion) evolutionary model. A more parsimonious explanation was that the bonobo-human labyrinthine shared morphology more closely retained the ancestral condition with chimpanzees being subsequently derived. Finally, these results might be a consequence of genetic diversity and incomplete lineage sorting. The remarkable symmetry of the Semicircular Canals was the second major finding of this article with possible applications in taphonomy. It has the potential to investigate altered fossils, inferring the probability of post-mortem deformation which can lead to difficulties in understanding taxonomic variation, phylogenetic relationships, and functional morphology. PMID:24710502

The human semicircular canals orientation is more similar to the bonobos than to the chimpanzees.

Directory of Open Access Journals (Sweden)

Marwan El Khoury

Full Text Available For some traits, the human genome is more closely related to either the bonobo or the chimpanzee genome than they are to each other. Therefore, it becomes crucial to understand whether and how morphostructural differences between humans, chimpanzees and bonobos reflect the well known phylogeny. Here we comparatively investigated intra and extra labyrinthine semicircular canals orientation using 260 computed tomography scans of extant humans (Homo sapiens, bonobos (Pan paniscus and chimpanzees (Pan troglodytes. Humans and bonobos proved more similarities between themselves than with chimpanzees. This finding did not fit with the well established chimpanzee - bonobo monophyly. One hypothesis was convergent evolution in which bonobos and humans produce independently similar phenotypes possibly in response to similar selective pressures that may be associated with postural adaptations. Another possibility was convergence following a "random walk" (Brownian motion evolutionary model. A more parsimonious explanation was that the bonobo-human labyrinthine shared morphology more closely retained the ancestral condition with chimpanzees being subsequently derived. Finally, these results might be a consequence of genetic diversity and incomplete lineage sorting. The remarkable symmetry of the Semicircular Canals was the second major finding of this article with possible applications in taphonomy. It has the potential to investigate altered fossils, inferring the probability of post-mortem deformation which can lead to difficulties in understanding taxonomic variation, phylogenetic relationships, and functional morphology.

[High-frequency rotation sensation function damage of the crista of the horizontal semicircular canal induced by gentamicin and its morphological basis.].

Science.gov (United States)

Chen, Liang; He, Ming; Wang, Wu-Qing

2009-12-25

The goal of the present study was to explore high-frequency rotation sensation function damage of the crista of the horizontal semicircular canal induced by gentamicin and its morphological basis. The guinea pigs were randomly divided into four groups (group 1, 2, 3 and control group, n=20). The animals of treated groups received gentamicin subcutaneously (50 mg/kg per day) for 1 week (group 1), 2 weeks (group 2) and 3 weeks (group 3), respectively. The animals of control group were administered with equal volume of saline subcutaneously. Videonystagmography (VNG) evoked by ice water or high-frequency rotations, and vestibular evoked potential (VsEP) evoked by low- and high-frequency rotations were recorded after the administration. After VNG and VsEP were examined, the cristae of the horizontal semicircular canals were prepared for scanning and transmission electron microscopy. The results are as follows: (1) In VNG examination, after ice water stimulation, no obvious nystagmus was observed in the animals of group 3, and there was no significant difference in nystagmus frequency and duration among group 1, 2 and control group (P>0.05). After high- frequency rotations, no obvious nystagmus was yet observed in the animals of group 3. There were significant differences in the nystagmus frequency and duration of the VNG waves between the experimental group 2 and control group (P0.05). (2) In VsEP examination, there was no significant difference in the parameters of VsEP among group 1, 2 and control group (P>0.05), and VsEP was not observed in group 3 after low-frequency rotations. After high- frequency rotations, compared with control group, the latencies and amplitudes of P1 and P2 in group 2 significantly decreased (P0.05). Group 3 had no response of VsEP to high-frequency rotations. (3) Electron microscopy was used to observe the crista hair cells of the four groups. In control group, the hair cells were normal. In group 1, almost normal appearance with slight

Semicircular canals circumvent Brownian Motion overload of mechanoreceptor hair cells

DEFF Research Database (Denmark)

Muller, Mees; Heeck, Kier; Elemans, Coen P H

2016-01-01

Vertebrate semicircular canals (SCC) first appeared in the vertebrates (i.e. ancestral fish) over 600 million years ago. In SCC the principal mechanoreceptors are hair cells, which as compared to cochlear hair cells are distinctly longer (70 vs. 7 μm), 10 times more compliant to bending (44 vs. 500...... nN/m), and have a 100-fold higher tip displacement threshold (hair cells where the bundle is approximated as a stiff, cylindrical elastic rod subject to friction and thermal agitation. Our models suggest that the above...... differences aid SCC hair cells in circumventing the masking effects of Brownian motion noise of about 70 nm, and thereby permit transduction of very low frequency (

[Objective characteristics of nystagmus in horizontal semicircular canal benign paroxysmal positional vertigo].

Science.gov (United States)

Chen, Fei-yun; Chen, Tai-sheng; Wen, Chao; Li, Shan-shan; Lin, Peng; Zhao, Hui; Liu, Qiang

2013-08-01

To discuss the objective characteristics and mechanism of nystagmus direction, intensity and time in horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) . A total of 233 patients with HSC-BPPV, whereas 179 horizontal semicircular canalithasis (HSC-Can) and 54 horizontal semicircular cupulolithiasis (HSC-Cup) were involved respectively. The induced nystagmus in roll tests recorded by video-nystagmograph(VNG) , whose direction, intensity and time characteristics were compared in various BPPV. Horizontal nystagmus was both induced by turning left or right in HSC-BPPV roll tests. The direction of the induced nystagmus was the same with turning in HSC-Can. The latency, duration time and intensity ([AKx(-)D] ± s) turning to lesion and normal side were (1.922 ± 1.501)s and (1.447 ± 0.855)s, (25.620 ± 10.409)s, and (22.110 ± 10.931)s, (56.441 ± 33.168)°/s and (24.239 ± 13.892) °/s in HSC-Can. The latency, duration time and intensity turning to lesion side were larger than normal side (t = 3.715, 15.219 and 4.070, P 0.05). The induced nystagmus intensity of head to two sides in roll tests for HSC-BPPV both follow Ewald's law, and the ratio between stronger and weaker are both 2: 1. These nystagmus parameters of VNG in roll tests are an objective guideline for BPPV diagnosis.

Development of conductive hearing loss due to posterior semicircular canal dehiscence.

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Kubota, Marie; Kubo, Kazuhiko; Yasui, Tetsuro; Matsumoto, Nozomu; Komune, Shizuo

2015-06-01

We herein report a case of posterior semicircular canal dehiscence (SCD) syndrome who had been audiologically followed up for eight years. The patient originally had sensorineural hearing loss. The audiogram had gradually transformed to pure conductive hearing loss. The posterior SCD was identified in CT scan. The reported case showed the possibility to distinguish the mechanism at play underlying the typical conductive hearing loss in SCD patients by tracing the transition of the hearing loss pattern. This information is of much help to predict the hearing outcomes if surgical intervention were chosen for the treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

International Nuclear Information System (INIS)

Hagiwara, Mari; Fatterpekar, Girish; Shaikh, Jamil A.; Fang, Yixin; Roehm, Pamela C.

2012-01-01

Previous studies suggest that semicircular canal dehiscences (SCDs) have a developmental origin. We hypothesized that if SCDs originate during development, incidence of radiographic SCDs in young children will be higher than in adults. Thirty-four temporal bone HRCTs of children younger than 2 years and 40 temporal bone HRCTs of patients older than 18 years were reformatted and re-evaluated for presence of SCD or canal thinning. Results were compared with indications for HRCT and clinical information. SCDs were detected in 27.3% of children younger than 2 years of age (superior, 13.8%; posterior, 20%) and in 3% of adults (P < 0.004). Of children with one radiographic dehiscence, 55.6% had multiple and 44% had bilateral SCDs on HRCT. No lateral canal SCDs were present. Thinning of bone overlying the semicircular canals was found in 44% of children younger than 2 years and 2.5% of adults (P < 0.0001). SCDs are more common on HRCTs of very young children. This supports the hypothesis that SCDs originate from discontinuation of bone deposition/maturation. However, SCDs on imaging do not necessarily correlate with canal dehiscence syndrome and should therefore be interpreted carefully. (orig.)

Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

Energy Technology Data Exchange (ETDEWEB)

Hagiwara, Mari; Fatterpekar, Girish [New York University School of Medicine, Department of Radiology, New York, NY (United States); Shaikh, Jamil A. [New York University School of Medicine, Department of Otolaryngology, New York, NY (United States); Fang, Yixin [New York University School of Medicine, Department of Otolaryngology, New York, NY (United States); New York University School of Medicine, Division of Biostatistics, Department of Environmental Medicine, New York, NY (United States); Roehm, Pamela C. [New York University School of Medicine, Department of Otolaryngology, New York, NY (United States); New York University School of Medicine, Department of Otolaryngology, Division of Otology/Neurotology, New York, NY (United States)

2012-12-15

Previous studies suggest that semicircular canal dehiscences (SCDs) have a developmental origin. We hypothesized that if SCDs originate during development, incidence of radiographic SCDs in young children will be higher than in adults. Thirty-four temporal bone HRCTs of children younger than 2 years and 40 temporal bone HRCTs of patients older than 18 years were reformatted and re-evaluated for presence of SCD or canal thinning. Results were compared with indications for HRCT and clinical information. SCDs were detected in 27.3% of children younger than 2 years of age (superior, 13.8%; posterior, 20%) and in 3% of adults (P < 0.004). Of children with one radiographic dehiscence, 55.6% had multiple and 44% had bilateral SCDs on HRCT. No lateral canal SCDs were present. Thinning of bone overlying the semicircular canals was found in 44% of children younger than 2 years and 2.5% of adults (P < 0.0001). SCDs are more common on HRCTs of very young children. This supports the hypothesis that SCDs originate from discontinuation of bone deposition/maturation. However, SCDs on imaging do not necessarily correlate with canal dehiscence syndrome and should therefore be interpreted carefully. (orig.)

Central Lesions With Selective Semicircular Canal Involvement Mimicking Bilateral Vestibulopathy

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Luke Chen

2018-04-01

Full Text Available Bilateral vestibulopathy (BVP, which is due to peripheral lesions, may selectively involve certain semicircular canal (SCC. Recent eye movement recordings with search coil and video head impulse test (HIT have provided insight in central lesions that can cause bilateral and selective SCC deficit mimicking BVP. Since neurological signs or ocular motor deficits maybe subtle or absent, it is critical to recognize central lesions correctly since there is prognostic and treatment implication. Acute floccular lesions cause bilateral horizontal SCC (HC impairment while leaving vertical SCC function unaffected. Vestibular nuclear lesions affect bilateral HC and posterior SCC (PC function, but anterior SCC (AC function is spared. When both eyes are recorded, medial longitudinal fasciculus lesions cause horizontal dysconjugacy in HC function and catch-up saccades, as well as selective deficiency of PC over AC function. Combined peripheral and central lesions may be difficult to distinguish from BVP. Anterior inferior cerebellar artery stroke causes two types of deficits: 1. ipsilateral pan-SCC deficits and contralateral HC deficit and 2. bilateral HC deficit with vertical SCC sparing. Metabolic disorders such as Wernicke encephalopathy characteristically involve HC but not AC or PC function. Gaucher disease causes uniform loss of all SCC function but with minimal horizontal catch-up saccades. Genetic cerebellar ataxias and cerebellar-ataxia neuropathy vestibular areflexia syndrome typically do not spare AC function. While video HIT does not replace the gold-standard, search coil HIT, clinicians are now able to rapidly and accurately identify specific pattern of SCC deficits, which can aid differentiation of central lesions from BVP.

Influencia de la edad y la menopausia en el origen de la Dehiscencia del Canal Semicircular Superior

OpenAIRE

Fernández Castaño, Carmen

2014-01-01

145 p. : il., col. La dehiscencia del canal semicircular superior (DCSS) es una forma de vestibulopatía periférica caracterizada por la ausencia de cobertura ósea en el techo de dicho canal, de este modo su luz interior queda anormalmente abierta al espacio intracraneal en contacto directo con la meninge que tapiza el suelo de la fosa media. Esta dehiscencia se limitaría a la cápsula ótica y no afectaría, aparentemente, al laberinto membranoso. Su presentación clínica es variable, siendo ...

The Effect of Superior Semicircular Canal Dehiscence on Intracochlear Sound Pressures

Science.gov (United States)

Nakajima, Hideko Heidi; Pisano, Dominic V.; Merchant, Saumil N.; Rosowski, John J.

2011-11-01

Semicircular canal dehiscence (SCD) is a pathological opening in the bony wall of the inner ear that can result in conductive hearing loss. The hearing loss is variable across patients, and the precise mechanism and source of variability is not fully understood. We use intracochlear sound pressure measurements in cadaveric preparations to study the effects of SCD size. Simultaneous measurement of basal intracochlear sound pressures in scala vestibuli (SV) and scala tympani (ST) quantifies the complex differential pressure across the cochlear partition, the stimulus that excites the partition. Sound-induced pressures in SV and ST, as well as stapes velocity and ear-canal pressure are measured simultaneously for various sizes of SCD followed by SCD patching. At low frequencies (<600 Hz) our results show that SCD decreases the pressure in both SV and ST, as well as differential pressure, and these effects become more pronounced as dehiscence size is increased. For frequencies above 1 kHz, the smallest pinpoint dehiscence can have the larger effect on the differential pressure in some ears. These effects due to SCD are reversible by patching the dehiscence.

Incidence of dehiscence of the bony roof of the superior semicircular canal by CT imaging

International Nuclear Information System (INIS)

Watanabe, Akira

2003-01-01

Dehiscence of the bony roof of the superior semicircular canal (SSCC) is rare, but it has been recognized by otologists since Minor et al first described superior canal dehiscence syndrome (SCDS). In this study, dehiscence of the bony roof of SSCC was incidentally detected in three patients with benign paroxysmal positional vertigo out of 49 serial patients with vertigo and dizziness by multi-slice computed tomography. Although detection of dehiscence of the SSCC by ultra-high-resolution CT imaging of the temporal bones has been required for a diagnosis of SCDS, this study showed that dehiscence of the bony roof of the SSCC can be an incidental finding and therefore is not specific for SCDS. (author)

Controle postural na síndrome de Pusher: influência dos canais semicirculares laterais Posture control in Pusher syndrome: influence of lateral semicircular canals

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Taiza Elaine Grespan dos Santos Pontelli

2005-08-01

Full Text Available A síndrome de Pusher caracteriza-se por uma alteração do equilíbrio na qual pacientes com lesões encefálicas empurram-se em direção ao lado parético utilizando o membro não-afetado. O papel do sistema vestibular na alteração postural da síndrome de Pusher ainda não foi devidamente elucidado. OBJETIVO: Neste estudo objetivamos avaliar o papel dos canais semicirculares horizontais na expressão clínica da síndrome de Pusher, através da aplicação das provas calórica e rotatória. FORMA DE ESTUDO: Observacional, clínico e prospectivo. MATERIAL E MÉTODO: Avaliamos 9 pacientes com AVC e síndrome de Pusher internados na Enfermaria de Neurologia do HCFMRP-USP. Os pacientes foram submetidos à avaliação neurológica clínica e neuropsicológica, NIHSS, Scale for Contraversive Pushing - SCP, teste calórico e teste rotatório. RESULTADOS: Foram estudados 9 pacientes (5 homens com idade média de 71,8 ± 5,9 anos e com NIHSS médio de 18.33. Três pacientes apresentaram preponderância direcional contralateral à lesão encefálica na prova calórica. Na prova rotatória, foram observados quatro pacientes com preponderância direcional na análise de velocidade da componente lenta. CONCLUSÃO: Os resultados do presente estudo indicam que a disfunção dos canais semicirculares não parece ser fundamental para a expressão da síndrome de Pusher.Pusher syndrome is an interesting disorder of balance in patients with encephalic lesions characterized by the peculiar behavior of actively pushing away from the non-hemiparetic side and resisting against passive correction, with a tendency to fall toward the paralyzed side. The role of vestibular system on the pushing behavior is not clear. AIM: To evaluate horizontal semicircular canal function in patients with Pusher syndrome, using caloric and rotation tests. STUDY DESIGN: Observational prospective. MATERIAL AND METHOD: We evaluated 9 inpatients with stroke and Pusher syndrome at the

Histamine H1 receptors are expressed in mouse and frog semicircular canal sensory epithelia.

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Botta, Laura; Tritto, Simona; Perin, Paola; Laforenza, Umberto; Gastaldi, Giulia; Zampini, Valeria; Zucca, Gianpiero; Valli, Stefano; Masetto, Sergio; Valli, Paolo

2008-03-05

Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. Their site and mechanism of action, however, are still poorly understood. To increase our knowledge of the histaminergic system in the vestibular organs, we have investigated the expression of H1 and H3 histamine receptors in the frog and mouse semicircular canal sensory epithelia. Analysis was performed by mRNA reverse transcriptase-PCR, immunoblotting and immunocytochemistry experiments. Our data show that both frog and mouse vestibular epithelia express H1 receptors. Conversely no clear evidence for H3 receptors expression was found.

Anterior semicircular canal benign paroxysmal positional vertigo and positional downbeating nystagmus.

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Lopez-Escamez, Jose A; Molina, Maria I; Gamiz, Maria J

2006-01-01

The aim of this study was to describe the clinical features and video-oculographic findings in patients with anterior semicircular canal benign paroxysmal positional vertigo (BPPV). This is a prospective case series. The study was set at an outpatient clinic in a general hospital. Fourteen individuals with symptoms of BPPV and positional downbeating nystagmus (pDBN) were included in the study. The diagnosis was based on a history of brief episodes of vertigo and the presence of pDBN confirmed in the video-oculographic examination during Dix-Hallpike test (DH) or head-hanging maneuver. Patients were treated by particle repositioning maneuver and the effectiveness was evaluated at 7, 30, and 180 days posttreatment. The treatment was repeated up to 4 times if pDBN was persistent. The main outcome measure is the number of patients without pDBN at 30 and 180 days. Video-oculography showed a predominant pDBN in response to DH. Of the 14 patients, 7 had arterial hypertension, and 5 of 14 cases presented abnormalities on the caloric test. Horizontal spontaneous nystagmus was found in 3 of 14 individuals. Positional nystagmus at different positional test was observed in 5 of 14 individuals, suggesting the involvement of several canals. Of the 14 patients, 10 (71%) did not present vertigo, and the positional tests were negative at 30 days. However, 3 cases presented a positive DH with persistence of BPPV episodes and pDBN at 30 days, and another developed a contralateral posterior canal affectation. One of the patients maintained a persistent pDBN at 180 days despite the repeated maneuvers. Video-oculography demonstrates that anterior canal BPPV is characterized by a predominant downbeating nystagmus in response to DH. These individuals may show alterations in the vestibular caloric, and they can have multicanal affectation.

Hierarchical Cluster Analysis of Semicircular Canal and Otolith Deficits in Bilateral Vestibulopathy

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Alexander A. Tarnutzer

2018-04-01

Full Text Available BackgroundGait imbalance and oscillopsia are frequent complaints of bilateral vestibular loss (BLV. Video-head-impulse testing (vHIT of all six semicircular canals (SCCs has demonstrated varying involvement of the different canals. Sparing of anterior-canal function has been linked to aminoglycoside-related vestibulopathy and Menière’s disease. We hypothesized that utricular and saccular impairment [assessed by vestibular-evoked myogenic potentials (VEMPs] may be disease-specific also, possibly facilitating the differential diagnosis.MethodsWe searched our vHIT database (n = 3,271 for patients with bilaterally impaired SCC function who also received ocular VEMPs (oVEMPs and cervical VEMPs (cVEMPs and identified 101 patients. oVEMP/cVEMP latencies above the 95th percentile and peak-to-peak amplitudes below the 5th percentile of normal were considered abnormal. Frequency of impairment of vestibular end organs (horizontal/anterior/posterior SCC, utriculus/sacculus was analyzed with hierarchical cluster analysis and correlated with the underlying etiology.ResultsRates of utricular and saccular loss of function were similar (87.1 vs. 78.2%, p = 0.136, Fisher’s exact test. oVEMP abnormalities were found more frequent in aminoglycoside-related bilateral vestibular loss (BVL compared with Menière’s disease (91.7 vs. 54.6%, p = 0.039. Hierarchical cluster analysis indicated distinct patterns of vestibular end-organ impairment, showing that the results for the same end-organs on both sides are more similar than to other end-organs. Relative sparing of anterior-canal function was reflected in late merging with the other end-organs, emphasizing their distinct state. An anatomically corresponding pattern of SCC/otolith hypofunction was present in 60.4% (oVEMPs vs. horizontal SCCs, 34.7% (oVEMPs vs. anterior SCCs, and 48.5% (cVEMPs vs. posterior SCCs of cases. Average (±1 SD number of damaged sensors was 6.8 ± 2.2 out of 10

Síndrome de Deiscência de Canal Semicircular Superior Superior Canal Dehiscence Syndrome

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Suzane da Cunha Ferreira

2006-06-01

Full Text Available A Síndrome de Deiscência de Canal Semicircular Superior (SDCSS, primeiramente descrita em 1998 por Minor et al., caracteriza-se por vertigem associada à presença de nistagmo, relacionados à exposição a estímulos sonoros intensos ou a modificações de pressão dentro da orelha média ou intracraniana. Disacusia, em sua maioria de padrão condutivo à audiometria tonal, também pode estar presente. Nesta revisão da literatura objetivou-se abordar a SDCSS, com seus principais sinais e sintomas, achados diagnósticos e tratamento, assim como enfatizar a importância de sua inclusão dentre as causas de vertigem, visto tratar-se de acometimento ainda pouco conhecido até mesmo entre especialistas. O diagnóstico correto, além de possibilitar seu tratamento, impede que abordagens diagnósticas e terapêuticas inapropriadas sejam realizadas.The Superior Canal Dehiscence Syndrome (SCDS was first reported by Minor at. Al. (1998, and has been characterized by vertigo and vertical-torsional eye movements related to loud sounds or stimuli that change middle ear or intracranial pressure. Hearing loss, for the most part with conductive patterns on audiometry, may be present in this syndrome. We performed a literature survey in order to to present symptoms, signs, diagnostic and therapeutic approaches to the SCDS, also aiming at stressing the great importance of including this syndrome among the tractable cause of vertigo. We should emphasize that this is a recent issue, still unknown by some specialists. The Correct SCDS diagnosis, besides enabling patient treatment, precludes misdiagnosis and inadequate therapeutic approaches.

Vestibular ablation and a semicircular canal prosthesis affect postural stability during head turns

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Thompson, Lara A.; Haburcakova, Csilla; Lewis, Richard F.

2016-01-01

In our study, we examined postural stability during head turns for two rhesus monkeys: one, single animal study contrasted normal and mild bilateral vestibular ablation and a second animal study contrasted severe bilateral vestibular ablation with and without prosthetic stimulation. The monkeys freely stood, unrestrained on a balance platform and made voluntary head turns between visual targets. To quantify each animals’ posture, motions of the head and trunk, as well as torque about the body’s center-of-mass, were measured. In the mildly ablated animal, we observed less foretrunk sway in comparison to the normal state. When the canal prosthesis provided electric stimulation to the severely ablated animal, it showed a decrease in trunk sway during head turns. Because the rhesus monkey with severe bilateral vestibular loss exhibited a decrease in trunk sway when receiving vestibular prosthetic stimulation, we propose that the prosthetic electrical stimulation partially restored head velocity information. Our results provide an indication that a semicircular canal prosthesis may be an effective way to improve postural stability in patients with severe peripheral vestibular dysfunction. PMID:27405997

Canal switch after canalith repositioning procedure for benign paroxysmal positional vertigo.

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Lin, Giant C; Basura, Gregory J; Wong, Hiu Tung; Heidenreich, Katherine D

2012-09-01

Canal switch is a complication following canalith repositioning procedure (CRP) for posterior canal benign paroxysmal positional vertigo (BPPV). Instead of being returned to the utricle, the loose otoconia migrate into the superior or horizontal semicircular canal. Patients remain symptomatic, and treatment can be ineffective unless the switch is recognized and additional repositioning maneuvers directed toward the appropriate semicircular canal are performed. This report provides the first videographic documentation of canal switch involving conversion of unilateral posterior semicircular canal BPPV to geotropic horizontal canalithiasis. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Superior Canal Dehiscence Syndrome: Lessons from the First 20 Years

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Bryan K. Ward

2017-04-01

Full Text Available Superior semicircular canal dehiscence syndrome was first reported by Lloyd Minor and colleagues in 1998. Patients with a dehiscence in the bone overlying the superior semicircular canal experience symptoms of pressure or sound-induced vertigo, bone conduction hyperacusis, and pulsatile tinnitus. The initial series of patients were diagnosed based on common symptoms, a physical examination finding of eye movements in the plane of the superior semicircular canal when ear canal pressure or loud tones were applied to the ear, and high-resolution computed tomography imaging demonstrating a dehiscence in the bone over the superior semicircular canal. Research productivity directed at understanding better methods for diagnosing and treating this condition has substantially increased over the last two decades. We now have a sound understanding of the pathophysiology of third mobile window syndromes, higher resolution imaging protocols, and several sensitive and specific diagnostic tests. Furthermore, we have a treatment (surgical occlusion of the superior semicircular canal that has demonstrated efficacy. This review will highlight some of the fundamental insights gained in SCDS, propose diagnostic criteria, and discuss future research directions.

[Clinical research of the otolith abnormal migration during canalith repositioning procedures for posterior semicircular canal benign paroxysmal positional vertigo].

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Ou, Yongkang; Zheng, Yiging; Zhu, Honglei; Chen, Ling; Zhong, Junwei; Tang, Xiaowu; Huang, Qiuhong; Xu, Yaodong

2015-01-01

To investigate the risk factor,type and characteristic nystagmus of the otolith abnormal migration during diagnosis and treatment for posterior semicircular canal benign paroxysmal positional vertigo (PSC-BPPV). The therapy and prevention is also discussed. Four hundred and seventy-nine patients with PSC-BPPV were treated by Epley's canalith repositioning procedures(CRP) from March 2009 to March 2012. We observed otolith abnormal migration complicating during diagnosis and treatment. According the type of otolith abnormal migration, the additional repositioning maneuver was performed. The rate of complication was 8. 1%(39/479), with canal conversion in 5.4%(26/479) and primarily canal reentry in 2.7%(13/479). The rate of incidence of conversion to horizontal canal conversion and anterior canal were 4. 8%(23/479)and 0. 6%(3/479) respectively. All the patient was cured in follow up. The risk factors were unappropriated head movement during or after CRP, including another Dix-Hallpike were performed immediately. To prevent the complications,the pathognostic positioning sequence and angle of head rotation are commenced during CRP. Appropriate short time postural restrictions post-treatment is necessary. Careful observation of nystagrnus variation is crucial to determine the otolith abnormal migration.

Ca(2+) currents and voltage responses in Type I and Type II hair cells of the chick embryo semicircular canal.

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Masetto, Sergio; Zampini, Valeria; Zucca, Giampiero; Valli, Paolo

2005-11-01

Type I and Type II hair cells, and Type II hair cells located in different zones of the semicircular canal crista, express different patterns of voltage-dependent K channels, each one specifically shaping the hair cell receptor potential. We report here that, close to hatching, chicken embryo semicircular canal Type I and Type II hair cells express a similar voltage-dependent L-type calcium current (I(Ca)), whose main features are: activation above -60 mV, fast activation kinetics, and scarce inactivation. I(Ca) should be already active at rest in Zone 1 Type II hair cells, whose resting membrane potential was on average slightly less negative than -60 mV. Conversely, I(Ca) would not be active at rest in Type II hair cells from Zone 2 and 3, nor in Type I hair cells, since their resting membrane potential was significantly more negative than -60 mV. However, even small depolarising currents would activate I(Ca) steadily in Zone 2 and 3 Type II hair cells, but not in Type I hair cells because of the robust repolarising action of their specific array of K(+) currents. The implications of the present findings in the afferent discharge are discussed.

The induction and compensation of asymmetric eye movements following unilateral blockage of a horizontal semicircular canal in the rabbit.

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Barmack, N H; Pettorossi, V E

1988-08-01

The influence of unilateral plugs of the left horizontal semicircular canal (LHC plugs) of rabbits on the development and compensation of asymmetric eye movements evoked by horizontal vestibular stimulation was studied. LHC plugs caused an immediate reduction of 50-65% in the gain of the horizontal vestibuloocular reflex (HVOR). This reduction in gain was achieved without altering the symmetry of the HVOR, and was accompanied by a change in the axial alignment of eye movements evoked by vestibular stimulation about the vertical (HVOR) and longitudinal (VVOR) axes. Postoperative asymmetry of eye movements developed 12-48 hr after the plugging operation. The development of asymmetry was reduced if the rabbit was restrained for 24 hr, thereby minimizing vestibular stimulation following the plugging operation. Over a 3-4 week period, the normal symmetry of eye movements was restored and the axial alignments of the HVOR and VVOR returned to the preoperative values. The gain of the HVOR did not recover. The horizontal cervicoocular reflex (HCOR) was examined before the plugging operation and after compensation of asymmetry was complete. The gain and phase of the HCOR were not altered. A relatively simple set of explanations at a cellular level is proposed to account for the induction and compensation of asymmetric eye movements following a unilateral plug of the horizontal semicircular canal.

The variability of inner ear orientation in saurischian dinosaurs: testing the use of semicircular canals as a reference system for comparative anatomy

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Jesús Marugán-Lobón

2013-08-01

Full Text Available The vestibular system of the inner ear houses three semicircular canals—oriented on three nearly-orthogonal planes—that respond to angular acceleration stimuli. In recent years, the orientation of the lateral semicircular canal (LSC has been regularly used to determine skull orientations for comparative purposes in studies of non-avian dinosaurs. Such orientations have been inferred based on fixing the LSC to a common set of coordinates (parallel to the Earth’s horizon, given that the orientation to gravity of this sensory system is assumed constant among taxa. Under this assumption, the LSC is used as a baseline (a reference system both to estimate how the animals held their heads and to describe craniofacial variation among dinosaurs. However, the available data in living birds (extant saurischian dinosaurs suggests that the orientation of the LSC in non-avian saurischian dinosaurs could have been very variable and taxon-specific. If such were the case, using the LSC as a comparative reference system would cause inappropriate visual perceptions of craniofacial organization, leading to significant descriptive inconsistencies among taxa. Here, we used Procrustes methods (Geometric Morphometrics, a suite of analytical tools that compares morphology on the basis of shared landmark homology, to show that the variability of LSC relative to skull landmarks is large (ca. 50° and likely unpredictable, thus making it an inconsistent reference system for comparing and describing the skulls of saurischian (sauropodomorph and theropod dinosaurs. In light of our results, the lateral semicircular canal is an inconsistent baseline for comparative studies of craniofacial morphology in dinosaurs.

Superior semicircular canal dehiscence in relation to the superior petrosal sinus: a potential cause of pulsatile tinnitus

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Liu, Z.; Bi, W.; Li, J.; Li, Q.; Dong, C.; Zhao, P.; Lv, H.; Wang, Z.

2015-01-01

Aim: To examine the association between superior semicircular canal dehiscence (SSCD) and pulsatile tinnitus (PT). Materials and methods: Two SSCD groups included 408 unilateral persistent PT patients, and 511 controls undergoing head and neck dual-phase contrast-enhanced computed tomography (DP-CECT) for reasons other than PT. The prevalence of type I (no the superior petrosal sinus running through the dehiscence) and type II (superior semicircular canal dehiscence in relation to the superior petrosal sinus) SSCD was analysed using chi-square test. Results: SSCD was identified in 5.1% (21/408) of PT ears, significantly different from 2% (8/408) of non-PT ears and 0.7% (7/1022) of controls. There was no significant difference in SSCD prevalence between non-PT ears in the PT group and controls. In the PT group, 15/21 ears were type II SSCD; 6/21 ears were type I. Fifteen combined non-PT and control ears with SSCD included two type II and 13 type I SSCD. The prevalence of type II SSCD in PT ears was significantly higher than that of non-PT ears in both groups, and the prevalence of type I SSCD in PT ears was similar to that of non-PT ears in both groups. Conclusion: Compared with type I SSCD, there may be a causal relationship between type II SSCD and PT. -- Highlights: •The prevalence of type II SSCD in PT ears was significantly higher than that in non-PT ears in both the PT group and controls. •The prevalence of type I SSCD was similar among the PT ears and non-PT ears. •The superior petrosal sinus running through the dehiscence may be essential for SSCD to induce PT. •Venous phase CT images with bone window settings is the modality method to differentiate type II from type I SSCD

The Density Difference of Cupula and Endolymph Changes the Mechanics of Semicircular Canals

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Kondrachuk, Alexander V.; Boyle, Richard D.

2011-11-01

A precise balance of cupula and endolymph densities is key to the proper sensing of angular acceleration by the semicircular canals (SC). Estimates show that a density difference of cupula and endolymph (DD) as small as 10 - 4 g/cm3 is sufficient to make the SC sensitive to gravity and centrifugal forces provided they are comparable with gravity. As a result this might cause vestibular disorders. There are conditions under which the DD may even exceed this value. One of them is a change of intra-labyrinth pressure (IP) that may take place during a spaceflight. Here, the effect of DD on SC dynamics is considered using a simplified one-dimensional toroidal mathematical model of a canal for rotation with constant or harmonically oscillating angular velocities. The DD results in: dependence of cupula dynamics on orientation of both the gravity vector relative to the SC plane and the axis of rotation, as well as on the distance between the axis of rotation and the center of SC; shift of the cupula to a new position of equilibrium that depends on both the gravity vector and the parameters of head rotation; and onset of cupula oscillations with multiple frequencies under harmonic stimulation. The DD effect may be important under conditions of artificial gravity where the directions of centrifugal forces, the values of which are comparable with Earth's gravity, the orientations of the axis of rotation of a space station, and the axes of the SCs change during movements of the individuals and their habitat.

Spatial coordination of compensatory eye movements in vertebrates: form and function.

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Graf, W

1988-01-01

The semicircular canals of the labyrinth of vertebrates provide one way of motion detection in three-dimensional space. The fully developed form of the vertebrate labyrinth consists of six semicircular canals, three on each side of the head, whose spatial arrangement (vertical canals are placed diagonally in the head, horizontal canals are oriented earth horizontally) follows three interconnected principles: 1) bilateral symmetry, 2) push-pull operational mode, and 3) mutual orthogonality. Other sensory and motor systems related to vestibular reflexes, such as the extraocular muscles or the "optokinetic" coordinate axes encoded in the activity of the visually driven cells of the accessory optic system, share the same geometrical framework. This framework is also reflected in the anatomical networks mediating compensatory eye movements, linking each of the semicircular canals to a particular set of extraocular muscles (so-called principal vestibuloocular reflex connections to yoke muscles). These classical vestibulo-oculomotor relationships have been verified at many levels of the vertebrate hierarchy, including lateral- and frontal-eyed animals. The particular spatial orientation of the semicircular canals requires further comment and phylogenetic evaluation. The spatial arrangement of the vertical canals is already present in fossil ostracoderms, and is also exemplified in lampreys, the modern forms of once abundant agnathan species that populated the Silurian and Devonian oceans. The lampreys and ostracoderms lack horizontal canals, which appear later in all descendent vertebrates. The fully developed vertebrate labyrinth with its six semicircular canals displays distinct differences that are obvious when comparing distant taxa (e.g. elasmobranchs versus other vertebrates). Whereas the common crus of the semicircular canals in teleosts through mammals is formed between the anterior and the posterior semicircular canal, it occurs between the anterior and the

Anatomy of the lamprey ear: morphological evidence for occurrence of horizontal semicircular ducts in the labyrinth of Petromyzon marinus

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Maklad, Adel; Reed, Caitlyn; Johnson, Nicholas S.; Fritzsch, Bernd

2014-01-01

In jawed (gnathostome) vertebrates, the inner ears have three semicircular canals arranged orthogonally in the three Cartesian planes: one horizontal (lateral) and two vertical canals. They function as detectors for angular acceleration in their respective planes. Living jawless craniates, cyclostomes (hagfish and lamprey) and their fossil records seemingly lack a lateral horizontal canal. The jawless vertebrate hagfish inner ear is described as a torus or doughnut, having one vertical canal, and the jawless vertebrate lamprey having two. These observations on the anatomy of the cyclostome (jawless vertebrate) inner ear have been unchallenged for over a century, and the question of how these jawless vertebrates perceive angular acceleration in the yaw (horizontal) planes has remained open. To provide an answer to this open question we reevaluated the anatomy of the inner ear in the lamprey, using stereoscopic dissection and scanning electron microscopy. The present study reveals a novel observation: the lamprey has two horizontal semicircular ducts in each labyrinth. Furthermore, the horizontal ducts in the lamprey, in contrast to those of jawed vertebrates, are located on the medial surface in the labyrinth rather than on the lateral surface. Our data on the lamprey horizontal duct suggest that the appearance of the horizontal canal characteristic of gnathostomes (lateral) and lampreys (medial) are mutually exclusive and indicate a parallel evolution of both systems, one in cyclostomes and one in gnathostome ancestors.

Influence of gravity on the spatial orientation of eye nystagmus induced by unilateral lesion of horizontal semicircular canal.

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Pettorossi, V E; Ermanno, M; Pierangelo, E; Silvarosa, G

2000-03-01

The influence of gravity in the orientation and slow phase eye velocity of the ocular nystagmus following unilateral damage of the cupula in the ampulla of the horizontal semicircular canal (UHCD) was investigated. The nystagmus was analysed at different sagittal head positions using the x-y infrared eye monitor technique. The nystagmus was almost horizontal at 0 degrees head pitch angle and remained partially fixed in space when the head was pitched upward or downward. The reorientation gain of the slow and quick phases was high (about 0.75) within +/- 45 degrees of head pitch angle, but beyond this range, it decreased greatly. The gain value depended on the lesion extension to otolithic receptors. The absolute value of the slow phase eye velocity of UHCD nystagmus was also modified systematically by the head pitch, showing a reduction in the upward and an increase in the downward.

Otitic meningitis, superior semicircular canal dehiscence, and encephalocele: a case series.

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Lim, Zixiang Michael; Friedland, Peter Leon; Boeddinghaus, Rudolf; Thompson, Andrew; Rodrigues, Stephen John; Atlas, Marcus

2012-06-01

Otitic meningitis in the postantibiotic era is still a serious condition, requiring intensive treatment and prolonged rehabilitation. In view of the significant morbidity and mortality rate, conditions that may increase the likelihood of otitic meningitis developing should be treated promptly. The incidence of meningitis after asymptomatic encephaloceles of the middle cranial fossa varies greatly, and the management differs between elective surgical repair and expectant careful observation. Superior semicircular canal dehiscences (SSCDs) are postulated to have a congenital origin and are associated with a thin or dehiscent tegmen. Several cases of simultaneous SCCD and tegmen defects have been reported, but the findings of otitic meningitis, SCCD, and encephaloceles has, to the best of our knowledge, not been previously explored in the literature. We reviewed a series of 4 patients who all presented with a combination of otitic meningitis, encephaloceles, and SSCD. All the 4 patients we reviewed had meningitis secondary to otitis media with computed tomographic scans confirming the presence of SCCD with ipsilateral tegmen tympani defects and associated cephaloceles. All patients were treated with intravenous antibiotics and underwent surgery that ranged from myringotomy and ventilation tube insertions, mastoidectomy, and burr hole drainage for temporal lobe abscess. They were all associated with intensive care unit admission, significant morbidity, and prolonged hospital stays. There were no mortalities. We propose that in all SSCD patients, a careful computed tomographic examination of the cranial base should be undertaken to exclude other associated tegmen tympani defects. In cases of SSCD requiring surgery, we support the view that elective surgical repair be recommended where asymptomatic ipsilateral encephaloceles are found, to reduce the risk of otitic meningitis.

Efferent innervation of turtle semicircular canal cristae: comparisons with bird and mouse

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Jordan, Paivi M.; Fettis, Margaret; Holt, Joseph C.

2014-01-01

In the vestibular periphery of nearly every vertebrate, cholinergic vestibular efferent neurons give rise to numerous presynaptic varicosities that target hair cells and afferent processes in the sensory neuroepithelium. Although pharmacological studies have described the postsynaptic actions of vestibular efferent stimulation in several species, characterization of efferent innervation patterns and the relative distribution of efferent varicosities among hair cells and afferents are also integral to understanding how efferent synapses operate. Vestibular efferent markers, however, have not been well characterized in the turtle, one of the animal models utilized by our laboratory. Here, we sought to identify reliable efferent neuronal markers in the vestibular periphery of turtle, to utilize these markers to understand how efferent synapses are organized, and to compare efferent neuronal labeling patterns in turtle with two other amniotes using some of the same markers. Efferent fibers and varicosities were visualized in the semicircular canal of Red-Eared Turtles (Trachemys scripta elegans), Zebra Finches (Taeniopygia guttata), and mice (Mus musculus) utilizing fluorescent immunohistochemistry with antibodies against choline acetyltransferase (ChAT). Vestibular hair cells and afferents were counterstained using antibodies to myosin VIIa and calretinin. In all species, ChAT labeled a population of small diameter fibers giving rise to numerous spherical varicosities abutting type II hair cells and afferent processes. That these ChAT-positive varicosities represent presynaptic release sites were demonstrated by colabeling with antibodies against the synaptic vesicle proteins synapsin I, SV2, or syntaxin and the neuropeptide calcitonin gene-related peptide (CGRP). Comparisons of efferent innervation patterns among the three species are discussed. PMID:25560461

Long-term results of middle fossa plugging of superior semicircular canal dehiscences: clinically and instrumentally demonstrated efficiency in a retrospective series of 16 ears.

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Thomeer, Hans; Bonnard, Damien; Castetbon, Vincent; Franco-Vidal, Valérie; Darrouzet, Patricia; Darrouzet, Vincent

2016-07-01

The objective of this study is to report the surgical outcome after middle fossa approach (MFA) plugging in patients suffering from a superior semi-circular canal dehiscence (SCD) syndrome. This is a retrospective case review. Tertiary referral center. Sixteen ears in 13 patients with a SCD syndrome suffering from severe and disabling vestibular symptoms with a bony dehiscence on CT scan >3 mm and decreased threshold of cervical vestibular evoked potentials (cVEMPs). We assessed preoperatively: clinical symptoms, hearing, cVEMPs threshold, size of dehiscence and videonystagmography (VNG) with caloric and 100 Hz vibratory tests. Postoperatively, we noted occurrences of neurosurgical complication, evolution of audiological and vestibular symptoms, and evaluation of cVEMP data. Tullio's phenomenon was observed in 13 cases (81.3 %) and subjectively reported hearing loss in seven (43.7 %). All patients were so disabled that they had to stop working. No neurosurgical complications were observed in the postoperative course. In three cases (16.6 %), an ipsilateral and transitory immediate postoperative vestibular deficit associated with a sensorineural hearing loss (SNHL) was noted, which totally resolved with steroids and bed rest. All patients were relieved of audiological and vestibular symptoms and could return to normal activity with a mean follow-up of 31.1 months (range 3-95). No patient had residual SNHL. cVEMPs were performed in 14 ears postoperatively and were normalized in 12 (85.7 %). Two of the three patients operated on both sides kept some degree of unsteadiness and oscillopsia. MFA plugging of the superior semi-circular canal is an efficient and non-hearing deteriorating procedure.

Assessment of the anatomical relationship between the arcuate eminence and superior semicircular canal by computed tomography

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Seo, Yoshinobu; Ito, Tamio; Sasaki, Takehiko; Nakagawara, Jyoji; Nakamura, Hirohiko

2007-01-01

The anatomical relationship between the arcuate eminence (AE) and the superior semicircular canal (SSC) was examined by computed tomography (CT) in 52 petrous bones of 26 patients. After acquiring volume data by multidetector CT, 1-mm thick oblique bone window images perpendicular to the SSC were obtained from the axial images. The distances between the AE and the SSC, and the SSC and the superior surface of the petrous bone were measured. The AE corresponded exactly with the SSC in only 2/52 petrous bones, and corresponded well in 7/52. The AE was lateral to the SSC in 25/52 cases, medial to the SSC in 6/52 cases, intersected in 3/52 cases, and was indiscernible in 9/52 cases. The distance between the SSC and the petrous surface was 0 mm in 45/52 petrous bones, 1 mm in 5/52, 2 mm in 1/52, and 3 mm in 1/52. The SSC typically does not correspond exactly with the AE, and is generally located just under the surface of the petrous bone. Planning of the middle cranial fossa approach requires location of the SSC by CT. (author)

Qualitative analysis of the Dix-Hallpike maneuver in multi-canal BPPV using a biomechanical model: Introduction of an expanded Dix-Hallpike maneuver for enhanced diagnosis of multi-canal BPPV

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Henri Traboulsi

2017-09-01

Conclusion: The Dix–Hallpike maneuver may cause simultaneous movement of otoliths present in multiple canals and create an obstacle to accurate diagnosis in multi-canal BPPV. An expanded Dix-Hallpike maneuver is described which adds intermediate steps with the head positioned to the right and left in the horizontal position before head-hanging. This expanded maneuver has helped to isolate affected semi-circular canals for individual assessment in multiple canal BPPV.

Radioanatomy of the singular nerve canal

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Muren, C. [Dept. of Diagnostic Radiology, Sabbatsbergs Hospital, Stockholm (Sweden); Wadin, K. [University Hospital, Uppsala (Sweden); Dimopoulos, P. [University Hospital, Uppsala (Sweden)

1991-08-01

The singular canal conveys vestibular nerve fibers from the ampulla of the posterior semicircular canal to the posteroinferior border of the internal auditory meatus. Radiographic identification of this anatomic structure helps to distinguish it from a fracture. It is also a landmark in certain surgical procedures. Computed tomography (CT) examinations of deep-frozen temporal bone specimens were compared with subsequently prepared plastic casts of these bones, showing good correlation between the anatomy and the images. The singular canal and its variable anatomy were studied in CT examinations of 107 patients. The singular canal could be identified, in both the axial and in the coronal planes. Its point of entry into the internal auditory meatus varied considerably. (orig.)

Otolith and canal reflexes in human standing

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Cathers, Ian; Day, Brian L; Fitzpatrick, Richard C

2005-01-01

We used galvanic vestibular stimulation (GVS) to identify human balance reflexes of the semicircular canals and otolith organs. The experiment used a model of vestibular signals arising from GVS modulation of the net signal from vestibular afferents. With the head upright, the model predicts that the GVS-evoked canal signal indicates lateral head rotation while the otolith signal indicates lateral tilt or acceleration. Both signify body sway transverse to the head. With the head bent forward, the model predicts that the canal signal indicates body spin about a vertical axis but the otolith signal still signifies lateral body motion. Thus, we compared electromyograms (EMG) in the leg muscles and body sway evoked by GVS when subjects stood with the head upright or bent forward. With the head upright, GVS evoked a large sway in the direction of the anodal electrode. This response was abolished with the head bent forward leaving only small, oppositely directed, transient responses at the start and end of the stimulus. With the head upright, GVS evoked short-latency (60–70 ms), followed by medium-latency (120 ms) EMG responses, of opposite polarity. Bending the head forward abolished the medium-latency but preserved the short-latency response. This is compatible with GVS evoking separate otolithic and canal reflexes, indicating that balance is controlled by independent canal and otolith reflexes, probably through different pathways. We propose that the short-latency reflex and small transient sway are driven by the otolith organs and the medium-latency response and the large sway are driven by the semicircular canals. PMID:15618274

Three-Dimensional Printed Prosthesis for Repair of Superior Canal Dehiscence.

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Kozin, Elliott D; Remenschneider, Aaron K; Cheng, Song; Nakajima, Hideko Heidi; Lee, Daniel J

2015-10-01

Outcomes following repair of superior canal dehiscence (SCD) are variable, and surgery carries a risk of persistent or recurrent SCD symptoms, as well as a risk of hearing loss and vestibulopathy. Poor outcomes may occur from inadequate repair of the SCD or mechanical insult to the membranous labyrinth. Repair of SCD using a customized, fixed-length prosthesis may address current operative limitations and improve surgical outcomes. We aim to 3-dimensionally print customized prostheses to resurface or occlude bony SCD defects. Dehiscences were created along the arcuate eminence of superior semicircular canals in cadaveric temporal bones. Prostheses were designed and created using computed tomography and a 3-dimensional printer. The prostheses occupied the superior semicircular canal defect, reflected in postrepair computed tomography scans. This novel approach to SCD repair could have advantages over current techniques. Refinement of prosthesis design and materials will be important if this approach is translated into clinical use. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

Assessment of the effects of superior canal dehiscence location and size on intracochlear sound pressures

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Niesten, Marlien E F; Stieger, Christof; Lee, Daniel J; Merchant, Julie P; Grolman, Wilko; Rosowski, John J; Nakajima, Hideko Heidi

2015-01-01

Superior canal dehiscence (SCD) is a defect in the bony covering of the superior semicircular canal. Patients with SCD present with a wide range of symptoms, including hearing loss, yet it is unknown whether hearing is affected by parameters such as the location of the SCD. Our previous human

Otolith-Canal Convergence In Vestibular Nuclei Neurons

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Dickman, J. David; Si, Xiao-Hong

2002-01-01

The current final report covers the period from June 1, 1999 to May 31, 2002. The primary objective of the investigation was to determine how information regarding head movements and head position relative to gravity is received and processed by central vestibular nuclei neurons in the brainstem. Specialized receptors in the vestibular labyrinths of the inner ear function to detect angular and linear accelerations of the head, with receptors located in the semicircular canals transducing rotational head movements and receptors located in the otolith organs transducing changes in head position relative to gravity or linear accelerations of the head. The information from these different receptors is then transmitted to central vestibular nuclei neurons which process the input signals, then project the appropriate output information to the eye, head, and body musculature motor neurons to control compensatory reflexes. Although a number of studies have reported on the responsiveness of vestibular nuclei neurons, it has not yet been possible to determine precisely how these cells combine the information from the different angular and linear acceleration receptors into a correct neural output signal. In the present project, rotational and linear motion stimuli were separately delivered while recording responses from vestibular nuclei neurons that were characterized according to direct input from the labyrinth and eye movement sensitivity. Responses from neurons receiving convergent input from the semicircular canals and otolith organs were quantified and compared to non-convergent neurons.

Eye size and visual acuity influence vestibular anatomy in mammals.

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Kemp, Addison D; Christopher Kirk, E

2014-04-01

The semicircular canals of the inner ear detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity require precise gaze stabilization mechanisms because they experience diminished visual functionality at low thresholds of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here, we examine the relationship between mean semicircular canal radius of curvature, eye size, and visual acuity in a large sample of mammals. Our results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that variation in mean semicircular canal radius of curvature among mammals is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. Our results also provide a possible functional explanation for the small semicircular canal radii of fossorial mammals and plesiadapiforms. Copyright © 2014 Wiley Periodicals, Inc.

Mechanical properties and motion of the cupula of the human semicircular canal.

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Selva, Pierre; Oman, Charles M; Stone, Howard A

2009-01-01

The mathematical model for the dynamics of the cupula-endolymph system of the inner ear semicircular canal, as elaborated by numerous investigators, remains a foundational tool in all of vestibular physiology. Most models represent the cupula as a linear spring-like element of stiffness K=DeltaP/DeltaV, where DeltaV is the volume displaced upon application of a pressure difference DeltaP. The parameter K directly influences the long time constant of the cupula-endolymph system. Given estimates of K based on experiments, we use thick and thin bending membrane theory, and also finite-element simulations based on more realistic cupula morphologies, to estimate the human cupula's Young's modulus E approximately 5.4 Pa. We show that for a model morphology, thick bending membrane theory and finite-element predictions are in good agreement, and conclude that the morphology of the attachment of the cupula to the slope of the crista should not greatly influence the volume displacement. We note, however, that other biological materials with very low E are hydrogels that have significant viscoelastic properties. Experiments to directly measure E and investigate potential viscoelastic behavior ultimately may be needed. In addition, based on experimental images we study two other different shapes for the cupula and quantify their impact on the deflection of the cupula. We also use a three-dimensional finite-element model to analyze both the shear strain distribution and its time evolution near the sensory epithelium. We conclude that stimulation of sensory hair cells probably begins at the centre of the crista and spreads toward the periphery of the cupula and down the sides of the crista. Thus, spatio-temporal variations in the shearing stimulus are predicted to impact subsequent transduction and encoding. Finally, modeling the fluid-filled vertical channels believed to lie within the cupula, we investigate the impact of different tube diameters on the transverse displacement

Long-term outcomes of a transmastoid lateral semicircular canal approach to congenital CSF otorrhea in children associated with recurrent meningitis and severe inner ear malformation.

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Wang, Jie; Li, Yongxin; Chen, Shubin; Hao, Xinping

2016-08-01

To investigate the long-term effectiveness of transmastoid lateral semicircular canal approach (TMLSCCA) to repair cerebrospinal fluid (CSF) leakage in children associated with recurrent meningitis and severe congenital inner malformation. A retrospective study was conducted in a university hospital, academic medical center. Fifteen children with recurrent meningitis, secondary to severe congenital inner ear malformation, were included in the study. All of them had CSF associated otorrhea and treated using TLSCCA to repair CSF otorrhea by packing the vestibule with muscle and fascia. Observation of the status of postoperative CSF leakage, recurrence of meningitis and complication were conducted. None of the cases had recurrent meningitis and CSF leakage after their TLSCCA procedure in the follow-up period of 1-8.5 years. One case presented with transient facial nerve paralysis and completely recovered 3 months later. TLSCCA for CSF otorrhea in children with recurrent meningitis secondary to congenital inner ear malformation is an alternative approach that offers some advantages. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Efficacy of quick repositioning maneuver for posterior semicircular canal benign paroxysmal positional vertigo in different age groups].

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Zhang, Hao; Li, Jinrang; Guo, Pengfei; Tian, Shiyu; Li, Keliang

2015-12-01

To observe the short and long-term efficacy of quick repositioning maneuver for posterior semicircular canal benign paroxysmal positional vertigo (PC-BPPV) in different age groups. The clinical data of 113 adult patients with single PC-BPPV who underwent quick repositioning maneuver from July 2009 to February 2015 were retrospectively analyzed. The quick repositioning maneuver was to roll the patient from involved side to healthy side in the coronal plane for 180° as quickly as possible. The patients were divided into 3 groups according to different ages: young group (age group (45 ≤ age group (≥ 60 years). The short and long term outcomes of the three groups were observed. The left ear was involved in 58 cases (51.3%) and the right ear in 55 cases (48.7%). The short term improvement rates of the young, middle-age and the old groups were 92.5%, 93.6% and 92.3% respectively, and the long term improvement rate was 90.0%, 85.1% and 73.1% respectively. There was no significant difference among the three groups in short and long term outcomes (P > 0.05). The recurrence rate of the three groups was 5.0%, 6.4% and 15.4% respectively, also no significant difference (P > 0.05). The quick repositioning maneuver along the coronal plane for PC-BPPV has a definite effect for every age groups. The method is simple, rapid and easy to master, and the patients are tolerated the maneuver well without evident side effect.

Influence of cochlear implantation on peripheral vestibular receptor function.

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Krause, Eike; Louza, Julia P R; Wechtenbruch, Juliane; Gürkov, Robert

2010-06-01

The objectives of this study were 1) to assess the influence of a cochlear implantation on peripheral vestibular receptor function in the inner ear in the implant and in the nonimplant side, and 2) to analyze a possible correlation with resulting vertigo symptoms. Prospective clinical study. Cochlear implant center at tertiary referral hospital. A total of 32 patients, aged 15 to 83 years, undergoing cochlear implantation were assessed pre- and postoperatively for caloric horizontal semicircular canal response and vestibular-evoked myogenic potentials of the sacculus, and postoperatively for subjective vertigo symptoms. Patients with vertigo were compared with patients without symptoms with regard to the findings of the vestibular function tests. Cochlear implantation represents a significant risk factor for horizontal semicircular canal impairment (P 0.05). Cochlear implantation is a relevant risk factor for damage of peripheral vestibular receptor function. Therefore, preservation not only of residual hearing function but also of vestibular function should be aimed for, by using minimally invasive surgical techniques. Copyright 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.

Prospective radiological study concerning a series of patients suffering from conductive or mixed hearing loss due to superior semicircular canal dehiscence.

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Martin, Christian; Chahine, Pierre; Veyret, Charles; Richard, Céline; Prades, Jean Michel; Pouget, Jean François

2009-08-01

The aim of this study is to appreciate the incidence of patients with isolated conductive hearing loss with normal drum due to superior semicircular canal dehiscence (SCD). It is a prospective radiological study. Two hundred and seventy-two patients with a normal drum suffering from isolated unilateral or bilateral conductive or mixed hearing loss were included in a prospective radiological study. A high resolution computerized tomography (HRCT) was performed in all the patients. Those who were found to have a unilateral or bilateral SCD underwent further etiological, clinical, audiologic evaluation. Ten patients with conductive or mixed hearing loss were found to have a unilateral or bilateral SCD. The disease was bilateral in five cases, and most often associated with a dehiscence of the tegmen tympani on both sides, supporting the theory of the congenital nature of the disease. There was no clear correlation between symptoms and the size of the SCD. Because patients were not suffering from incapacitating vestibular symptoms, they were not operated for surgical occlusion of the SCD, and were referred to a hearing aid specialist to improve hearing. Conductive or mixed hearing loss due to SCD is relatively frequent, justifying in our opinion that a systematic HRCT be carried out before surgery of any patient with conductive hearing loss.

Hearing eyeball and/or eyelid movements on the side of a unilateral superior semicircular canal dehiscence.

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Bertholon, Pierre; Reynard, Pierre; Lelonge, Yann; Peyron, Roland; Vassal, François; Karkas, Alexandre

2018-02-01

Hearing of eyeball movements has been reported in superior semicircular canal dehiscence (SSCD), but not hearing of eyelid movements. Our main objective was to report the hearing of eyeball and/or eyelid movements in unilateral SSCD. Our secondary objective was to access its specificity to SSCD and discuss the underlying mechanism. Six patients with SSCD who could hear their eyeball and/or eyelid movements were retrospectively reviewed. With the aim of comparisons, eight patients with an enlarged vestibular aqueduct (EVA), who share the same mechanism of an abnormal third window, were questioned on their ability to hear their eyeball and/or eyelid movements. Three patients with SSCD could hear both their eyeball and eyelid movements as a soft low-pitch friction sound. Two patients with SSCD could hear only their eyelid movements, one of whom after the surgery of a traumatic chronic subdural hematoma. The latter remarked that every gently tapping on the skin covering the burr-hole was heard in his dehiscent ear as the sound produced when banging on a drum, in keeping with a direct transmission of the sound to the inner ear via the cerebrospinal fluid. One patient with SSCD, who could hear only his eyeball movements, had other disabling symptoms deserving operation through a middle fossa approach with an immediate relief of his symptoms. None of the eight patients with EVA could hear his/her eyeball or eyelid movements. Hearing of eyeball and/or eyelid movements is highly suggestive of a SSCD and do not seem to occur in EVA. In case of radiological SSCD, clinicians should search for hearing of eyeball and/or eyelid movements providing arguments for a symptomatic dehiscence. The underlying mechanism is discussed particularly the role of a cerebrospinal fluid transmission.

The prevalence of superior semicircular canal dehiscence in conductive and mixed hearing loss in the absence of other pathology using submillimetric temporal bone computed tomography.

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Lee, Young Hen; Rivas-Rodriguez, Francisco; Song, Jae-Jun; Yang, Kyung-Sook; Mukherji, Suresh K

2014-01-01

The objective of this study was to assess the relationship between superior semicircular canal dehiscence (SSCD) and hearing impairment. We retrospectively compared the prevalence of SSCD in the ears classified as conductive hearing loss (CHL), mixed hearing loss (MHL), and normal hearing status using submillimetric temporal bone computed tomography (TBCT) on the basis of coronal and additional reformatted planes dedicated to SSCD. From the patients with CHL (n = 127) and MHL (n = 45), the overall prevalence of SSCD in the ears classified as CHL, MHL, and normal hearing status were 6.6%, 7.2%, and 3.0%, respectively. Furthermore, the odds ratio for SSCD in the absence of any cause of hearing loss (eg, dysfunction of the tympanic membrane or middle ear, TBCT abnormalities, otosclerosis, trauma, surgery) was 5.35 in MHL (4/27; P = 0.037, 95% confidence interval, 1.1-25.81) and 3.31 in CHL (5/61; P = 0.115, 95% confidence interval, 0.75-14.63), compared with normal hearing status. Bony covering of the SSC should be specifically evaluated in patients with hearing impairment using submillimetric TBCT.

Utricular paresis and semicircular canal hyperactivity: a distinct otolith syndrome.

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Angeli, Simon I; Snapp, Hillary; Velandia, Sandra; Morgenstein, Kari

2015-04-01

Although combined utricular and canal paresis has been described previously, this is the first report of canal hyperactivity associated with utricular hypofunction. Unsteadiness and swaying were the most common symptoms, and patients with shorter duration of symptoms also had positional vertigo. We propose that this syndrome is a variant of utricular dysfunction and should be considered in the differential diagnosis of peripheral vestibular disorders. To describe a syndrome of instability associated with utricular dysfunction and hyperactive caloric responses. The study comprised 11 consecutive patients exhibiting abnormalities of the eccentric subjective visual vertical test (e-SVV) and high responses during the caloric test of the videonystagmography (VNG). We carried out a review of symptoms, physical examination, and vestibular tests. There was no gender predilection or obvious etiology. The patients' main complaint included instability with linear symptoms (i.e., tilting, rocking, and swaying), with positional vertigo as a secondary symptom. Oculomotor testing, visual fixation index, and brain MRI were normal, excluding a central nervous system disorder. VNG was essentially normal except for hyperactive responses during the caloric testing in all patients. Abnormal e-SVV was found in 10 patients unilaterally and bilaterally in 1 patient. Abnormal oVEMP was found in seven of seven patients, further supporting a utricular site of lesion.

The reliability of nonlinear least-squares algorithm for data analysis of neural response activity during sinusoidal rotational stimulation in semicircular canal neurons.

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Ren, Pengyu; Li, Bowen; Dong, Shiyao; Chen, Lin; Zhang, Yuelin

2018-01-01

Although many mathematical methods were used to analyze the neural activity under sinusoidal stimulation within linear response range in vestibular system, the reliabilities of these methods are still not reported, especially in nonlinear response range. Here we chose nonlinear least-squares algorithm (NLSA) with sinusoidal model to analyze the neural response of semicircular canal neurons (SCNs) during sinusoidal rotational stimulation (SRS) over a nonlinear response range. Our aim was to acquire a reliable mathematical method for data analysis under SRS in vestibular system. Our data indicated that the reliability of this method in an entire SCNs population was quite satisfactory. However, the reliability was strongly negatively depended on the neural discharge regularity. In addition, stimulation parameters were the vital impact factors influencing the reliability. The frequency had a significant negative effect but the amplitude had a conspicuous positive effect on the reliability. Thus, NLSA with sinusoidal model resulted a reliable mathematical tool for data analysis of neural response activity under SRS in vestibular system and more suitable for those under the stimulation with low frequency but high amplitude, suggesting that this method can be used in nonlinear response range. This method broke out of the restriction of neural activity analysis under nonlinear response range and provided a solid foundation for future study in nonlinear response range in vestibular system.

Single-channel L-type Ca2+ currents in chicken embryo semicircular canal type I and type II hair cells.

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Zampini, Valeria; Valli, Paolo; Zucca, Giampiero; Masetto, Sergio

2006-08-01

Few data are available concerning single Ca channel properties in inner ear hair cells and particularly none in vestibular type I hair cells. By using the cell-attached configuration of the patch-clamp technique in combination with the semicircular canal crista slice preparation, we determined the elementary properties of voltage-dependent Ca channels in chicken embryo type I and type II hair cells. The pipette solutions included Bay K 8644. With 70 mM Ba(2+) in the patch pipette, Ca channel activity appeared as very brief openings at -60 mV. Ca channel properties were found to be similar in type I and type II hair cells; therefore data were pooled. The mean inward current amplitude was -1.3 +/- 0.1 (SD) pA at - 30 mV (n = 16). The average slope conductance was 21 pS (n = 20). With 5 mM Ba(2+) in the patch pipette, very brief openings were already detectable at -80 mV. The mean inward current amplitude was -0.7 +/- 0.2 pA at -40 mV (n = 9). The average slope conductance was 11 pS (n = 9). The mean open time and the open probability increased significantly with depolarization. Ca channel activity was still present and unaffected when omega-agatoxin IVA (2 microM) and omega-conotoxin GVIA (3.2 microM) were added to the pipette solution. Our results show that types I and II hair cells express L-type Ca channels with similar properties. Moreover, they suggest that in vivo Ca(2+) influx might occur at membrane voltages more negative than -60 mV.

BENIGN PAROXYSMAL POSITIONAL VERTIGO (BPPV) — A ...

African Journals Online (AJOL)

Enrique

OVERVIEW OF SEMICIRCULAR CANAL FUNCTION. The three semicircular canals are arranged at right angles to each other in the inner ear ... nerve is stimulated, resulting in the brain sensing the head movement (Fig. 1). PATRICK DE .... The Dix-Hallpike test to the left (A — patient seated on couch, B — head. 45° to side ...

Horizontal canal benign paroxysmal positional vertigo: diagnosis and treatment of 37 patients

Directory of Open Access Journals (Sweden)

Eliana Teixeira Maranhão

2015-06-01

Full Text Available Benign paroxysmal positional vertigo (BPPV, the most frequent cause of vertigo is associated with high morbidity in the elderly population. The most common form is linked to debris in the posterior semicircular canal. However, there has been an increasing number of reported BPPV cases involving the horizontal canals. The purpose of this article is to highlight the clinical features, diagnosis, and treatment in 37 patients with horizontal canal BPPV; twenty-six with geotropic nystagmus, and eleven with the apogeotropic form. Treatment consisted of the Gufoni manoeuver in eighteen patients (48.6%, the barbecue 360° maneuver in twelve patients (32.4%, both manoeuvers in four patients (10.8%, both manoeuvers plus head shaking in one patient (2.7%, and the Gufoni maneuver plus head shaking in two patients. Cupulolithiasis patients were asked to sleep in a forced prolonged position. We obtained a complete resolution of vertigo and nystagmus in 30 patients (81.0% on the initial visit.

Comparative analysis of vestibular ecomorphology in birds.

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Benson, Roger B J; Starmer-Jones, Ethan; Close, Roger A; Walsh, Stig A

2017-12-01

The bony labyrinth of vertebrates houses the semicircular canals. These sense rotational accelerations of the head and play an essential role in gaze stabilisation during locomotion. The sizes and shapes of the semicircular canals have hypothesised relationships to agility and locomotory modes in many groups, including birds, and a burgeoning palaeontological literature seeks to make ecological interpretations from the morphology of the labyrinth in extinct species. Rigorous tests of form-function relationships for the vestibular system are required to support these interpretations. We test the hypothesis that the lengths, streamlines and angles between the semicircular canals are related to body size, wing kinematics and flying style in birds. To do this, we applied geometric morphometrics and multivariate phylogenetic comparative methods to a dataset of 64 three-dimensional reconstructions of the endosseous labyrinth obtained using micro-computed tomography scanning of bird crania. A strong relationship between centroid size of the semicircular canals and body size indicates that larger birds have longer semicircular canals compared with their evolutionary relatives. Wing kinematics related to manoeuvrability (and quantified using the brachial index) explain a small additional portion of the variance in labyrinth size. We also find strong evidence for allometric shape change in the semicircular canals of birds, indicating that major aspects of the shape of the avian labyrinth are determined by spatial constraints. The avian braincase accommodates a large brain, a large eye and large semicircular canals compared with other tetrapods. Negative allometry of these structures means that the restriction of space within the braincase is intense in small birds. This may explain our observation that the angles between planes of the semicircular canals of birds deviate more strongly from orthogonality than those of mammals, and especially from agile, gliding and flying

Otolith and Vertical Canal Contributions to Dynamic Postural Control

Science.gov (United States)

Black, F. Owen

1999-01-01

The objective of this project is to determine: 1) how do normal subjects adjust postural movements in response to changing or altered otolith input, for example, due to aging? and 2) how do patients adapt postural control after altered unilateral or bilateral vestibular sensory inputs such as ablative inner ear surgery or ototoxicity, respectively? The following hypotheses are under investigation: 1) selective alteration of otolith input or abnormalities of otolith receptor function will result in distinctive spatial, frequency, and temporal patterns of head movements and body postural sway dynamics. 2) subjects with reduced, altered, or absent vertical semicircular canal receptor sensitivity but normal otolith receptor function or vice versa, should show predictable alterations of body and head movement strategies essential for the control of postural sway and movement. The effect of altered postural movement control upon compensation and/or adaptation will be determined. These experiments provide data for the development of computational models of postural control in normals, vestibular deficient subjects and normal humans exposed to unusual force environments, including orbital space flight.

Superior canal dehiscence in a patient with three failed stapedectomy operations for otosclerosis: a case report

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Sudhoff Holger H

2011-02-01

Full Text Available Abstract Introduction This case illustrates that superior semicircular canal dehiscence syndrome can be associated with a "pseudo"-conductive hearing loss, a symptom that overlaps with the clinical appearance of otosclerosis. Case presentation We present the case of a 48-year-old German Caucasian woman presenting with hearing loss on the left side and vertigo. She had undergone three previous stapedectomies for hearing improvement. Reformatted high-resolution computed tomographic scanning and the patient's history confirmed the diagnosis of concurrent canal dehiscence syndrome. Conclusion Failure of hearing improvement after otosclerosis surgery may indicate an alternative underlying diagnosis which should be explored by further appropriate evaluation.

Lipoatrofia semicircular: una revisión sistemática de la literatura Semicircular lipoatrophy: a sistematic review of the literature

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Rafael Díaz Sarmiento

2011-03-01

Full Text Available Introducción: La lipoatrofia semicircular (LS es un trastorno benigno del tejido subcutáneo, de causa desconocida. Se caracteriza por depresiones semicirculares en la cara anterolateral de los muslos, unilaterales o bilaterales. Se relaciona con condiciones ambientales laborales, microtraumas repetidos y factores personales. Se plateó esta revisión sistemática de la literatura científica para caracterizar el conocimiento existente. Métodos: Revisión sistemática. Bases de datos: IBECS, IBSST, LILACS, IME, OSH-UPDATE, ISI-WOK, PubMed, CIS-DOC y Cochrane. Se incluyeron los artículos sobre lipoatrofia semicircular relacionada con condiciones de trabajo y medioambientales. Se utilizaron los niveles de evidencia científica del Scottish Intercollegiate Guidelines Network. Resultados: Se recuperaron 66 artículos. Solo 22 cumplieron los criterios de inclusión: Quince con nivel de evidencia 3 y 7 con nivel 4. Siete estudios de series de casos y ocho de casos únicos, sumaron 838 casos, informados entre 1982-2010. Los principales factores de riesgo para LS son: Microtraumas repetidos, humedad relativa baja y electricidad en los edificios modernos de oficinas. Las depresiones semicirculares ocurren en la cara anterolateral de muslos, sin alteración de la piel, en mujeres (85%, sin signos inflamatorios con histopatología inespecífica. La resonancia magnética, radiología y los anticuerpos antinucleares son negativos. El diagnóstico es clínico, apoyado con ecografía. El tratamiento psicológico y fisioterapia pueden ser útiles. Las medidas preventivas de mayor impacto son controlar los factores mencionados. Conclusiones: Existe insuficiente evidencia científica sobre las causas de LS. Es un trastorno prevalente, que genera alarma, relacionado con las condiciones de trabajo. Es necesario continuar la investigación sobre agentes causales.Introduction: The semicircular lipoatrophy (LS is a benign disorder of the subcutaneous tissue with

Selective otolith dysfunctions objectively verified.

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Manzari, Leonardo; MacDougall, Hamish G; Burgess, Ann M; Curthoys, Ian S

2014-01-01

Vertigo and vigorous horizontal spontaneous nystagmus in a presenting patient is usually taken to indicate unilaterally reduced horizontal canal function. However here we report results which question that presumption. In three such patients with an acute vestibular syndrome, complete testing of all peripheral vestibular sense organs using new tests of canal and otolith function (vHIT and VEMPs) showed that semicircular canal function was normal, but that there were unilateral otolithic deficits which probably caused their acute syndrome.

Integration of canal and otolith inputs by central vestibular neurons is subadditive for both active and passive self-motion: implication for perception.

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Carriot, Jerome; Jamali, Mohsen; Brooks, Jessica X; Cullen, Kathleen E

2015-02-25

Traditionally, the neural encoding of vestibular information is studied by applying either passive rotations or translations in isolation. However, natural vestibular stimuli are typically more complex. During everyday life, our self-motion is generally not restricted to one dimension, but rather comprises both rotational and translational motion that will simultaneously stimulate receptors in the semicircular canals and otoliths. In addition, natural self-motion is the result of self-generated and externally generated movements. However, to date, it remains unknown how information about rotational and translational components of self-motion is integrated by vestibular pathways during active and/or passive motion. Accordingly, here, we compared the responses of neurons at the first central stage of vestibular processing to rotation, translation, and combined motion. Recordings were made in alert macaques from neurons in the vestibular nuclei involved in postural control and self-motion perception. In response to passive stimulation, neurons did not combine canal and otolith afferent information linearly. Instead, inputs were subadditively integrated with a weighting that was frequency dependent. Although canal inputs were more heavily weighted at low frequencies, the weighting of otolith input increased with frequency. In response to active stimulation, neuronal modulation was significantly attenuated (∼ 70%) relative to passive stimulation for rotations and translations and even more profoundly attenuated for combined motion due to subadditive input integration. Together, these findings provide insights into neural computations underlying the integration of semicircular canal and otolith inputs required for accurate posture and motor control, as well as perceptual stability, during everyday life. Copyright © 2015 the authors 0270-6474/15/353555-11$15.00/0.

[Necessity of repeated roll test in horizontal semicircular canalithasis positioned diagnosis].

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Lu, H H; Zhao, Y; Chen, T S; Xu, K X; Wang, W; Liu, Q; Wen, C; Li, S S; Li, X J; Han, X; Lin, P

2016-04-07

To investigate the influence of repeated roll test in horizontal semicircular canalithasis(HSC-Can) positioned diagnosis, so as to investigate the cecessity of repeated roll test. The patients with a chief complaint of positional vertigo accepted two consecutive cycles roll test, the evoked nystagmus characteristics of each cycle recorded by video-nystagmuograph(VNG), whose direction, intensity, time and other parameters characteristics were analyzed in 51 HSC-Can. Horizontal nystagmus in the same direction with turning were induced in HSC-Can roll test. In 51 HSC-Can, roll test cycle 1 and cycle 2 induced nystagmus same strength side in 26 cases(51.0%), of which 19 cases with stronger nystagmus intensity in cycle 2, another 7 cases were weaker; the opposite strength side of the two loops induced nystagmus, and cycle 1 evoked nystagmus intensity were weaker than cycle 2, based on cycle 2 results determined HSC-Can affected side in 25 cases (49.0%). Lesion and normal side in cycle 1 induced nystagmus duration (x±s, the same below) were (13.4±11.5)s and (14.1±9.9)s, respectively intensity (18.1±22.4)°/s and (13.0±12.0)°/s; as in cycle 2 induced nystagmus duration was (20.7±10.2)s and (18.0±12.0)s, strength respectively(40.4±28.0)°/s and (15.6 ±11.2)°/s. Cycle 2 ipsilateral rotor position evoked nystagmus showed longer duration and stronger intensity than cycle 1. Between two cycle induced ipsilateral nystagmus duration, intensity differences were statistically significant (t values were -4.233 and -5.154, P=0.000). 51 HSC-Can patients, 44 patients selected repositioning maneuver, after 1-2 times of maneuver, 41 cases (93.2%) showed complete resolution of symptoms, all cases's symptoms were improved; other 7 patients selected medication only. The proposed suspicious HSC-Can patients should receive at least two cycles roll test, and mainly in the second cycle could determine the location of the responsible semicircular canals.

Cerebellum Abnormalities, the 5th C in CHARGE Syndrome

NARCIS (Netherlands)

Wong, Tsz; de Geus, Christa; Meiners, Linda C; Sival, Deborah; Yu, Tian; Basson, M. Albert; Arts, Cornelia

Introduction and background: Children with CHARGE syndrome often have balance problems due to hypoplasia of the semicircular canals. Balance involves the complex task of integrating postural responses and multisensory (visual, labyrinthine from the semi-circular canals, and proprioceptive) feedback.

Intracranially protruded bilateral posterior and superior SCCs with multiple dehiscences in a patient with positional vertigo: CT and MR imaging findings and review of literature

International Nuclear Information System (INIS)

Kundaragi, Nischal G; Mudali, Srinivasa; Karpagam, Bulabai; Priya, Rathna

2014-01-01

We report a rare case of intracranially protruded posterior and superior semicircular canals beyond the margins of temporal bone with bony roof dehiscence in bilateral posterior and left superior semicircular canals in a patient with benign paroxysmal positional vertigo (BPPV)

MR Imaging of the Internal Auditory Canal and Inner Ear at 3T: Comparison between 3D Driven Equilibrium and 3D Balanced Fast Field Echo Sequences

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Byun, Jun Soo; Kim, Hyung Jin; Yim, Yoo Jeong; Kim, Sung Tae; Jeon, Pyoung; Kim, Keon Ha [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sam Soo; Jeon, Yong Hwan; Lee, Ji Won [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

2008-06-15

To compare the use of 3D driven equilibrium (DRIVE) imaging with 3D balanced fast field echo (bFFE) imaging in the assessment of the anatomic structures of the internal auditory canal (IAC) and inner ear at 3 Tesla (T). Thirty ears of 15 subjects (7 men and 8 women; age range, 22 71 years; average age, 50 years) without evidence of ear problems were examined on a whole-body 3T MR scanner with both 3D DRIVE and 3D bFFE sequences by using an 8-channel sensitivity encoding (SENSE) head coil. Two neuroradiologists reviewed both MR images with particular attention to the visibility of the anatomic structures, including four branches of the cranial nerves within the IAC, anatomic structures of the cochlea, vestibule, and three semicircular canals. Although both techniques provided images of relatively good quality, the 3D DRIVE sequence was somewhat superior to the 3D bFFE sequence. The discrepancies were more prominent for the basal turn of the cochlea, vestibule, and all semicircular canals, and were thought to be attributed to the presence of greater magnetic susceptibility artifacts inherent to gradient-echo techniques such as bFFE. Because of higher image quality and less susceptibility artifacts, we highly recommend the employment of 3D DRIVE imaging as the MR imaging choice for the IAC and inner ear

The Dix-Hallpike test and the canalith repositioning maneuver.

Science.gov (United States)

Viirre, Erik; Purcell, Ian; Baloh, Robert W

2005-01-01

The Dix-Hallpike test and the canalith repositioning maneuver (CRM) are used to diagnose and treat benign positional vertigo (BPV). Dix-Hallpike is the standard procedure for diagnosis of BPV, but if the horizontal canal is not tested for BPV and the Dix-Hallpike is only carried out once, the condition may not be diagnosed and appropriately treated. We describe our method of testing for BPV and treating it with CRM. The Dix-Hallpike test involves rapidly moving the patient from a sitting position to "head hanging," where the patient's head is at least 10 degrees below horizontal. This is performed initially for the posterior semicircular canals. If these movements fail to elicit vertigo and nystagmus, tests of the horizontal semicircular canals are performed by laying the patient on each side. Importantly, if there is no vertigo or nystagmus elicited by testing the horizontal semi-circular canals, the posterior semicircular canals are tested again. It appears that being held in the head hanging positions and then left and right lateral positions will often allow the canaliths to collect such that the Dix-Hallpike test will become positive. Failure to repeat the tests of the posterior semicircular canals may result in a falsely negative test. Testing the horizontal canals and repeating the Dix-Hallpike test will reduce the likelihood of patients undergoing extra testing or other consequences of misdiagnosis. If, during any of this testing, a movement elicits vertigo or nystagmus, the appropriate CRM is then carried out.

The effects of aging on clinical vestibular evaluations

Directory of Open Access Journals (Sweden)

Maxime eMaheu

2015-09-01

Full Text Available Balance disorders are common issues for aging populations due to the effects of normal aging on peripheral vestibular structures. These changes affect the results of vestibular function evaluations and make the interpretation of these results more difficult. The objective of this article is to review the current state of knowledge of clinically relevant vestibular measures. We will first focus on otolith function assessment methods cVEMP and oVEMP, then the caloric and vHIT methods for semi-circular canals assessment. cVEMP and oVEMP are useful methods, though research on the effects of age for some parameters are still inconclusive. vHIT results are largely independent of age as compared to caloric stimulation and should therefore be preferred for the evaluation of the semi-circular canals function.

The delayed rectifier, IKI, is the major conductance in type I vestibular hair cells across vestibular end organs

Science.gov (United States)

Ricci, A. J.; Rennie, K. J.; Correia, M. J.

1996-01-01

Hair cells were dissociated from the semicircular canal, utricle, lagena and saccule of white king pigeons. Type I hair cells were identified morphologically based on the ratios of neck width to cuticular plate width (NPR rectifier characterized previously in semicircular canal hair cells as IKI.

Clinical review of inner ear malformation

International Nuclear Information System (INIS)

Kokai, Hiromi; Oohashi, Masami; Ishikawa, Kazuo; Harada, Kouji; Hiratsuka, Hitoshi; Ogasawara, Makoto; Miyashita, Souji; Terayama, Yoshihiko

2003-01-01

We had 126 patients with inner ear malformation diagnosed with temporal bone computed tomography (CT) scans at Azabu Triology Hospital between 1996 and 2002. We classified cases of inner ear malformation according to Jackler et al. The incidence of inner ear malformation in our series was as follows; labyrinthine anomalies 61% (isolated lateral semicircular canal dysplasia 56%, compound semicircular canal dysplasia 4%, semicircular canal aplasia 1%), cochlear anomalies 24%, enlargement of the vestibular aqueduct 12%, narrow internal auditory canal 2%, complete labyrinthine aplasia 1%, enlargement of the cochlear aqueduct 0%. The most frequent anomaly was isolated lateral semicircular canal dysplasia. We did not detect any significant clinical features in this anomaly. There were 2 patients with cochlear anomalies who had past histories of meningitis. Some patients with enlargement of the vestibular aqueduct had frequent attacks of fluctuating hearing. Clinically it is important to detect patients with inner ear malformation such as cochlear anomalies and enlargement of the vestibular aqueduct usually accompanied by congenital sensorineural hearing loss. For patients with congenital sensorineural hearing loss, we recommend temporal bone CT scan. (author)

Vestibular neuritis: three-dimensional videonystagmography and vestibular evoked myogenic potential results.

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Chen, C W; Young, Y H; Wu, C H

2000-10-01

Eight patients diagnosed with vestibular neuritis received the newly developed three-dimensional videonystagmography (3D VNG) and vestibular evoked myogenic potential (VEMP) examination in order to localize the lesion site. Two (25%) of the 8 patients exhibited spontaneous nystagmus with 3 components, indicating that both the horizontal semicircular canal (HSCC) and anterior semicircular canal (ASCC) were affected. The remaining 6 patients (75%) displayed only horizontal nystagmus, meaning that only the HSCC was involved. Seven (88%) of the 8 patients had bilateral normal VEMPs, revealing sparing of the posterior semicircular canal (PSCC). In a comparative study, another seven patients with vestibular neuritis 1 year post-treatment also received the caloric test, 3D VNG and VEMP examination. Only one patient exhibited spontaneous nystagmus. An absent caloric response of the lesioned side persisted in 5 (71%) of the 7 patients. However, all patients showed normal VEMPs bilaterally. 3D VNG and VEMP examination indicates that vestibular neuritis mainly affects the superior division of the vestibular nerve, which innervates the HSCC and ASCC. Meanwhile, the function of the PSCC and saccule, innervated by the inferior vestibular nerve, is preserved.

Evaluation of diagnostic tests of the otolith organs and their application in various vestibular pathologies

NARCIS (Netherlands)

Winters, S.M.

2014-01-01

Current vestibular testing is limited. The general function of the vestibular system on both sides of the head can be tested, and one part of the peripheral vestibular organ, the horizontal semicircular canal, can be tested unilaterally. However, recently a test for the function of the otolith

Influence of vestibular activation on respiration in humans

Science.gov (United States)

Monahan, Kevin D.; Sharpe, Melissa K.; Drury, Daniel; Ertl, Andrew C.; Ray, Chester A.

2002-01-01

The purpose of this study was to determine the effects of the semicircular canals and otolith organs on respiration in humans. On the basis of animal studies, we hypothesized that vestibular activation would elicit a vestibulorespiratory reflex. To test this hypothesis, respiratory measures, arterial blood pressure, and heart rate were measured during engagement of semicircular canals and/or otolith organs. Dynamic upright pitch and roll (15 cycles/min), which activate the otolith organs and semicircular canals, increased respiratory rate (Delta2 +/- 1 and Delta3 +/- 1 breaths/min, respectively; P < 0.05). Dynamic yaw and lateral pitch (15 cycles/min), which activate the semicircular canals, increased respiration similarly (Delta3 +/- 1 and Delta2 +/- 1, respectively; P < 0.05). Dynamic chair rotation (15 cycles/min), which mimics dynamic yaw but eliminates neck muscle afferent, increased respiration (Delta3 +/- 1; P < 0.05) comparable to dynamic yaw (15 cycles/min). Increases in respiratory rate were graded as greater responses occurred during upright (Delta5 +/- 2 breaths/min) and lateral pitch (Delta4 +/- 1) and roll (Delta5 +/- 1) performed at 30 cycles/min. Increases in breathing frequency resulted in increases in minute ventilation during most interventions. Static head-down rotation, which activates otolith organs, did not alter respiratory rate (Delta1 +/- 1 breaths/min). Collectively, these data indicate that semicircular canals, but not otolith organs or neck muscle afferents, mediate increased ventilation in humans and support the concept that vestibular activation alters respiration in humans.

Otolithic disease: clinical features and the role of vestibular evoked myogenic potentials.

Science.gov (United States)

Curthoys, Ian S; Manzari, Leonardo

2013-07-01

Through selective tests of the function of the canal and otolith sense organs, it is possible to assert that patient conditions are purely otolithic and that the canals are not involved. The video head impulse test selectively tests each semicircular canal; the ocular vestibular-evoked myogenic potential to 500 Hz Fz (Fz is the location on the forehead in the midline at the hairline) bone-conducted vibration (BCV) selectively tests the utricular macula and the cervical vestibular-evoked myogenic potential to 500 Hz Fz BCV selectively tests the saccular macula. The development of new specific tests of otolith function has shown that some patients may have specific deficits of just otolithic function. In the authors' experience, patients who complain strongly of postural unsteadiness should be suspected to have otolithic deficits. They may also have vertigo and in some cases have spontaneous nystagmus of peripheral origin, even though their semicircular canal function is normal. The prognosis for such patients is good. They usually appear to regain their postural stability spontaneously over weeks (or longer), even though they still have an otolithic deficit as shown by objective tests when they are free of symptoms. It is not known what procedures may accelerate the recovery of otolith function. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

ANALYSIS OF REMOTE SENSING ARCHAEOLOGY ON TRAFFIC FUNCTION TRANSFORMATION OF TONGJI GRAND CANAL IN SUI AND TANG DYNASTIES

Institute of Scientific and Technical Information of China (English)

WANG Xin-yuan; HE Hui; ZHOU Ying-qiu; GAO Chao; HAN Shuang-wang

2006-01-01

In China, most directions of river flowing are from west to east. During historic period, since the water traffic played an important role, it was very important to form a cross-horizontal net of water carriage route. Canals should be dug so as to make up the lack of north-south river. Tongji Grand Canal, dug in the first year of Daye (605 A.D.) in the Sui Dynasty, was the important component of north-south system of Grand Canals in China. It promoted economic and social development of the Sui, Tang and Song dynasties (605 A.D.-1279 A.D.). As Tongji Canal (i.e.Tongji Grand Canal) flowed across the Huaibei Plain, which is aggraded by abundant mud and sand deposit resulted from the Huanghe (Yellow) River flooding, many traces (such as old channel) and human culture heritages were buried under mud-sand. Tongji Canal was silted up, and disappeared in the Jin Dynasty (1115 A.D.-1234 A.D.). From then on, there were many different stories about the flowing route of the canal in historical literature. Based on space-bone and air-bone remote sensing imagery, we attempt to search the old channel of Tongji Canal, and supplement historical record. The paper discusses transformation process of Tongji Canal's traffic function, and resumptively summarizes the reasons of the transformation, which results from synthetic function of physical geographical, political, economic, and social conditions.

Plasticity of the human otolith-ocular reflex

Science.gov (United States)

Wall, C. 3rd; Smith, T. R.; Furman, J. M.

1992-01-01

The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

On the time course of short-term forgetting: a human experimental model for the sense of balance.

Science.gov (United States)

Tribukait, Arne; Eiken, Ola

2016-02-01

The primary aim of this study was to establish whether the decline of the memory of an angular displacement, detected by the semicircular canals, is best characterized by an exponential function or by a power function. In 27 subjects a conflict was created between the semicircular canals and the graviceptive systems. Subjects were seated, facing forwards, in the gondola of a large centrifuge. The centrifuge was accelerated from stationary to 2.5Gz. While the swing out of the gondola (66°) during acceleration constitutes a frontal plane angular-displacement stimulus to the semicircular canals, the graviceptive systems persistently signal that the subject is upright. During 6 min at 2.5Gz the perceived head and body position was recorded; in darkness the subject repeatedly adjusted the orientation of a luminous line so that it appeared to be horizontal. Acceleration of the centrifuge induced a sensation of tilt which declined with time in a characteristic way. A three-parameter exponential function (Y = Ae(-bt) + C) and a power function (Y = At(-b) + C) were fitted to the data points. The inter-individual variability was considerable. In the vast majority of cases, however, the exponential function provided a better fit (in terms of RMS error) than the power function. The mean exponential function was: y = 27.8e(-0.018t) + 0.5°, where t is time in seconds. Findings are discussed with connection to possible underlying neural mechanisms; in particular, the head-direction system and short-term potentiation and persistent action potential firing in the hippocampus are considered.

Viscoelastic assessment of anal canal function using acoustic reflectometry: a clinically useful technique.

Science.gov (United States)

Mitchell, Peter J; Klarskov, Niels; Telford, Karen J; Hosker, Gordon L; Lose, Gunnar; Kiff, Edward S

2012-02-01

Anal acoustic reflectometry is a new reproducible technique that allows a viscoelastic assessment of anal canal function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, opening and closing elastance, and hysteresis. The aim of this study was to assess whether the parameters measured in anal acoustic reflectometry are clinically valid between continent and fecally incontinent subjects. This was an age- and sex-matched study of continent and incontinent women. The study was conducted at a university teaching hospital. One hundred women (50 with fecal incontinence and 50 with normal bowel control) were included in the study. Subjects were age matched to within 5 years. Parameters measured with anal acoustic reflectometry and manometry were compared between incontinent and continent groups using a paired t test. Diagnostic accuracy was assessed by the use of receiver operator characteristic curves. Four of the 5 anal acoustic reflectometry parameters at rest were significantly different between continent and incontinent women (eg, opening pressure in fecally incontinent subjects was 31.6 vs 51.5 cm H2O in continent subjects, p = 0.0001). Both anal acoustic reflectometry parameters of squeeze opening pressure and squeeze opening elastance were significantly reduced in the incontinent women compared with continent women (50 vs 99.1 cm H2O, p = 0.0001 and 1.48 vs 1.83 cm H2O/mm, p = 0.012). In terms of diagnostic accuracy, opening pressure at rest measured by reflectometry was significantly superior in discriminating between continent and incontinent women in comparison with resting pressure measured with manometry (p = 0.009). Anal acoustic reflectometry is a new, clinically valid technique in the assessment of continent and incontinent subjects. This technique, which assesses the response of the anal canal to distension and relaxation, provides a detailed viscoelastic assessment of anal canal function. This technique

Anatomy, Physiology and Function of the Auditory System

Science.gov (United States)

Kollmeier, Birger

The human ear consists of the outer ear (pinna or concha, outer ear canal, tympanic membrane), the middle ear (middle ear cavity with the three ossicles malleus, incus and stapes) and the inner ear (cochlea which is connected to the three semicircular canals by the vestibule, which provides the sense of balance). The cochlea is connected to the brain stem via the eighth brain nerve, i.e. the vestibular cochlear nerve or nervus statoacusticus. Subsequently, the acoustical information is processed by the brain at various levels of the auditory system. An overview about the anatomy of the auditory system is provided by Figure 1.

Magnetic resonance cisternography using the fast spin echo method for the evaluation of vestibular schwannoma

Energy Technology Data Exchange (ETDEWEB)

Nishizawa, Shigeru; Yokoyama, Tetsuo; Uemura, Kenichi [Hamamatsu Univ. School of Medicine, Shizuoka (Japan)

1999-04-01

Neuroimaging of vestibular schwannoma was performed with the fat-suppression spoiled gradient recalled acquisition in the steady state (SPGR) method and magnetic resonance (MR) cisternography, which is a fast spin echo method using a long echo train length, for the preoperative evaluation of the lateral extension of the tumor in the internal auditory canal, and the anatomical identification of the posterior semicircular canal and the nerves in the canal distal to the tumor. The SPGR method overestimated the lateral extension in eight cases, probably because of enhancement of the nerves adjacent to the tumor in the canal. The posterior semicircular canal could not be clearly identified, and the cranial nerves in the canal were shown only as a nerve bundle. In contrast, MR cisternography showed clear images of the lateral extension of the tumor and the facial and cochlear nerves adjacent to the tumor in the internal auditory canal. The anatomical location of the posterior semicircular canal was also clearly shown. These preoperative findings are very useful to plan the extent to which the internal auditory canal can be opened, and for intraoperative identification of the nerves in the canal. MR cisternography is less invasive since no contrast material or radiation is required, as with thin-slice high-resolution computed tomography (CT). MR cisternography should replace high-resolution CT for the preoperative neuroradiological evaluation of vestibular schwannoma. (author)

Hydrostatic fluid pressure in the vestibular organ of the guinea pig.

Science.gov (United States)

Park, Jonas J-H; Boeven, Jahn J; Vogel, Stefan; Leonhardt, Steffen; Wit, Hero P; Westhofen, Martin

2012-07-01

Since inner ear hair cells are mechano-electric transducers the control of hydrostatic pressure in the inner ear is crucial. Most studies analyzing dynamics and regulation of inner ear hydrostatic pressure performed pressure measurements in the cochlea. The present study is the first one reporting about absolute hydrostatic pressure values in the labyrinth. Hydrostatic pressure of the endolymphatic system was recorded in all three semicircular canals. Mean pressure values were 4.06 cmH(2)O ± 0.61 in the posterior, 3.36 cmH(2)O ± 0.94 in the anterior and 3.85 cmH(2)O ± 1.38 in the lateral semicircular canal. Overall hydrostatic pressure in the vestibular organ was 3.76 cmH(2)O ± 0.36. Endolymphatic hydrostatic pressure in all three semicircular canals is the same (p = 0.310). With regard to known endolymphatic pressure values in the cochlea from past studies vestibular pressure values are comparable to cochlear values. Until now it is not known whether the reuniens duct and the Bast's valve which are the narrowest passages in the endolymphatic system are open or closed. Present data show that most likely the endolymphatic system is a functionally open entity.

Telescience testbed: Operational support functions for biomedical experiments

Science.gov (United States)

Yamashita, Masamichi; Watanabe, Satoru; Shoji, Takatoshi; Clarke, Andrew H.; Suzuki, Hiroyuki; Yanagihara, Dai

A telescience testbed was conducted to study the methodology of space biomedicine with simulated constraints imposed on space experiments. An experimental subject selected for this testbedding was an elaborate surgery of animals and electrophysiological measurements conducted by an operator onboard. The standing potential in the ampulla of the pigeon's semicircular canal was measured during gravitational and caloric stimulation. A principal investigator, isolated from the operation site, participated in the experiment interactively by telecommunication links. Reliability analysis was applied to the whole layers of experimentation, including design of experimental objectives and operational procedures. Engineering and technological aspects of telescience are discussed in terms of reliability to assure quality of science. Feasibility of robotics was examined for supportive functions to reduce the workload of the onboard operator.

MR score system on spatium perilymphaticum gadolinium opacification and its application for diagnosis of Meniere's disease

International Nuclear Information System (INIS)

Fang Zheming; Liu Ying; Cao Dairong; Chen Xi

2012-01-01

Objective: To propose a MR scoring methods for spatium perilymphaticum gadolinium opacification and explore the value of their diagnosis of Meniere's disease. Methods: Fifty-one asymptomatic and 65 symptomatic patients with Meniere's disease were enrolled in this study. MR imaging of spatium perilymphaticum after intratypanic gadolinium injection were analyzed with following scoring method. (1) Semicircular canal not visualized equal to score 0; some visualized equal score 1; full visualized equal score 2.(2)There were high-signal and low-signal in the vestibule, low-signal areas above the lateral semicircular canal plane equal score 6; low signal areas down to lateral semicircular canal plane equal score 3; no higher signal in the vestibule area equal score 0. (3) Basal turn of cochlea: full visualized equal score 3; part visualized equal score 2; scala vestibule of basal turn smaller than scala tympani equal score 1 regardless of full or visualized in basal turn; no visualized equal score 0. Medial turn of cochlea: full visualized equal score 2; part visualized equal score 1; no visualized equal score 0. Apical turn of cochlea: visualized equal score 1; no visualized equal score 0. One radiologist scored all cases with double blind. SPSS 17.0 software was used to conduct multiple independent-samples nonparametric tests, multivariate Logistic regression, and ROC curve analysis. Evaluate the sensitivity and specificity for diagnosis of Meniere's disease with the scoring system. Results: (1) Meniere's disease summation score 0 to 12, median 9 (quarter spacing 4.5); no symptoms group summation score 15 to 18,median 17 (quarter spacing 3), two group differences has statistics significance (Wilcoxon rank and inspection U=-9.118, P=0.00). (2) Based on summation score for the diagnosis of Meniere's disease, tangent point was 14.5, Youden index 0.969, specificity 100.0%, sensitivity 96.9%.(3) Let cochlear, vestibular, semicircular canal scoring

Pathologic Changes of the Peripheral Vestibular System Secondary to Chronic Otitis Media.

Science.gov (United States)

da Costa Monsanto, Rafael; Erdil, Mehmet; Pauna, Henrique F; Kwon, Geeyoun; Schachern, Patricia A; Tsuprun, Vladimir; Paparella, Michael M; Cureoglu, Sebahattin

2016-09-01

To evaluate the histopathologic changes of dark, transitional, and hair cells of the vestibular system in human temporal bones from patients with chronic otitis media. Comparative human temporal bone study. Otopathology laboratory. To compare the density of vestibular dark, transitional, and hair cells in temporal bones with and without chronic otitis media, we used differential interference contrast microscopy. In the chronic otitis media group (as compared with the age-matched control group), the density of type I and type II hair cells was significantly decreased in the lateral semicircular canal, saccule, and utricle (P otitis media group in the posterior semicircular canal (P = .005), but that of type II cells was not (P = .168). The mean number of dark cells was significantly decreased in the chronic otitis media group in the lateral semicircular canal (P = .014) and in the posterior semicircular canal (P = .002). We observed no statistically significant difference in the density of transitional cells between the 2 groups (P > .1). The findings of our study suggest that the decrease in the number of vestibular sensory cells and dark cells could be the cause of the clinical symptoms of imbalance of some patients with chronic otitis media. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Superior Canal Dehiscence Syndrome Affecting 3 Families.

Science.gov (United States)

Heidenreich, Katherine D; Kileny, Paul R; Ahmed, Sameer; El-Kashlan, Hussam K; Melendez, Tori L; Basura, Gregory J; Lesperance, Marci M

2017-07-01

Superior canal dehiscence syndrome (SCDS) is an increasingly recognized cause of hearing loss and vestibular symptoms, but the etiology of this condition remains unknown. To describe 7 cases of SCDS across 3 families. This retrospective case series included 7 patients from 3 different families treated at a neurotology clinic at a tertiary academic medical center from 2010 to 2014. Patients were referred by other otolaryngologists or were self-referred. Each patient demonstrated unilateral or bilateral SCDS or near dehiscence. Clinical evaluation involved body mass index calculation, audiometry, cervical vestibular evoked myogenic potential testing, electrocochleography, and multiplanar computed tomographic (CT) scan of the temporal bones. Zygosity testing was performed on twin siblings. The diagnosis of SCDS was made if bone was absent over the superior semicircular canal on 2 consecutive CT images, in addition to 1 physiologic sign consistent with labyrinthine dehiscence. Near dehiscence was defined as absent bone on only 1 CT image but with symptoms and at least 1 physiologic sign of labyrinthine dehiscence. A total of 7 patients (5 female and 2 male; age range, 8-49 years) from 3 families underwent evaluation. Family A consisted of 3 adult first-degree relatives, of whom 2 were diagnosed with SCDS and 1 with near dehiscence. Family B included a mother and her child, both of whom were diagnosed with unilateral SCDS. Family C consisted of adult monozygotic twins, each of whom was diagnosed with unilateral SCDS. For all cases, dehiscence was located at the arcuate eminence. Obesity alone did not explain the occurrence of SCDS because 5 of the 7 cases had a body mass index (calculated as weight in kilograms divided by height in meters squared) less than 30.0. Superior canal dehiscence syndrome is a rare, often unrecognized condition. This report of 3 multiplex families with SCDS provides evidence in support of a potential genetic contribution to the etiology

User manual for semi-circular compact range reflector code: Version 2

Science.gov (United States)

Gupta, Inder J.; Burnside, Walter D.

1987-01-01

A computer code has been developed at the Ohio State University ElectroScience Laboratory to analyze a semi-circular paraboloidal reflector with or without a rolled edge at the top and a skirt at the bottom. The code can be used to compute the total near field of the reflector or its individual components at a given distance from the center of the paraboloid. The code computes the fields along a radial, horizontal, vertical or axial cut at that distance. Thus, it is very effective in computing the size of the sweet spot for a semi-circular compact range reflector. This report describes the operation of the code. Various input and output statements are explained. Some results obtained using the computer code are presented to illustrate the code's capability as well as being samples of input/output sets.

Functional consequences of structural differences in stingray sensory systems. Part I: mechanosensory lateral line canals.

Science.gov (United States)

Jordan, Laura K; Kajiura, Stephen M; Gordon, Malcolm S

2009-10-01

Short range hydrodynamic and electrosensory signals are important during final stages of prey capture in elasmobranchs (sharks, skates and rays), and may be particularly useful for dorso-ventrally flattened batoids with mouths hidden from their eyes. In stingrays, both the lateral line canal and electrosensory systems are highly modified and complex with significant differences on ventral surfaces that relate to feeding ecology. This study tests functional hypotheses based on quantified differences in sensory system morphology of three stingray species, Urobatis halleri, Myliobatis californica and Pteroplatytrygon violacea. Part I investigates the mechanosensory lateral line canal system whereas part II focuses on the electrosensory system. Stingray lateral line canals include both pored and non-pored sections and differ in branching complexity and distribution. A greater proportion of pored canals and high pore numbers were predicted to correspond to increased response to water flow. Behavioral experiments were performed to compare responses of stingrays to weak water jets mimicking signals produced by potential prey at velocities of 10-20 cm s(-1). Bat rays, M. californica, have the most complex and broadly distributed pored canal network and demonstrated both the highest response rate and greater response intensity to water jet signals. Results suggest that U. halleri and P. violacea may rely on additional sensory input, including tactile and visual cues, respectively, to initiate stronger feeding responses. These results suggest that stingray lateral line canal morphology can indicate detection capabilities through responsiveness to weak water jets.

Unilateral posterior canal-plugging surgery for intractable bilateral posterior canal-type benign paroxysmal positional vertigo.

Science.gov (United States)

Hotta, Sayaka; Imai, Takao; Higashi-Shingai, Kayoko; Okazaki, Suzuyo; Okumura, Tomoko; Uno, Atsuhiko; Ohta, Yumi; Morihana, Tetsuo; Sato, Takashi; Inohara, Hidenori

2017-10-01

To investigate the effectiveness of unilateral posterior semicircular canal (PSCC)-plugging surgery for patients with intractable bilateral PSCC-type benign paroxysmal positional vertigo (P-BPPV). From July 2011 to December 2015, we diagnosed 136 patients with P-BPPV. Of these, 3 patients had bilateral P-BPPV, and in 2 of the 3, the condition had been refractory to conservative treatment for more than 1 year. We planned a staged PSCC-plugging surgery for these 2 patients; initially one side was treated, and the contralateral side was treated 6 months later. After the first surgery, both patients experienced improvement in symptoms of vertigo and nystagmus on the operated side and no change on the non-operated side. Patients underwent the Epley maneuver for the non-operated side. In one case, the non-operated side was cured. In the other case, although the P-BPPV was not completely resolved, the patient was satisfied with the result of unilateral surgery because he was now able to turn in bed to the operated side without vertigo. Before surgery, he had experienced vertigo when turning even slightly in bed. We propose that even unilateral PSCC-plugging surgery is effective for some patients with intractable bilateral P-BPPV. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Labyrinthine dehiscence in a child

International Nuclear Information System (INIS)

Paladin, Angelisa M.; Phillips, Grace S.; Raske, Molly E.; Sie, Kathleen C.Y.

2008-01-01

A 4-year-old boy presented with moderate to profound mixed hearing loss in the right ear and moderate to severe mixed hearing loss in the left ear, prompting a temporal bone CT scan. Images revealed partial dehiscence of the right posterior semicircular canal. Semicircular canal dehiscence and its associated clinical syndrome have been described in adults. We present this case as a unique finding in a child and discuss the possible clinical and research implications. (orig.)

Condutas pós-manobra de Epley em idosos com VPPB de canal posterior Conduct after Epley's maneuver in elderly with posterior canal BPPV in the posterior canal

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Ana Paula do Rego André

2010-06-01

Full Text Available A Vertigem Postural Paroxística Benigna é a mais comum das vestibulopatias periféricas, principalmente em idosos e apresenta como etiologia predominante nessa população à degeneração da mácula utricular. OBJETIVO: Comparar a eficácia das condutas pós-manobra de Epley. Desenho do Estudo: Estudo de coorte contemporâneo longitudinal. MATERIAL E MÉTODO: Participaram do estudo 53 voluntários com Vertigem Postural Paroxística Benigna de canal semicircular posterior, distribuídos em Grupo 1, submetidos à manobra de Epley associada ao uso do colar cervical e orientações pós-manobra; Grupo 2 submetido a manobra de Epley sem uso do colar cervical e/ou restrições pós-manobra, e Grupo 3 submetido à manobra de Epley associada com o uso de um minivibrador, sem uso de colar cervical e/ou restrições pós-manobra. RESULTADOS: Nos três grupos, o número de manobras de Epley variou de uma a três. Aplicou-se o Dizziness Handicap Inventory brasileiro pré e pós-tratamento e observou-se diferença estatisticamente significativa na maioria dos escores pré e pós-tratamento para os grupos avaliados. CONCLUSÃO: Independentemente da conduta pós-manobra de Epley selecionada para o tratamento da Vertigem Postural Paroxística Benigna, essa se mostrou eficaz quando se comparou o Dizziness Handicap Inventory brasileiro pré e pós-tratamento.Benign Paroxysmal Positional Vertigo is the most common peripheral vestibular disorder, especially in the elderly and presents as the predominant etiology in this population of the degeneration of the utricular macula. AIM: To compare the effectiveness of the approaches after Epley maneuver. Study Design: longitudinal cohort. MATERIALS AND METHODS: The study included 53 volunteers with Benign Paroxysmal Positional Vertigo of the posterior semicircular canal, divided into Group 1, who underwent Epley maneuver associated with the use of neck collar and post-maneuver instructions, Group 2 underwent the Epley

Refractory Positional Vertigo With Apogeotropic Horizontal Nystagmus After Labyrinthitis: Surgical Treatment and Identification of Dysmorphic Ampullae.

Science.gov (United States)

Ahmed, Sameer; Heidenreich, Katherine D; McHugh, Jonathan B; Altschuler, Richard A; Carender, Wendy J; Telian, Steven A

2015-09-01

To describe the rationale, intraoperative details, and histopathologic findings discovered when treating an unusual case of apogeotropic horizontal canal positional vertigo with a transmastoid labyrinthectomy. A single case report. Therapeutic. Resolution of apogeotropic nystagmus and improvement of positional vertigo. The apogeotropic variant of horizontal canal positional vertigo can be a difficult entity to treat. This report describes a patient who developed profound sensorineural hearing loss and vertigo after an acute left labyrinthitis. Ten months later, she developed vertigo with apogeotropic positional nystagmus involving the left horizontal semicircular canal. Particle repositioning maneuvers and vestibular physical therapy were unsuccessful. In addition, she developed intermittent positional vertigo affecting the ipsilateral vertical semicircular canals. Given the persistence of her vertigo, multiple canal involvement, and patient preference for definitive treatment, a transmastoid labyrinthectomy was performed. Intraoperatively, the ampulla of the horizontal canal as well as that of the other canals was grossly abnormal as later confirmed on histology. After surgery, her apogeotropic nystagmus and vertigo resolved, and her balance ability gradually improved to a highly functional level. This case illustrates a unique form of positional vertigo that developed and persisted after acute labyrinthitis. Conservative measures were unsuccessful and a transmastoid labyrinthectomy documented dense inflammatory tissue involving all three ampullae. We postulate that the post-labyrinthitic inflammatory changes resulted in mass loading of the membranous ampullae, causing abnormal nystagmus patterns and positional vertigo, which resolved after the labyrinthectomy.

Semicircular Horizontal Approach in Breast Reduction: Clinical Experience in 38 Cases

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Hee Su Shin

2015-07-01

Full Text Available BackgroundVarious techniques are used for performing breast reduction. Wise-pattern and vertical scar techniques are the most commonly employed approaches. However, a vertical scar in the mid-lower breast is prominent and aesthetically less pleasant. In contrast, a semicircular horizontal approach does not leave a vertical scar in the mid breast and transverse scars can be hidden in the inframammary fold. In this paper, we describe the experiences and results of semicircular horizontal breast reductions performed by a single surgeon.MethodsBetween September 1996 and October 2013, our senior author used this technique in 38 cases in the US and at our institution. We used a superiorly based semicircular incision, where the upper skin paddle was pulled down to the inframammary fold with the nipple-areola complex pulled through the keyhole.ResultsThe average total reduction per breast was 584 g, ranging from 286 to 794 g. The inferior longitudinal pedicle was used in all the cases. The average reduction of the distance from the sternal notch to the nipple was 13 cm (range, 11-15 cm. The mean decrease in the bra cup size was 1.7 cup sizes (range, a decrease of 1 to 3. We obtained very satisfactory results with a less noticeable scar, no complication such as necrosis of the nipple or the skin flap, wound infection, aseptic necrosis of the breast tissue, or wound dehiscence. One patient had a small hematoma that resolved spontaneously.ConclusionsThis technique is straightforward and easy to learn, and offers a safe, effective, and predictable way for treating mammary hypertrophy.

Application of digital tomosynthesis to radiographic diagnosis of the temporal bone. Studies on visualization in normal subjects

International Nuclear Information System (INIS)

Kawai, Takashi

1995-01-01

To examine the usefulness of digital tomosynthesis for conducting radiographic diagnosis of the temporal bone, visualization of various aural structures such as the semicircular canals, cochlea, vestibular apparatus, ossicles of the ear and facial nerve canal was examined in 18 volunteers. The visualization of temporal bone specimens by digital tomosynthesis and CT images (slice thickness: 1.5 mm) was compared. The results showed that this system (Digital Tomosynthesis) produced clear images of bony labyrinthine structures such as the semicircular canals, cochlea, and vestibular apparatus. Visualization of the ossicles was also clear, and their continuity could be comprehended better than on CT images. This system also provided good visualization of the labyrinthine and tympanic parts of the facial nerve canal, although CT images had greater sharpness. Visualization of the lower half of the mastoid part was poor with this system. (author)

The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon

International Nuclear Information System (INIS)

Zhang, Xue; Wang, Yong; Fan, Junjie; Zhong, Yong; Zhang, Rui

2014-01-01

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically

The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon

Science.gov (United States)

Zhang, Xue; Wang, Yong; Fan, Junjie; Zhong, Yong; Zhang, Rui

2014-09-01

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically.

The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xue, E-mail: zhangxue.iecas@yahoo.com; Wang, Yong; Fan, Junjie; Zhong, Yong; Zhang, Rui [Institute of Electronics, Chinese Academy of Sciences, Peking, 100190 China (China)

2014-09-15

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically.

Lipoatrofia semicircular: un nuevo trastorno de salud relacionado con el trabajo Semicircular lipoatrophy: a new occupational disease

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Helena Pañella

2008-02-01

Full Text Available En febrero de 2007, una gran empresa de Barcelona notificó un brote de una rara lesión llamada lipoatrofia semicircular que afectaba a casi 200 personas de los aproximadamente 1.000 trabajadores de plantilla. En septiembre de ese mismo año se habían notificado más de 600 casos, también en otros centros de trabajo, sobre todo de Barcelona pero también del resto de España. Se realizó un estudio de casos y controles que identificó como factores de riesgo de esta lesión la baja humedad relativa del interior de los edificios y la utilización de mesas de trabajo con bordes delgados y angulares. Cuatro meses después de notificarse los primeros casos, se presentó un protocolo de actuación ante casos de lipoatrofia dirigido a los profesionales sanitarios de los servicios de prevención de las empresas y de las mutuas de accidentes de trabajo y de enfermedades profesionales. La implantación de estas medidas de control se ha traducido en una drástica reducción de la incidencia y en la curación de una proporción significativa de los casos.In February 2007, an outbreak of 200 cases of a rare condition called semicircular lipoatrophy was notified by a company of Barcelona with about 1,000 workers. In September of that year, more that 600 cases had been notified in other workplaces, most of them in Barcelona, but also in other Spanish cities. A case-control study identified the low indoor relative humidity and working tables with thin edges as risk factors. Four months after the onset of the outbreak, the guidelines for the management of similar work-related outbreaks were published. They were addressed to health care workers of occupational health services and insurance organisations of occupational injuries and professional diseases. The implementation of the recommended interventions has been followed by a dramatic reduction of the incidence of new cases as well as by the recovery of a significant proportion of cases.

Stability of guest molecules in urea canal complexes by canal polymerization

International Nuclear Information System (INIS)

Yoshii, Fumio; Makuuchi, Keizo

1995-01-01

It was found that various organic materials are attracted into urea canal by hexanediol diacrylate (HDDA) and long chain compounds. This means that materials which does not form complex by itself are induced in canal by HDDA and long chain compounds. To include with stability perfumes, insecticides, attractants and repellents in urea canal, leaf alcohol was used as a model compound for guest molecules in the canal. The leaf alcohol from the canal released gradually over many days and the release was inhibited for 15 days by long chain compounds and for 30 days by polymerized HDDA after irradiation. After releasing, the leaf alcohol in the canal remained 25 % stable for long chain compounds and 40 % for polymerized HDDA. The dose required for stabilization of leaf alcohol in the urea canal by canal polymerization of HDDA was 30 kGy. (author)

Root canal irrigants

OpenAIRE

Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

2010-01-01

Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

Design, Development and Testing of a Semicircular Type Capacitive Angular Position Sensor

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Nikhil GAURAV

2011-06-01

Full Text Available A low cost semicircular type capacitive angular position sensor has been designed, developed and tested. It is made of two semicircular parallel plates where one plate is fixed and another plate is connected with the rotor whose angular position is to be measured. When the angular position of the rotor changes with respect to the fixed plate, the overlapping area between the two plates of the capacitor is varied causing a change in capacitance value. Capacitance variation obtained due to the change in angular position is in the nano farad range. For signal conditioning, series R-L-C resonating circuit instead of conventional bridge circuit has been used to convert the sensor capacitance variation in to voltage. Experimental result shows that the capacitance for change in angular position 0º-180º increases linearly and for 180º-360º it decreases linearly. To get a linearly increasing response of same slope for the full scale of 0º-360º, a suitable linearising circuit has been designed, developed and tested. Sensor output along with the signal conditioning shows good linearity and repeatability.

MRI measurement for inner ear structures

International Nuclear Information System (INIS)

Li Shuling; Liu Huaijun; Chi Chen; Qin Ruiping; Shi Zhaoxia

2003-01-01

Objective: To reconstruct the image of inner ear by using 3D-FASE heavily T 2 WI, and to establish MRI measurement criterion of inner ear structures. Methods: One hundred and six inner ears of 53 healthy volunteers underwent MRI heavily T2-weighted axial scanning by using 3D fast advanced spin echo sequence. All the original images were transferred to an online workstation. Analyze AVW software was used for image post-processing. All the structures of inner ear were reconstructed, rotated from various angles and measured by using maximum intensity projection (MIP). Results: (1) All the structures of inner ear and internal auditory channel (IAC) could be visualized clearly by using 3D-FASE heavily T 2 WI. (2) Using analysis of variance, there was no age, side or race-related difference in inner ear volume, but it was bigger in male than in female [(0.242 ± 0.0236) mm 3 (male) versus (0.226 ± 0.021) mm 3 (female)]. There was no age, side-related differences in three semicircular canal height and vestibule vertical diameter, but, again, they were bigger in male than in female. The height of upper, lateral and posterior semicircular canal were (5.511 ± 0.626) mm (male) versus (5.167 ± 0.357) mm (female); (3.763 ± 0.495) mm (male) versus (3.446 ± 0.405) mm (female); (5.227 ± 0.547) mm (male) versus (4.786 ± 0.500) mm (female). There was no age, sex or side-related differences in three semicircular canal diameter and cochlea. The diameter of upper, lateral and posterior semicircular canal were (1.06 ± 0.119) mm, (1.14 ± 0.181) mm, and (1.22 ± 0.196)mm; the external diameter of cochlea basal turn was (6.520 ± 0.475) mm, the diameter of cochlea basal turn was (1.413 ± 0.144) mm, and cochlea height was (4.100 ± 0.405) mm. Conclusion: (1) For the first time, the MRI measurement criterion of inner ear structures is established. (2) Vestibule and three semicircular canal of inner ear are bigger in male than in female

Mejoras en el canal de Panamá

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Brandl, Charles McG.

1963-07-01

Full Text Available The Panama Canal, together with the Suez Canal, is an engineering accomplishment which is now regarded as a master work marking the initiation of modern civil engineering. Other projects, also of great magnitude, do not seem to maintain the reputation of the above two, because they cannot continue to serve their function with sustained usefulness in the new circumstances of today. The Panama Canal, with its limited dock capacity, and the narrow, so called Serpent, canal, has had to cope with a continuously increasing volume of shipping traffic; a natural consequence of commercial evolution. In order to keep up with these increasing demands, it has been necessary to carry out an almost uninterrupted series of modifications and improvements, affecting both the method of operation and organisation, and the actual nature of the canal. Thanks to these alterations the Panama Canal has continued to maintain, at least nominally, an adequate standard of functional efficiency. At present the canal is being widened over certain sections to enable the easy passage of ships of great displacement. The work is being done very rapidly, and in order to gain time, it has been distributed to various contractors simultaneously.El canal a través del ismo de Panamá es una obra de ingeniería civil que, junto con el de Suez, empiezan ya a clasificarse como obras maestras que señalan el primer jalón del desarrollo de la ingeniería moderna. Otras obras, también importantes, no conservan, sin embargo, la misma reputación que aquéllas, por no seguir un paralelismo con las exigencias en cada época. El canal de Panamá, con sus exclusas, y angosto paso llamado de la. Culebra, ha tenido que afrontar un tráfico creciente de navíos que siguen la evolución del tiempo. Para conseguir este paralelismo, tanto el material de explotación como la organización, dragados y mejoras, han tenido que conocer una sucesión ininterrumpida de modificaciones que han permitido

CT study of 17 cases of congenital cochlear abnormality. Embryologic and anatomo-functional relationship

OpenAIRE

Maurício, JC; Biscoito, L; Branco, G

1993-01-01

In this review of cochlear malformations, 17 cases were studied by CT scan (high resolution-target program) including 10 males and 7 females. The anomaly was bilateral in 12 cases and unilateral in 7 (the latter included 2 Mondini type aplasias and one Michel). The cochlear malformation (whose most frequent expression was the cochlear hypoplasia with 1 or 1 1/2 spires-65% of the cases) was associated to semicircular canals and/or vestibular aqueduct anomaly in 82% of the patients; it was excl...

Preservation of vestibular function after scala vestibuli cochlear implantation.

Science.gov (United States)

Suzuki, Mitsuya; Goto, Takio; Kashio, Akinori; Yasui, Takuya; Sakamoto, Takashi; Ito, Ken; Yamasoba, Tatsuya

2011-10-01

A 58-year-old man, in whom the cochlear implant (CI) had been inserted into the left ear, had right middle-ear cancer. The CI was removed immediately before receiving subtotal removal of right temporal bone. Four months later, the CI was again inserted in his left cochlea. Because of obliterated scala tympani, the 22 active electrodes of the CI were placed into the scala vestibuli. After the surgery, the patient complained that he experienced rotary vertigo and "jumbling of vertical direction" of objects on walking. Using rotation test, we evaluated vestibular function of remaining left ear. Numerous horizontal nystagmus beats were induced during earth-vertical axis rotation, whereas vertical downbeat nystagmus was scarcely induced during off-vertical axis rotation. The horizontal vestibulo-ocular reflex (VOR) was almost normally induced by sinusoidal stimulation at 0.8Hz. These data suggest that the scala vestibuli insertion of CI would be not so invasive against the lateral semicircular canal. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Interaction of Aquifer and River-Canal Network near Well Field.

Science.gov (United States)

Ghosh, Narayan C; Mishra, Govinda C; Sandhu, Cornelius S S; Grischek, Thomas; Singh, Vikrant V

2015-01-01

The article presents semi-analytical mathematical models to asses (1) enhancements of seepage from a canal and (2) induced flow from a partially penetrating river in an unconfined aquifer consequent to groundwater withdrawal in a well field in the vicinity of the river and canal. The nonlinear exponential relation between seepage from a canal reach and hydraulic head in the aquifer beneath the canal reach is used for quantifying seepage from the canal reach. Hantush's (1967) basic solution for water table rise due to recharge from a rectangular spreading basin in absence of pumping well is used for generating unit pulse response function coefficients for water table rise in the aquifer. Duhamel's convolution theory and method of superposition are applied to obtain water table position due to pumping and recharge from different canal reaches. Hunt's (1999) basic solution for river depletion due to constant pumping from a well in the vicinity of a partially penetrating river is used to generate unit pulse response function coefficients. Applying convolution technique and superposition, treating the recharge from canal reaches as recharge through conceptual injection wells, river depletion consequent to variable pumping and recharge is quantified. The integrated model is applied to a case study in Haridwar (India). The well field consists of 22 pumping wells located in the vicinity of a perennial river and a canal network. The river bank filtrate portion consequent to pumping is quantified. © 2014, National GroundWater Association.

[Positioning diagnosis of benign positional paroxysmal vertigo by VNG].

Science.gov (United States)

Wang, Na; Chen, Taisheng; Lin, Peng; Song, Wei; Dong, Hong

2009-07-01

To analyze the value of positioning diagnosis of VNG (Videonystagmograph) in patients with benign paroxysmal positional vertigo (BPPV). One hundred and twenty-six patients with BPPV were enrolled in this retrospective study. Their positional nystagmus recorded by VNG in Dix-Hallpike and roll tests were analyzed to summarize the characteristics of nystagmus on nystagmography of various BPPV. Of 126 patients with BPPV diagnosed in our center, the posterior semicircular canals (PSC) were involved in 98 patients (77.8%), whereas the horizontal semicircular canal (HSC) and anterior semicircular canal (ASC) were involved in 17 (13.5%) and 5 (3.9%), respectively. Six patients (4.8%) confirmed combined-BPPV had HSC-BPPV and ipsilateral PSC-BPPV. Twenty-eight patients with PSC-BPPV had reversal phase on nystagmography. The nystagmus of patients with P/ASC-canalithiasis showed upward/downward on the vertical phase of nystagmography and orientated the opposite side on horizontal phase in the head hanging position, and the nystagmus reversed when returned to sit. Nystagmus on horizontal phase could be provoked when the head turned to both sides of the roll tests in patients with HSC-BPPV. If the nystagmus and the head-turning shared the same direction, then HSC-canalithiasis was confirmed, and the direction of the head-turning which provoked the stronger nystagmus indicates the lesion side. If the nystagmus and the head-turning had the opposite direction, then HSC-cupulolithiasis was confirmed, and the direction of the head-turning which provoked the weaker nystagmus indicates the lesion side. Positional nystagmus can be recorded objectively using VNG, According to which positioning the semicircular canal involved would be easier and more accurate. The recording conserved also could be helpful for clinical diagnosis and repositioning of BPPV.

Canal shaping of different single-file systems in curved root canals

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Maurizio D'Amario

2017-12-01

Full Text Available Background/Purpose: This study compared maintenance of canal anatomy, occurrence of apical transportation, and working time observed after instrumentation with One Shape New Generation rotary system (Micro-Mega, with those observed after instrumentation with Reciproc (VDW and WaveOne (Dentsply-Maillefer reciprocating systems. Materials and methods: The mesial canals of 45 mandibular molars (curvature angles between 35° and 45° were selected. Specimens were randomly divided into three groups, and canal preparations were performed using One Shape, Reciproc, or WaveOne systems (size #25. A digital double radiographic technique was used to determine apical transportation and change in angle of curvature. Also, working time and instrument failures were recorded. Data were statistically analyzed. Results: During preparation, no file fractured. No statistically significant differences were found among groups. No system showed a significantly faster preparation time than others (P>0.05. All instruments maintained the original canal curvature well and were safe to use. Conclusion: Both continuous rotary instrument and reciprocating systems did not have any influence on the presence of apical transportation or caused an alteration in angle of canal curvature. Keywords: canal curvature, canal straightening, endodontics, reciprocating motion, single file instrumentation

Transparent model of temporal bone and vestibulocochlear organ made by 3D printing.

Science.gov (United States)

Suzuki, Ryoji; Taniguchi, Naoto; Uchida, Fujio; Ishizawa, Akimitsu; Kanatsu, Yoshinori; Zhou, Ming; Funakoshi, Kodai; Akashi, Hideo; Abe, Hiroshi

2018-01-01

The vestibulocochlear organ is composed of tiny complex structures embedded in the petrous part of the temporal bone. Landmarks on the temporal bone surface provide the only orientation guide for dissection, but these need to be removed during the course of dissection, making it difficult to grasp the underlying three-dimensional structures, especially for beginners during gross anatomy classes. We report herein an attempt to produce a transparent three-dimensional-printed model of the human ear. En bloc samples of the temporal bone from donated cadavers were subjected to computed tomography (CT) scanning, and on the basis of the data, the surface temporal bone was reconstructed with transparent resin and the vestibulocochlear organ with white resin to create a 1:1.5 scale model. The carotid canal was stuffed with red cotton, and the sigmoid sinus and internal jugular vein were filled with blue clay. In the inner ear, the internal acoustic meatus, cochlea, and semicircular canals were well reconstructed in detail with white resin. The three-dimensional relationships of the semicircular canals, spiral turns of the cochlea, and internal acoustic meatus were well recognizable from every direction through the transparent surface resin. The anterior semicircular canal was obvious immediately beneath the arcuate eminence, and the topographical relationships of the vestibulocochlear organ and adjacent great vessels were easily discernible. We consider that this transparent temporal bone model will be a very useful aid for better understanding of the gross anatomy of the vestibulocochlear organ.

Design Of The Canal System Of KLA-60 Condensation Produce

International Nuclear Information System (INIS)

Sriawan; Wiranto, Slamet

2000-01-01

The RSG-GAS reactor pool ventilation system (KLA-60) which be used to avoid circulation of contamination air in the reactor hall, flow the 60% air from the pool surface to stack through the various filters. In case the isolation building the air from the pool surface is flooded back to the operation hall after exceed the heat exchanger, cooler and the various filters. One of the weakness of this system and must be solved by RSG is handing of the condensation water because in the canal system of the KLA-60 condensation produce is to be found some soiled like algae and to go the reactor pool. To solve this problem should be carried out research about the canal system of KLA-60 condensation produce and design the new canal system to find the good function. At the first design is carried out study about the function of the old of canal system of KLA-60 condensation produce. Base on this study have been carried out design of the canal system KLA-60 condensation produce, with can prevent the soiled to go to the reactor pool

Ontogeny of mouse vestibulo-ocular reflex following genetic or environmental alteration of gravity sensing.

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Mathieu Beraneck

Full Text Available The vestibular organs consist of complementary sensors: the semicircular canals detect rotations while the otoliths detect linear accelerations, including the constant pull of gravity. Several fundamental questions remain on how the vestibular system would develop and/or adapt to prolonged changes in gravity such as during long-term space journey. How do vestibular reflexes develop if the appropriate assembly of otoliths and semi-circular canals is perturbed? The aim of present work was to evaluate the role of gravity sensing during ontogeny of the vestibular system. In otoconia-deficient mice (ied, gravity cannot be sensed and therefore maculo-ocular reflexes (MOR were absent. While canals-related reflexes were present, the ied deficit also led to the abnormal spatial tuning of the horizontal angular canal-related VOR. To identify putative otolith-related critical periods, normal C57Bl/6J mice were subjected to 2G hypergravity by chronic centrifugation during different periods of development or adulthood (Adult-HG and compared to non-centrifuged (control C57Bl/6J mice. Mice exposed to hypergravity during development had completely normal vestibulo-ocular reflexes 6 months after end of centrifugation. Adult-HG mice all displayed major abnormalities in maculo-ocular reflexe one month after return to normal gravity. During the next 5 months, adaptation to normal gravity occurred in half of the individuals. In summary, genetic suppression of gravity sensing indicated that otolith-related signals might be necessary to ensure proper functioning of canal-related vestibular reflexes. On the other hand, exposure to hypergravity during development was not sufficient to modify durably motor behaviour. Hence, 2G centrifugation during development revealed no otolith-specific critical period.

[Root canal treatment of mandibular first premolar with 4 root canals: a case report].

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Liu, Xin-yang; Zhan, Fu-Liang

2015-10-01

The mandibular first premolar can be considered one of the most challenging teeth to treat, due to the complexity of its root canal morphology and increased incidence of multiple canals. A case of endodontic treatment of a mandibular first premolar exhibiting a total of 4 distinct root canals and 4 apical foramina was described. Anatomic variation of root canal morphology should be considered in endodontic treatment to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation might allow the flow of sealer into the narrowed but unprepared part of the canal, thereby facilitating optimum chemo-mechanical debridement of the root canal system.

Vestibular evoked myogenic potentials and video head impulse test in patients with vertigo, dizziness and imbalance.

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Skorić, Magdalena Krbot; Adamec, Ivan; Pavičić, Tin; Pavlović, Ivan; Ruška, Berislav; Crnošija, Luka; Habek, Mario

2017-05-01

The aim of this study was to compare vestibular evoked myogenic potentials (VEMP) and video head impulse test (vHIT) results in patients presenting with vertigo and dizziness. We retrospectively analyzed data of all patients with the chief complaint of vertigo, dizziness, or imbalance that underwent VEMP and vHIT from January 2015 to January 2016. A total of 117 patients (73 females, mean age 53.92±16.76) fulfilled inclusion criteria: group 1 included patients with the final diagnosis of vestibular neuritis (VN) (N=31 (16 right and 15 left VN)), group 2 included patients with the final diagnosis of vertigo of central origin (N=23) and group 3 included patients with the final diagnosis of unspecified dizziness (N=63). There was significant correlation between oVEMP asymmetry and asymmetry of the lateral canals 60ms gains on vHIT (r=0.225, p=0.026). Significant correlation between oVEMP and vHIT asymmetry was present in VN patients (r=0.749, p<0.001), while no correlation was found in the groups 2 and 3. oVEMP and vHIT lateral canals asymmetries were significantly greater in patients with vestibular neuritis. Furthermore, positive correlations of oVEMP amplitudes with 60ms gain of the lateral semicircular canal and slope of the anterior semicircular canal on vHIT, and cVEMP with slope of the posterior semicircular canal on the vHIT were found. These changes were significantly more pronounced in patients with vestibular neuritis. In conclusion, VEMPs and vHIT data should be used complementarily; asymmetry on both tests strongly supports peripheral vestibular system involvement. Copyright © 2017 Elsevier Ltd. All rights reserved.

MULTIPLE SPINAL CANAL MENINGIOMAS

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Nandigama Pratap Kumar

2016-10-01

Full Text Available BACKGROUND Meningiomas of the spinal canal are common tumours with the incidence of 25 percent of all spinal cord tumours. But multiple spinal canal meningiomas are rare in compare to solitary lesions and account for 2 to 3.5% of all spinal meningiomas. Most of the reported cases are both intra cranial and spinal. Exclusive involvement of the spinal canal by multiple meningiomas are very rare. We could find only sixteen cases in the literature to the best of our knowledge. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for single lesion. We analysed the literature, with illustration of our case. MATERIALS AND METHODS In September 2016, we performed a literature search for multiple spinal canal meningiomas involving exclusively the spinal canal with no limitation for language and publication date. The search was conducted through http://pubmed.com, a wellknown worldwide internet medical address. To the best of our knowledge, we could find only sixteen cases of multiple meningiomas exclusively confined to the spinal canal. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for solitary intradural extra medullary spinal canal meningioma at D4-D6 level, again presented with spastic quadriparesis of two years duration and MRI whole spine demonstrated multiple intradural extra medullary lesions, which were excised completely and the histopathological diagnosis was transitional meningioma. RESULTS Patient recovered from his weakness and sensory symptoms gradually and bladder and bowel symptoms improved gradually over a period of two to three weeks. CONCLUSION Multiple

Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

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Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul

2001-01-01

To identify and evaluate the normal anatomy of nerve canals in the fundus of the internal auditory canal which can be visualized on high-resolution temporal bone CT. We retrospectively reviewed high-resolution (1 mm thickness and interval contiguous scan) temporal bone CT images of 253 ears in 150 patients who had not suffered trauma or undergone surgery. Those with a history of uncomplicated inflammatory disease were included, but those with symptoms of vertigo, sensorineural hearing loss, or facial nerve palsy were excluded. Three radiologists determined the detectability and location of canals for the labyrinthine segment of the facial, superior vestibular and cochlear nerve, and the saccular branch and posterior ampullary nerve of the inferior vestibular nerve. Five bony canals in the fundus of the internal auditory canal were identified as nerve canals. Four canals were identified on axial CT images in 100% of cases; the so-called singular canal was identified in only 68%. On coronal CT images, canals for the labyrinthine segment of the facial and superior vestibular nerve were seen in 100% of cases, but those for the cochlear nerve, the saccular branch of the inferior vestibular nerve, and the singular canal were seen in 90.1%, 87.4% and 78% of cases, respectiveIy. In all detectable cases, the canal for the labyrinthine segment of the facial nerve was revealed as one which traversed anterolateralIy, from the anterosuperior portion of the fundus of the internal auditory canal. The canal for the cochlear nerve was located just below that for the labyrinthine segment of the facial nerve, while that canal for the superior vestibular nerve was seen at the posterior aspect of these two canals. The canal for the saccular branch of the inferior vestibular nerve was located just below the canal for the superior vestibular nerve, and that for the posterior ampullary nerve, the so-called singular canal, ran laterally or posteolateralIy from the posteroinferior aspect of

Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

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Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

2001-12-01

To identify and evaluate the normal anatomy of nerve canals in the fundus of the internal auditory canal which can be visualized on high-resolution temporal bone CT. We retrospectively reviewed high-resolution (1 mm thickness and interval contiguous scan) temporal bone CT images of 253 ears in 150 patients who had not suffered trauma or undergone surgery. Those with a history of uncomplicated inflammatory disease were included, but those with symptoms of vertigo, sensorineural hearing loss, or facial nerve palsy were excluded. Three radiologists determined the detectability and location of canals for the labyrinthine segment of the facial, superior vestibular and cochlear nerve, and the saccular branch and posterior ampullary nerve of the inferior vestibular nerve. Five bony canals in the fundus of the internal auditory canal were identified as nerve canals. Four canals were identified on axial CT images in 100% of cases; the so-called singular canal was identified in only 68%. On coronal CT images, canals for the labyrinthine segment of the facial and superior vestibular nerve were seen in 100% of cases, but those for the cochlear nerve, the saccular branch of the inferior vestibular nerve, and the singular canal were seen in 90.1%, 87.4% and 78% of cases, respectiveIy. In all detectable cases, the canal for the labyrinthine segment of the facial nerve was revealed as one which traversed anterolateralIy, from the anterosuperior portion of the fundus of the internal auditory canal. The canal for the cochlear nerve was located just below that for the labyrinthine segment of the facial nerve, while that canal for the superior vestibular nerve was seen at the posterior aspect of these two canals. The canal for the saccular branch of the inferior vestibular nerve was located just below the canal for the superior vestibular nerve, and that for the posterior ampullary nerve, the so-called singular canal, ran laterally or posteolateralIy from the posteroinferior aspect of

Scanning electron microscopy investigation of canal cleaning after canal preparation with nickel titanium files

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Živković Slavoljub

2010-01-01

Full Text Available Introduction. Root canal preparation is the most important phase of endodontic procedure and it consists of adequate canal space cleaning and shaping. In recent years, rotary instruments and techniques have gained importance because of the great efficacy, speed and safety of the preparation procedure. Objective. The aim of this research was to investigate the influence of different NiTi files on the canal wall cleaning quality, residual dentine debris and smear layer. Methods. The research was conducted on extracted human teeth in vitro conditions. Teeth were divided in 7 main groups depending on the kind of instruments used for root canal preparation: ProTaper, GT, ProFile, K-3, FlexMaster, hand ProTaper and hand GT. Root canal preparation was accomplished by crown-down technique. Prepared samples were assessed on scanning electron microscopy JEOL, JSM-6460 LV. The evaluation of dentine debris was done with 500x magnification, and the evaluation of smear layer with 1,000 times magnification. Quantitive assessment of dentine debris and smear layer was done according to the criteria of Hulsmann. Results. The least amount of debris and smear layer has been found in canals shaped with ProFile instruments, and the largest amount in canals shaped with FlexMaster instruments. Canal cleaning efficacy of hand GT and ProTaper files has been similar to cleaning efficacy of rotary NiTi files. Statistic analysis has shown a significant difference in amount of dentine debris and smear layer on the canal walls between sample groups shaped with different instruments. Conclusion. Completely clean canals have not been found in any tested group of instruments. The largest amount of debris and smear layer has been found in the apical third of all canals. The design and the type of endodontic instruments influence the efficacy of the canal cleaning.

Curved canals: Ancestral files revisited

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Jain Nidhi

2008-01-01

Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

Laser scanning dental probe for endodontic root canal treatment

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Blank, Molly A. B.; Friedrich, Michal; Hamilton, Jeffrey D.; Lee, Peggy; Berg, Joel; Seibel, Eric J.

2011-03-01

Complications that arise during endodontic procedures pose serious threats to the long-term integrity and health of the tooth. Potential complexities of root canals include residual pulpal tissue, cracks, mesial-buccal 2 and accessory canals. In the case of a failed root canal, a successful apicoectomy can be jeopardized by isthmuses, accessory canals, and root microfracture. Confirming diagnosis using a small imaging probe would allow proper treatment and prevent retreatment of endodontic procedures. An ultrathin and flexible laser scanning endoscope of 1.2 to 1.6mm outer diameter was used in vitro to image extracted teeth with varied root configurations. Teeth were opened using a conventional bur and high speed drill. Imaging within the opened access cavity clarified the location of the roots where canal filing would initiate. Although radiographs are commonly used to determine the root canal size, position, and shape, the limited 2D image perspective leaves ambiguity that could be clarified if used in conjunction with a direct visual imaging tool. Direct visualization may avoid difficulties in locating the root canal and reduce the number of radiographs needed. A transillumination imaging device with the separated illumination and light collection functions rendered cracks visible in the prepared teeth that were otherwise indiscernible using reflected visible light. Our work demonstrates that a small diameter endoscope with high spatial resolution may significantly increase the efficiency and success of endodontic procedures.

Effects of runoff harvesting through semi-circular bund on some soil characteristics

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M. Heshmati

2018-04-01

Full Text Available In this study, to investigate the effects of runoff harvesting on soil properties in the semiarid forest, runoff harvesting through semi-circular bund was considered as a method to conserve soil and thereby combat tree mortality. In order to evaluate this hypothesis, runoff was harvested through the semi-circular bund affecting soil quality and moisture storage. The selected forest site is located in Kalehzard, Kermanshah, in Zagros region of western Iran. The experiment was a randomized complete block design with four treatment plots: bund with protection, protection treatment, bund without protection and control treatment. The results showed that the mean values of soil organic carbon in the bund with protection, protection treatment, bund without protection and  control treatment were 2.35, 2.40, 1.90, and 1.80%, respectively, indicating no significant difference among them in the first year, while there were significant (p> 0.05 increases in the bund with protection and protection treatment after three years. Furthermore, coarse and very coarse soil aggregates increased significantly in the bund with protection treatment. This treatment also attributed to significant reduction in soil bulk density from 1.46 (in the first year to 1.32 (in the third year, which enhanced soil moisture content. Finally it was found that bunds with protection significantly curtail dieback and adverse re-growing of stands due to the coupled effects of bund building and protection to curtail forest mortality in the semi-arid regions.

Gene Therapy Restores Balance and Auditory Functions in a Mouse Model of Usher Syndrome.

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Isgrig, Kevin; Shteamer, Jack W; Belyantseva, Inna A; Drummond, Meghan C; Fitzgerald, Tracy S; Vijayakumar, Sarath; Jones, Sherri M; Griffith, Andrew J; Friedman, Thomas B; Cunningham, Lisa L; Chien, Wade W

2017-03-01

Dizziness and hearing loss are among the most common disabilities. Many forms of hereditary balance and hearing disorders are caused by abnormal development of stereocilia, mechanosensory organelles on the apical surface of hair cells in the inner ear. The deaf whirler mouse, a model of human Usher syndrome (manifested by hearing loss, dizziness, and blindness), has a recessive mutation in the whirlin gene, which renders hair cell stereocilia short and dysfunctional. In this study, wild-type whirlin cDNA was delivered to the inner ears of neonatal whirler mice using adeno-associated virus serotype 2/8 (AAV8-whirlin) by injection into the posterior semicircular canal. Unilateral whirlin gene therapy injection was able to restore balance function as well as improve hearing in whirler mice for at least 4 months. Our data indicate that gene therapy is likely to become a treatment option for hereditary disorders of balance and hearing. Copyright © 2017. Published by Elsevier Inc.

Using residual tritiated water from Cernavoda NPP to study Danube - Black Sea Canal hydrodynamics

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Varlam, C.; Stefanescu, I.; Lazar, R.; Varlam, M.; Patrascu, V.; Bucur, C.; Bobric, E.

2003-01-01

By benefiting of Cernavoda NPP's location in the neighbourhood of Danube - Black Sea Canal one suggests extending the area of interest along this canal particularly to use the residual tritiated water from this CANDU type reactor as tracing means in the study of canal's hydrodynamics. This canal appears to be ideal for such a study because releases in normal operation of NPP are occasional. The tritiated water can be used for simulating the transport and dispersion of soluble pollutants because it has the same physical characteristics as the usual water. By measuring response curves produced at injecting a known amount of tracer one can developed an efficient method for estimating: the soluble pollutant velocity along the canal; attenuation rate of concentration peak as a function of time as well as the time required by the propagation front of the soluble pollutant to reach a given point along the canal. In this work the calculation of the mixture length as a function of the particular characteristics of the canal is presented as well as different experimental formulas. Also the reference level of tritium concentration in the investigated area is established for future experiments

Endoscopic root canal treatment.

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Moshonov, Joshua; Michaeli, Eli; Nahlieli, Oded

2009-10-01

To describe an innovative endoscopic technique for root canal treatment. Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Endoscopic root canal treatment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment.

Decreased levels of matrix metalloproteinase-2 in root-canal exudates during root canal treatment.

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Pattamapun, Kassara; Handagoon, Sira; Sastraruji, Thanapat; Gutmann, James L; Pavasant, Prasit; Krisanaprakornkit, Suttichai

2017-10-01

To determine the matrix metalloproteinase-2 (MMP-2) levels in root-canal exudates from teeth undergoing root-canal treatment. The root-canal exudates from six teeth with normal pulp and periradicular tissues that required intentional root canal treatment for prosthodontic reasons and from twelve teeth with pulp necrosis and asymptomatic apical periodontitis (AAP) were sampled with paper points for bacterial culture and aspirated for the detection of proMMP-2 and active MMP-2 by gelatin zymography and the quantification of MMP-2 levels by ELISA. By gelatin zymography, both proMMP-2 and active MMP-2 were detected in the first collection of root-canal exudates from teeth with pulp necrosis and AAP, but not from teeth with normal pulp, and their levels gradually decreased and disappeared at the last collection. Consistently, ELISA demonstrated a significant decrease in MMP-2 levels in the root-canal exudates of teeth with pulp necrosis and AAP following root canal procedures (papical lesions, similar to the clinical application of MMP-8 as a biomarker. Copyright © 2017 Elsevier Ltd. All rights reserved.

External auditory canal atresia of probable congenital origin in a dog.

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Schmidt, K; Piaia, T; Bertolini, G; De Lorenzi, D

2007-04-01

A nine-month-old Labrador retriever was referred to the Clinica Veterinaria Privata San Marco because of frequent headshaking and downward turning of the right ear. Clinical examination revealed that there was no external acoustic meatus in the right ear. Computed tomography confirmed that the vertical part of the right auditory canal ended blindly, providing a diagnosis of external auditory canal atresia. Cytological examination and culture of fluid from the canal and the bulla revealed only aseptic cerumen; for this reason, it was assumed that the dog was probably affected by a congenital developmental deformity of the external auditory canal. Reconstructive surgery was performed using a "pull-through" technique. Four months after surgery the cosmetic and functional results were satisfactory.

Design of canals

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Swamee, P K

2015-01-01

The book presents firsthand material from the authors on design of hydraulic canals. The book discusses elements of design based on principles of hydraulic flow through canals. It covers optimization of design based on usage requirements and economic constraints. The book includes explicit design equations and design procedures along with design examples for varied cases. With its comprehensive coverage of the principles of hydraulic canal design, this book will prove useful to students, researchers, and practicing engineers. End-of-chapter pedagogical elements make it ideal for use in graduate courses on hydraulic structures offered by most civil engineering departments across the world.

Palaeobiology of Hyaenodon exiguus (Hyaenodonta, Mammalia) based on morphometric analysis of the bony labyrinth.

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Pfaff, Cathrin; Nagel, Doris; Gunnell, Gregg; Weber, Gerhard W; Kriwet, Jürgen; Morlo, Michael; Bastl, Katharina

2017-02-01

Species of the extinct genus Hyaenodon were among the largest carnivorous mammals from the Late Eocene through Early Miocene in North America, Europe and Asia. The origin, phylogeny and palaeobiology of Hyaenodonta are still ambiguous. Most previous studies focused on teeth and dental function in these highly adapted species, which might be influenced by convergent morphologies. The anatomy of the bony labyrinth in vertebrates is generally quite conservative and, additionally, was used in functional-morphological studies. This study provides the first anatomical description of the bony labyrinth of the extinct European species Hyaenodon exiguus in comparison to selected extant carnivoran taxa discussed from a functional-morphological perspective. Hyaenodon exiguus may have occupied a hyaena-like dietary niche with a semi-arboreal lifestyle, based on the relative height, width and length of the semicircular canals of the inner ear. However, this contradicts previous functional-morphological studies focusing on the diameter of the canals, which presumably represent the signal of locomotion mode. © 2016 Anatomical Society.

[Treatment of gynecomastia by a combined method of liposuction and semicircular periareolar incision glandular organ partial resection].

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Liu, Su; Kuang, Ruixia; Chen, Zhenyu; Li, Huichao; Zhang, Weina; Wang, Zhiguo; Miao, Yuanxin; Chen, Lu

2008-12-01

To evaluate the effect of the combined method of liposuction and semicircular periareolar incision glandular organ partial resection in the treatment of gynecomastia. From June 2004 to June 2006, 40 patients, aged 11-41 years old, were treated, with no-nodule (n = 10), nodule (n = 22) and female-breast-like with nodules (n = 8). Three patients were unilateral and 37 ones were bilateral. The levels of serum prolactin, luteinizing hormone, follicle stimulating hormone, estradiol, testosterone and cortisol were normal in 38 patients, while in the other 2 patients, the levels of serum prolactin, luteinizing hormone, follicle stimulating hormone and estradiol were higher than normal, and the testosterone level was lower. Liposuction alone was performed in 10 no-nodule patients (lipo-type), and combined liposuction and semicircular periareolar incision glandular organ partial resection were conducted in the other 30 patients (lipo-glandular type). RESULTS; Except for 2 cases in which hematoma and a small amount of effusion were found on the first and second day postoperatively and then obtained healing by first intention right after hematoma removal in time, all the other patients incisions obtained healing by first intention. Nipple numbness occurred in 3 cases on the first day postoperatively and no special treatment was conducted. There was still nipple hypesthesia in these 3 cases after 6-month follow-up. There were no complications such as hematoma, effusion, nipple and mammary areola necrosis, and nipple hypesthesia in other patients. All the 40 patients were followed up for 6-24 months (13 months on average). They were satisfied with their chest figures and no recurrence was observed. The combined method of liposuction and semicircular periareolar incision glandular organ partial resection in the treatment of gynecomastia has many advantages, such as safe, micro-scars, natural and beautiflhl male breast figures as well as high patients' satisfaction.

An evaluation of canal curvature at the apical one third in type II mesial canals of mandibular molars

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Hye-Rim Yun

2012-05-01

Full Text Available Objectives The purpose of this study was to evaluate the buccolingual curvature at the apical one third in type II mesial canals of mandibular molars using the radius and angle of curvature. Materials and Methods Total 100 mandibular molars were selected. Following an endodontic access in the teeth, their distal roots were removed. #15 H- or K-files (Dentsply Maillefer were inserted into the mesiobuccal and mesiolingual canals of the teeth. Radiographs of the teeth were taken for the proximal view. Among them, type II canals were selected and divided into two subgroups, IIa and IIb. In type IIa, two separate canals merged into one canal before reaching the apex and in type IIb, two separate canals merged into one canal within the apical foramen. The radius and angle of curvature of specimens were examined. Results In type II, mean radius of curvature in mesiolingual and mesiobuccal canals were 2.82 mm and 3.58 mm, respectively. The radius of the curvature of mesiolingual canals were significantly smaller than that of mesiobuccal canals in type II, and especially in type IIa. However, there were no statistically significant differences in radius of curvature between mesiobuccal and mesiolingual canals in type IIb and there were no significant differences in angle of curvature between type IIa and IIb. Conclusion In this study, type II mesial canals of mandibular molars showed severe curvature in the proximal view. Especially, mesiolingual canals of type IIa had more abrupt curvature than mesiobuccal canals at the apical one third.

Osmolarity and root canal antiseptics.

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Rossi-Fedele, G; Guastalli, A R

2014-04-01

Antiseptics used in endodontics for disinfection purposes include root canal dressings and irrigants. Osmotic shock is known to cause the alteration of microbial cell viability and might have a role in the mechanism of action of root canal antiseptics. The aim of this review was to determine the role of osmolarity on the performance of antiseptics in root canal treatment. A literature search using the Medline electronic database was conducted up to 30 May 2013 using the following search terms and combinations: 'osmolarity AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmolality AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmotic AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmosis AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; sodium chloride AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm'. Publications were included if the effects of osmolarity on the clinical performance of antiseptics in root canal treatment were stated, if preparations with different osmolarities values were compared and if they were published in English. A hand search of articles published online, 'in press' and 'early view', and in the reference list of the included papers was carried out following the same criteria. A total of 3274 publications were identified using the database, and three were included in the review. The evidence available in endodontics suggests a possible role for hyperosmotic root canal medicaments as disinfectants, and that there is no influence of osmolarity on the tissue dissolution capacity of sodium hypochlorite. There are insufficient data to obtain a sound conclusion regarding the role of hypo-osmosis in root canal disinfection, or osmosis in any further desirable

Differences between otolith- and semicircular canal-activated neural circuitry in the vestibular system.

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Uchino, Yoshio; Kushiro, Keisuke

2011-12-01

In the last two decades, we have focused on establishing a reliable technique for focal stimulation of vestibular receptors to evaluate neural connectivity. Here, we summarize the vestibular-related neuronal circuits for the vestibulo-ocular reflex, vestibulocollic reflex, and vestibulospinal reflex arcs. The focal stimulating technique also uncovered some hidden neural mechanisms. In the otolith system, we identified two hidden neural mechanisms that enhance otolith receptor sensitivity. The first is commissural inhibition, which boosts sensitivity by incorporating inputs from bilateral otolith receptors, the existence of which was in contradiction to the classical understanding of the otolith system but was observed in the utricular system. The second mechanism, cross-striolar inhibition, intensifies the sensitivity of inputs from both sides of receptive cells across the striola in a single otolith sensor. This was an entirely novel finding and is typically observed in the saccular system. We discuss the possible functional meaning of commissural and cross-striolar inhibition. Finally, our focal stimulating technique was applied to elucidate the different constructions of axonal projections from each vestibular receptor to the spinal cord. We also discuss the possible function of the unique neural connectivity observed in each vestibular receptor system. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Cropping practices, soil properties, pedotransfer functions and organic carbon storage at Kuanria canal command area in India

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Mandal, Krishna Gopal; Kundu, Dilip Kumar; Singh, Ravender; Kumar, Ashwani; Rout, Rajalaxmi; Padhi, Jyotiprakash; Majhi, Pradipta; Sahoo, Dillip Kumar

2013-01-01

Effects of cropping practices on soil properties viz. particle size distribution, pH, bulk density (BD), field capacity (FC, -33 kPa), permanent wilting point (PWP, -1500 kPa), available water capacity (AWC) and soil organic carbon (SOC) were assessed. The pedotransfer functions (PTFs) were developed for saturated hydraulic conductivity (Ks), water retention at FC and PWP of soils for different sites under major cropping system in a canal irrigated area. The results revealed that the soils ar...

[Continuous observation of canal aberrations in S-shaped simulated root canal prepared by hand-used ProTaper files].

Science.gov (United States)

Xia, Ling-yun; Leng, Wei-dong; Mao, Min; Yang, Guo-biao; Xiang, Yong-gang; Chen, Xin-mei

2009-08-01

To observe the formation of canal aberrations in S-shaped root canals prepared by every file of hand-used ProTaper. Fifteen S-shaped simulated resin root canals were selected. Each root canal was prepared by every file of hand-used ProTaper following the manufacturer instruction. The images of canals prepared by S1, S2, F1, F2 and F3 were taken and stored, which were divided into group S1, S2, F1, F2 and F3. One image of canal unprepared was superposed with the images of the same root canal in these five groups respectively to observe the types and number of canal aberrations, which included unprepared area, danger zone, ledge, elbow, zip and perforation. SPSS12.0 software pakage was used for Fisher's exact probabilities in 2x2 table. Unprepared area decreased following preparation by every file of ProTaper, but it still existed when the canal preparation was finished. The incidence of danger zone, elbow and zip in group F1 was 15/15, 11/15, 4/15, respectively, which was significantly higher than that in group S2(2/15,0,0) (PProTaper.The presence of unprepared area suggests that it is essential to rinse canal abundantly during complicated canal preparation and canal antisepsis after preparation.

Anatomic study on mental canal and incisive nerve canal in interforaminal region in Chinese population.

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Xu, Yun; Suo, Ning; Tian, Xiufen; Li, Fei; Zhong, Guangxin; Liu, Xiaoran; Bao, Yongxing; Song, Tao; Tian, Hua

2015-08-01

This study was aimed to detect the positions of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region in Chinese population to supply the reference data of the surgical safe zone in chin for clinicians. A total of 80 formalin-fixed semi-mandibles of Chinese adult cadavers were dissected, the positions and courses of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region were measured. The mental foramina were present in all cases (100 %), and most of them were located below 2nd premolar (58.75 %). Accessory mental foramina were observed in 5 %. The anterior end of mandibular canal, extending along the course of 7.37 ± 1.10 mm above the lower border of mandible to interforaminal region about 3.54 ± 0.70 mm medial to the mental foramen, most often ended below between the two premolars (73.75 %), where it continued as the incisive nerve canal (100 %) and the mental canal (96.25 %). Mental canal, with the wall formed by compact bone, being 2.60 ± 0.60 mm in diameter and 4.01 ± 1.20 mm in length, opened into mental foramen. Incisive nerve canal, with the wall formed by thin compact bone and/or partly or completely by spongy bone, being 1.76 ± 0.27 mm in diameter and 24.87 ± 2.23 mm in length, extended to the incisor region along the course of 9.53 ± 1.43 mm above the lower border of mandible, and most often ended below the lateral incisor (70.00 %). This research recommended for chin operations in Chinese population: the surgical safe zone could be set in the region about over 4 mm anterior to the mental foramen, and over 12 mm above inferior border of mandible for anterior alveolar surgery, or within 9 mm above inferior border of mandible for genioplasty.

Periapical repair after root canal filling with different root canal sealers.

Science.gov (United States)

Tanomaru-Filho, Mário; Tanomaru, Juliane Maria Guerreiro; Leonardo, Mario Roberto; da Silva, Lea Assed Bezerra

2009-01-01

The aim of this study was to evaluate periapical repair after root canal filling with different endodontic sealers. Sixty-four root canals from dog s teeth were filled, divided into 4 groups (n=16). Root canals were instrumented with K-type files and irrigated with 1% sodium hypochlorite solution. Root canals were filled in the same session by active lateral condensation of the cones and sealers: Intrafill, AH Plus, Roeko Seal and Resilon/Epiphany System. After 90 days, the animals were euthanized and the tissues to be evaluated were processed and stained with hematoxylin and eosin. For histopathological analysis, the following parameters were evaluated: inflammatory process, mineralized tissue resorption, and apical mineralized tissue deposition. Histopathological analysis demonstrated that Intrafill had less favorable results in terms of apical and periapical repair, compared to the other sealers (p0.05). In conclusion, AH Plus and the materials Roeko Seal and Epiphany are good options for clinical use in Endodontics.

A comparative evaluation of the increase in root canal surface area and canal transportation in curved root canals by three rotary systems: A cone-beam computed tomographic study

Science.gov (United States)

Prasanthi, Nalam NVD; Rambabu, Tanikonda; Sajjan, Girija S; Varma, K Madhu; Satish, R Kalyan; Padmaja, M

2016-01-01

Aim: The aim of this study was to measure the increase in root canal surface area and canal transportation after biomechanical preparation at 1, 3, and 5 mm short of the apex with three different rotary systems in both continuous rotary and reciprocating rotary motions. Materials and Methods: Sixty freshly extracted human mandibular molars with mesial root canal curvatures between 20° and 30° were included in the study. Teeth were randomly distributed into three groups (n = 20). Biomechanical preparations were done in all the mesial canals. In Group 1, instrumentation was done with ProTaper universal rotary files, Group 2, with K3XF rotary files, and Group 3, with LSX rotary files. Each group was further subdivided into subgroups A and B (n = 10) where instrumentation was done by continuous rotary and reciprocating rotary techniques, respectively. Increase in root canal surface area and canal transportation was measured using the preoperative and postoperative cone-beam computed tomography scans. Statistical Analysis: The data were analyzed by one-way ANOVA followed by Tukey pairwise multiple comparison tests. Results: Increase in root canal surface area was significantly more (P 0.05) in increase of root canal surface area and canal transportation between continuous rotary and reciprocating rotary techniques for ProTaper Universal, K3XF and LSX groups. Conclusion: LSX rotary system showed minimal increase of root canal surface area and minimal canal transportation when compared to ProTaper and K3XF rotary systems. PMID:27656062

Unpredictable Root Canal Morphology: Expect the Unexpected

Directory of Open Access Journals (Sweden)

Sohez J Makani

2015-01-01

Full Text Available Background: A maxillary first molar with more than four canals is an interesting example of anatomic variations, especially when two of these canals are detected, with separate apical foramen in the distal root. The inability to locate the unexpected canals of various anatomical configuration and subsequently treat them , may lead to therapeutic failures. Endodontic retreatment is usually the modality of choice in such cases. This report describes a case of a maxillary first molar with five canals (two mesial canals in mesial root, two distal canals in two distal roots and a palatal canal in palatal root. Additionally it shows a rare anatomic configuration and emphasizes the importance of identifying additional canals.

A novel pathogenic variant c.975G>A (p.Trp325*) in the POU3F4 gene in Yakut family (Eastern Siberia, Russia) with the X-linked deafness-2 (DFNX2).

Science.gov (United States)

Barashkov, Nikolay A; Klarov, Leonid A; Teryutin, Fedor M; Solovyev, Aisen V; Pshennikova, Vera G; Konnikova, Edilia E; Romanov, Georgii P; Tobokhov, Alexander V; Morozov, Igor V; Bondar, Alexander A; Posukh, Olga L; Dzhemileva, Lilya U; Tomsky, Mikhail I; Khusnutdinova, Elza K; Fedorova, Sardana A

2018-01-01

Here, we report a novel hemizygous transition c.975G>A (p.Trp325*) in POU3F4 gene (Xq21) found in two deaf half-brothers from one Yakut family (Eastern Siberia, Russia) with identical inner ear abnormalities ("corkscrew" cochlea with an absence of modiolus) specific to X-linked deafness-2 (DFNX2). Comprehensive clinical evaluation (CT and MR-imaging, audiological and stabilometric examinations) of available members of this family revealed both already known (mixed progressive hearing loss) and additional (enlargement of semicircular canals and postural disorders) clinical DFNX2 features in affected males with c.975G>A (p.Trp325*). Moreover, mild enlargement of semicircular canals, postural abnormalities and different types of hearing thresholds were found in female carrier of this POU3F4-variant. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical study on unilateral hearing loss in children

International Nuclear Information System (INIS)

Masuda, Sawako; Usui, Satoko

2007-01-01

A series of 60 children was studied (aged 0 to 10 years, 32 boys, 28 girls) with severe unilateral sensorineural hearing loss of unknown etiology. There were two peaks, at 0 and 6 years. In 19 children, hearing loss was identified during a conservative general health checkup for school or preschool children. In 21 children aged 0 years, 16 were suspected of hearing loss by newborn hearing screening. Temporal bone computed tomography scans were examined in 51 patients. Sixteen ears (31.4%) with hearing loss had inner ear and/or internal auditory canal abnormalities. In one patient, the anomaly was the presence of a bony wall dividing the internal auditory canal into two separate compartments associated with severe inner ear hypoplasia. Two patients had a common cavity. In one of these patients, the anomaly was revealed because of severe bacterial meningitis, and another was detected by newborn hearing screening. Six patients had a narrow internal auditory canal, 4 had a narrow internal auditory canal and hypoplastic cochlea, and 1 had a narrow internal auditory canal and cystic vestibule, and lateral semicircular canal dysplasia. Two patients had a cystic vestibule and lateral semicircular canal dysplasia. One case showed fluctuation of the hearing level in the contralateral ear with normal hearing during the observation period at an average of 20 months. The number of children whose unilateral hearing loss is detected early by newborn hearing screening has enormously increased. Strategies for follow-up, early intervention, and support for families are necessary for young children with unilateral hearing impairment. (author)

Imaging of congenital anomalies of the temporal bone.

Science.gov (United States)

Benton, C; Bellet, P S

2000-02-01

This article briefly presents the embryology of the ear and discusses the external auditory canal and middle ear, including first branchial cleft anomalies, external auditory canal atresia and stenoses, congenital cholesteatoma, and congenital teratoma. Topics related to the labyrinths include aplasia, the common-chamber anomaly, the pseudo-Mondini and Mondini malformations, semicircular canal dysplasia, and the large vestibular aqueduct. Vascular malformations and variations also are presented, including the absent and aberrant internal carotid artery, the persistent stapedial artery, and high jugular bulb; cerebrospinal fluid and perilymph fistulas are the subjects of the final section.

Research progress of antagonistic interactions among root canal irrigations disease

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Chen QU

2013-07-01

Full Text Available Root canal therapy is the most effective way to treat various pulposis and periapical disease. Simple mechanical apparatus can not clean root canal thoroughly, but may affect tight filling instead. It can achieve a satisfactory cleansing effect only when it is combined with a chemical solution. Irrigation fluid for root canal should possess the properties of tissue dissolution, antimicrobial, lubrication, and removal of smear layer. So far, no solution is able to fulfill all these functions. Therefore, a combined use of multiple irrigation solutions is suggested. It can not only achieve good effect in cleaning and disinfection, also it can lower the concentration of different solutions, thus reducing the side effects. Nevertheless, some experiments proved that antagonism existed among the chemicals used for irrigations. The purpose of present article is to review the antagonistic effect among the chemicals used for irrigation when they are used together for root canal treatment.

Mandibular second premolar with three canals: Re-treatment of a case with unusual root canal anatomy

Directory of Open Access Journals (Sweden)

Niranjan Desai

2011-01-01

Full Text Available A thorough knowledge of root canal anatomy along with the anatomical variations that may be present is essential for success of endodontic therapy. Unusual presentations in the number of the roots or the canals should be expected in every tooth. Mandibular second premolars are thought of as having a single root and canal. Studies have stated that the prevalence of three canals with three orifices in this tooth is 0.4%. The mandibular second premolar is particularly difficult to treat owing to the fact that a wide variation in the number, location and curvature of the roots and canals exist. Added to this is the fact that the access opening is restricted and location of the lingually placed orifices is difficult. This case report details the re-treatment of a mandibular second premolar with three canals and three separate orifices using the surgical microscope.

The circulation of the cerebrospinal fluid (CSF) in the spinal canal

Science.gov (United States)

Sanchez, Antonio L.; Martinez-Bazan, Carlos; Lasheras, Juan C.

2016-11-01

Cerebrospinal Fluid (CSF) is secreted in the choroid plexus in the lateral sinuses of the brain and fills the subarachnoid space bathing the external surfaces of the brain and the spinal canal. Absence of CSF circulation has been shown to impede its physiological function that includes, among others, supplying nutrients to neuronal and glial cells and removing the waste products of cellular metabolism. Radionuclide scanning images published by Di Chiro in 1964 showed upward migration of particle tracers from the lumbar region of the spinal canal, thereby suggesting the presence of an active bulk circulation responsible for bringing fresh CSF into the spinal canal and returning a portion of it to the cranial vault. However, the existence of this slow moving bulk circulation in the spinal canal has been a subject of dispute for the last 50 years. To date, there has been no physical explanation for the mechanism responsible for the establishment of such a bulk motion. We present a perturbation analysis of the flow in an idealized model of the spinal canal and show how steady streaming could be responsible for the establishment of such a circulation. The results of this analysis are compared to flow measurements conducted on in-vitro models of the spinal canal of adult humans.

The study of thermal tunable coupling between a Superconducting photonic crystal waveguide and semi-circular photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Oskooi, Somayeh; Barvestani, Jamal, E-mail: barvestani@tabrizu.ac.ir

2016-08-15

Highlights: • The light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal has been studied. • We utilized the finite difference time domain and plane wave expansion methods in the calculations. • The effect of the size of the nearest neighbor rods of waveguide on the coupling efficiency has been investigated. • The coupling efficiencies are reported versus the temperature of the superconducting waveguide. - Abstract: Through the present study, we investigated the light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal. By using the finite difference time domain method, we evaluated the coupling efficiency between the mentioned structures at the various temperatures for different waveguide sizes. Calculation demonstrated that the coupling efficiency strongly depended on the temperature of the superconductor. The peak value of the coupling efficiency was influenced by the size of the nearest neighbor rods of waveguide. The results have shown that it is possible to obtain high efficiency at the desired temperature with proper selection of physical parameters in far-infrared frequency region. This structure has great potential in the optical integration and other areas.

[The importance of vestibular evoked myogenic potentials for the assessment of the otolith function in the patients presenting with benign paroxysmal positional vertigo].

Science.gov (United States)

Kunel'skaya, N L; Baybakova, E V; Guseva, A L; Chugunova, M A; Manaenkova, E A

The objective of the present study was to evaluate the otolith function in the patients presenting with idiopathic benign paroxysmal positional vertigo (pBPPV) attributable to the occlusion of the posterior semicircular canal (PSCC) of the inner ear with the use of vestibular evoked myogenic potentials (VEMP). Cervical (cVEMP) and ocular VEMP (oVEMP) were measured in 34 patients with idiopathic pBPPV before and 7 days after the treatment by means of reposition maneuvers. The results of the repeated Dix-Hallpike test performed 7 days after the repositioning maneuver were negative in 27 patients and positive in 7 patients. There was no statistically significant difference in the amplitude of cervical VEMP between the healthy and affected ears either before or after the repositioning treatment. The measurement of oVEMP revealed a reduction of the response amplitude on the affected side. The average values of the plnl on the healthy side were 12.84±1.09 and those on the affected side 4.62±0.69 (potolith function.

The enlargement of geniculate fossa of facial nerve canal: a new CT finding of facial nerve canal fracture

International Nuclear Information System (INIS)

Gong Ruozhen; Li Yuhua; Gong Wuxian; Wu Lebin

2006-01-01

Objective: To discuss the value of enlargement of geniculate fossa of facial nerve canal in the diagnosis of facial nerve canal fracture. Methods: Thirty patients with facial nerve canal fracture underwent axial and coronal CT scan. The correlation between the fracture and the enlargement of geniculate fossa of facial nerve canal was analyzed. The ability of showing the fracture and enlargement of geniculate fossa of facial nerve canal in axial and coronal imaging were compared. Results: Fracture of geniculate fossa of facial nerve canal was found in the operation in 30 patients, while the fracture was detected in CT in 18 patients. Enlargement of geniculate ganglion of facial nerve was detected in 30 patients in the operation, while the enlargement of fossa was found in CT in 28 cases. Enlargement and fracture of geniculate fossa of facial nerve canal were both detected in CT images in 18 patients. Only the enlargement of geniculate fossa of facial nerve canal was shown in 12 patients in CT. Conclusion: Enlargement of geniculate fossa of facial nerve canal was a useful finding in the diagnosis of fracture of geniculate fossa in patients with facial paralysis, even no fracture line was shown on CT images. (authors)

Industrial canal waterfronts in The Netherlands : transforming the canal zones of B5

NARCIS (Netherlands)

Curulli, G.I.

2012-01-01

Industrial Canal Waterfronts in The Netherlands provides a comprehensive presentation of the characteristics and challenges of five interconnected and dismissed industrial canal zones located in the Dutch Brabant cities of Eindhoven, Breda, Tilburg, s’-Hertogenbosch and Helmond (B5). Through the

Three-dimensional Fourier transformation constructive interference in steady state magnetic resonance imaging of the inner ear in patients with unilateral and bilateral Meniere's disease

NARCIS (Netherlands)

Mateijsen, DJM; Van Hengel, PWJ; Krikke, AP; Van Huffelen, WM; Wit, HP; Albers, FWJ

Objective: In this study, three-dimensional Fourier transformation constructive interference in steady state (3DFT-CISS) magnetic resonance imaging was used to quantify the distance between the vertical part of the posterior semicircular canal and the posterior fossa as a measure of the

Diagnosis and root canal treatment in a mandibular premolar with three canals.

Science.gov (United States)

Soares, Lanuce Rosa; Arruda, Marcos; de Arruda, Marcos Pôrto; Rangel, Andréa Leão; Takano, Edson; de Carvalho Júnior, Jacy Ribeiro; Saquy, Paulo Cesar

2009-01-01

This paper presents a case report of a left mandibular second premolar with three canals and three different apical foramina. A 39-year-old male patient presented to our clinic with pain in the mandibular left second premolar. Initially, pain was caused by cold stimulus and later was spontaneously. The intraoral clinical examination revealed a fractured amalgam restoration with occlusal caries. Percussion and cold (Endo-Frost) tests were positive. The radiographic examination showed the presence of two roots. The probable diagnosis was an acute pulpitis. After access cavity, it was observed remaining roof of the pulp chamber and mild bleeding in the tooth lingual area, indicating the possible presence of a third canal. The endodontic treatment was completed in a single session using Root ZX apex locator and K3 NiTi rotary system with surgical diameter corresponding to a .02/45 file in the three canals and irrigation with 1% sodium hypochlorite. The canals were obtured with gutta-percha cones and Sealer 26 using the lateral condensation technique. After 1 year of follow-up, the tooth was asymptomatic and periapical repair was observed radiographically. Internal alterations should be considered during the endodontic treatment of mandibular second premolars. The correct diagnosis of these alterations by the analysis of preoperative radiographs can help the location of two or more canals, thereby avoiding root therapy failure.

Squamous cell carcinoma of the anal canal.

LENUS (Irish Health Repository)

Martin, F T

2012-01-31

Squamous cell carcinoma ofthe anal canal represents 1.5% of all malignancies affectingthe gastrointestinal tract. Over the past 20 years dramatic changes have been seen in both the epidemiological distribution of the disease and in the therapeutic modalities utilised to manage it. CLINICAL MANAGEMENT: Historically abdominoperineal resection had been the treatment of choice with local resection reserved for early stage disease. Work by Nigro et al. has revolutionised how we currently manage carcinoma of the anal canal, demonstrating combined modality chemoradiotherapy as an appropriate alternative to surgical resection with the benefit of preserving sphincter function. Surgery is then reserved for recurrent disease with salvage abdominoperineal resection. This article reviews current literature and highlights the changing therapeutic modalities with selected clinical cases

Functional characterization of fidgetin, an AAA-family protein mutated in fidget mice

International Nuclear Information System (INIS)

Yang Yan; Mahaffey, Connie L.; Berube, Nathalie; Nystuen, Arne; Frankel, Wayne N.

2005-01-01

The mouse fidget mutation is an autosomal recessive mutation that renders reduced or absent semicircular canals, microphthalmia, and various skeletal abnormalities to affected mice. We previously identified the defective gene which encodes fidgetin, a new member of the ATPases associated with diverse cellular activities (AAA proteins). Here, we report on the subcellular localization of fidgetin as well as that of two closely related proteins, fidgetin-like 1 and fidgetin-like 2. Epitope-tagging and immunostaining revealed that both fidgetin and fidgetin-like 2 were predominantly localized to the nucleus, whereas fidgetin-like 1 was both nuclear and cytoplasmic. Furthermore, deletion studies identified a putative bipartite nuclear localization signal in the middle portion of the fidgetin protein. Since AAA proteins are known to form functional hetero- or homo-hexamers, we used reciprocal immunoprecipitation to examine the potential interaction among these proteins. We found that fidgetin interacted with itself and this specific interaction was abolished when either the N- or C-terminus of the protein was truncated. Taken together, our results suggest that fidgetin is a nuclear AAA-family protein with the potential to form homo-oligomers, thus representing the first step towards the elucidation of fidgetin's cellular function and the disease mechanism in fidget mutant mice

Computed tomography findings in large vestibular aqueduct syndrome.

Science.gov (United States)

Ma, Xiufang; Yang, Ying; Xia, Ming; Li, Dumin; Xu, Anting

2009-07-01

Patients with large vestibular aqueduct syndrome (LVAS) have disturbed morphogenesis of bony labyrinth. Semicircular canal anomalies are common in LVAS. To describe the additional inner ear anomalies on CT imaging in pediatric patients with LVAS, and to investigate the lateral semicircular canal (LSCC) anomalies associated with LVAS by measurement of the LSCC bony island width. We retrospectively reviewed the digitally stored temporal bone CT imaging obtained for 23 patients with LVAS, additional inner ear anomalies were noted, and measurements of the LSCC bony island width were made on axial CT scans on the workstation. Measurements were compared to the normative data obtained from 20 patients without sensorineural hearing loss. Of the 23 patients (bilateral in 22 and unilateral in 1), additional inner ear malformations were identified in 21 cases presenting either singly or in combination. A small LSCC bony island (Mondini deformity was identified in 6 ears.

Symmetries of a generic utricular projection: neural connectivity and the distribution of utricular information.

Science.gov (United States)

Chartrand, Thomas; McCollum, Gin; Hanes, Douglas A; Boyle, Richard D

2016-02-01

Sensory contribution to perception and action depends on both sensory receptors and the organization of pathways (or projections) reaching the central nervous system. Unlike the semicircular canals that are divided into three discrete sensitivity directions, the utricle has a relatively complicated anatomical structure, including sensitivity directions over essentially 360° of a curved, two-dimensional disk. The utricle is not flat, and we do not assume it to be. Directional sensitivity of individual utricular afferents decreases in a cosine-like fashion from peak excitation for movement in one direction to a null or near null response for a movement in an orthogonal direction. Directional sensitivity varies slowly between neighboring cells except within the striolar region that separates the medial from the lateral zone, where the directional selectivity abruptly reverses along the reversal line. Utricular primary afferent pathways reach the vestibular nuclei and cerebellum and, in many cases, converge on target cells with semicircular canal primary afferents and afference from other sources. Mathematically, some canal pathways are known to be characterized by symmetry groups related to physical space. These groups structure rotational information and movement. They divide the target neural center into distinct populations according to the innervation patterns they receive. Like canal pathways, utricular pathways combine symmetries from the utricle with those from target neural centers. This study presents a generic set of transformations drawn from the known structure of the utricle and therefore likely to be found in utricular pathways, but not exhaustive of utricular pathway symmetries. This generic set of transformations forms a 32-element group that is a semi-direct product of two simple abelian groups. Subgroups of the group include order-four elements corresponding to discrete rotations. Evaluation of subgroups allows us to functionally identify the

Mechanical nonlinearity elimination with a micromechanical clamped-free semicircular beams resonator

Science.gov (United States)

Chen, Dongyang; Chen, Xuying; Wang, Yong; Liu, Xinxin; Guan, Yangyang; Xie, Jin

2018-04-01

This paper reports a micro-machined clamped-free semicircular beam resonator aiming to eliminate the nonlinearity that widely exists in traditional mechanical resonators. Cubic coefficients over vibration displacement due to axial extension of the beams are analyzed through theoretical modelling, and the corresponding frequency effect is demonstrated. With the device working in the elastic vibration mode, the cubic coefficients are eliminated by using a free end to release the nonlinear extension of beams and thus the inside axial stress. The amplitude-frequency (A-f) effect is overcome in a large region of source power, and the coefficient of frequency softening is linearized in a large region of polarization voltage. As a result, the resonator can be driven at larger vibration amplitude to achieve a high signal to noise ratio and power handling performance.

Acoustic impedances of ear canals measured by impedance tube

DEFF Research Database (Denmark)

Ciric, Dejan; Hammershøi, Dorte

2007-01-01

During hearing sensitivity tests, the sound field is commonly generated by an earphone placed on a subject ear. One of the factors that can affect the sound transmission in the ear is the acoustic impedance of the ear canal. Its importance is related to the contribution of other elements involved...... in the transmission such as the earphone impedance. In order to determine the acoustic impedances of human ear canals, the standardized method for measurement of complex impedances used for the measurement of the audiometric earphone impedances is applied. It is based on the transfer function between two microphone...... locations in an impedance tube. The end of the tube representing the measurement plane is placed at the ear canal entrance. Thus, the impedance seen from the entrance inward is measured on 25 subjects. Most subjects participated in the previous measurement of the ratio between the pressures at the open...

Hydrocele of the canal of Nuck

Directory of Open Access Journals (Sweden)

Nourah ALSaleh

2018-02-01

Full Text Available Hydrocele of the canal of Nuck is a rare condition in female children caused by a failure of complete obliteration of the canal of Nuck. The canal of Nuck is an abnormal patent pouch of the peritoneum extending anterior to the round ligament of the uterus into the labia majora. Incomplete obliteration of this canal (patent processus vaginalis can result in either an inguinal hernia or a hydrocele. Here, we report two cases of hydrocele of the canal of Nuck presented within a two-month period. In the first case, incarcerated right-sided inguinal hernia was suspected while the second case was clinically diagnosed as encysted hydrocele of canal of Nuck. Both patients underwent surgical exploration. Hydrocelectomy with high ligation was also performed. One month after the surgery, the first patient showed signs of hydrocele on contralateral side, while the other patient showed no sign of contralateral hydrocele or hernia.

Assessment of three root canal preparation techniques on root canal geometry using micro-computed tomography: In vitro study

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Shaikha M Al-Ali

2012-01-01

Full Text Available Aim: To assess the effects of three root canal preparation techniques on canal volume and surface area using three-dimensionally reconstructed root canals in extracted human maxillary molars. Materials and Methods: Thirty extracted Human Maxillary Molars having three separate roots and similar root shape were randomly selected from a pool of extracted teeth for this study and stored in normal saline solution until used. A computed tomography scanner (Philips Brilliance CT 64-slice was used to analyze root canals in extracted maxillary molars. Specimens were scanned before and after canals were prepared using stainless steel K-Files, Ni-Ti rotary ProTaper and rotary SafeSiders instruments. Differences in dentin volume removed, the surface area, the proportion of unchanged area and canal transportation were calculated using specially developed software. Results: Instrumentation of canals increased volume and surface area. Statistical analysis found a statistically significant difference among the 3 groups in total change in volume (P = 0.001 and total change in surface area (P = 0.13. Significant differences were found when testing both groups with group III (SafeSiders. Significant differences in change of volume were noted when grouping was made with respect to canal type (in MB and DB (P < 0.05. Conclusion: The current study used computed tomography, an innovative and non destructive technique, to illustrate changes in canal geometry. Overall, there were few statistically significant differences between the three instrumentation techniques used. SafeSiders stainless steel 40/0.02 instruments exhibit a greater cutting efficiency on dentin than K-Files and ProTaper. CT is a new and valuable tool to study root canal geometry and changes after preparation in great details. Further studies with 3D-techniques are required to fully understand the biomechanical aspects of root canal preparation.

21 CFR 872.3810 - Root canal post.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and support...

Semiconductor laser irradiation improves root canal sealing during routine root canal therapy

Science.gov (United States)

Hu, Xingxue; Wang, Dashan; Cui, Ting; Yao, Ruyong

2017-01-01

Objective To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT). Methods Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10). The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically rinsed for 60 seconds as positive control groups; Groups E and F without treatment of root canal prior to RCT as negative control groups. Root canal sealing of Groups A, C and E were evaluated by measurements of apical microleakage. The teeth from Groups B, D and F were sectioned, and the micro-structures were examined with scanning electron microscopy (SEM). One way ANOVA and LSD-t test were used for statistical analysis (α = .05). Results The apical sealing of both the laser irradiated group and the ultrasonic irrigated group were significantly different from the control group (pirrigated group (p>0.5). SEM observation showed that most of the dentinal tubules in the laser irradiation group melted, narrowed or closed, while most of the dentinal tubules in the ultrasonic irrigation group were filled with tooth paste. Conclusion The application of semiconductor laser prior to root canal obturation increases the apical sealing of the roots treated. PMID:28957407

Inner ear anomalies causing congenital sensorineural hearing loss: CT and MR imaging findings

International Nuclear Information System (INIS)

Hong, Hyun Sook; Paik, Sang Hyun; Cha, Jang Gyu; Park, Seong Jin; Joh, Joon Hee; Park, Jai Soung; Kim, Dae Ho; Lee, Hae Kyung; Kim, Shi Chan

2005-01-01

Many congenital dysplasias of the osseous labyrinth have been identified, and the differential diagnosis of these dysplasias is essential for delivering proper patient management. We retrospectively reviewed the computed tomography (CT) and magnetic resonance (MR) imaging findings of 20 children who had congenital sensorineural hearing loss. The children included cases of enlarged vestibular aqueduct and endolymphatic sac (n=8), aplasia of the semicircular canal (n=4), lateral semicircular canal-vestibule dysplasia (n=3), common cavity malformations with a large vestibule (n=1), cochlear hypoplasia (n=1), Mondini's dysplasia with large vestibular aqueduct (n=1), Mondini's dysplasia with a large vestibule (n=1), and small internal auditory canal (n=1). Six cases were unilateral. Nine cases had combined deformities, and nine cased had cochlear implants. CT was performed with a 1.0-mm thickness in the direct coronal and axial sections with using bone algorithms. MR was performed with a temporal 3D T2 FSE 10-mm scan and with routine brain images. We describe here the imaging features for the anomalies of the inner ear in patients suffering from congenital sensorineural hearing loss

The shape of the human lumbar vertebral canal A forma do canal vertebral lombar humano

Directory of Open Access Journals (Sweden)

Edmundo Zarzur

1996-09-01

Full Text Available Literature on the anatomy of the human vertebral column characterizes the shape of the lumbar vertebral canal as triangular. The purpose of the present study was to determine the precise shape of the lumbar vertebral canal. Ten lumbar vertebral columns of adult male cadavers were dissected. Two transverse sections were performed in the third lumbar vertebra. One section was performed at the level of the lower border of the ligamenta flava, and the other section was performed at the level of the pedicles. The shape of the lumbar vertebral canal at the level of the pedicles tends to be oval or circular, whereas the shape of the lumbar vertebral canal at the level of the lower border of the ligamenta flava is triangular. Thus, the shape of the human lumbar vertebral canal is not exclusively triangular, as reported in the literature. It is related to the level of the transversal section performed on the lumbar vertebra. This finding should be taken into consideration among factors involved in the spread of solutions introduced into the epidural space.A literatura sobre a anatomia da coluna vertebral descreve como sendo triangular o formato do canal vertebral na região lombar. O objetivo deste estudo é determinar a real forma do canal da coluna vertebral lombar.Dez colunas vertebrais de cadáveres de homens adultos foram dissecadas. Dois cortes transversais foram executados na terceira vértebra lombar. Um corte foi feito no nível das bordas inferiores de dois ligamentos amarelos vizinhos e o outro corte foi transversal, no nível dos pedículos. A forma do canal vertebral variou: no nível dos pedículos ela tende a ser oval ou circular e junto às bordas inferiores dos ligamentos amarelos passa a ser triangular. Portanto, a forma do canal vertebral lombar não é somente triangular; ela depende do nível em que se faz o corte transversal da vértebra. Estes achados devem ser levados em consideração entre os fatores envolvidos na difusão das

Action antiadipogenic of weak magnetic fields: A model for the study of the etiology of the semicircular lipoatrophy in media occupational; Accion antiadipogenica de campos magneticos debiles: un modelo para el estudio de la etiologia de la lipoatrofia semicircular en medios ocupacionales

Energy Technology Data Exchange (ETDEWEB)

Martinez Pascual, M. A.; Paino Belarrinaga, C. L.; Trillo ruiz, M. A.; Ubeda Maeso, A.

2013-07-01

Although several studies have suggested a possible association between exposure to environmental magnetic fields of industrial frequency and semicircular lipoatrophy, a mechanism that justifies the potential action of these fields magnetic on the adipo genesis has not been identified. The study investigated the in vitro action of a field weak magnetic on the adipo genesis of human adipose tissue-derived stem cells. (Author)

Dorello's Canal for Laymen: A Lego-Like Presentation.

Science.gov (United States)

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-06-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students.

Microbiological examination of infected dental root canals.

Science.gov (United States)

Gomes, B P F A; Pinheiro, E T; Gadê-Neto, C R; Sousa, E L R; Ferraz, C C R; Zaia, A A; Teixeira, F B; Souza-Filho, F J

2004-04-01

The aim of this study was to investigate the root canal microbiota of primary and secondary root-infected canals and the association of constituent species with specific endodontic signs and symptoms. Microbial samples were taken from 60 root canals, 41 with necrotic pulp tissues (primary infection) and 19 with failed endodontic treatment (secondary infection). Strict anaerobic techniques were used for serial dilution, plating, incubation and identification. A total of 224 cultivable isolates were recovered belonging to 56 different bacterial species. Individual root canals yielded a maximum of 10 bacterial species. Of the bacterial isolates, 70% were either strict anaerobes or microphilic. The anaerobes most frequently isolated were: Peptostreptococcus micros (35%), Fusobacterium necrophorum (23.3%), Fusobacterium nucleatum (11.7%), Prevotella intermedia/nigrescens (16.7%), Porphyromonas gingivalis (6.7%) and Porphyromonas endodontalis (5%). The root canal microflora of untreated teeth with apical periodontitis was found to be mixed, comprising gram-negative and gram-positive and mostly anaerobic microorganisms and usually containing more than 3 species per canal. On the other hand, facultative anaerobic and gram-positive bacteria predominated in canals with failed endodontic treatment, which harbored 1-2 species per canal. Suggested relationships were found between anaerobes, especially gram-negatives, and the presence or history of pain, tenderness to percussion and swelling (PEubacterium spp. (both Pspp. (Pspp. (Pspp. (Pspp. (Pspp. (Pspp. (Pspp. (Pspp., P. micros, F. necrophorum (P<0.05). Our findings indicate potential complex interactions of species resulting in characteristic clinical pictures which cannot be achieved by individual species alone. They also indicate that the microbiota of primary infected canals with apical periodontitis differs in number and in species from the secondary infected canals by using the culture technique.

External dose conversion factor from canal water

International Nuclear Information System (INIS)

Bhargava, Pradeep; Chitra, S.; Mhatre, Arti S.; Singh, Kapil Deo

2016-01-01

External dose needs to be estimated for the radioactivity discharged into the canal, as it constitutes one of the pathways of exposure to the public. Two activities are considered here: i) a walk along the bank of the canal ii) and the walk on the bridge. A concentration of 1 Bq/l is assumed here for the gross beta activity for the estimation of the dose conversion factor. A canal of width 14.39 m and the depth of 2.5 m is considered for this study. Length of the canal is taken to be infinite. Canal side wall is assumed to be the 25 cm thick concrete. Two points are selected, one on the bank, and the second on a bridge 1 m above the top surface of canal water. Dose Conversion factors for the person moving on the Bridge (at one meter above the water surface) and standing on bank of canal is estimated by using the QAD CG code for 137 Cs. Dose conversion factors for the location mentioned above are found to be 1.11E-10 Sv/hr/(Bq/l) and 1.55 E-11 Sv/hr/(Bq/l) for bridge and bank of canal respectively. (author)

Clinical significance of dental root canal microflora.

Science.gov (United States)

Gomes, B P; Lilley, J D; Drucker, D B

1996-01-01

Previous work by this group has shown that a significant association exists between pain and the presence of either Prevotella or Peptostreptococcus spp. in dental root canals. The aim of this study was to examine a more extensive series of canals microbiologically, to determine whether any other particular endodontic symptoms or clinical signs showed specific associations with individual bacterial species. Seventy root canals were examined microbiologically and clinical data collected to investigate in detail such associations. Of the canals studied, 37 were associated with pain, 49 with tenderness to percussion, 23 with swelling, six with purulent exudate and 57 presented with wet root canals. Anaerobes were isolated from 70.3% of painful canals and from 29.7% of pain-free canals. Significant associations were found between (a) pain and either Prevotella spp. or peptostreptococci, both with P spp. (P Eubacterium spp. (P spp. or Pstr. micros, both with P spp. (each P Eubacterium, Peptostreptococcus, Prevotella or Propionibacterium (each P < 0.05). It was concluded that several different endodontic clinical signs and symptoms are significantly associated with specific bacterial species.

Science.gov (United States)

Aranda-Moreno, C.; Herrera-Rangel, A.

2017-01-01

SUMMARY The aim of this study was to assess the function of the utricle and horizontal semicircular canals in patients with type 2 diabetes mellitus receiving primary health care, with/without a history of falls. 101 patients with type 2 diabetes mellitus, 34 to 84 years old (26 with and 75 without a history of falls) and 51 healthy volunteers (40-83 years old) accepted to participate. They denied having a history of dizziness, vertigo, unsteadiness, hearing loss, or neurological disorders. None of them were seeking care due to sensory or balance decline. After a clinical evaluation and report of symptoms related to balance using a standardised questionnaire, lateral canal function was assessed by sinusoidal rotation at 0.16 Hz and 1.28 Hz (60°/sec peak velocity), otolith function was assessed by static visual vertical (average of 10 trials) and dynamic visual vertical during unilateral centrifugation (300°/sec at 3.5 cm) and static posturography was performed on hard/ soft surface with eyes open/closed. Compared to healthy volunteers, patients showed decreased responses to unilateral centrifugation, but similar responses to horizontal canal stimuli (independently of age, peripheral neuropathy or a history of falls) (ANCoVA p diabetes mellitus, receiving primary healthcare who are not seeking care due to sensory or balance decline, utricular function may be impaired even in the absence of horizontal canal dysfunction or a history of falls. PMID:28530263

Utricular hypofunction in patients with type 2 diabetes mellitus.

Science.gov (United States)

Jáuregui-Renaud, K; Aranda-Moreno, C; Herrera-Rangel, A

2017-10-01

The aim of this study was to assess the function of the utricle and horizontal semicircular canals in patients with type 2 diabetes mellitus receiving primary health care, with/without a history of falls. 101 patients with type 2 diabetes mellitus, 34 to 84 years old (26 with and 75 without a history of falls) and 51 healthy volunteers (40-83 years old) accepted to participate. They denied having a history of dizziness, vertigo, unsteadiness, hearing loss, or neurological disorders. None of them were seeking care due to sensory or balance decline. After a clinical evaluation and report of symptoms related to balance using a standardised questionnaire, lateral canal function was assessed by sinusoidal rotation at 0.16 Hz and 1.28 Hz (60°/sec peak velocity), otolith function was assessed by static visual vertical (average of 10 trials) and dynamic visual vertical during unilateral centrifugation (300°/sec at 3.5 cm) and static posturography was performed on hard/ soft surface with eyes open/closed. Compared to healthy volunteers, patients showed decreased responses to unilateral centrifugation, but similar responses to horizontal canal stimuli (independently of age, peripheral neuropathy or a history of falls) (ANCoVA p diabetes mellitus, receiving primary healthcare who are not seeking care due to sensory or balance decline, utricular function may be impaired even in the absence of horizontal canal dysfunction or a history of falls. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

El Canal del Atazar I

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López de Berges y de los Santos, Emilio

1967-03-01

Full Text Available The Atazar Canal helps to supply Madrid with water, from the rivers Lozoya, Jarama and Sorbe. The section which operates at present starts at the Torrelaguna dam and finishes at the El Goloso reservoir. Later a further section will be added, from the Atazar dam, on the Lozoya river, to link up with the control dam at Torrelaguna. The canal capacity is 16 m3/sec, and it is 43.47 km long. It has a slope of 4/10.000. The cross section is similar to that of the Jarama canal, already built. There are interconnections between this canal and the Canal Alto, which previously supplied the high and medium part of Madrid. To overcome the ground unevenness 5 syphons have been built, the most important of which is the Colmenar Goloso syphon, which is 10.88 km in length. Construction commenced on December 10, 1962, and water reached Madrid on June 15th, 1966. The initial budget for this project was 1,500 million pesetas.El canal del Atazar refuerza considerablemente el abastecimiento de aguas a Madrid, procedentes de los ríos Lozoya, Jarama y, en un próximo futuro, del Sorbe. El tramo, actualmente en funcionamiento, empieza en el salto de Torrelaguna y finaliza en los depósitos de El Goloso. Más adelante se completará su trazado mediante un nuevo tramo que partirá del embalse de Atazar, en el Lozoya, para unirse al actual en el depósito regulador de Torrelaguna. Su capacidad es de 16 m3/s; su longitud, 43,471 km, y su pendiente, 4 diezmilésimas. La sección tipo es análoga a la del canal del Jarama, de construcción anterior. Mediante la oportuna obra de transvase se realizan intercambios entre este Canal y el Canal Alto que abastecía anteriormente la parte media y alta de la capital. Para salvar los desniveles del terreno se han construido 5 sifones, siendo el más importante el de Colmenar-Goloso, con una longitud de 10,8S4 km. El comienzo de las obras tuvo lugar el 10 de diciembre de 1962, y el agua llegó a Madrid el 15 de junio de 1966. Su

Detection of Mesiobuccal Canal in Maxillary Molars and Distolingual Canal in Mandibular Molars by Dental CT: A Retrospective Study of 100 Cases

Directory of Open Access Journals (Sweden)

Sushma Rathi

2010-01-01

Full Text Available Objective. To detect presence of MB2 canal in maxillary molars and distolingual canal in mandibular molars by Dental CT. Material and Methods. A retrospective study of 100 Dental CTs was done. Axial and paraxial images obtained were used to assess the presence of MB2 canal in maxillary molars and distolingual canal in mandibular molars. Results. The youngest patient was of 11 years while the eldest patient was of 77 years. Males were 58 in number and females were 42 in number. MB2 canals were present in 57 patients and distolingual canal was present in 18 patients. Maximum MB2 canals were present in age group between 51 and 60 years, while distolingual canals were present in age group of 21–30 years. Conclusion. Dental CT allows adequate visualization of variation in root canal morphology and can be important diagnostic tool for successful endodontic therapy.

Spontaneous nystagmus in benign paroxysmal positional vertigo: is it a new sign?

Science.gov (United States)

Hajiabolhassan, Fahimeh; Tavanai, Elham

2013-01-01

Benign Paroxysmal Positional Vertigo (BPPV) is a condition that indicates a benign inner ear disorder. It is generally believed that BPPV is due to the dislodged otoconial particles from otolith organs and unusual collection of them within any of semicircular canals or even in all three semicircular canals. Although the typical features of nystagmus in BPPV have been well-studied, very few studies (just four articles) have highlighted the presence of spontaneous nystagmus in BPPV recently. During the past 10 years, 2850 patients have been examined at the audiology unit of our department, and 254 patients have received diagnoses of BPPV but recently 2 patients presented with BPPV and spontaneous nystagmus, a new symptom that has been never observed in our clinical records. We herein describe this rare symptom in 2 case of BPPV. A 50-year-old woman with BPPV who showed an 18 degree spontaneous nystagmus treated with Epley maneuver and a 53-year-old man with 3 degree spontaneous nystagmus.

77 FR 42644 - Safety Zone; Canal Fest of the Tonawandas, Erie Canal, Tonawanda, NY

Science.gov (United States)

2012-07-20

.... ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on the... Canal during the Canal Fest of the Tonawandas Fireworks display. This temporary safety zone is necessary to protect spectators and vessels from the hazards associated with a fireworks display. DATES: This...

Water Environment Evolution along the China Grand Canal

International Nuclear Information System (INIS)

Mao, F; Wu, Y X; Yang, B F; Li, X J

2014-01-01

The China Grand Canal is one of the earliest canals in the world, having lasted for nearly 3000 years. Even its section canals have a rich history, such as the North-South Grand Canal that was established during the Sui Dynasty, whereas the Beijing-Hangzhou Canal was excavated during the Yuan Dynasty and the east line of the South-to-North Water Diversion. As one of the longest in the world, the China Grand Canal's total length is over 3500 kilometers. This length includes the navigable, unnavigable, and underground sections. Making the best use of situations and according to local conditions, the Chinese people harmoniously constructed the Beijing-Hangzhou Canal with nature. Tens of millions of workers took nearly 3000 years to complete the great shipping system. Navigable sections still exist for up to 900 kilometers and the volume of freight traffic is approximately 300 million tons. The canal remains the main logistical channel of the North-to-South Coal Transportation, South-to-North Water Diversion, and resources circulation. To date, China is promoting the success of heritage application. Part of these efforts is the declaration of the China Grand Canal as a World Cultural Heritage by 2014. In addition, the east route of the South-to-North Water Transfer project is planned to be navigable by 2016. The ancient Beijing-Hangzhou Grand Canal will usher in the new ecological civilization and cultural revival along the canal. This paper presents technical methods of water environment evolution research on the river system, river, and water quality along the Beijing-Hangzhou Canal through the integration of historical literature and modern remote sensing image data. The study carried out water environment investigation and analysis along the Beijing-Hangzhou canal by using ETM, SPOT image data, and GPS measurement data. Spatial and temporal evolution characteristics and regulations of the Beijing-Hangzhou Grand Canal regional water environment in the span of

Computed tomography of the facial canal

International Nuclear Information System (INIS)

Kiuchi, Sousuke

1983-01-01

The radiological details of the facial canal was investigated by computed tomography. In the first part of this study, dry skulls were used to delineate the full course of the facial canal by computed tomography. In the second part of this study, the patients with chronic otitis media and secondary cholesteatoma were evaluated. The labyrinthine and tympanic parts of the canal were well demonstrated with the axial scanning, and the mastoid part with the coronal scanning. Moreover, computed tomography showed excellent delineation of the middle ear contents. In patients with secondary cholesteatoma, the destructions of the intratympanic course of the bony facial canal were also assessed preoperatively. (author)

Radiation-induced external ear canal cholesteatoma-like disease

Energy Technology Data Exchange (ETDEWEB)

Ishihara, Akiko; Okuno, Hideji; Noguchi, Keisuke; Komatsuzaki, Atsushi [Tokyo Medical and Dental Univ. (Japan). School of Medicine

1999-06-01

Three cases of cholesteatoma-like disease in the ear canals after radiation therapy for head and neck tumor were reported. Effect of irradiation on bone and soft tissue including skin brings about pathological reaction to the external ear canal as well. Two types of disease resembling cholesteatomas have been recognized: keratosis obturans (KO) and external auditory canal cholesteatoma (EACC). KO appears to be derived from disease of canal skin involved with keratinization, creating a widning of the canal. EACC, on the other hand, seems to develop in the disease of bony canal where a localized absorption of its bone with invasion of squamous epithelium takes place. (author)

Acceleration induced water removal from ear canals.

Science.gov (United States)

Kang, Hosung; Averett, Katelee; Jung, Sunghwan

2017-11-01

Children and adults commonly experience having water trapped in the ear canals after swimming. To remove the water, individuals will shake their head sideways. Since a child's ear canal has a smaller diameter, it requires more acceleration of the head to remove the trapped water. In this study, we theoretically and experimentally investigated the acceleration required to break the surface meniscus of the water in artificial ear canals and hydrophobic-coated glass tubes. In experiments, ear canal models were 3D-printed from a CT-scanned human head. Also, glass tubes were coated with silane to match the hydrophobicity in ear canals. Then, using a linear stage, we measured the acceleration values required to forcefully eject the water from the artificial ear canals and glass tubes. A theoretical model was developed to predict the critical acceleration at a given tube diameter and water volume by using a modified Rayleigh-Taylor instability. Furthermore, this research can shed light on the potential of long-term brain injury and damage by shaking the head to push the water out of the ear canal. This research was supported by National Science Foundation Grant CBET-1604424.

Hood Canal Steelhead - Hood Canal Steelhead Supplementation Experiment

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Hood Canal Steelhead Project is a 17-year before-after-control-impact experiment that tests the effects of supplementation on natural steelhead populations in...

Canal Centring Ability of ProTaper and Mtwo Rotary Systems in Curved Canals

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Turkaydin Dilek Erbay

2014-07-01

Full Text Available The purpose of this investigation was to compare centring ratio of ProTaper and Mtwo rotary systems. 60 mandibular molar teeth which had 25, 30 and 35 degree curvature in mesio-buccal root canal were used. Group 1 had 25°, Group 2 had 30°, and Group 3 had 35° curvatures. The roots were sectioned horizontally at 2 mm away from the apex. The apical region was then observed under a stereo-microscope. In each group, teeth were instrumented using ProTaper and Mtwo systems. After canal preparation, digital images of apical part of canals were taken. These images were then superimposed by using Adobe Photoshop CS2 programme. The data were analyzed using ANOVA and Student’s t-test.

Effect of field-of-view on the Coriolis illusion

NARCIS (Netherlands)

Groen, E.L.; Muis, H.; Kooi, F.L.

2008-01-01

Tilting the head during rotation about an Earth-vertical axis produces cross-coupled stimulation of the semicircular canals. Without visual feedback on the actual self-motion, this leads to the so-called Coriolis illusion. We investigated the effect of the field-of-view (FOV) on the magnitude and

Concomitant occurrence of cochleosaccular dysplasia and Down's syndrome.

Science.gov (United States)

Walby, A P; Schuknecht, H F

1984-07-01

Inherited cochleosaccular dysplasia occurred in a woman coincidentally with Down's syndrome. Study of the right temporal bone revealed abnormalities of the cochlea and saccule consistent with Scheibe 's original description. There was also a short cochlea and small lateral semicircular canal consistent with previous descriptions of Down's syndrome.

Effect of canal preparation with TRUShape and Vortex rotary instruments on three-dimensional geometry of oval root canals.

Science.gov (United States)

Arias, Ana; Paqué, Frank; Shyn, Stephanie; Murphy, Sarah; Peters, Ove A

2018-04-01

The purpose of this study was to assess the geometry of non-round root canals after preparation with TRUShape (a novel instrument with s-shaped longitudinal design) in comparison to conventional rotary instrumentation using micro-computed tomography. Twenty distal root canals of mandibular molars were randomly distributed in two groups to be shaped with either TRUShape or Vortex rotaries. Percentages of unprepared surface and volume of dentin removal for the entire canal and for the apical 4 mm were calculated. Canal transportation and the structure model index (SMI) were assessed. Data were compared with Student t-tests. Shaping with both techniques resulted in similar prepared surface and volume of dentin removed, as well as the extent of canal transportation. The SMI shape factor was significantly lower for TRUShape preparations (P = 0.04) suggesting less rounding during rotary preparation. Although both instruments were suitable for the preparation of oval canals, TRUShape appeared to better conform to the original ribbon-shaped anatomy. © 2017 Australian Society of Endodontology Inc.

Meatoplasty in Canal wall down Surgery: Our Experience and Literature Review

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Faramarz Memari

2017-01-01

Full Text Available Introduction: Meatoplasty is the final and essential step in performing effective canal wall down surgery for chronic otitis media. In this article we review some previous techniques and discuss our preferred method. Materials and Methods: In this observational case series study, we used this technique in 53 patients (28 male and 25 female between January 2005 and January 2008. Our survey was completed in 31 patients. Results: Twenty-six patients (83.9% said their ear appeared normal after the procedure, but five patients (16.1% complained of some minor change in the shape of their ear. Twenty-nine patients (93.5% had a completely wide ear canal. The ear canal had some degree of stenosis in two patients (6.5% post-operatively. Conclusion: This technique offers good functional and cosmetic results with minimal manipulation and minimal anatomic disruption.

Effects of Sustained Otolith-Only Stimulation on Post-Rotational Nystagmus.

Science.gov (United States)

Shaikh, Aasef G; Solomon, David

2017-06-01

Constant velocity rotations in darkness evoke vestibulo-ocular reflex in form of pre- and post-rotational nystagmus under cerebellar supervision. Reorientation of the head with respect to gravity, stimulating otolith and semicircular canal, during post-rotational phase rapidly suppresses the post-rotational nystagmus. We asked if pure otolith stimulation without semicircular canal signal is sufficient for the suppression of post-rotational nystagmus. The experimental paradigm comprised of on-axis rotations in the horizontal plane when the subject was sitting upright, followed by a novel stimulus that combined off-axis centrifugation in the horizontal plane with amplitude matched, yet out-of-phase, on-axis horizontal rotation-double centrifugation. The resultant effect of double centrifugation was pure otolith stimulation that constantly changed direction, yet completely canceled out angular velocity (no horizontal semicircular canal stimulation). Double centrifugation without pre-existing on-axis rotations evoked mixture of horizontal and vertical eye movements, latter reflected the known uncertainty of the vestibular system to differentiate whether the sensory signal is related to low-frequency translations in horizontal plane or head tilts relative to the gravity. Double centrifugation during post-rotational phase suppressed the peak slow phase eye velocity of the post-rotational nystagmus, hence affecting the vestibular ocular reflex gain (eye velocity/head velocity) matrix. The decay time constant, however, was unchanged. Amount of suppression of the peak slow phase eye velocity of the post-rotational nystagmus during double centrifugation correlated with the peak vertical eye velocity evoked by the pure otolith stimuli in the absence of pre-existing on axis rotations. In post-rotational phase, the pure otolith signal affects vestibular ocular reflex gain matrix but does not affect the time constant.

Three distal root canals in mandibular first molar with different canal configurations: Report of two cases and literature review

Directory of Open Access Journals (Sweden)

Parul Bansal

2015-01-01

Full Text Available With the increasing number of reports of aberrant root canal morphology, the clinician needs to be aware of the variable anatomy. Various case reports have been published with the finding of middle mesial canal in mandibular first molar, however finding of three distal canals in distal roots of mandibular first molar is rare. This article reports endodontic management of two mandibular first molars presented with three distal canals present in a single distal root (Sert and Bayirli type XVIII and distal and distolingual root.

canal24

Data.gov (United States)

California Natural Resource Agency — Canal system center lines in the Central Valley of California and adjacent areas captured from 1:24,000-scale USGS topographic maps. Updates and modifications made...

The Functioning of Drainage Canal Near Barrage “Brzeg Dolny” on the Odra River in 1971–2009

Directory of Open Access Journals (Sweden)

Olszewska Beata

2014-10-01

Full Text Available The paper analyses the amount of water flowing into the drainage canal in comparison to the levels of the Odra waters in the Brzeg Dolny – Wały cross section (upper water in the barrage. The results of the measurement of the flow intensity in the canal in 1971–2009 provided the basis for the evaluation.

The fluid mechanics of root canal irrigation.

Science.gov (United States)

Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

2010-12-01

Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

The fluid mechanics of root canal irrigation

International Nuclear Information System (INIS)

Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

2010-01-01

Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

Some History and Hydrology of the Panama Canal

National Research Council Canada - National Science Library

Pabst, Arthur

2000-01-01

At the request of the Panama Canal Commission (now Panama Canal Authority), the Hydrologic Engineering Center participated in the development of a model to simulate the existing operation of the Panama Canal System...

Sensory perception. [role of human vestibular system in dynamic space perception and manual vehicle control

Science.gov (United States)

1974-01-01

The effect of motion on the ability of men to perform a variety of control actions was investigated. Special attention was given to experimental and analytical studies of the dynamic characteristics of the otoliths and semicircular canals using a two axis angular motion simulator and a one axis linear motion simulator.

The influence of unilateral saccular impairment on functional balance performance and self-report dizziness.

Science.gov (United States)

McCaslin, Devin L; Jacobson, Gary P; Grantham, Sarah L; Piker, Erin G; Verghese, Susha

2011-09-01

Postural stability in humans is largely maintained by vestibular, visual, and somatosensory inputs to the central nervous system. Recent clinical advances in the assessment of otolith function (e.g., cervical and ocular vestibular evoked myogenic potentials [cVEMPs and oVEMPs], subjective visual vertical [SVV] during eccentric rotation) have enabled investigators to identify patients with unilateral otolith impairments. This research has suggested that patients with unilateral otolith impairments perform worse than normal healthy controls on measures of postural stability. It is not yet known if patients with unilateral impairments of the saccule and/or inferior vestibular nerve (i.e., unilaterally abnormal cVEMP) perform differently on measures of postural stability than patients with unilateral impairments of the horizontal SCC (semicircular canal) and/or superior vestibular nerve (i.e., unilateral caloric weakness). Further, it is not known what relationship exists, if any, between otolith system impairment and self-report dizziness handicap. The purpose of this investigation was to determine the extent to which saccular impairments (defined by a unilaterally absent cVEMP) and impairments of the horizontal semicircular canal (as measured by the results of caloric testing) affect vestibulospinal function as measured through the Sensory Organization Test (SOT) of the computerized dynamic posturography (CDP). A secondary objective of this investigation was to measure the effects, if any, that saccular impairment has on a modality-specific measure of health-related quality of life. A retrospective cohort study. Subjects were assigned to one of four groups based on results from balance function testing: Group 1 (abnormal cVEMP response only), Group 2 (abnormal caloric response only), Group 3 (abnormal cVEMP and abnormal caloric response), and Group 4 (normal control group). Subjects were 92 adult patients: 62 were seen for balance function testing due to complaints

Influence of a glide path on apical extrusion of debris during canal preparation using single-file systems in curved canals.

Science.gov (United States)

Topçuoğlu, H S; Düzgün, S; Akpek, F; Topçuoğlu, G; Aktı, A

2016-06-01

To evaluate the effect of a glide path on the amount of apically extruded debris during canal preparation using single-file systems in curved canals. Ninety extracted mandibular molar teeth were randomly assigned to six groups (n = 15 for each group) for canal instrumentation. Endodontic access cavities were prepared in each tooth. In three of the six groups, a glide path was not created whereas a glide path was created using PathFile instruments on the mesial canals of all teeth in the remaining three groups. The mesial canals of the teeth were then instrumented with the following single-file instrument systems: WaveOne, Reciproc and OneShape. Debris extruded apically during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were then stored in an incubator at 70 °C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data obtained were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The OneShape file was associated with less debris extrusion than the Reciproc and WaveOne files when canal instrumentation was performed without a glide path (P files (P > 0.05). There was no significant difference amongst the OneShape, Reciproc and WaveOne files when a glide path was created before canal preparation in curved root canals (P > 0.05). All systems extruded significantly less debris in groups with a glide path than in groups without a glide path (P < 0.05). All instruments were associated with apical extrusion of debris. Creating a glide path prior to canal instrumentation reduced the amount of apically extruded debris in curved canals. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The osseous external auditory canal : Surgery, shape, and sound

NARCIS (Netherlands)

van Spronsen, E.

2018-01-01

This thesis describes three aspects of the osseous external auditory canal (OEAC) which are related to each other: Surgery of the OEAC, the shape of the OEAC and the perceived sound quality due to the resonance function of the OEAC. Several aspects of the surgical intervention (Canalplasty) in

Mutation of Rubie, a novel long non-coding RNA located upstream of Bmp4, causes vestibular malformation in mice.

Directory of Open Access Journals (Sweden)

Kristina A Roberts

Full Text Available The vestibular apparatus of the vertebrate inner ear uses three fluid-filled semicircular canals to sense angular acceleration of the head. Malformation of these canals disrupts the sense of balance and frequently causes circling behavior in mice. The Epistatic circler (Ecl is a complex mutant derived from wildtype SWR/J and C57L/J mice. Ecl circling has been shown to result from the epistatic interaction of an SWR-derived locus on chromosome 14 and a C57L-derived locus on chromosome 4, but the causative genes have not been previously identified.We developed a mouse chromosome substitution strain (CSS-14 that carries an SWR/J chromosome 14 on a C57BL/10J genetic background and, like Ecl, exhibits circling behavior due to lateral semicircular canal malformation. We utilized CSS-14 to identify the chromosome 14 Ecl gene by positional cloning. Our candidate interval is located upstream of bone morphogenetic protein 4 (Bmp4 and contains an inner ear-specific, long non-coding RNA that we have designated Rubie (RNA upstream of Bmp4 expressed in inner ear. Rubie is spliced and polyadenylated, and is expressed in developing semicircular canals. However, we discovered that the SWR/J allele of Rubie is disrupted by an intronic endogenous retrovirus that causes aberrant splicing and premature polyadenylation of the transcript. Rubie lies in the conserved gene desert upstream of Bmp4, within a region previously shown to be important for inner ear expression of Bmp4. We found that the expression patterns of Bmp4 and Rubie are nearly identical in developing inner ears.Based on these results and previous studies showing that Bmp4 is essential for proper vestibular development, we propose that Rubie is the gene mutated in Ecl mice, that it is involved in regulating inner ear expression of Bmp4, and that aberrant Bmp4 expression contributes to the Ecl phenotype.

Canal of Nuck hernia: a multimodality imaging review

Energy Technology Data Exchange (ETDEWEB)

Rees, Mitchell A. [University of Pittsburgh Medical Center, Department of Radiology, Pittsburgh, PA (United States); Squires, James E. [Children' s Hospital of Pittsburgh of UPMC, Department of Gastroenterology, Pittsburgh, PA (United States); Tadros, Sameh; Squires, Judy H. [University of Pittsburgh Medical Center, Department of Radiology, Pittsburgh, PA (United States); Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Pittsburgh, PA (United States)

2017-07-15

Canal of Nuck abnormalities are a rare but important cause of morbidity in girls, most often those younger than 5 years of age. The canal of Nuck, which is the female equivalent of the male processus vaginalis, is a protrusion of parietal peritoneum that extends through the inguinal canal and terminates in the labia majora. The canal typically obliterates early in life, but in some cases the canal can partially or completely fail to close, potentially resulting in a hydrocele or hernia of pelvic contents. Recognition of this entity is especially important in cases of ovarian hernia due to the risk of incarceration and torsion. We aim to increase awareness of this condition by reviewing the embryology, anatomy and diagnosis of canal of Nuck disorders with imaging findings on US, CT and MRI using several cases from a single institution. (orig.)

Canal of Nuck hernia: a multimodality imaging review

International Nuclear Information System (INIS)

Rees, Mitchell A.; Squires, James E.; Tadros, Sameh; Squires, Judy H.

2017-01-01

Canal of Nuck abnormalities are a rare but important cause of morbidity in girls, most often those younger than 5 years of age. The canal of Nuck, which is the female equivalent of the male processus vaginalis, is a protrusion of parietal peritoneum that extends through the inguinal canal and terminates in the labia majora. The canal typically obliterates early in life, but in some cases the canal can partially or completely fail to close, potentially resulting in a hydrocele or hernia of pelvic contents. Recognition of this entity is especially important in cases of ovarian hernia due to the risk of incarceration and torsion. We aim to increase awareness of this condition by reviewing the embryology, anatomy and diagnosis of canal of Nuck disorders with imaging findings on US, CT and MRI using several cases from a single institution. (orig.)

A Comparison between heat transfer performance of rectangular and semicircular tubes considering boundary effects on Brownian motions in the presence of Ag / water nanofluids: Applicable in the design of cooling system of photovoltaic cells.

Science.gov (United States)

Jafarimoghaddam, Amin; Aberoumand, Sadegh

2017-01-01

The present study aims to experimentally investigate heat transfer performance of rectangular and semicircular tubes in the presence of Ag / water nanofluids. The nanoparticles of Ag (silver) were used in seven different volume concentrations of 0.03%, 0.07%, 0.1%, 0.2%, 0.4%, 1% and 2%. The experiment was conducted in relatively low Reynolds numbers of 301 to 740. A heater with the power of 200 W was used to keep the outer surface of the tubes under a constant heat flux condition. In addition, the rectangular tube has been designed within the same length as the semicircular one and also within the same hydraulic diameter. Moreover, the average nanoparticles size was 20 nm. The outcome results of the present empirical work indicate that, for all the examined Reynolds numbers, the semicircular tube has higher convective heat transfer coefficient for all the utilized volume concentrations of Ag nanoparticles. The possible reasons behind this advantage are discussed through the present work mainly by taking the boundary effect on Brownian motions into account. Coming to this point that the conventional design for cooling system of photovoltaic cells is a heat sink with the rectangular graves, it is discussed that using a semicircular design may have the advantage over the rectangular one in convective heat transfer coefficient enhancement and hence a better cooling performance for these solar cells.

A Comparison between heat transfer performance of rectangular and semicircular tubes considering boundary effects on Brownian motions in the presence of Ag / water nanofluids: Applicable in the design of cooling system of photovoltaic cells.

Directory of Open Access Journals (Sweden)

Amin Jafarimoghaddam

Full Text Available The present study aims to experimentally investigate heat transfer performance of rectangular and semicircular tubes in the presence of Ag / water nanofluids. The nanoparticles of Ag (silver were used in seven different volume concentrations of 0.03%, 0.07%, 0.1%, 0.2%, 0.4%, 1% and 2%. The experiment was conducted in relatively low Reynolds numbers of 301 to 740. A heater with the power of 200 W was used to keep the outer surface of the tubes under a constant heat flux condition. In addition, the rectangular tube has been designed within the same length as the semicircular one and also within the same hydraulic diameter. Moreover, the average nanoparticles size was 20 nm. The outcome results of the present empirical work indicate that, for all the examined Reynolds numbers, the semicircular tube has higher convective heat transfer coefficient for all the utilized volume concentrations of Ag nanoparticles. The possible reasons behind this advantage are discussed through the present work mainly by taking the boundary effect on Brownian motions into account. Coming to this point that the conventional design for cooling system of photovoltaic cells is a heat sink with the rectangular graves, it is discussed that using a semicircular design may have the advantage over the rectangular one in convective heat transfer coefficient enhancement and hence a better cooling performance for these solar cells.

Endodontic Management of a Maxillary Lateral Incisor with 4 Root Canals and a Dens Invaginatus Tract.

Science.gov (United States)

Nosrat, Ali; Schneider, S Craig

2015-07-01

Dens invaginatus (DI) is associated with complex internal anatomy. This article represents a maxillary lateral incisor with 5 root canals including DI. The treatment was planned and performed using cone-beam computed tomographic (CBCT) imaging. After clinical and radiographic evaluations, tooth #7 was diagnosed with DI and pulp necrosis with symptomatic apical periodontitis. Periapical radiographs of the tooth showed 2 roots and complex internal anatomy. CBCT evaluation revealed tooth #7 had 5 separate canals (4 root canals and 1 DI canal extending through the root to the periodontal ligament), communication between DI and the root canal system, and severe and multiple curvatures of the palatal canals. Root canal treatment was completed in 2 visits. Modified access openings were required to safely treat the dilacerated palatal canals. At the 6-month re-evaluation, the patient reported he had remained asymptomatic and his tooth had remained functional since the treatment was completed. Clinical examination showed tooth #7 had no sensitivity to percussion or palpation, probe depths within normal limits (≤3 mm), and no mobility. Radiographic assessment of the tooth showed significant osseous healing of the preoperative lesion. Three-dimensional imaging is a valuable tool for endodontic management of teeth with complex internal anatomy. Three-dimensional imaging is recommended for evaluating and treatment planning cases with DI. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Inner ear anomalies seen on CT images in people with Down syndrome

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Intrapiromkul, Jarunee; Aygun, Nafi; Yousem, David M. [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Tunkel, David E. [The Johns Hopkins Medical Institutions, Department of Otolaryngology-Head and Neck Surgery, Baltimore, MD (United States); Carone, Marco [University of California, Division of Biostatistics, School of Public Health, Berkeley, CA (United States)

2012-12-15

Although dysplasia of inner ear structures in Down syndrome has been reported in several histopathological studies, the imaging findings have not been widely studied. To evaluate the prevalence and clinical significance of inner ear anomalies detected on CT images in patients with Down syndrome. The temporal bone CT images of patients with Down syndrome were assessed for inner ear anomalies; clinical notes and audiograms were reviewed for hearing loss. Logistic regression models were employed to identify which CT findings were associated with sensorineural hearing loss (SNHL). Inner ear anomalies were observed in 74.5% (38/51) of patients. Malformed bone islands of lateral semicircular canal (LSCC), narrow internal auditory canals (IACs), cochlear nerve canal stenoses, semicircular canal dehiscence (SCCD), and enlarged vestibular aqueducts were detected in 52.5% (53/101), 24.5% (25/102), 21.4% (21/98), 8.8% (9/102) and 2% (2/101) of patients' ears, respectively. IAC stenosis had the highest odds ratio (OR = 5.37, 95% CI: 1.0-28.9, P = 0.05) for SNHL. Inner ear anomalies occurred in 74.5% of our population, with malformed (<3 mm) bone island of LSCC being the most common (52.5%) anomaly. Narrow IAC was seen in 24.5% of patients with Down syndrome and in 57.1% of ears with SNHL. High-resolution CT is a valuable for assessing the cause of hearing loss in people with Down syndrome. (orig.)

Inner ear anomalies seen on CT images in people with Down syndrome

International Nuclear Information System (INIS)

Intrapiromkul, Jarunee; Aygun, Nafi; Yousem, David M.; Tunkel, David E.; Carone, Marco

2012-01-01

Although dysplasia of inner ear structures in Down syndrome has been reported in several histopathological studies, the imaging findings have not been widely studied. To evaluate the prevalence and clinical significance of inner ear anomalies detected on CT images in patients with Down syndrome. The temporal bone CT images of patients with Down syndrome were assessed for inner ear anomalies; clinical notes and audiograms were reviewed for hearing loss. Logistic regression models were employed to identify which CT findings were associated with sensorineural hearing loss (SNHL). Inner ear anomalies were observed in 74.5% (38/51) of patients. Malformed bone islands of lateral semicircular canal (LSCC), narrow internal auditory canals (IACs), cochlear nerve canal stenoses, semicircular canal dehiscence (SCCD), and enlarged vestibular aqueducts were detected in 52.5% (53/101), 24.5% (25/102), 21.4% (21/98), 8.8% (9/102) and 2% (2/101) of patients' ears, respectively. IAC stenosis had the highest odds ratio (OR = 5.37, 95% CI: 1.0-28.9, P = 0.05) for SNHL. Inner ear anomalies occurred in 74.5% of our population, with malformed (<3 mm) bone island of LSCC being the most common (52.5%) anomaly. Narrow IAC was seen in 24.5% of patients with Down syndrome and in 57.1% of ears with SNHL. High-resolution CT is a valuable for assessing the cause of hearing loss in people with Down syndrome. (orig.)

Type III apical transportation of root canal

Directory of Open Access Journals (Sweden)

Shiv P Mantri

2012-01-01

Full Text Available Procedural accidents leading to complications such as canal transportation have been ascribed to inapt cleaning and shaping concepts. Canal transportation is an undesirable deviation from the natural canal path. Herewith a case of apical transportation of root canal resulting in endodontic retreatment failure and its management is presented. A healthy 21-year-old young male presented discomfort and swelling associated with painful endodontically retreated maxillary incisor. Radiograph revealed periradicular radiolucency involving underfilled 11 and overfilled 12. Insufficiently obturated 11 exhibited apical transportation of canal. This type III transportation was treated by periradicular surgery and repair using white mineral trioxide aggregate (MTA. Comfortable asymptomatic patient presented uneventful healing at third and fourth month recall visits. A decrease in the size of radiolucency in radiograph supported the clinical finding. In the present case, MTA is useful in repairing the transportation defect. The result of these procedures is predictable and successful.

Mandibular molar with five root canals.

Science.gov (United States)

Barletta, Fernando Branco; Dotto, Sidney Ricardo; Reis, Magda de Sousa; Ferreira, Ronise; Travassos, Rosana Maria Coelho

2008-12-01

The purpose of this study was to demonstrate the importance of knowledge of the internal anatomy of root canals for the success of endodontic treatment. Lack of knowledge of anatomic variations and their characteristics in different teeth has been pointed out as one of the main causes of endodontic therapy failure. In this report, the authors describe the endodontic treatment of a mandibular first molar with five root canals, evaluate the rate of occurrence of this number of canals, and discuss the importance of their identification and treatment.

Lumbar Vertebral Canal Diameters in Adult Ugandan Skeletons ...

African Journals Online (AJOL)

Background: Normal values of lumbar vertebral canal diameters are useful in facilitating diagnosis of lumbar vertebral canal stenosis. Various studies have established variation on values between different populations, gender, age, and ethnic groups. Objectives: To determine the lumbar vertebral canal diameters in adult ...

Impact of canal water shortages on groundwater in the Lower Bari Doab Canal system in Pakistan

International Nuclear Information System (INIS)

Shakir, A.S.; Rehman, H.U.; Khan, N.M.; Qazi, A.U.

2011-01-01

This paper presents rigorous analysis of shortage of canal water supplies, crop water requirements, and groundwater use and its quality in the command of Lower Bari Doab Canal, Pakistan. The annual canal water supplies are 36% less than the crop water requirements. This shortage further increases to 56% if actual canal supplies (averaged over last ten years) are compared with the crop water requirement. The groundwater levels are depleting at the rate of 30 to 40 cm per year in most parts of the LBDC command and this tendency of lowering may increase in future due to further increase in crop water requirements. The analysis of data for the last seven years indicate that quality of groundwater in most parts of LBDC command is generally good (64% of the area) or marginally acceptable (28%) for irrigation use. However, declining trends in groundwater quality are visible and can create long term sustain ability problems if proper remedial actions are not taken well in time. (author)

Environmental pollution and shipping feasibility of the Nicaragua Canal

International Nuclear Information System (INIS)

Chen, Jihong; Zeng, Xin; Deng, Yibing

2016-01-01

In recent years, the Nicaraguan government's renewed interest in constructing this interoceanic canal has once again aroused widespread concern, particularly in the global shipping industry. The project's immense ecological risks, coupled with the recent expansions of both the Panama Canal and the Suez Canal, have raised questions among scientists and experts about its viability. Whether the Nicaragua Canal is really feasible for international shipping, given its high marine pollution risks, requires the further study. This paper discusses and analyses the feasibility of the Nicaragua Canal in the context of its environmental impact and value as a shipping service. This paper aims to provide an important information reference to inform strategic decision-making among policymakers and stakeholders. Our research results indicate that the environmental complexity, economic costs and safety risks of building a new transoceanic canal are simply too high to justify the project. - Highlights: • The Nicaragua Canal is a long-standing controversial maritime project. • We develop specific analysis of the high environmental pollution risks of the canal. • The shipping service feasibility of the canal is faced with great uncertainty. • The government and stakeholders are suggested to be discreet to the mega project.

The failures of root canal preparation with hand ProTaper.

Science.gov (United States)

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C; Tuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-07-01

The failures of root canal preparation are due to some anatomical deviation (canal in "C" or "S") and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Our study was made on technique errors while preparing the canal roots with hand ProTaper. Our study was made "in vitro" on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment.

Patients with vestibular loss, tullio phenomenon, and pressure-induced nystagmus: vestibular atelectasis?

Science.gov (United States)

Wenzel, Angela; Ward, Bryan K; Schubert, Michael C; Kheradmand, Amir; Zee, David S; Mantokoudis, Georgios; Carey, John Patrick

2014-06-01

To propose an etiology for a syndrome of bilateral vestibular hypofunction and sound and/or pressure-evoked eye movements with normal hearing thresholds. Retrospective case series. Tertiary care referral center. Four patients with bilateral vestibular hypofunction, sound and/or pressure-evoked nystagmus and normal hearing thresholds were identified over a 3-year period. No evidence of other known vestibular disorders was identified. None of these patients presented with a history of exposure to toxins, radiation, aminoglycosides or chemotherapy; head trauma; or a family history of inherited vestibular loss. All patients underwent high-resolution CT scan of the temporal bones to evaluate for labyrinthine dehiscence. Additionally, all individuals underwent audiometric testing to ANSI standards, vestibular-evoked myogenic potentials (VEMP) testing using either click stimulus cervical VEMPs (cVEMPs), or tone burst ocular VEMPs (oVEMPs). Bithermal caloric stimulation was used to measure horizontal semicircular canal function, with either videonystagmography (VNG) or electronystagmography (ENG) to record eye movements. Individual responses of each of the 6 semicircular canals (SCC) to rapid head rotations were tested with the bedside head impulse test. We identified 4 patients with a combination of bilateral vestibular hypofunction and sound and/or pressure-induced eye movements, normal-hearing thresholds and no evidence for any other vestibular disorder. We suggest that this unique combination of symptoms should be considered as the clinical presentation of vestibular atelectasis, which has been previously described histologically as collapse of the endolymph-containing portions of the labyrinth.

Infected Hydrocele of the Canal of Nuck

Directory of Open Access Journals (Sweden)

Parkash Mandhan

2013-01-01

Full Text Available Hydrocele of the canal of Nuck in children is rare. It may present as incarcerated inguinal hernia and necessitates emergency exploration. Risk of infection in hydrocele of the canal of nuck is very rare. We present a case report of a 5-year-old girl who presented with a left tender inguinolabial region swelling with fever, tachycardia, and mild dehydration. The clinical features were suggestive of strangulated left inguinal hernia and further imaging and surgical exploration revealed it to be an infected hydrocele of the canal of Nuck. High ligation and hydrocelectomy were performed. Hydrocele of the canal of Nuck in a female child presenting with an inguinal swelling should be considered in differential diagnosis.

Incidence and characteristics of mandibular accessory canals: A radiographic investigation.

Science.gov (United States)

Borgonovo, Andrea Enrico; Taschieri, Silvio; Vavassori, Virna; Re, Dino; Francetti, Luca; Corbella, Stefano

2017-11-01

The aim of the present study was to explore, through tridimensional reconstructions of cone-beam computed tomography (CBCT) scans, the presence and the characteristics of mandibular accessory canals. For each included participant, the presence of accessory canals was recorded. The diameter of the canal, as well as the distance between the canal walls and the walls of the mandibular bone (lingual, buccal, cranial and caudal), were measured and recorded. Mandibular accessory canals could be found in 8.8% of participants. Retromolar canals were the most frequently found accessory mandibular canals. Accessory mandibular canals were found in a relatively high number of participants through the examination of CBCT scans and tridimensional reconstruction. The presence of such structures should be considered cautiously when planning and performing surgical interventions in mandibular area. © 2017 John Wiley & Sons Australia, Ltd.

Malignant transformation from benign papillomatosis of the external auditory canal.

Science.gov (United States)

Miah, Mohammed S; Crawford, Mairi; White, Sharon J; Hussain, Syed Shah Musheer

2012-06-01

Report a case of malignant transformation of benign ear canal papillomatosis to malignant squamous cell carcinoma (SCC) of the temporal bone. A 73-year-old with papillomata involving the posterior and inferior walls of the right external auditory canal (EAC), which subsequently transformed into SCC. Radical mastoidectomy and excision of the tumor and then radical radiotherapy. Loco-regional disease control. Recovery of facial nerve function. Approximately 20 months post-treatment, the patient remains disease free. No recovery of facial nerve function. Malignant transformation of a benign EAC papilloma to SCC of the temporal bone has not been reported previously. The association of human papillomavirus with temporal bone SCC has been reported in small number of studies with human papillomavirus subtypes 16 and 18 isolated in a high proportion of cases. With the increased availability in genotyping, the question over whether there should be further genetic analysis of benign lesions to assess their susceptibility to malignant transformation has merit.

21 CFR 872.3820 - Root canal filling resin.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate, intended...

Vestibular Stimulation for ADHD: Randomized Controlled Trial of Comprehensive Motion Apparatus

Science.gov (United States)

Clark, David L.; Arnold, L. Eugene; Crowl, Lindsay; Bozzolo, Hernan; Peruggia, Mario; Ramadan, Yaser; Bornstein, Robert; Hollway, Jill A.; Thompson, Susan; Malone, Krista; Hall, Kristy L.; Shelton, Sara B.; Bozzolo, Dawn R.; Cook, Amy

2008-01-01

Objective: This research evaluates effects of vestibular stimulation by Comprehensive Motion Apparatus (CMA) in ADHD. Method: Children ages 6 to 12 (48 boys, 5 girls) with ADHD were randomized to thrice-weekly 30-min treatments for 12 weeks with CMA, stimulating otoliths and semicircular canals, or a single-blind control of equal duration and…

Comparison of the rheological properties of four root canal sealers

Institute of Scientific and Technical Information of China (English)

Seok Woo Chang; Kwang Shik Bae; Young-Kyu Lee; Qiang Zhu; Won Jun Shon; Woo Cheol Lee; Kee Yeon Kum; Seung Ho Baek; In Bog Lee; Bum-Soon Lim

2015-01-01

The flowability of a root canal sealer is clinically important because it improves the penetration of the sealer into the complex root canal system. The purpose of this study was to compare the flowabilities of four root canal sealers, measured using the simple press method (ISO 6876), and their viscosities, measured using a strain-controlled rheometer. A newly developed, calcium phosphate-based root canal sealer (Capseal) and three commercial root canal sealers (AH Plus, Sealapex and Pulp Canal Sealer EWT) were used in this study. The flowabilities of the four root canal sealers were measured using the simple press method (n55) and their viscosities were measured using a strain-controlled rheometer (n55). The correlation between these two values was statistically analysed using Spearman’s correlation test. The flow diameters and the viscosities of the root canal sealers were strongly negatively correlated (r520.8618). The viscosity of Pulp Canal Sealer EWT was the lowest and increased in the following order:AH Plus,Sealapex,Capseal (P,0.05). All of the tested root canal sealers showed characteristic time-and temperature-dependent changes in their rheological properties. The viscosities measured using the strain-controlled rheometer were more precise than the flowabilities measured using the simple press method, suggesting that the rheometer can accurately measure the rheological properties of root canal sealers.

Management of Acquired Atresia of the External Auditory Canal.

Science.gov (United States)

Bajin, Münir Demir; Yılmaz, Taner; Günaydın, Rıza Önder; Kuşçu, Oğuz; Sözen, Tevfik; Jafarov, Shamkal

2015-08-01

The aim was to evaluate surgical techniques and their relationship to postoperative success rate and hearing outcomes in acquired atresia of the external auditory canal. In this article, 24 patients with acquired atresia of the external auditory canal were retrospectively evaluated regarding their canal status, hearing, and postoperative success. Acquired stenosis occurs more commonly in males with a male: female ratio of 2-3:1; it seems to be a disorder affecting young adults. Previous ear surgery (13 patients, 54.2%) and external ear trauma (11 patients, 45.8%) were the main etiological factors of acquired ear canal stenosis. Mastoidectomy (12/13) and traffic accidents (8/11) comprise the majority of these etiological factors. Endaural incision is performed in 79.2% and postauricular incision for 20.8% of cases during the operation. As types of surgical approach, transcanal (70.8%), transmastoid (20.8%), and combined (8.4%) approaches are chosen. The atretic plate is generally located at the bony-cartilaginous junction (37.5%) and in the cartilaginous canal (33.3%); the bony canal is involved in a few cases only. Preserved healthy canal skin, split- or full-thickness skin grafts, or pre- or postauricular skin flaps are used to line the ear canal, but preserved healthy canal skin is preferred. The results of surgery are generally satisfactory, and complications are few if surgical principles are followed.

Comparative Anatomy of the Bony Labyrinth (Inner Ear) of Placental Mammals

Science.gov (United States)

Ekdale, Eric G.

2013-01-01

Background Variation is a naturally occurring phenomenon that is observable at all levels of morphology, from anatomical variations of DNA molecules to gross variations between whole organisms. The structure of the otic region is no exception. The present paper documents the broad morphological diversity exhibited by the inner ear region of placental mammals using digital endocasts constructed from high-resolution X-ray computed tomography (CT). Descriptions cover the major placental clades, and linear, angular, and volumetric dimensions are reported. Principal Findings The size of the labyrinth is correlated to the overall body mass of individuals, such that large bodied mammals have absolutely larger labyrinths. The ratio between the average arc radius of curvature of the three semicircular canals and body mass of aquatic species is substantially lower than the ratios of related terrestrial taxa, and the volume percentage of the vestibular apparatus of aquatic mammals tends to be less than that calculated for terrestrial species. Aspects of the bony labyrinth are phylogenetically informative, including vestibular reduction in Cetacea, a tall cochlear spiral in caviomorph rodents, a low position of the plane of the lateral semicircular canal compared to the posterior canal in Cetacea and Carnivora, and a low cochlear aspect ratio in Primatomorpha. Significance The morphological descriptions that are presented add a broad baseline of anatomy of the inner ear across many placental mammal clades, for many of which the structure of the bony labyrinth is largely unknown. The data included here complement the growing body of literature on the physiological and phylogenetic significance of bony labyrinth structures in mammals, and they serve as a source of data for future studies on the evolution and function of the vertebrate ear. PMID:23805251

Serum uric acid levels correlate with benign paroxysmal positional vertigo.

Science.gov (United States)

Celikbilek, A; Gencer, Z K; Saydam, L; Zararsiz, G; Tanik, N; Ozkiris, M

2014-01-01

Benign paroxysmal positional vertigo (BPPV) is a frequently encountered condition that can severely affect the quality of life. In this study, we aimed to assess the possible relations between serum uric acid (SUA) levels and BPPV. Fifty patients with BPPV, and 40 age- and sex-matched control subjects were enrolled in the study. All the patients and controls underwent a complete audio-vestibular test battery including the Dix-Hallpike maneuver and supine roll test for posterior semicircular canal (PSC) and horizontal semicircular canal, respectively. Routine hematological and biochemical analyses were performed in both groups. In the BPPV group, measurements of SUA levels were repeated 1 month after the vertigo attack. The lipid profiles and SUA levels were higher in patients with BPPV than detected in controls (P multiple logistic regression models (P decrement in SUA level 1 month after the vertigo attack compared with the values obtained during the attack (P 0.05). Elevated SUA is positively correlated with BPPV, requiring further efforts to clarify the exact mechanism. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Middle mesial canals in mandibular molars: incidence and related factors.

Science.gov (United States)

Nosrat, Ali; Deschenes, Raney J; Tordik, Patricia A; Hicks, M Lamar; Fouad, Ashraf F

2015-01-01

Although the internal anatomy of mandibular molars has been extensively studied, information about middle mesial (MM) canals is limited. The primary aim of this retrospective study was to evaluate the incidence of MM canals in mandibular first and second molars. The secondary aim was to correlate the incidence of MM canals with variables of molar type, sex, age, ethnicity, and presence of a second distal canal. All mature permanent first and second mandibular molars treated from August 2012 to May 2014 were included in the analysis. After completion of root canal instrumentation in all main canals, the clinician inspected the isthmus area of the mesial root using the dental operating microscope. If there was a catch point in this area with a file or explorer, the operator spent more time attempting to negotiate an MM canal. Seventy-five mandibular first and second molars were treated during the specified period. Fifteen (20%) teeth had negotiable MM canals. The incidence of MM canals was 32.1% in patients ≤ 20 years old, 23.8% in patients 21-40 years old, and 3.8% in patients > 40 years. Analysis of data revealed a significant difference in the distribution of MM canals among different age groups (P molar type, and presence of a second distal canal were not significant. The incidence of negotiable MM canals overall and their frequency of identification in younger patients were higher than in previous reports. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Radiographic evaluation of the quality of root canal obturation of single-matched cone Gutta-percha root canal filling versus hot lateral technique

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Randa Suleiman Obeidat

2014-01-01

Full Text Available Aim: The aim of this study is to evaluate radiographically the quality of root canal filling in mesiodistal and buccolingual view when comparing matched cone condensation and warm lateral Gutta-percha condensation using system B heating instrument in a low-heat warm lateral condensation technique in0 vitro. Materials and Methods: A total of 40 mandibular premolars with straight single canals were divided into two groups with 20 each. The root canals were shaped by hand file and Revo-S rotary files to size (25, 0.06 at the end point, then they filled by Gutta-percha cone and meta-seal sealer. In group A, a single matched cone technique was used to fill the root canals. In group B, a hot lateral condensation using system B instrument at 101°C was performed. Result: The result of this study showed no significant difference in density of Gutta-percha fill in apical and coronal two-third when comparing matched cone root canal filling and hot lateral technique (P > 0.05. The only significant difference (P < 0.05 was in matched cone between buccolingual and mesiodistal view in the coronal two-third. Conclusion: Within the limitation of this study, single matched cone technique has a good density in the apical one-third as that of the hot lateral technique so it may be used for filling narrow canals. In the coronal two-third of the root canal, single matched cone technique showed inferior density of root canal filling which can be improved by using accessory cones Gutta-percha in wide canal.

Newer Root Canal Irrigants in Horizon: A Review

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Sushma Jaju

2011-01-01

Full Text Available Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.

Vertigo with sudden hearing loss: audio-vestibular characteristics.

Science.gov (United States)

Pogson, Jacob M; Taylor, Rachael L; Young, Allison S; McGarvie, Leigh A; Flanagan, Sean; Halmagyi, G Michael; Welgampola, Miriam S

2016-10-01

Acute vertigo with sudden sensorineural hearing loss (SSNHL) is a rare clinical emergency. Here, we report the audio-vestibular test profiles of 27 subjects who presented with these symptoms. The vestibular test battery consisted of a three-dimensional video head impulse test (vHIT) of semicircular canal function and recording ocular and cervical vestibular-evoked myogenic potentials (oVEMP, cVEMP) to test otolith dysfunction. Unlike vestibular neuritis, where the horizontal and anterior canals with utricular function are more frequently impaired, 74 % of subjects with vertigo and SSNHL demonstrated impairment of the posterior canal gain (0.45 ± 0.20). Only 41 % showed impairment of the horizontal canal gains (0.78 ± 0.27) and 30 % of the anterior canal gains (0.79 ± 0.26), while 38 % of oVEMPs [asymmetry ratio (AR) = 41.0 ± 41.3 %] and 33 % of cVEMPs (AR = 47.3 ± 41.2 %) were significantly asymmetrical. Twenty-three subjects were diagnosed with labyrinthitis/labyrinthine infarction in the absence of evidence for an underlying pathology. Four subjects had a definitive diagnosis [Ramsay Hunt Syndrome, vestibular schwannoma, anterior inferior cerebellar artery (AICA) infarction, and traction injury]. Ischemia involving the common-cochlear or vestibulo-cochlear branches of the labyrinthine artery could be the simplest explanation for vertigo with SSNHL. Audio-vestibular tests did not provide easy separation between ischaemic and non-ischaemic causes of vertigo with SSNHL.

Neuronal hyperplasia in the anal canal

DEFF Research Database (Denmark)

Fenger, C; Schrøder, H D

1990-01-01

In a consecutive series of minor surgical specimens from the anal canal, neuronal hyperplasia was found in nine of 56 haemorrhoidectomy specimens and in four of 23 fibrous polyps. In an additional series of 14 resections of the anal canal, neuronal hyperplasia was present in six cases, of which f...

THE BUSINESS OF THE CANAL: THE ECONOMICS AND POLITICS OF THE CARTER ADMINISTRATION’S PANAMA CANAL ZONE INITIATIVE, 1978

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Mary C. Swilling

2004-01-01

Full Text Available The Carter-Torrijos Treaty of 1978, the initiative to relinquish controi of the Panama Canal Zone to the Republic of Panama, allowed Panama for the first time in its short history to become an autonomous nation and to take control of its destiny as a global trading crossroads. Conservatives rallied against President Carter and accused him of jeopardizing U. S. security and hegemony. Fears were that Panama did not have the economic or technical resources to maintain Canal operations, lacked the administrative knowledge and resources to manage the business of the Canal, lacked the military presence to insure security of the Canal, and did not have the political and social will to maintain the environmental integrity of the region. In short, disastrous results were predicted. Carter prevailed. December 31, 1999 saw the surrender of the Canal Zone, and all its facilities, to Panama. This paper discusses events that precipitated Carter’s decision, economic and political arguments presented during the 1977-78 debate, implementation of the treaty, and an evaluation of the ‘business of the Canal’ today.

Hydrology and environmental aspects of Erie Canal (1817-99)

Science.gov (United States)

Langbein, Walter Basil

1976-01-01

As the first major water project in the United States, the old Erie Canal provides an example of the hydrological and environmental consequences of water development. The available record shows that the project aroused environmental fears that the canal might be impaired by the adverse hydrologic effects of land development induced by the canal. Water requirements proved greater than anticipated, and problems of floods and hydraulic inefficiencies beset navigation throughout its history. The Erie Canal proved the practicality of major hydraulic works to the extent that operations and maintenance could cope with the burdens of deficiencies in design. The weight of prior experience that upland streams, such as the Potomac and Mohawk Rivers, had proved unsatisfactory for dependable navigation, led to a decision to build an independent canal which freed the location from the constraints of river channels and made possible a cross-country water route directly to Lake Erie. The decision on dimensioning the canal prism--chiefly width and depth-involved balance between a fear of building too small and thus not achieving the economic potentials, and a fear of building too expensively. The constraints proved effective, and for the first part of its history the revenues collected were sufficient to repay all costs. So great was the economic advantage of the canal that the rising trend in traffic soon induced an enlargement of the canal cross section, based upon a new but riskier objective-build as large as the projected trend in toll revenues would finance. The increased revenues did not materialize. Water supplies were a primary concern for both the planners and the operators of the canal. Water required for lockage, although the most obvious to the planners, proved to be a relatively minor item compared with the amounts of water that were required to compensate for leakage through the bed and banks of the canal. Leakage amounted to about 8 inches of depth per day. The total

Single-rooted maxillary first molar with a single canal: endodontic retreatment.

Science.gov (United States)

de la Torre, Francisco; Cisneros-Cabello, Rafael; Aranguren, José Luis; Estévez, Roberto; Velasco-Ortega, Eugenio; Segura-Egea, Juan José

2008-12-01

This case report presents an unusual root canal system in a maxillary first molar tooth: a single canal in a single root. The endodontic access cavity displayed only 1 canal orifice. This case demonstrated that: 1) clinicians must have adequate knowledge about root canal morphology and its variations; 2) the location and morphology of root canals should be identified radiologically before the root canal treatment; and 3) careful examination of radiographs and the internal anatomy of teeth is essential.

The failures of root canal preparation with hand ProTaper

OpenAIRE

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C.; Ţuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-01-01

The failures of root canal preparation are due to some anatomical deviation (canal in “C” or “S”) and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Objectives: Our study was made on technique errors while preparing the canal roots with hand ProTaper. Methodology: Our study was made “in vitro” on 84 extracted teeth (molars, premolars, incisors and canines). The canal roo...

Root canal treatment of mandibular second premolar tooth with taurodontism

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Vujašković Mirjana

2008-01-01

Full Text Available INTRODUCTION Taurodontism is a morphoanatomical change in the shape of a tooth. An enlarged body of a tooth with smaller than usual roots is a characteristic feature. Internal tooth anatomy correlates with this appearance, which means that a taurodontal tooth has a large pulp chamber and apically positioned furcations. This dental anomaly may be associated with different syndromes and congenital discoders. CASE OUTLINE The case report presents the patient of a rare case of taurodontism in the mandibular second premolar with chronic periodontitis. Endodontic treatment was performed after dental history and clinical examination. Special care is required in all segments of endodontic treatment of a taurodontal tooth from the identification orifice, canal exploration, determining working length, cleaning and shaping and obturation of the root canal. Precurved K-file was used for canal exploration and location of the furcation. One mesial and one distal canal with the buccal position were identified in the apical third of the root canal. The working lengths of two canals were determined by radiographic interpretation with two K-files in each canal and verified with the apex locator. During canal instrumentation, the third canal was located in the disto-lingual position. The working length of the third canal was established using the apex locator. CONCLUSION Thorough knowledge of tooth anatomy and its variations can lead to lower percentage of endodontic failure. Each clinical case involving these teeth should be investigated carefully, clinically and radiographically to detect additional root canals. High quality radiographs from different angles and proper instrumentarium improve the quality of endodontic procedure.

[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.

Environmental pollution and shipping feasibility of the Nicaragua Canal.

Science.gov (United States)

Chen, Jihong; Zeng, Xin; Deng, Yibing

2016-12-15

In recent years, the Nicaraguan government's renewed interest in constructing this interoceanic canal has once again aroused widespread concern, particularly in the global shipping industry. The project's immense ecological risks, coupled with the recent expansions of both the Panama Canal and the Suez Canal, have raised questions among scientists and experts about its viability. Whether the Nicaragua Canal is really feasible for international shipping, given its high marine pollution risks, requires the further study. This paper discusses and analyses the feasibility of the Nicaragua Canal in the context of its environmental impact and value as a shipping service. This paper aims to provide an important information reference to inform strategic decision-making among policymakers and stakeholders. Our research results indicate that the environmental complexity, economic costs and safety risks of building a new transoceanic canal are simply too high to justify the project. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of periapical health, quality of root canal filling, and ...

African Journals Online (AJOL)

Sixty three teeth were found to have short root canal fillings, whereas 74 teeth had adequate root canal fillings, and the remaining 10 teeth had over extended root canal filling. A significant correlation was observed between the length of root filling and apical periodontitis (P = 0,023). Inadequately dense root canal filling was ...

Mobilização do osso pisiforme no tratamento da neuropraxia do nervo ulnar no canal de Guyon: relato de caso Pisiform bone mobilization for treating ulnar nerve neuropraxia at Guyon's canal: case report

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Júlio Guilherme Silva

2009-12-01

Full Text Available As neuropraxias do nervo ulnar são lesões bastante freqüentes que provocam efeitos deletérios, como diminuição de força muscular e parestesias; geralmente ocorrem no nível do epicôndilo medial e do túnel ulnar (canal de Guyon. São escassos os relatos referentes a técnicas de terapia manual para compressões do nervo ulnar no canal de Guyon. Este trabalho relata o uso da técnica de mobilização do pisiforme na compressão do nervo ulnar no canal de Guyon de um homem que sofreu luxação do punho direito aos 8 anos e, aos 25, queixava-se de um deficit para adução do dedo mínimo, que atrapalhava a realização de algumas atividades de vida diária. O paciente foi submetido a uma única sessão de mobilização articular do pisiforme. Após a aplicação da técnica, o sinal positivo do teste foi eliminado, restabelecendo-se a função de adução do 5o dedo. Embora carecendo de maior fundamentação teórica, pode-se afirmar que a técnica usada, de mobilização articular do osso pisiforme, é eficaz para melhora do quadro de paresia por neuropraxia do nervo ulnar no canal de Guyon.A common ulnar nerve neuropraxia is lesion that may result in muscle strength decrease and/or paresthesia; it usually takes place at medial epicondyle level and the ulnar tunnel (Guyon's canal. Studies on manual therapy techniques for ulnar nerve compression in Guyon's canal are scarce. This paper reports the use of a technique of pisiform bone mobilization for relieving ulnar nerve compression in Guyon's canal, in a man who had suffered a luxation of the right wrist at the age of 8 and, at 25, complained of adduction deficit of the fifth finger that interfered in his daily life activities. He was submitted to one session of pisiform mobilization; after the session, the positive test sign was eliminated, thus restoring the fifth finger function. Though lacking further grounding, it may be said that the technique used, of mobilizing the pisiform bone

Endodontic management of a permanent mandibular first molar with six canals

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Mohammad Ahmad Alenezi

2016-01-01

Full Text Available An excellent knowledge of root canal anatomy of teeth is a golden standard for the successful clinical outcome of root canal therapy. Several anatomic variations may occur in a permanent mandibular first molar. Usually, three to four root canals are found, but six to eight canals have been reported. A 22-year-old Bangladeshi woman was referred for endodontic treatment of mandibular right first molar. Rigorous clinical examination revealed the presence of three canals in mesial root and three canals in distal root as well. The dentists should expect any variation in root canal system and use the diagnostic tools to manage the cases.

MRI diagnosis of intraspinal dermoid ruptured into central spinal canal

International Nuclear Information System (INIS)

Zhang Yong; Cheng Jingliang; Wang Juan; Li Huali; Ren Cuiping; Zhang Yan; Gao Xuemei

2009-01-01

Objective: To evaluate the appearances of intraspinal dermoid ruptured into the central spinal canal, as well as the MRI diagnosis and differential diagnosis. Methods: Eleven cases of intraspinal dermoid ruptured into the central spinal canal were reviewed. Six cases underwent whole spine MRI scan, 2 cases with thoracic and lumbar spine MRI, as well as 3 cases only with lumbar spine MRI. Results: Free fat droplets within spinal cord central canal demonstrated high signal intensity on T 1 WI, slight declined signal intensity on T 2 WI, and extremely low signal on fat suppression sequence. Of the 11 cases, 2 cases broke into neighboring central spinal canal of the dermoid, 3 cases scattered within thoracic spinal cord central canal, 4 cases discontinuously distributed in the whole spinal cord central canal, 2 cases showed continuous distribution. Conclusion: Intraspinal dermoid ruptured in the central spinal canal had specific appearance on MRI, when a dermoid tumor is suspected, MRI of the entire spine were recommended to detect possible leakage of' fat within central spinal canal. (authors)

Lipoatrofia semicircular: Nuestra experiencia dos años después (2007-2009 Semicircular Lipoatrophy: Our experience two years later (2007-2009

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Antonio Ortega Díaz de Cevallos

2009-12-01

Full Text Available Fundamento y objetivos: Describir y analizar la presentación clínica y la evolución tras la corrección de determinados factores ambientales, de nuestra serie de casos de lipoatrofia semicircular en el entorno laboral, con especial atención a la resolución de la lesión y valorar la posible asociación con otras patologías desde el punto de vista etiológico o que pudieran formar parte de un síndrome más complejo. Pacientes y método: Trabajadores atendidos entre la primavera de 2007 y el verano de 2009. En la primera consulta se efectúa historia clínica detallada, con medición y localización de la lesión, realización de analítica y de ecografía de la zona supuestamente afecta. Posteriormente tras haberse tomado las medidas recomendadas en las empresas para eliminar la electricidad estática, se incluyen controles cada tres meses con anamnesis, exploración física y ecografía comparativas. Resultados: El 96,7% son mujeres, sin predominio de ninguna edad Todos trabajan en puestos con material informático y abundante cableado eléctrico. Las localizaciones, salvo 3 casos (2 en brazo y uno en región glútea, fueron a nivel de cara anterolateral de muslos y con valores medios de 69x20x73 cm. (altoxanchoxlargo. Evolutivamente a los 6 meses un 93% de casos mostraban remisión clínica (62% completa, 31% parcial; al año solamente 2 casos no han mostrado ninguna variación habiendo un 69% de resoluciones completas. Ningún caso ha presentado otra patología relacionada. En el primer año de control hubo 36 nuevos casos, en el segundo 22 y 4 en los 6 meses trascurridos del tercero. Conclusiones: Las características clínicas son superponibles a las de otras series publicadas en cuanto a manifestaciones, tipo de trabajador afecto y predominio de presentación en mujeres. En cuanto a la evolución una vez modificado el entorno laboral, es evidente la tendencia a la resolución, mucho más rápida que en los casos antiguamente

Three root canals in the maxillary second premolar

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de Almeida-Gomes Fabio

2009-01-01

Full Text Available In this study, we report an endodontic treatment of the maxillary second premolar with three root canals and distinct foramens. The possibility of three root canals in this tooth is quite small; however, it must be taken into account in clinical and radiographic evaluation during endodontic treatment. Many times, their presence is noticed only after canal treatment due to continuing post-operative discomfort.

The crazy project – Canal Istanbul

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Seda Kundak

2011-10-01

Full Text Available It was late April 2011 when “the Crazy Project - Canal Istanbul” was proposed by the Prime Minister of Turkey, during his election campaign.  Although the idea of an artificial canal is not new, since it is initiated without any consensus between the people and institutions in Istanbul, the project immediately set a large number of debates. These vary from the legitimacy of decentralization of governance, to potential impacts of the canal on international politics, economy, environment and urban life.  Regarding past infrastructure projects in Istanbul, such large scale investments have caused extensive acceleration in construction sector in one hand and social and economic shifts on the other.  In this paper, the Canal Istanbul Project is evaluated according to basic motivations and claims of the PM, multi-perspective view through challenges and limitation that the project is likely to face with and speculations on implementation approach. The final discussion on the project is based on benefits/losses of Istanbul once the project will be implemented.

A mathematical model for describing the mechanical behaviour of root canal instruments.

Science.gov (United States)

Zhang, E W; Cheung, G S P; Zheng, Y F

2011-01-01

The purpose of this study was to establish a general mathematical model for describing the mechanical behaviour of root canal instruments by combining a theoretical analytical approach with a numerical finite-element method. Mathematical formulas representing the longitudinal (taper, helical angle and pitch) and cross-sectional configurations and area, the bending and torsional inertia, the curvature of the boundary point and the (geometry of) loading condition were derived. Torsional and bending stresses and the resultant deformation were expressed mathematically as a function of these geometric parameters, modulus of elasticity of the material and the applied load. As illustrations, three brands of NiTi endodontic files of different cross-sectional configurations (ProTaper, Hero 642, and Mani NRT) were analysed under pure torsion and pure bending situation by entering the model into a finite-element analysis package (ANSYS). Numerical results confirmed that mathematical models were a feasible method to analyse the mechanical properties and predict the stress and deformation for root canal instruments during root canal preparation. Mathematical and numerical model can be a suitable way to examine mechanical behaviours as a criterion of the instrument design and to predict the stress and strain experienced by the endodontic instruments during root canal preparation. © 2010 International Endodontic Journal.

Perfluoroalkyl substances in waters along the Grand Canal, China.

Science.gov (United States)

Piao, H T; Jiao, X C; Gai, N; Chen, S; Lu, G H; Yin, X C; Yamazaki, E; Yamashita, N; Tan, K Y; Yang, Y L; Pan, J

2017-07-01

The Grand Canal, also known as the Beijing-Hangzhou Grand Canal, is a UNESCO World Heritage Site and the longest canal in the world. It is an important trunk line of the South-to-North Water Diversion Project in China. The contamination status and spatial distributions of perfluoroalky substances (PFASs) in waters of the Grand Canal were investigated. The total concentrations of PFASs (∑PFASs) range from 7.8 ng/L to 218.0 ng/L, with high ∑PFASs occurring in the southern part of the Grand Canal which is located in a highly urbanized and economically developed region. The dominance of PFOA showed a decreasing trend toward north while shorter chain homologue proportions increased in the northern part of the Canal which mainly traverses underdeveloped and rural areas in Eastern China. Positive correlations were observed between ∑PFASs and the population density as well as GDP per capita. Intersection with large rivers may affect the contamination levels and composition of PFASs in the water of the Grand Canal near the intersection sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

A STUDY OF ROOT CANAL MORPHOLOGY OF Cebus apella TEETH ESTUDO ANATÔMICO DO CANAL RADICULAR DE DENTES DE Cebus apella

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Priscilla Rocha Afonso

2008-12-01

Full Text Available Realizou-se um estudo anatômico em dentes do Cebus apella, para análise da anatomia interna do canal radicular dessa espécie, normatizando seu uso como modelo experimental. Utilizaram-se doze animais adultos. Após a remoção do tecido orgânico, os dentes foram removidos, seccionados e fotografados, sendo analisados com um estereomicroscópio. Os resultados mostraram que os dentes apresentaram características semelhantes às dos seres humanos, mas com algumas peculiaridades, tais como: a anatomia do canal radicular variou de oval para circular; nos caninos inferiores, os canais são semelhantes a um rim, o que reflete o contorno externo da raiz; nos molares superiores, os canais mesiobucal e distobucal são ovais, seguindo o contorno geral do dente. Os autores concluem que esta espécie pode ser utilizada como modelo em pesquisas odontológicas, principalmente em estudos do tratamento do sistema de canal radicular.

PALAVRAS-CHAVES: Anatomia, dentes, Cebus apella. An anatomic study of Cebus apella root teeth was performed to analyze the internal anatomy of permanent dentition, normalizing its use as experimental model endodontic research. Twelve adult animals were used in this study. After the removal of the organic tissue, the all teeth were removed, sectioned, analyzed and photographed with a stereomicroscope. The results showed that the anatomy of root canal of this species are similar to human dental anatomy, considering the shape, pathway and number of canals, but with some peculiarities, such as: the root canal anatomy varied from oval to circular; in the lower canines, the canals are resembled a kidney, reflecting the outside contour of the root; in the upper molars, the mesiobuccal and distobuccal canals are oval, following the general contour of the tooth. The authors conclude that this primate can be applied as models for study of root canal treatment in human beings, in special the upper central and lateral incisors

Computed tomography in lumbar canal stenosis

International Nuclear Information System (INIS)

Ohta, Shu; Baba, Itsushi; Ishida, Akihisa; Sumida, Tadayuki; Sasaki, Seishu

1984-01-01

Preoperative CT was done in 39 patients with lumbar canal stenosis. Marked symmetrical narrowing of the whole vertebral canal was seen in the group with nervous symptoms in the cauda equina. Deformed bilateral intervertebral joints were seen in the group with both nervous symptoms in the cauda equina and radicular sciatica. The lateral recess on the affected side was markedly narrowed by the projection of the upper and lower joints and herniation. In the group with radicular sciatica, the vertebral canal itself was not so narrowed, but the unilateral intervertebral joint was extremely deformed, causing a narrowing of the lateral recess. There were large differences in the angle of the left and right intervertebral joints. (Namekawa, K)

Multislice spiral computed tomography imaging in congenital inner ear malformations.

Science.gov (United States)

Ma, Hui; Han, Ping; Liang, Bo; Tian, Zhi-liang; Lei, Zi-qiao; Kong, Wei-jia; Feng, Gan-sheng

2008-01-01

The purpose of this study is to evaluate the usefulness of multislice spiral computed tomography (CT) in the diagnosis of congenital inner ear malformations. Forty-four patients with sensorineural hearing loss were examined on a Somatom Sensation 16 (Siemens) CT scanner. The 3-dimensional reconstructions and multiplanar reformation (MPR) were performed using the volume-rendering technique (VRT) on the workstation. Of the 44 patients examined for this study, 25 patients were found to be normal and 19 patients (36 ears) were diagnosed with congenital inner ear malformations. Of the malformations, the axial, MPR, and VRT images can all display the site and degree in 33 of the ears. Volume-rendering technique images were superior to the axial images in displaying the malformations in 3 ears with small lateral semicircular canal malformations. The common malformations were Michel deformity (1 ear), common cavity deformity (3 ears), incomplete partition I (3 ears), incomplete partition II (Mondini deformity) (5 ears), vestibular and semicircular canal malformations (14 ears), enlarged vestibular aqueduct (16 ears, 6 of which had other malformations), and internal auditory canal malformation (8 ears, all accompanied by other malformations). Multislice spiral CT allows a comprehensively assessment of various congenital inner ear malformations through high-quality MPR and VRT reconstructions. Volume-rendering technique images can display the site and degree of the malformation 3-dimensionally and intuitionisticly. This is very useful to the cochlear implantation.

Cell wall canals formed upon growth of Candida maltosa in the presence of hexadecane are associated with polyphosphates.

Science.gov (United States)

Zvonarev, Anton N; Crowley, David E; Ryazanova, Lubov P; Lichko, Lydia P; Rusakova, Tatiana G; Kulakovskaya, Tatiana V; Dmitriev, Vladimir V

2017-05-01

Canals are supramolecular complexes observed in the cell wall of Candida maltosa grown in the presence of hexadecane as a sole carbon source. Such structures were not observed in glucose-grown cells. Microscopic observations of cells stained with diaminobenzidine revealed the presence of oxidative enzymes in the canals. 4΄,6΄-diamino-2-phenylindole staining revealed that a substantial part of cellular polyphosphate was present in the cell wall of cells grown on hexadecane in condition of phosphate limitation. The content and chain length of polyphosphates were higher in hexadecane-grown cells than in glucose grown ones. The treatment of cells with yeast polyphosphatase PPX1 resulted in the decrease of the canal size. These data clearly indicated that polyphosphates are constituents of canals; they might play an important role in the canal structure and functioning. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

C-shaped root canal in a maxillary first molar: a case report.

Science.gov (United States)

Yilmaz, Z; Tuncel, B; Serper, A; Calt, S

2006-02-01

This case report presents an unusual C-shaped root canal system in a maxillary first molar tooth. Although C-shaped root canals are most frequently seen in the mandibular second molar, they may also appear in maxillary molars. A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars. The present case describes a C-shaped canal in the buccal root of a maxillary first molar. The endodontic access cavity displayed two canal orifices, one leading to the canal system in the buccal root, the other into the palatal root canal system. In the buccal root, what appeared to be the mesial and distal canals joined to form a single C-shaped canal. --Careful examination of radiographs and the internal anatomy of teeth is essential.-- The location and morphology of root canals should be identified at high magnification under the microscope.

Comparison among manual instruments and PathFile and Mtwo rotary instruments to create a glide path in the root canal preparation of curved canals.

Science.gov (United States)

Alves, Vanessa de Oliveira; Bueno, Carlos Eduardo da Silveira; Cunha, Rodrigo Sanches; Pinheiro, Sérgio Luiz; Fontana, Carlos Eduardo; de Martin, Alexandre Sigrist

2012-01-01

Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation. The goal of this study was to evaluate the occurrences of apical transportation and canal aberrations produced with different instruments used to create a glide path in the preparation of curved root canals, namely manual K-files (Dentsply Maillefer, Ballaigues, Switzerland) and PathFile (Dentsply Maillefer) and Mtwo (Sweden and Martina, Padua, Italy) nickel-titanium rotary files. The mesial canals of 45 mandibular first and second molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 3 groups with 15 canals each, and canal preparation was performed by an endodontist using #10-15-20 K-type stainless steel manual files (group M), #13-16-19 PathFile rotary instruments (group PF), and #10-15-20 Mtwo rotary instruments (group MT). The double digital radiograph technique was used, pre- and postinstrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the central axis of the canals were compared by superimposition through computerized analysis and with the aid of magnification. The specimens were analyzed by 3 evaluators, whose calibration was checked using the Kendall agreement test. No apical transportation or aberration in root canal morphology occurred in any of the teeth; therefore, no statistical analysis was conducted. Neither the manual instruments nor the PathFile or Mtwo rotary instruments used to create a glide path had any influence on the occurrence of apical transportation or produced any canal aberration. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Fractional-order mathematical model of an irrigation main canal pool

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Shlomi N. Calderon-Valdez

2015-09-01

Full Text Available In this paper a fractional order model for an irrigation main canal is proposed. It is based on the experiments developed in a laboratory prototype of a hydraulic canal and the application of a direct system identification methodology. The hydraulic processes that take place in this canal are equivalent to those that occur in real main irrigation canals and the results obtained here can therefore be easily extended to real canals. The accuracy of the proposed fractional order model is compared by deriving two other integer-order models of the canal of a complexity similar to that proposed here. The parameters of these three mathematical models have been identified by minimizing the Integral Square Error (ISE performance index existing between the models and the real-time experimental data obtained from the canal prototype. A comparison of the performances of these three models shows that the fractional-order model has the lowest error and therefore the higher accuracy. Experiments showed that our model outperformed the accuracy of the integer-order models by about 25%, which is a significant improvement as regards to capturing the canal dynamics.

The bony labyrinth of the middle Pleistocene Sima de los Huesos hominins (Sierra de Atapuerca, Spain).

Science.gov (United States)

Quam, Rolf; Lorenzo, Carlos; Martínez, Ignacio; Gracia-Téllez, Ana; Arsuaga, Juan Luis

2016-01-01

fully resolved, the low placement of the posterior canal in Neandertals may be related to some combination of absolutely large brain size, a wide cranial base, and an archaic pattern of brain allometry. This more general explanation would not necessarily follow taxonomic lines, even though this morphology of the bony labyrinth occurs at high frequencies among Neandertals. While a functional interpretation of the relatively small vertical canals in the Neandertal clade remains elusive, the relative proportions of the semicircular canals is one of several derived Neandertal features in the Atapuerca (SH) crania. Examination of additional European middle Pleistocene specimens suggests that the full suite of Neandertal features in the bony labyrinth did not emerge in Europe until perhaps <200 kya. Copyright © 2015 Elsevier Ltd. All rights reserved.

THE EVOLUTION OF CANALIZATION AND THE BREAKING OF VON BAER'S LAWS: MODELING THE EVOLUTION OF DEVELOPMENT WITH EPISTASIS.

Science.gov (United States)

Rice, Sean H

1998-06-01

Evolution can change the developmental processes underlying a character without changing the average expression of the character itself. This sort of change must occur in both the evolution of canalization, in which a character becomes increasingly buffered against genetic or developmental variation, and in the phenomenon of closely related species that show similar adult phenotypes but different underlying developmental patterns. To study such phenomena, I develop a model that follows evolution on a surface representing adult phenotype as a function of underlying developmental characters. A contour on such a "phenotype landscape" is a set of states of developmental characters that produce the same adult phenotype. Epistasis induces curvature of this surface, and degree of canalization is represented by the slope along a contour. I first discuss the geometric properties of phenotype landscapes, relating epistasis to canalization. I then impose a fitness function on the phenotype and model evolution of developmental characters as a function of the fitness function and the local geometry of the surface. This model shows how canalization evolves as a population approaches an optimum phenotype. It further shows that under some circumstances, "decanalization" can occur, in which the expression of adult phenotype becomes increasingly sensitive to developmental variation. This process can cause very similar populations to diverge from one another developmentally even when their adult phenotypes experience identical selection regimes. © 1998 The Society for the Study of Evolution.

Radiographic evaluation of the course and visibility of the mandibular canal

International Nuclear Information System (INIS)

Jung, Yun Hoa; Cho, Bong Hae

2014-01-01

This study was performed to investigate the course of the mandibular canal on panoramic radiography and the visibility of this canal on both panoramic radiography and cone-beam computed tomography (CBCT). The study consisted of panoramic radiographs and CBCT images from 262 patients. The course of the mandibular canal, as seen in panoramic radiographs, was classified into four types: linear, elliptical, spoon-shaped, and turning curves. The visibility of this canal from the first to the third molar region was evaluated by visually determining whether the mandibular canal was clearly visible, probably visible, or invisible. The visibility of the canal on panoramic radiographs was compared with that on CBCT images. Elliptical curves were most frequently observed along the course of the mandibular canal. The percentage of clearly visible mandibular canals was the highest among the spoon-shaped curves and the lowest among the linear curves. On panoramic radiographs, invisible mandibular canals were found in 22.7% of the examined sites in the first molar region, 11.8% in the second molar region, and 1.3% in the third molar region. On CBCT cross-sectional images, the mandibular canal was invisible in 8.2% of the examined sites in the first molar region, 5.7% in the second molar region, and 0.2% in the third molar region. The visibility of this canal was lower in the first molar region than in the third molar region. The mandibular canal presented better visibility on CBCT images than on panoramic radiographs.

About ecological aspects of "Eurasia" canal construction

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G. M. Abdurakhmanov

2010-01-01

Full Text Available Ecological aspects of "Eurasia" canal construction are considered here. The fact that can negatively affect natural area preservation (preserves, reserves, located in Kumo-Manych depression, along where the canal construction will take place, is shown in this article.

The effects of betahistine in addition to epley maneuver in posterior canal benign paroxysmal positional vertigo.

Science.gov (United States)

Guneri, Enis Alpin; Kustutan, Ozge

2012-01-01

The purpose of this study is to evaluate the effects of betahistine in addition to Epley maneuver on the quality of life of patients with posterior semicircular canal benign paroxysmal positional vertigo (BPPV) of the canalithiasis type. Double-blind, randomized, controlled clinical trial. Academic university hospital. Seventy-two patients were enrolled in the study. The first group was treated with Epley maneuver only. The second group received placebo drug 2 times daily for 1 week in addition to Epley maneuver, and the third group received 24 mg betahistine 2 times daily for 1 week in addition to Epley maneuver. The effectiveness of the treatments was assessed in each group as well as between them by analyzing and comparing data of 4 different vertigo symptom scales. Epley maneuver, alone or combined with betahistine or placebo, was found to be very effective with a primary success rate of 86.2%. The symptoms were significantly reduced in group 3 patients overall, and those patients younger or older than 50 years of age who had hypertension, with symptom onset <1 month, and with attack duration of less than a minute did significantly better with the combination of betahistine 48 mg daily. Betahistine in addition to Epley maneuver is more effective than Epley maneuver alone or combined with placebo with regard to improvement of symptoms in certain patients. However, future clinical studies covering more patients to investigate the benefit of medical treatments in addition to Epley maneuver are needed.

MANAGEMENT OF LUMBAR SPINAL CANAL STENOSIS

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Mukhergee G. S

2016-06-01

degenerative. This process is most commonly localised to the facet joints and ligamentum flavum, with the resultant arthritic changes in the joints visible on radiographic studies. Frequently, these abnormalities are symmetrical and bilateral. The L4-L5 level is the most commonly involved, followed by L5-S1 and L3-L4 disc herniation and spondylolisthesis may exacerbate the narrowing further. 1. METHODS This study was taken up to evaluate the management of lumbar spinal canal stenosis cases. The study was conducted from May 2012 to October 2014: A total of 86 patients of 55-70 age groups with degenerative LCS were followed prospectively from May 2012 to October 2014. All the treatment methods were explained to patients and treatment method was determined by patient’s choice. The sample is divided into two groups 42 surgical and 44 conservative based on patient’s preference. MEASUREMENT OF OUTCOME Outcomes were measures of bodily pain and physical function on the medical outcomes study 36-item short-Form General Health Study (SF-36 22-25 and on the modified Oswestry Disability Index 26 measured at 6 weeks, 3 months, 6 months, and 1 year and 18 months. SF-36 scores range from 0 to 100 with higher scores indicating less severe symptoms. The Oswestry Disability Index ranges from 0 to 100, with lower scores indicating less severe symptoms. STUDY INTERVENTION The protocol surgery was standard posterior decompressive laminectomy operated by three surgeons. The type of nonsurgical care included physical therapy (68% of patients, epidural injections (56%, the use of anti-inflammatory drugs (55% and use of opioid analgesics (27%. Informed consent was taken from every patient after explaining the particulars of study interventions. In this study, 82% patients (n=70 were in age group 50-59 years with an average age of 50.2 years with a total sample size of 86 patients followed by 60-69 years age group. Both the surgical and conservative groups had similar sex distribution. Initially

Discharge Estimation in a Lined Canal Using Information Entropy

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Yen-Chang Chen

2014-03-01

Full Text Available This study applies a new method and technology to measure the discharge in a lined canal in Taiwan. An Acoustic Digital Current Meter mounted on a measurement platform is used to measure the velocities over the full cross-section for establishing the measurement method. The proposed method primarily employs Chiu’s Equation which is based on entropy to establish a constant ratio the relation between the maximum and mean velocities in an irrigation canal, and compute the maximum velocity by the observed velocity profile. In consequence, the mean velocity of the lined canal can be rapidly determined by the maximum velocity and the constant ratio. The cross-sectional area of the artificial irrigation canal can be calculated for the water stage. Finally, the discharge in the lined canal can be efficiently determined by the estimated mean velocity and the cross-sectional area. Using the data of discharges and stages collected in the Wan-Dan Canal, the correlation of stage and discharge is also developed for remote real-time monitoring and estimating discharge from the pumping station. Overall, Chiu’s Equation is demonstrated to reliably and accurately measure discharge in a lined canal, and can serve as reference for future calibration for a stage-discharge rating curve.

ROOT CANAL IRRIGANTS AND IRRIGATION TECHNIQUES: A REVIEW

OpenAIRE

Aniketh; Mohamed; Geeta; Nandakishore; Gourav Kumar; Patrick Timothy; Jayson Mathew; Sahle Abdul

2015-01-01

Root canal irrigation is not much emphasised in endodontic therapy. Most articles discussed are on root canal shaping and obturation not much emphasis is given for irrigation. There are many irrigation solutions which are introduced into market. The primary objective of root canal therapy is the ret ention of the pulpless or pulpally involved tooth with its associated periapical tissues in a healthy state. Achievement of this objective requires that the pulpal spaces and con...

Maxillary second molar with four roots and five canals

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Xinjia Sha

2018-06-01

Full Text Available In this case report, we present a maxillary second molar variant, which had two palatal roots with two canals and two buccal roots with three canals, including a second mesiobuccal canal. A 44-year-old female patient complained about a tooth crown fracture and severe pain in her right maxillary second molar. A clinical intraoral inspection and radiography were carried out on the tooth, and a diagnosis of chronic apical periodontitis was made. Four roots (two buccal and two palatal and five canals (three buccal and two palatal were found. The anatomical variation of the tooth was further confirmed by cone-beam computed tomography, a cone-fit procedure, and a radiograph with a shifted projection angle. Root-canal treatment was performed under an endodontic microscope.

Root canal treatment and special needs patients.

Science.gov (United States)

Yap, E; Parashos, P; Borromeo, G L

2015-04-01

To identify current trends of root canal treatment for patients with special needs. A postal questionnaire was sent to General Dentists in Victoria, Australia and Endodontists and Special Needs Dentists across Australia to determine the extent of root canal treatment performed on special needs patients. Over a four-month period, 1120 questionnaires were distributed with an overall response rate of 63.9% (n = 716). Response rates were 63.2% (n = 655), 68.5% (n = 50) and 100.0% (n = 11) amongst General Dentists, Endodontists and Special Needs Dentists, respectively. Endodontists (95.7%) and Special Needs Dentists (100.0%) performed significantly more root canal treatment on adult patients with special needs compared with 51.2% of General Dentists, (P special needs patients compared with only 29.7% of General Dentists (P special needs patients was more likely to be carried out by specialist dental practitioners who were more likely to utilize a pharmacological approach for behaviour guidance and to perform single-visit root canal treatment compared with General Dentists. A multidisciplinary approach for special needs patients who require root canal treatment provides an opportunity for these patients to retain their dentition. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Effect of the Presence of Semi-circular Cylinders on Heat Transfer From Heat Sources Placed in Two Dimensional Channel

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Ahmed W. Mustava

2013-04-01

Full Text Available The effect of a semi-circular cylinders in a two dimensional channel on heat transfer by forced convection from two heat sources with a constant temperature has been studied numerically. Each channel contains two heat sources; one on the upper surface of the channel and the other on the lower surface of the channel. There is semi-circular cylinder under the source in upper surface and there is semi-circular cylinder above the source in lower surface. The location of the second heat source with its semi-cylinder has been changed and keeps the first source with its semi- cylinder at the same location. The flow and temperature field are studied numerically with different values of Reynolds numbers and for different spacing between the centers of the semi-cylinders. The laminar flow field is analyzed numerically by solving the steady forms of the two-dimensional incompressible Navier- Stokes and energy equations.  The Cartesian velocity components and pressure on a collocated (non-staggered grid are used as dependent variables in the momentum equations, which discretized by finite volume method, body fitted coordinates are used to represent the complex channel geometry accurately, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass.  The range of Reynolds number is (Re= 100 – 800 and the range of the spacing between the semi-cylinders is(1-4 and the Prandtl number is 0.7.The results showed that increasing the spacing between the semi-cylinders increases the average of Nusselt number of the first heat source for all Reynolds numbers. As well as the results show that the best case among the cases studied to enhance the heat transfer is when the second heat source and its semi-cylinder located on at the distance (S=1.5 from the first half of the cylinder and the Reynolds number is greater than (Re ≥ 400 because of the

An endodontic management of mandibular third molar with five root canals

OpenAIRE

Dakshita Joy Sinha; Ashish Amit Sinha

2014-01-01

The existence of several anatomical variations in the root canal system may contribute to failure of the root canal therapy. The planning and performing of endodontic therapy requires knowledge of the internal dental morphology. This paper reports the case of a left mandibular third molar that presented with five root canals; a case of unusual root canal morphology so as to demonstrate the anatomic variations in mandibular third molars. Root canal therapy and case management are described. Th...

The Effect of Canal Contamination with Saliva on Apical Sealing

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S Sabaghi

2014-08-01

Full Text Available Introduction: Root canal obturation aims at sealing the root canal system to prevent re-contamination of canal and periapical space. Presence of moisture in canal before obturation may posit a negative effect on the quality of canal sealing. Therefore, this study was conducted to investigate the effect of canal contamination with saliva on apical microleakage. Methods: In this laboratory study, 58 human uni-root teeth were cleaned and shaped for obturation with gutta percha and sealer AH26. In the case group, specimens were contaminated with human saliva immediately before obturation, whereas the teeth in the control group were kept dry. All canals were filled by lateral condensation technique. Moreover, the teeth were placed in methylene blue dye for 3 days. Dye penetration was measured using a stereomicrosope. As a matter of fact, the study data were analyzed via utilizing t-test. Results: A significant difference was found between the two groups in regard with the apical leakage(P<0.001. The microleakage mean of dye in the dry group was 3/48mm, whereas it was 6/36mm in the saliva contaminated group. Conclusion: The study findings revealed that complete drying of canal can improve apical sealing.

An endodontic management of mandibular third molar with five root canals

Directory of Open Access Journals (Sweden)

Dakshita Joy Sinha

2014-01-01

Full Text Available The existence of several anatomical variations in the root canal system may contribute to failure of the root canal therapy. The planning and performing of endodontic therapy requires knowledge of the internal dental morphology. This paper reports the case of a left mandibular third molar that presented with five root canals; a case of unusual root canal morphology so as to demonstrate the anatomic variations in mandibular third molars. Root canal therapy and case management are described. This report highlights the importance of looking for additional roots and root canals so as to enable clinicians to treat a case successfully, which might have ended in failure.

Optimizing the chemical aspect of root canal irrigation

OpenAIRE

de Macedo, R.G.

2013-01-01

Root canal treatment is aimed at the removal of inflamed and infected tissue present in the root canal system. It will prevent the entrance of new microorganisms or nutrients in order to maintain or create a healthy environment around the root. There is sufficient evidence that shows that traditional endodontic therapy cannot make the root canal system completely free of bacteria. Moreover, it may not always result in complete healing of apical periodontitis, highlighting the need of optimizi...

Magnetic resonance imaging of the internal auditory canal

International Nuclear Information System (INIS)

Daniels, D.L.; Herfkins, R.; Koehler, P.R.; Millen, S.J.; Shaffer, K.A.; Williams, A.L.; Haughton, V.M.

1984-01-01

Three patients with exclusively or predominantly intracanalicular neuromas and 5 with presumably normal internal auditory canals were examined with prototype 1.4- or 1.5-tesla magnetic resonance (MR) scanners. MR images showed the 7th and 8th cranial nerves in the internal auditory canal. The intracanalicular neuromas had larger diameter and slightly greater signal strength than the nerves. Early results suggest that minimal enlargement of the nerves can be detected even in the internal auditory canal

Quantifying canal leakage rates using a mass-balance approach and heat-based hydraulic conductivity estimates in selected irrigation canals, western Nebraska, 2007 through 2009

Science.gov (United States)

Hobza, Christopher M.; Andersen, Michael J.

2010-01-01

The water supply in areas of the North Platte River Basin in the Nebraska Panhandle has been designated as fully appropriated or overappropriated by the Nebraska Department of Natural Resources (NDNR). Enacted legislation (Legislative Bill 962) requires the North Platte Natural Resources District (NPNRD) and the NDNR to develop an Integrated Management Plan (IMP) to balance groundwater and surface-water supply and demand in the NPNRD. A clear understanding of the groundwater and surface-water systems is critical for the development of a successful IMP. The primary source of groundwater recharge in parts of the NPNRD is from irrigation canal leakage. Because canal leakage constitutes a large part of the hydrologic budget, spatially distributing canal leakage to the groundwater system is important to any management strategy. Surface geophysical data collected along selected reaches of irrigation canals has allowed for the spatial distribution of leakage on a relative basis; however, the actual magnitude of leakage remains poorly defined. To address this need, the U.S. Geological Survey, in cooperation with the NPNRD, established streamflow-gaging stations at upstream and downstream ends from two selected canal reaches to allow a mass-balance approach to be used to calculate daily leakage rates. Water-level and sediment temperature data were collected and simulated at three temperature monitoring sites to allow the use of heat as a tracer to estimate the hydraulic conductivity of canal bed sediment. Canal-leakage rates were estimated by applying Darcy's Law to modeled vertical hydraulic conductivity and either the estimated or measured hydraulic gradient. This approach will improve the understanding of the spatial and temporal variability of canal leakage in varying geologic settings identified in capacitively coupled resistivity surveys. The high-leakage potential study reach of the Tri-State Canal had two streamflow-gaging stations and two temperature monitoring

Maxillary First Molars with 2 Distobuccal Canals: A Case Series.

Science.gov (United States)

Fogel, Howard M; Cunha, Rodrigo Sanches

2017-11-01

An appreciation of the anatomic complexity of the root canal system is essential at every step of endodontic treatment. Endodontic treatment of teeth with unusual root canal anatomy presents a unique challenge. Eight patients underwent nonsurgical root canal treatment of 3-rooted maxillary first molars in a specialty endodontic private practice. Four cases of Weine type II and 4 cases of Weine type III canal configurations in the distobuccal root of maxillary first molars were presented.This article highlighted an uncommon anatomic variation of 2 canals in the distobuccal root of the maxillary first molar. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Assessment of bifid and trified mandicular canals using cone beam computed tomography

Energy Technology Data Exchange (ETDEWEB)

Rashsyren, Oyuntugs [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Mongolian National University Medical Science, Ulaanbaatar (United States); Choi, Jin Woo; Han, Won Jeong; Kim Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

2014-09-15

To investigate the prevalence of bifid and trifid mandibular canals using cone-beam computed tomography (CBCT) images, and to measure their length, diameter, and angle. CBCT images of 500 patients, involving 755 hemi-mandibles, were used for this study. The presence and type of bifid mandibular canal was evaluated according to a modified classification of Naitoh et al. Prevalence rates were determined according to age group, gender, and type. Further, their diameter, length, and angles were measured using PACSPLUS Viewer and ImageJ 1.46r. Statistical analysis with chi-squared and analysis of variance (ANOVA) tests was performed. Bifid and trifid mandibular canals were found in 22.6% of the 500 patients and 16.2% of the 755 sides. There was no significant difference between genders and among age groups. The retromolar canal type accounted for 71.3% of the identified canals; the dental canal type, 18.8%; the forward canal type, 4.1%; and the trifid canal type, 5.8%. Interestingly, seven cases of the trifid canal type, which has been rarely reported, were observed. The mean diameter of the bifid and trifid mandibular canals was 2.2 mm and that of the main mandibular canal was 4.3 mm. Their mean length was 16.9 mm; the mean superior angle was 149.2 degrees, and the mean inferior angle was 37.7 degrees. Bifid and trifid mandibular canals in the Korean population were observed at a relatively high rate through a CBCT evaluation, and the most common type was the retromolar canal. CBCT is suggested for a detailed evaluation of bifid and trifid mandibular canals before mandibular surgery.

A study of incisive canal using a cone beam computed tomography

International Nuclear Information System (INIS)

Kim, Gyu Tae; Hwang, Eui Hwan; Lee, Sang Rae

2004-01-01

To investigate the anatomical structure of the incisive canal radiographically by a cone beam computed tomography. 38 persons (male 26, female 12) were chosen to take images of maxillary anterior region in dental CT mode using a cone beam computed tomography. The tube voltage were 65, 67, and 70 kVp, the tube current was 7 mA, and the exposure time was 13.3 seconds. The FH plane of each person was parallel to the floor. The images were analysed on the CRT display. The mean length of incisive canal was 15.87 mm ± 2.92. The mean diameter at the side of palate and nasal fossa were 3.49 mm ± 0.76 and 3.89 mm ± 1.06, respectively. In the cross-sectional shape of incisive canal, 50% were round, 34.2% were ovoid, and 15.8% were lobulated. 87% of incisive canal at the side of nasal fossa have one canal, 10.4% have two canals, and 2.6% have three canals, but these canals were merged into one canal in the middle portion of palate. The mean angles of the long axis of incisive canal and central incisor to the FH plane were 110.3 ± 6.96 and 117.45 ± 7.41, respectively. The angles of the long axis of incisive canal and central incisor to the FH plane were least correlated (r 0.258). This experiment suggests that a cone beam computed radiography will be helpful in surgery or implantation on the maxillary incisive area.

A study of incisive canal using a cone beam computed tomography

Energy Technology Data Exchange (ETDEWEB)

Kim, Gyu Tae; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

2004-03-15

To investigate the anatomical structure of the incisive canal radiographically by a cone beam computed tomography. 38 persons (male 26, female 12) were chosen to take images of maxillary anterior region in dental CT mode using a cone beam computed tomography. The tube voltage were 65, 67, and 70 kVp, the tube current was 7 mA, and the exposure time was 13.3 seconds. The FH plane of each person was parallel to the floor. The images were analysed on the CRT display. The mean length of incisive canal was 15.87 mm {+-} 2.92. The mean diameter at the side of palate and nasal fossa were 3.49 mm {+-} 0.76 and 3.89 mm {+-} 1.06, respectively. In the cross-sectional shape of incisive canal, 50% were round, 34.2% were ovoid, and 15.8% were lobulated. 87% of incisive canal at the side of nasal fossa have one canal, 10.4% have two canals, and 2.6% have three canals, but these canals were merged into one canal in the middle portion of palate. The mean angles of the long axis of incisive canal and central incisor to the FH plane were 110.3 {+-} 6.96 and 117.45 {+-} 7.41, respectively. The angles of the long axis of incisive canal and central incisor to the FH plane were least correlated (r 0.258). This experiment suggests that a cone beam computed radiography will be helpful in surgery or implantation on the maxillary incisive area.

Bilateral duplication of the internal auditory canal

International Nuclear Information System (INIS)

Weon, Young Cheol; Kim, Jae Hyoung; Choi, Sung Kyu; Koo, Ja-Won

2007-01-01

Duplication of the internal auditory canal is an extremely rare temporal bone anomaly that is believed to result from aplasia or hypoplasia of the vestibulocochlear nerve. We report bilateral duplication of the internal auditory canal in a 28-month-old boy with developmental delay and sensorineural hearing loss. (orig.)

33 CFR 117.769 - Black Rock Canal.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Black Rock Canal. 117.769 Section 117.769 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.769 Black Rock Canal. The draws of the...

Radiographic versus electronic root canal working length determination

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Lumnije Kqiku

2011-01-01

Conclusions: The present ex vivo study showed that electronic root canal working length determination is not superior to radiographic methods. Both methods provided a good performance in determining the root canal working length.

46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Vessels transiting the Panama and Suez Canals. 69.7... MEASUREMENT OF VESSELS MEASUREMENT OF VESSELS General § 69.7 Vessels transiting the Panama and Suez Canals. (a... Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules of...

Evaluation of root canal morphology of human mandibular incisors in Yazd

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Tabrizi-zadeh M. Assistant Professor

2003-06-01

Full Text Available Statement of Problem: The main objective of endodontic therapy is chemomechanical cleansing of entire pulp cavity and its complete obturation with an inert material. During this procedure, the failure of detection and inadequate cleaning of a canal will result in failed endodontic therapy. Therefore, the dentist must have enough knowledge of root canal morphology to treat a tooth successfully."nAim: The aim of this study was to determine the number and type of root canals of mandibular incisor teeth."nMaterials and Methods: In order to do this in-vitro, descriptive study, 68 non-carious mandibular incisor teethj collected from different clinics in Yazd, were immersed in indian ink, decalcified and cleared."nResults: It was found that 55.9% of the teeth had two separate canals that in 5.5% of them, the canals"nmerged before' apical foramen. In 4.4% of these samples, two separate canals existed along the whole"nroot."nConclusion: Considering high percentage of two canals in lower mandibular incisors, during access preparation, more attempts in detection of the second canal, is emphasized.

Prevalence of the middle mesial canal in non surgical root canal treated mandibular first and second molars in a local military population

Science.gov (United States)

2016-06-13

or second mandibular molar), sex, and age. Materials and Methods Approximately 7, 000 dental records in paper chart format were reviewed at a...Army Post Graduate Dental School Douglas D. Lancaster, COL, DC 3 August 2016 Prevalence of the middle mesial canal in non-surgical root canal...Methods: 7000 dental records were reviewed for non-surgical root canals performed from October 1970 to October 2015. The data collected included

Effects of canal enlargement and irrigation needle depth on the cleaning of the root canal system at 3 mm from the apex

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Ho-Jin Moon

2012-02-01

Full Text Available Objectives The aim of this study was to test the hypothesis, that the effectiveness of irrigation in removing smear layer in the apical third of root canal system is dependent on the depth of placement of the irrigation needle into the root canal and the enlargement size of the canal. Materials and Methods Eighty sound human lower incisors were divided into eight groups according to the enlargement size (#25, #30, #35 and #40 and the needle penetration depth (3 mm from working length, WL-3 mm and 9 mm from working length, WL-9 mm. Each canal was enlarged to working length with Profile.06 Rotary Ni-Ti files and irrigated with 5.25% NaOCl. Then, each canal received a final irrigation with 3 mL of 3% EDTA for 4 min, followed by 5 mL of 5.25% NaOCl at different level (WL-3 mm and WL-9 mm from working length. Each specimen was prepared for the scanning electron microscope (SEM. Photographs of the 3mm area from the apical constriction of each canal with a magnification of ×250, ×500, ×1,000, ×2,500 were taken for the final evaluation. Results Removal of smear layer in WL-3 mm group showed a significantly different effect when the canal was enlarged to larger than #30. There was a significant difference in removing apical smear layer between the needle penetration depth of WL-3 mm and WL-9 mm. Conclusions Removal of smear layer from the apical portion of root canals was effectively accomplished with apical instrumentation to #35/40 06 taper file and 3 mm needle penetration from the working length.

Air-Leak Effects on Ear-Canal Acoustic Absorbance

Science.gov (United States)

Rasetshwane, Daniel M.; Kopun, Judy G.; Gorga, Michael P.; Neely, Stephen T.

2015-01-01

Objective: Accurate ear-canal acoustic measurements, such as wideband acoustic admittance, absorbance, and otoacoustic emissions, require that the measurement probe be tightly sealed in the ear canal. Air leaks can compromise the validity of the measurements, interfere with calibrations, and increase variability. There are no established procedures for determining the presence of air leaks or criteria for what size leak would affect the accuracy of ear-canal acoustic measurements. The purpose of this study was to determine ways to quantify the effects of air leaks and to develop objective criteria to detect their presence. Design: Air leaks were simulated by modifying the foam tips that are used with the measurement probe through insertion of thin plastic tubing. To analyze the effect of air leaks, acoustic measurements were taken with both modified and unmodified foam tips in brass-tube cavities and human ear canals. Measurements were initially made in cavities to determine the range of critical leaks. Subsequently, data were collected in ears of 21 adults with normal hearing and normal middle-ear function. Four acoustic metrics were used for predicting the presence of air leaks and for quantifying these leaks: (1) low-frequency admittance phase (averaged over 0.1–0.2 kHz), (2) low-frequency absorbance, (3) the ratio of compliance volume to physical volume (CV/PV), and (4) the air-leak resonance frequency. The outcome variable in this analysis was the absorbance change (Δabsorbance), which was calculated in eight frequency bands. Results: The trends were similar for both the brass cavities and the ear canals. ΔAbsorbance generally increased with air-leak size and was largest for the lower frequency bands (0.1–0.2 and 0.2–0.5 kHz). Air-leak effects were observed in frequencies up to 10 kHz, but their effects above 1 kHz were unpredictable. These high-frequency air leaks were larger in brass cavities than in ear canals. Each of the four predictor variables

C-SHAPED CONFIGURATION OF THE ROOT CANAL SYSTEM – PROBLEMS AND SOLUTIONS.

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Janet Kirilova

2014-06-01

Full Text Available Introduction: The patients with C-shaped configuration of the root canal system are definitely a problem in the everyday dental practice. The C-shaped configuration of the root canal can be seen in the mandibular and maxillary molars. The treatment of these teeth is very difficult. Purpose: To trace the treatment of clinical cases with C-shaped configuration of the root canal system. Material and methods: There are some different cases that are described with a C-shaped configuration of the root canal system with one, two, three and four separate root canals. Careful exploration of the floor of the pulp chamber, inspection with magnification, use of ultrasonic irrigation and a modified filling technique are of particular use. Results and Discussion: Clinical cases of a C-shaped pulp chamber and root canal system shows that this root canal aberration occurs in a wide variety and variability with a single root canal up to two, three and four separate root canals. The diameter of the root canal themselves also varies from very wide to such with a small diameter. Conclusions: Knowledge of the different anatomical variations will improve the endododntic practice of the general dental practitioners.

Canal transportation and centering ability of protaper and self-adjusting file system in long oval canals: An ex-vivo cone-beam computed tomography analysis.

Science.gov (United States)

Shah, Dipali Yogesh; Wadekar, Swati Ishwara; Dadpe, Ashwini Manish; Jadhav, Ganesh Ranganath; Choudhary, Lalit Jayant; Kalra, Dheeraj Deepak

2017-01-01

The purpose of this study was to compare and evaluate the shaping ability of ProTaper (PT) and Self-Adjusting File (SAF) system using cone-beam computed tomography (CBCT) to assess their performance in oval-shaped root canals. Sixty-two mandibular premolars with single oval canals were divided into two experimental groups ( n = 31) according to the systems used: Group I - PT and Group II - SAF. Canals were evaluated before and after instrumentation using CBCT to assess centering ratio and canal transportation at three levels. Data were statistically analyzed using one-way analysis of variance, post hoc Tukey's test, and t -test. The SAF showed better centering ability and lesser canal transportation than the PT only in the buccolingual plane at 6 and 9 mm levels. The shaping ability of the PT was best in the apical third in both the planes. The SAF had statistically significant better centering and lesser canal transportation in the buccolingual as compared to the mesiodistal plane at the middle and coronal levels. The SAF produced significantly less transportation and remained centered than the PT at the middle and coronal levels in the buccolingual plane of oval canals. In the mesiodistal plane, the performance of both the systems was parallel.

Shaping ability of several nickel–titanium systems in double-curved simulated canals

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Mothanna Alrahabi

2017-06-01

Conclusion: The iRaCe, ProTaper Next, Wave One, and TF systems preserved the original shape of the double-curved (S-shaped canal with minimum root canal transportation. These systems produced satisfactory root canal instrumentation in S-shaped canals.

Diagnosis of ossicular deformities and inner ear anomalies by high resolution CT scanning of the temporal bone

International Nuclear Information System (INIS)

Isono, Michio

1988-01-01

A comparative study was undertaken to determine the optimum slice thickness and slice gaps that can define the fine contour and continuity of the ossicles and the inner ear. Horizontal tomography was proved to be contributory enough to obtain the whole ossicular chains and the whole labyrinthine capsule. Comparison of 1.5 mm slice thickness / 1.5 mm slice gaps, 1.0 mm slice thickness / 1.0 mm slice gaps and 1.5 mm slice thickness / 1.0 mm slice gaps revealed that the last condition was optimal for demonstrating the ossicular chains, the first for the inner ear. A significant relationship was found between CT findings and surgical findings of ossicular chains in chronic otitis media and cholesteatoma. Radiological classification of the inner ear malformation, which was obtained by this method, were agenesis of the whole labyrinthine capsule, agenesis of the cochlea, slight protrusion of the cochlear growth, poor cochlear turning, agenesis of all the semicircular canals, anterior semicircular canals (s.c.) without posterior and lateral s.c., anterior s.c. without hypoplasia of posterior s.c. and aplasia of lateral s.c., and smallness of the vestibule. (author) 59 refs

Therapeutic approach to Gradenigo's syndrome: a case report

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Aspris Andreas

2010-05-01

Full Text Available Abstract Introduction Traditional management of Gradenigo's syndrome requires aggressive and radical surgery without any attempt to preserve hearing. Recent reports, however, describe a successful outcome after conservative surgical intervention without labyrinthectomy. A similar outcome has also been reported in patients who were only prescribed with antibiotics and did not undergo myringotomy. Case presentation We report the case of a 24-year-old Caucasian Greek woman with Gradenigo's syndrome who was treated by draining her petrous apex via an infralabyrithine approach between her posterior semicircular canal and the jugular bulb. Her inner ear was not sacrificed during the procedure. She presented pre-operatively with ipsilateral conductive hearing loss, which recovered completely four weeks after the surgery. Conclusions Patients with Gradenigo's syndrome may be successfully treated with a combination of long-term permanent drainage and ventilation of the apical cells with corresponding hearing preservation. This can be achieved via a combination of transmastoid, infralabyrinthine and suprajugular approaches, if such would be allowed by the anatomy of the region or if there is enough space between the posterior semicircular canal and the jugular bulb.

Diagnosis of ossicular deformities and inner ear anomalies by high resolution CT scanning of the temporal bone

Energy Technology Data Exchange (ETDEWEB)

Isono, Michio

1988-04-01

A comparative study was undertaken to determine the optimum slice thickness and slice gaps that can define the fine contour and continuity of the ossicles and the inner ear. Horizontal tomography was proved to be contributory enough to obtain the whole ossicular chains and the whole labyrinthine capsule. Comparison of 1.5 mm slice thickness / 1.5 mm slice gaps, 1.0 mm slice thickness / 1.0 mm slice gaps and 1.5 mm slice thickness / 1.0 mm slice gaps revealed that the last condition was optimal for demonstrating the ossicular chains, the first for the inner ear. A significant relationship was found between CT findings and surgical findings of ossicular chains in chronic otitis media and cholesteatoma. Radiological classification of the inner ear malformation, which was obtained by this method, were agenesis of the whole labyrinthine capsule, agenesis of the cochlea, slight protrusion of the cochlear growth, poor cochlear turning, agenesis of all the semicircular canals, anterior semicircular canals (s.c.) without posterior and lateral s.c., anterior s.c. without hypoplasia of posterior s.c. and aplasia of lateral s.c., and smallness of the vestibule. (author) 59 refs.

Report from the Panama Canal Stakeholder Working Group.

Science.gov (United States)

2013-03-01

This project assists the Texas Department of Transportation (TxDOT) in assessing the potential impacts of the Panama Canal expansion on Texas ports and the landside transportation system. TxDOT formed a Panama Canal Stakeholder Working Group (PCSWG) ...

Comparison of Curved Root Canals Prepared with Various Chelating Agents

Science.gov (United States)

2012-06-01

aqueous base (11). According to Bramante and Betti, instrumentation with NiTi hand files using EDTA caused greater deviation of the root canal from...15. Peters OA, Peters CI, Schonenberger K, Barbakow F. ProTaper rotary root canal preparation: effects of canal anatomy on final shape analysed by

Evolution of spinal cord injuries due to cervical canal stenosis without radiographic evidence of trauma (SCIWORET): a prospective study.

Science.gov (United States)

Lamothe, G; Muller, F; Vital, J-M; Goossens, D; Barat, M

2011-06-01

Traumatic spinal cord injuries on cervical canal stenosis represent a steadily increasing pathology, of which clinical and functional outcomes remain largely unknown. We present the results of a prospective study of 20 patients followed for one year who had presented with traumatic spinal cord injury involving initially acute neurological symptoms and cervical canal stenosis defined in the imaging by a Torg ratio0.65, without vertebral fracture. Traumatic spinal cord injuries on cervical canal stenosis are caused mainly by falls in the elderly population and by unsafe behaviour among younger subjects. Most of the patients present with initially incomplete tetraplegia, and two thirds have centromedullary syndrome. Association of complete tetraplegia with advanced age would seem to be a predictive factor of death in the early post-traumatic period. For incomplete tetraplegics, the main phase of neurological and functional recovery is observed over the first six months. Radiological data and timing of surgery do not appear to affect the prognosis. This study underlines the need for individualized specialized care of patients with spinal cord injuries on cervical canal stenosis, particularly according to their demographic and lesional characteristics. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Morphometric study of the lumbar spinal canal in the Korean population.

Science.gov (United States)

Lee, H M; Kim, N H; Kim, H J; Chung, I H

1995-08-01

The anatomic dimensions of the vertebral body and spinal canal of the lumbar spine were analyzed in Koreans. To determine the normal dimension of the lumbar spinal canal in Koreans, to determine whether there are any racial differences in the morphometry of the lumbar spinal canal, and to provide criteria for diagnosing spinal stenosis in the Far Eastern Asian. Some radiologic and anatomic studies have been conducted regarding the size of the lumbar spinal canal of whites and blacks in western and African countries. One-thousand-eight-hundred measurements were performed on the transverse and sagittal diameters of vertebral bodies and spinal canals using complete sets of 90 lumbar vertebrae. The mean mid-sagittal diameter of the lumbar spinal canal in the Korean population was less than that measured in white and African populations, but there was no significant differences between the Korean, white, and African populations regarding the transverse diameter of the lumbar spinal canal. The mid-sagittal diameter of the lumbar spinal canal is narrowest in the Far Eastern Asian population; the radiologic criteria of spinal stenosis should be reconsidered for these people.

Root Canal Configuration of Mandibular First and Second Premolars in an Iranian Population

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Nemat Eskandarzadeh

2007-08-01

Full Text Available

Background and aims. It is critical to have a proper knowledge of the normal anatomy of the pulp and its variations for the success of endodontic treatment. The aim of this study was to determine the canal configuration and the prevalence of C-shaped canals in mandibular first and second premolars in a North-Western Iranian population.

Materials and methods. A total of 163 extracted mandibular first and 103 mandibular second premolars were injected with India ink and demineralized . They were made clear and transparent with methyl salicylate and the anatomy of their canal(s was studied.

Results. The results showed that 98% of mandibular first premolars had one root, 2% had two roots, 70.6% had one canal, 27.8% had two canals, 1.2% had three canals and the prevalence of C-shaped canals was 2.4%. All mandibular second premolars had one root, 80.5% had one canal, 17.5% had two canals and the prevalence of C-shaped canals was 2%.

Conclusion. It is important that clinicians, before treatment of mandibular first and second premolars, pay complete attention to radiographs, have a true concept of the number of root(s and canal(s, and prepare a correct access cavitiy.

RETRATAMENTO ENDODÔNTICO: ESTUDO COMPARATIVO ENTRE TÉCNICA MANUAL, ULTRA-SOM E CANAL FINDER ENDODONTIC RETREATMENT: COMPARATIVE STUDY BETWEEN MANUAL TECHNIQUE, ULTRASONIC SCALER, AND CANAL FINDER

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Clovis Monteiro BRAMANTE

1998-01-01

Full Text Available Instrumentações manual, ultra-sônica e com Canal Finder foram utilizadas para retratamento de 30 dentes com canais obturados com guta-percha e óxido de zinco e eugenol. Avaliaram-se: 1. tempo gasto para a penetração inicial até o ápice; 2. tempo para completar a limpeza; 3. extrusão de material e 4. limpeza dos canais. O Canal Finder foi a técnica que propiciou melhor limpeza, seguida da manual e da ultra-sônica. A parede palatina do canal foi constantemente mais limpa do que a vestibular. Quanto à extrusão, a técnica de ultra-som foi a que propiciou mais extravasamento de material obturador.Endodontic retreatment of 30 teeth filled with guta percha and zinc oxide-eugenol was carried out using manual instrumentation, ultrasonic scaler, and the Canal Finder System. The following variables were evaluated: time spent to reach the apex; time spent to complete cleaning of the canal; apical extrusion of material; and cleanliness of the canals. Results showed the Canal Finder System as providing the highest level of cleanliness of the canal system; lingual walls were constantly cleaner than buccal walls; ultrasonic technique presented a greater degree of apical extrusion of filling material.

Comparative study of 6 rotary nickel-titanium systems and hand instrumentation for root canal preparation in severely curved root canals of extracted teeth.

Science.gov (United States)

Celik, Davut; Taşdemir, Tamer; Er, Kürşat

2013-02-01

Some improvements have been developed with new generations of nickel-titanium (NiTi) rotary instruments that led to their successful and extensive application in clinical practice. The purpose of this in vitro study was to compare the root canal preparations performed by using GT Series X and Twisted File systems produced by innovative manufacturing process with Revo-S, RaCe, Mtwo, and ProTaper Universal systems manufactured directly from conventional nitinol and with stainless steel K-Flexofile instruments. The mesiobuccal root canals of 140 maxillary first permanent molars that had between 30°-40° curvature angle and 4- to 9-mm curvature radius of the root canal were used. After root canal preparations made by using GT Series X, Twisted File, Revo-S, RaCe, Mtwo, and ProTaper Universal NiTi rotary systems and stainless steel K-Flexofile instruments, transportation occurred in the root canal, and alteration of working length (WL) was assessed by using a modified double-digital radiographic technique. The data were compared by the post hoc Tukey honestly significant difference test. NiTi rotary systems caused less canal transportation and alteration of WL than K-Flexofile instruments (P .05) except 2.5 mm from the WL. At this level ProTaper Universal system caused significant canal transportation (P ProTaper Universal rotary systems manufactured by traditional methods. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evolution of canals system linking the Vistula, Dnieper and Neman basins

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Brykala, Dariusz; Badziai, Vitali

2014-05-01

The aim of this study is to reconstruct landscape changes in the Polesie Region - one of the largest European swampy areas (Belarus), as a result of the creation and operation of a network of canals. From the 16th century efforts were undertaken to connect the Polish areas located in the drainage basins of the Black Sea and Baltic Sea with canals. Already in 1631 the Polish Sejm (parliament) approved the project to build a canal linking the River Berezina (Dnieper basin) with the River Neris (Neman basin). However, the complicated political and economic situation of the country did not allow doing this. Only in the second half of the 18th c. hetman Ogiński financed the construction of a canal linking the Dnieper and Neman basins. The canal connecting the River Szczara (Neman basin) with the River Jasiołda (Pripyat basin) was named after its creator - the Ogiński Canal. At the same time the construction of the Królewski (Royal) Canal linking the River Muchavets (Vistula basin) and the River Pina (Pripyat basin) was under way. The construction of the canal was completed in 1783. The winding channels of the Pina and Muchavets were straightened, and the numerous canals feeding the waterway system drained vast area of marshes and wetlands of the Polesia Region. The last element that connects the catchments of the Vistula and Neman is the Augustów Canal built in the years 1825-1839 (linking the catchments of the Biebrza and Neman). Numerous changes in political boundaries in the watershed area between the Black Sea and the Baltic Sea drainage basins caused the destruction of the hydraulic structures. All the analysed canals were completely destroyed during the two world wars. In the last 200 years the amount and type of locks and weirs has changed. For example, there were no weirs on the Royal Canal in the late 18th c., in the middle of the 19th c. there were 22 such structures, while now that number has gone down to 10. All canals were created for economic reasons

Effect of Instrument Design and Access Outlines on the Removal of Root Canal Obturation Materials in Oval-shaped Canals.

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Niemi, Tuomas K; Marchesan, Melissa A; Lloyd, Adam; Seltzer, Robert J

2016-10-01

The aim of this study was to compare the effectiveness of TRUShape (TS) instruments with ProFile Vortex Blue (VB) instruments for the removal of obturation materials during retreatment of single-canal mandibular premolars performed through 2 access outlines. Initial root canal treatment was completed through a contracted endodontic cavity (CEC) design. Canals were instrumented to an F2 ProTaper instrument, obturated with warm lateral condensation of gutta-percha with AH Plus sealer, and allowed to set for 30 days at 37°C and 100% humidity. For retreatment, specimens were divided into 2 groups (n = 24) on the basis of access outline, CEC or traditional endodontic cavity (TEC). Retreatment was initiated by using ProTaper Retreatment instruments (D1-D3). Specimens were then stratified, further divided (n = 12), and reinstrumented up to TS 40 .06v or 40 .06 VB. Irrigation was performed by using 8.25% NaOCl and QMix 2in1. Retreatment time was recorded. Teeth were sectioned and photographed, and the percentage of remaining obturation materials was measured. Data were analyzed with Kruskal-Wallis analysis of variance for two-factor tests (α canal surface when compared with TEC-VB, CEC-TS, and TEC-TS (P ≤ .05). None of these other combinations were different from each other (P > .05). Significantly more time was required for retreatment with CEC-TS (27.68 ± 1.4 minutes) than the other groups (P root canal surface of mandibular premolars. However, in the presence of a CEC access design, using TS instruments removed more obturating material in single-rooted, oval-shaped canals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Root canal preparation in endodontics: conventional versus laser methods

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Goodis, Harold E.; White, Joel M.; Marshall, Sally J.; Marshall, Grayson W.; Moskowitz, Emrey

1992-06-01

Conventional cleaning and shaping of root canal systems employs hand and/or rotary instrumentation to remove the contents of the canal and shape the canal to receive a filling material. With the advent of the Nd:YAG laser system another method of accomplishing proper cleaning and shaping is evaluated. Single rooted teeth were radiographed bucco- lingually and mesio-distally and were divided into 2 groups. The first group was accessed and the root canal systems cleaned and shaped with a step back technique utilizing hand files and gates glidden burs. At completion of the procedure the teeth were again radiographed at the same positions as those prior to the procedure. The teeth were split longitudinally and examined under scanning electron microscopy to assess cleaning. The second group of teeth were accessed, and cleaning and shaping was accomplished using the Nd:YAG laser in combination with hand files and rotary instruments. These teeth were subjected to the same analysis as those in the first group. The before and after radiographs of each group were subjected to image analysis to determine effectiveness of the two methods in shaping the canal systems. We will discuss the ability of Nd:YAG to clean and shape root canal spaces and remove smear layer and organic tissue remnants from those areas.

ROUTING DEMAND CHANGES TO USERS ON THE WM LATERAL CANAL WITH SACMAN

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Most canals have either long travel times or insufficient in-canal storage to operate on-demand. Thus, most flow changes must be routed through the canal. Volume compensation has been proposed as a method for easily applying feedforward control to irrigation canals. SacMan (Software for Automated Ca...

MR determination of neonatal spinal canal depth.

Science.gov (United States)

Arthurs, Owen; Thayyil, Sudhin; Wade, Angie; Chong, W K Kling; Sebire, Neil J; Taylor, Andrew M

2012-08-01

Lumbar punctures (LPs) are frequently performed in neonates and often result in traumatic haemorrhagic taps. Knowledge of the distance from the skin to the middle of the spinal canal (mid-spinal canal depth - MSCD) may reduce the incidence of traumatic taps, but there is little data in extremely premature or low birth weight neonates. Here, we determined the spinal canal depth at post-mortem in perinatal deaths using magnetic resonance imaging (MRI). Spinal canal depth was measured in 78 post-mortem foetuses and perinatal cases (mean gestation 26 weeks; mean weight 1.04kg) at the L3/L4 inter-vertebral space at post-mortem MRI. Both anterior (ASCD) and posterior (PSCD) spinal canal depth were measured; MSCD was calculated and modelled against weight and gestational age. ASCD and PSCD (mm) correlated significantly with weight and gestational age (all r>0.8). A simple linear model MSCD (mm)=3×Weight (kg)+5 was the best fit, identifying an SCD value within the correct range for 87.2% (68/78) (95% CI (78.0, 92.9%)) cases. Gestational age did not add significantly to the predictive value of the model. There is a significant correlation between MSCD and body weight at post-mortem MRI in foetuses and perinatal deaths. If this association holds in preterm neonates, use of the formula MSCD (mm)=3×Weight (kg)+5 could result in fewer traumatic LPs in this population. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

MR determination of neonatal spinal canal depth

Energy Technology Data Exchange (ETDEWEB)

Arthurs, Owen, E-mail: owenarthurs@uk2.net [Centre for Cardiovascular MR, Great Ormond Street Hospital for Children, London WC1N 3JH (United Kingdom); Thayyil, Sudhin, E-mail: s.thayyil@ucl.ac.uk [Academic Neonatology, Institute for Women' s Health, London WC1E 6AU (United Kingdom); Wade, Angie, E-mail: a.wade@ucl.ac.uk [Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London (United Kingdom); Chong, W.K., E-mail: Kling.Chong@gosh.nhs.uk [Paediatric Neuroradiology, Great Ormond Street Hospital for Children, London (United Kingdom); Sebire, Neil J., E-mail: Neil.Sebire@gosh.nhs.uk [Histopathology, Great Ormond Street Hospital for Children, London WC1E 6AU (United Kingdom); Taylor, Andrew M., E-mail: a.taylor76@ucl.ac.uk [Centre for Cardiovascular MR, Cardiorespiratory Unit, Great Ormond Street Hospital for Children and UCL Institute of Cardiovascular Science, London WC1E 6AU (United Kingdom)

2012-08-15

Objectives: Lumbar punctures (LPs) are frequently performed in neonates and often result in traumatic haemorrhagic taps. Knowledge of the distance from the skin to the middle of the spinal canal (mid-spinal canal depth - MSCD) may reduce the incidence of traumatic taps, but there is little data in extremely premature or low birth weight neonates. Here, we determined the spinal canal depth at post-mortem in perinatal deaths using magnetic resonance imaging (MRI). Patients and methods: Spinal canal depth was measured in 78 post-mortem foetuses and perinatal cases (mean gestation 26 weeks; mean weight 1.04 kg) at the L3/L4 inter-vertebral space at post-mortem MRI. Both anterior (ASCD) and posterior (PSCD) spinal canal depth were measured; MSCD was calculated and modelled against weight and gestational age. Results: ASCD and PSCD (mm) correlated significantly with weight and gestational age (all r > 0.8). A simple linear model MSCD (mm) = 3 Multiplication-Sign Weight (kg) + 5 was the best fit, identifying an SCD value within the correct range for 87.2% (68/78) (95% CI (78.0, 92.9%)) cases. Gestational age did not add significantly to the predictive value of the model. Conclusion: There is a significant correlation between MSCD and body weight at post-mortem MRI in foetuses and perinatal deaths. If this association holds in preterm neonates, use of the formula MSCD (mm) = 3 Multiplication-Sign Weight (kg) + 5 could result in fewer traumatic LPs in this population.

CANAL user's manual

International Nuclear Information System (INIS)

Faya, A.; Wolf, L.; Todreas, N.

1979-11-01

CANAL is a subchannel computer program for the steady-state and transient thermal hydraulic analysis of BWR fuel rod bundles. The purpose of this manual is to introduce the user into the mechanism of running the code by providing information about the input data and options

GEOPOLITICS AND TRANSPORTATION. UNITED STATES AND PANAMA CANAL

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Benea Ciprian Beniamin

2009-05-01

Full Text Available This article presents the great connection which exists between the realization of Panama Canal and the rising power on United States; and how this state, after the construction of this canal, could promote efficiently at global level its interests.

Child Development in the Context of Adversity: Experiential Canalization of Brain and Behavior

Science.gov (United States)

Blair, Clancy; Raver, C. Cybele

2012-01-01

The authors examine the effects of poverty-related adversity on child development, drawing upon psychobiological principles of experiential canalization and the biological embedding of experience. They integrate findings from research on stress physiology, neurocognitive function, and self-regulation to consider adaptive processes in response to…

SCADA system with predictive controller applied to irrigation canals

OpenAIRE

Figueiredo, João; Botto, Miguel; Rijo, Manuel

2013-01-01

This paper applies a model predictive controller (MPC) to an automatic water canal with sensors and actuators controlled by a network (programmable logic controller), and supervised by a SCADA system (supervisory control and a data acquisition). This canal is composed by a set of distributed sub-systems that control the water level in each canal pool, constrained by discharge gates (control variables) and water off-takes (disturbances). All local controllers are available through an industria...

Endodontic management of a mandibular first molar with six root canal systems.

Science.gov (United States)

Jain, Dilip; Reddy, Smitha; Venigalla, Bhuvan Shome; Kamishetty, Shekhar

2015-01-01

Internal anatomy of pulp is complex. The first mandibular molars typically have two roots, one mesial with two root canals and another distal root, which contains one or two canals. A 20-year-old female patient reported with intermittent pain and incomplete root canal treatment in left lower back region since 1-week. Refined access cavity revealed initially two canals in mesial and two canals in the distal root. With operating microscope and cone beam computerized tomography, two additional canals (L-mesio-buccal and B-mesio-lingual) were identified in mesial root. One-year follow-up showed patient was asymptomatic and complete healing of periapical radiolucency.

Topographical evaluation of the mandibular canal through panoramic radiograph

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Ingrid Macedo Oliveira

2016-10-01

Full Text Available The mandibular canal is located inside the body of the mandible and may have anatomical variations. The topographic knowledge of the mandibular canal by the Dental surgeons is fundamental to achieving success in surgical planning, anesthetics and clinical interventions involving the jaw. To study the anatomy of the mandibular canal through panoramic radiographs. A retrospective descriptive study, developed after review and approval by the Ethics and Research Committee with the number of opinion 431095. Were analyzed 252 panoramic radiographs of patients of male and female attended in dental clinics UNINOVAFAPI University Center, Teresina-Pi, Brazil. The radiographs were analyzed with the aid of a light box and each antimere the jaw was observed separately. The classification of Nortjé and Langlais for description of the topography of the mandibular canal were used. Descriptive statistical analysis was performed with SPSS version 18.0. There was a prevalence of 38.89% in both antimeres, of mandibular channel the Type II. The type IV was present in 25.4% in the right hemi-arch and 26.6% on the left. Mandibular canal with unilateral bifurcation was observed in 0.77% of the sample and molar straight channel has not been identified. We observed anatomical variations as for the number and path, of the mandibular canal with the highest prevalence of Types II and IV, and the absence of bifurcations. Most was mandibular channels showed no bifurcation. The panoramic radiograph showed up an aid important to identify the mandibular canal and its variations.

Cervical spinal canal narrowing and cervical neurologi-cal injuries

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ZHANG Ling

2012-04-01

Full Text Available 【Abstract】Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms in-cluding neck pain, headache, weakness and parasthesisas. According to previous and recent clinical researches, we investigated the geometric parameters of normal cervical spinal canal including the sagittal and transverse diameters as well as Torg ratio. The mean sagittal diameter of cervical spinal canal at C 1 to C 7 ranges from 15.33 mm to 20.46 mm, the mean transverse diameter at the same levels ranges from 24.45 mm to 27.00 mm and the mean value of Torg ratio is 0.96. With respect to narrow cervical spinal canal, the following charaterstics are found: firstly, extension of the cervical spine results in statistically significant stenosis as compared with the flexed or neutral positions; secondly, females sustain cervical spinal canal narrowing more easily than males; finally, the consistent narrowest cervical canal level is at C 4 for all ethnicity, but there is a slight variation in the sagittal diameter of cervical spinal stenosis (≤14 mm in Whites, ≤ 12 mm in Japanese, ≤13.7 mm in Chinese. Narrow sagittal cervical canal diameter brings about an increased risk of neurological injuries in traumatic, degenerative and inflam-matory conditions and is related with extension of cervical spine, gender, as well as ethnicity. It is hoped that this re-view will be helpful in diagnosing spinal cord and neuro-logical injuries with the geometric parameters of cervical spine in the future. Key words: Spinal cord injuries; Spinal stenosis; Trauma, nervous system

[Diagnostic value of high-resolution computed tomography imaging in congenital inner ear malformations].

Science.gov (United States)

Sun, Xiaowei; Ding, Yuanping; Zhang, Jianji; Chen, Ying; Xu, Anting; Dou, Fenfen; Zhang, Zihe

2007-02-01

To observe the inner ear structure with volume rendering (VR) reconstruction and to evaluate the role of high-resolution computed tomography (HRCT) in congenital inner ear malformations. HRCT scanning was performed in 10 patients (20 ears) without ear disease (control group) and 7 patients (11 ears) with inner ear malformations (IEM group) and the original data was processed with VR reconstruction. The inner ear osseous labyrinth structure in the images generated by these techniques was observed respectively in the normal ears and malformation ears. The inner ear osseous labyrinth structure and the relationship was displayed clearly in VR imaging in the control group,meanwhile, characters and degree of malformed structure were also displayed clearly in the IEA group. Of seven patients (11 ears) with congenital inner ear malformations, the axial, MPR and VR images can display the site and degree in 9 ears. VR images were superior to the axial images in displaying the malformations in 2 ears with the small lateral semicircular canal malformations. The malformations included Mondini deformity (7 ears), vestibular and semicircular canal malformations (3 ears), vestibular aqueduct dilate (7 ears, of which 6 ears accompanied by other malformations) , the internal auditory canal malformation (2 ears, all accompanied by other malformations). HRCT can display the normal structure of bone inner ear through high quality VR reconstructions. VR images can also display the site and degree of the malformations three-dimensionally and intuitively. HRCT is valuable in diagnosing the inner ear malformation.

A review of potential tsunami impacts to the Suez Canal

Science.gov (United States)

Finkl, C.; Pelinovsky, E.

2012-04-01

Destructive tsunamis in the eastern Mediterranean and Red seas, induced by earthquakes and/or volcanic activity, pose potential hazards to docked seaport shipping and fixed harbor infrastructure as well as to in-transit international shipping within the Suez Canal. Potential vulnerabilities of the Suez Canal to possible tsunami impacts are reviewed by reference to geological, historical, archaeoseismological, and anecdotal data. Tsunami catalogues and databases compiled by earlier researchers are perused to estimate potential return periods for tsunami events that could affect directly the Suez Canal and its closely associated operational infrastructures. Analysis of these various records indicates a centurial return period, or multiples thereof, for long-wave repetition that could generally affect the Nile Delta. It is estimated that tsunami waves 2 m high would have a breaking length about 5 km down Canal whereas a 10 m wave break would occur about 1 km into the Canal. Should a tsunami strike the eastern flanks of the Nile Delta, it would damage Egypt's maritime infrastructure and multi-national commercial vessels and military ships then using the Canal.

Study of mastoid canals and grooves in north karnataka human skulls.

Science.gov (United States)

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-08-01

This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding.

Shaping ability of nickel-titanium rotary instruments in curved root canals.

Science.gov (United States)

Talati, Ali; Moradi, Saeed; Forghani, Maryam; Monajemzadeh, Ali

2013-01-01

Disinfection and subsequent obturation of the root canal space require adequate mechanical enlargement of the canals. The purpose of this in vitro study was to compare the shaping ability of Mtwo, RaCe and Medin rotary instruments during the preparation of curved root canals. Sixty mesiobuccal root canals of mandibular molars with severe curvatures between 25-35(°) and radius of 4-9 mm were randomly divided into three groups of 20 canals each. Using pre- and post-instrumentation radiographs, straightening of the canal and the apical transportation were determined with AutoCAD software. The data were analyzed using Chi square, analysis of variance, and post-hoc tests and the significance level was set at P0.05). Under the conditions of this in vitro study, Mtwo instruments seemed superior to the two other rotary instruments.

Two-Rooted Maxillary First Molars with Two Canals: A Case Series

OpenAIRE

Shakouie, Sahar; Mokhtari, Hadi; Ghasemi, Negin; Gholizadeh, Seddigheh

2013-01-01

Thorough understanding of the anatomic and internal morphology of a root canal system is absolutely essential for the success of endodontic treatment. Since permanent maxillary first molars have shown variation in internal anatomy, morphology, this tooth has been reviewed extensively. Presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. In this report, three cases are presented, which involve the root canal...

Effect of Suez Canal Marine Sediment on Sorption of Cesium

International Nuclear Information System (INIS)

Hassan, H.B.

2016-01-01

Suez Canal is surrounded by navigation, industrial, agricultural activities and suffers from high rate of population growth that discharging waste into Suez Canal. The Suez Canal coastal waters are influenced by a complex variety of physical, geochemical and biological processes, which influence the behavior, transport and fate of containments released into the marine environment. Sorption of releasing containment such as cesium in Suez Canal water is investigated because of its toxic effect on the marine environment. The object of present study is to determine the effects some of physical and chemical characteristics of collected sediment samples from the three important locations on Suez Canal (Suez Bay, Bitter Lakes and El- Temsah Lake beaches) on sorption behavior of cesium by using batch experiment. Batch experiment was used to study the sorption of the cesium ion. The sorption process is dependent on mineral constituents of Suez Canal sediment and their characteristics. Analytical methods which included particle size and X-ray diffraction (XRD) analyses found that particle size of Suez Canal sediment samples is characterized by sand to fine sand and quartz is the main mineralogical species. Distribution coefficient (K d ) which represent geochemical processes and particle size of these sediment samples effect on the degree of cesium sorption to the sediment. Also (K d ) increase with increase cation exchangeable capacity (CEC). The Suez Canal sediment samples have low (K d ) values which effected by their physical and chemical properties. Sample (2) has highest distribution coefficient (K d ) between measured samples due to containing ratio 30% of fine sand and high ratio of organic matter.

Viperous fangs: development and evolution of the venom canal.

Science.gov (United States)

Zahradnicek, Oldrich; Horacek, Ivan; Tucker, Abigail S

2008-01-01

Fangs are specialised long teeth that contain either a superficial groove (Gila monster, Beaded lizard, some colubrid snakes), along which the venom runs, or an enclosed canal (viperid, elapid and atractaspid), down which the venom flows inside the tooth. The fangs of viperid snakes are the most effective venom-delivery structures among vertebrates and have been the focus of scientific interests for more than 200 years. Despite this interest the questions of how the canal at the centre of the fang forms remains unresolved. Two different hypotheses have been suggested. The mainstream hypothesis claims that the venom-conducting canal develops by the invagination of the epithelial wall of the developing tooth germ. The sides of this invagination make contact and finally fuse to form the enclosed canal. The second hypothesis, known as the "brick chimney", claims the venom-conducting canal develops directly by successive dentine deposition as the tooth develops. The fang is thus built up from the tip to the base, without any folding of the tooth surface. In an attempt to cast further light on this subject the early development of the fangs was followed in a pit viper, Trimeresurus albolabris, using the expression of Sonic hedgehog (Shh). We demonstrate that the canal is indeed formed by an early folding event, resulting from an invagination of epithelial cells into the dental mesenchyme. The epithelial cells proliferate to enlarge the canal and then the cells die by apoptosis, forming an empty tube through which the poison runs. The entrance and discharge orifices at either end of the canal develop by a similar invagination but the initial width of the invagination is very different from that in the middle of the tooth, and is associated with higher proliferation. The two sides of the invaginating epithelium never come into contact, leaving the orifice open. The mechanism by which the orifices form can be likened to that observed in reptiles with an open groove along

Kyphoplasty for osteoporotic fractures with spinal canal compromise

International Nuclear Information System (INIS)

Gan Minfeng; Yang Huilin; Zou Jun; Wang Genlin; Mei Xin; Zhou Feng; Chen Liang; Jiang Weimin

2010-01-01

Objective: To explore the feasibility and clinical outcome of kyphoplasty in the treatment of osteoporotic fractures with canal compromise. Methods: A total of 16 patients with osteoporotic fractures with canal compromise without neurological deficit were attempted to be treated by kyphoplasty. During kyphoplasty, modified techniques including staged bone cement injection and dynamic fluoroscopic monitoring were used. Pain was measured using the self-reporting Visual Analogue pain Scale (VAS) preoperatively, postoperatively and in the final follow-up. Disability was measured using the Oswestry Disability questionnaire (ODI) preoperatively, postoperatively and in the final follow-up. The height of the compromised vertebral body, the kyphotic angle and the spinal canal compromise were measured preoperatively, postoperatively and in the final follow-up. Results: Operations were completed smoothly, with the exception of one patient with less cement leakage but without clinical symptom occurred. Relief of pain was achieved after kyphoplasty. The mean VAS score of these patients decreased from 8.1 ± 1.2 pre-operatively to 2.7 ± 0.6 post-operatively (P 0.05). In the final follow-up, the spinal canal compromise was (14.4 ± 3.1)%. Conclusion: Kyphoplasty is a relatively safe and effective method for the treatment of osteoporotic fractures with canal compromise without neurological deficit. (authors)

Mechanics of the Panama Canal slides

Science.gov (United States)

Becker, George F.

1917-01-01

Dr. Becker visited the Canal Zone in 1913 as a geologist of the United States Geological Survey and since that time has given the problem the benefit of his study. His appointment as a member of the committee of the National Academy of Sciences has made it appropriate for his conclusions, based upon his personal observations and already reported in part to the Canal Commission, to be stated for the benefit of his associates and other American scientists and engineers.

Root canal treatment of a maxillary first premolar with three roots

OpenAIRE

Mathew, Josey; Devadathan, Aravindan; Syriac, Gibi; Shamini, Sai

2015-01-01

Successful root canal treatment needs a thorough knowledge of both internal and external anatomy of a tooth. Variations in root canal anatomy constitute an impressive challenge to the successful completion of endodontic treatment. Undetected extra roots and canals are a major reason for failed root canal treatment. Three separate roots in a maxillary first premolar have a very low incidence of 0.5?6%. Three rooted premolars are anatomically similar to molars and are sometimes called ?small mo...

CANAL code

International Nuclear Information System (INIS)

Gara, P.; Martin, E.

1983-01-01

The CANAL code presented here optimizes a realistic iron free extraction channel which has to provide a given transversal magnetic field law in the median plane: the current bars may be curved, have finite lengths and cooling ducts and move in a restricted transversal area; terminal connectors may be added, images of the bars in pole pieces may be included. A special option optimizes a real set of circular coils [fr

Endodontic management of radix paramolaris with six canals: a clinical case report.

Science.gov (United States)

Acharya, N; Singh, A; Samant, P S; Gautam, V

2013-01-01

Endodontic therapy of mandibular molars is a challenging task due to its varied root canal morphology. A mandibular first molar with additional buccal root (Radix paramolaris) and additional distolingual root (Radix Entomolaris) is an example of its varied anatomy. A successful management of atypical root canal configurations is an important aspect in determining the success rate of root canal therapy. The detail knowledge of the root morphology and canal anatomy allows the clinician for accurate location of the extra roots and canals and accordingly the refinement of the access cavity for the stress free entry of complex anatomy. Hence, for a successful root canal therapy, clinician must be aware of the external and internal anatomic variations .The aim of this clinical case report is to present and describe the unusual presence of two separate mesial roots and six root canals in mandibular first molar, detected during routine endodontic therapy.

Root canal morphology of primary molars: a micro-computed tomography study.

Science.gov (United States)

Fumes, A C; Sousa-Neto, M D; Leoni, G B; Versiani, M A; da Silva, L A B; da Silva, R A B; Consolaro, A

2014-10-01

This was to investigate the root canal morphology of primary molar teeth using micro-computed tomography. Primary maxillary (n = 20) and mandibular (n = 20) molars were scanned at a resolution of 16.7 μm and analysed regarding the number, location, volume, area, structured model index (SMI), area, roundness, diameters, and length of canals, as well as the thickness of dentine in the apical third. Data were statistically compared by using paired-sample t test, independent sample t test, and one-way analysis of variance with significance level set as 5%. Overall, no statistical differences were found between the canals with respect to length, SMI, dentine thickness, area, roundness, and diameter (p > 0.05). A double canal system was observed in the mesial and mesio-buccal roots of the mandibular and maxillary molars, respectively. The thickness in the internal aspect of the roots was lower than in the external aspect. Cross-sectional evaluation of the roots in the apical third showed flat-shaped canals in the mandibular molars and ribbon- and oval-shaped canals in the maxillary molars. External and internal anatomy of the primary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a thorough understanding of the morphological variations of root canals in primary molars to overcome problems related to shaping and cleaning procedures, allowing appropriate management strategies for root canal treatment.

Optimizing the chemical aspect of root canal irrigation

NARCIS (Netherlands)

de Macedo, R.G.

2013-01-01

Root canal treatment is aimed at the removal of inflamed and infected tissue present in the root canal system. It will prevent the entrance of new microorganisms or nutrients in order to maintain or create a healthy environment around the root. There is sufficient evidence that shows that

Forced extrusion for removal of impacted third molars close to the mandibular canal Extrusión forzada para extraer los terceros molares impactados cerca del canal mandibular

Directory of Open Access Journals (Sweden)

Dennis Flanagan DDS

2012-03-01

Full Text Available Impacted mandibular third molars can be located in close proximity to the mandibular canal. This creates a risk for the nerve or artery injury. These are contained in the canal. However, the impacted third molar can be moved coronally by orthodontic means, after removal of overlying bone, and safely extracted. The orthodontic intervention slowly moves the tooth apex away from the mandibular canal and reduces the potential for a neural injury. This method may be useful for older patients with root apices that approximate or are actually located in the mandibular canal. This technique needs further study. There is a theoretical potential for neural or arterial injury from physical contact of the tooth apex as it moves by or through the mandibular canal.Los terceros molares inferiores impactados pueden localizarse muy cerca del canal mandibular. Esto constituye un riesgo de lesión del nervio o la arteria, que se localizan dentro del canal. No obstante, el tercer molar impactado puede desplazarse en dirección coronal con ortodoncia, tras ostectomía del hueso suprayacente, y extraerse sin riesgos. La intervención ortodóncica desplaza lentamente el ápice del diente fuera del canal mandibular y reduce la posibilidad de lesión neural. Este método puede ser útil para pacientes de edad avanzada con ápices dentales que se aproximan o en realidad se localizan en el canal mandibular. La técnica necesita un estudio adicional. Hay la posibilidad teórica de lesión neural o arterial a partir del contacto físico del ápice del diente a medida que se desplaza a través del canal mandibular.

Three-dimensional analysis of mesiobuccal root canal of Japanese maxillary first molar using Micro-CT

International Nuclear Information System (INIS)

Yamada, Masashi; Ide, Yoshinobu; Matsunaga, Satoru; Kato, Hiroshi; Nakagawa, Kan-Ichi

2011-01-01

The objective of this study was to three-dimensionally observe the morphological characteristics of mesiobuccal root canals of Japanese maxillary first molars using microcomputed tomography (Micro-CT) and classify root canal variations. This study used 90 maxillary first molars. Three-dimensional reconstruction was performed using data obtained by Micro-CT, and cross-sections of the root canals were observed. Moreover, the root canal morphology was classified by the configuration and root canal diameter, and was evaluated for occurrence using the classification by Weine et al. (1969) as a reference. Overall, single root canals were observed in 44.4%, incomplete separation root canals in 22.3%, and completely separate root canals (upper and lower separation root canals) in 33.3%. Mesiobuccal root canals often had intricate configurations, and accessory root canals (lateral canals and apical ramifications) were observed in most of the mesiobuccal root canals (76.7%), irrespective of whether there were ramifications of the main root canals. While there were no marked differences in the incidence of root canal ramifications between this study and earlier reports, the incidence of accessory root canals was higher in this study. This result may be explained by the far more superior visualization ability of Micro-CT than conventional methods, which allowed the detection of microscopic apical ramifications previously difficult to observe. (author)

AFSC/ABL: Lynn Canal Overwinter Acoustic Survey, 2004-2005

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

Direct and CT measurements of canals and foramina of the skull base

International Nuclear Information System (INIS)

Berlis, A.; Schumacher, M.; Putz, R.

1992-01-01

This investigation is based on measurements of 60 macerated adult European skulls from the Alexander-Ecker Collection at the Anatomy Department of the University of Freiburg. Computer tomographical (CT) and anatomical measurements were compared to assess the accuracy of the CT representation of osseous structures. Nine structures were examined: the optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum,foramen Vesalii (venosum), carotid canal, internal auditory canal and hypoglossal canal. Results show a good and even excellent correlation if the cranial opening is approximately at a right angle to the scanline. For this reason, the results of the coronal examination of the internal auditory canal are less satisfactory, and the coronal and axial measurements of the hypoglossal canal show only a moderately good correlation. (author)

Three cases of tuberculous otitis media

International Nuclear Information System (INIS)

Oh, Jin Hwan; Sung, Ki Joon; Kim, Myung Soon; Kwon, Taek Sang; Yoon, Byoung Moon

1998-01-01

We report the imaging features of three cases of tuberculous otitis media. All three patients underwent temporal bone CT scanning, and in two, additional MRI scanning was performed. The three cases showed soft tissue density in the external auditory canal, and in two, destruction of the trabeculation and internal cortex of the mastoid bone was noted. In two patients with facial palsy, erosion of the facial canal was seen. On MRI, abundant granulomatous tissue was noted in the middle ear cavity and mastoid air cells. In one case, abnormal enhancement of the cochlea, and of the facial and eighth cranial nerve in the internal acoustic canal was seen. Another case showed enhancement of the vestibule and lateral semicircular canal. If radiologic evaluation of chronic otitis media reveals destruction of the tegmen and trabeculation of the mastoid bone, together with abundant granulation tissue and enhancement of the internal ear, tuberculous otitis media may be included in the differential diagnosis

Three cases of tuberculous otitis media

Energy Technology Data Exchange (ETDEWEB)

Oh, Jin Hwan; Sung, Ki Joon; Kim, Myung Soon; Kwon, Taek Sang; Yoon, Byoung Moon [Yonsei Univ. Wonju College of Medicine, Wonju (Korea, Republic of)

1998-07-01

We report the imaging features of three cases of tuberculous otitis media. All three patients underwent temporal bone CT scanning, and in two, additional MRI scanning was performed. The three cases showed soft tissue density in the external auditory canal, and in two, destruction of the trabeculation and internal cortex of the mastoid bone was noted. In two patients with facial palsy, erosion of the facial canal was seen. On MRI, abundant granulomatous tissue was noted in the middle ear cavity and mastoid air cells. In one case, abnormal enhancement of the cochlea, and of the facial and eighth cranial nerve in the internal acoustic canal was seen. Another case showed enhancement of the vestibule and lateral semicircular canal. If radiologic evaluation of chronic otitis media reveals destruction of the tegmen and trabeculation of the mastoid bone, together with abundant granulation tissue and enhancement of the internal ear, tuberculous otitis media may be included in the differential diagnosis.

On the ecological role of Copepoda in the Suez Canal marine ...

African Journals Online (AJOL)

Moreover, the importance of copepods in the marine food web and secondary productivity in the canal water, as well as their response to environmental variations in the Suez Canal ecosystem were discussed. KEY WORDS: Zooplankton, Copepoda, food web, marine ecosystem, Suez Canal Egyptian Journal of Biology ...

Root canal treatment of bilateral three-rooted maxillary first premolars

Directory of Open Access Journals (Sweden)

Bhavana Gandhi

2012-01-01

Full Text Available In endodontics, several anatomic variations occur in teeth, both externally and in the internal root morphology, which play a very significant role in the diagnosis and treatment outcome. A thorough knowledge of the root canal anatomy, careful interpretation of the angled radiographs, proper endodontic access cavity preparation, and exploration of the root canal are the prerequisites for endodontic success. In a maxillary first premolar, it is rare to find extra roots and canals, and the aim of the present article is to report a case about the successful diagnosis and clinical management of bilateral three-rooted maxillary first premolars, with three independent root canals.

Radioactivity level of the gamma emitters in Ismailia Canal environment

International Nuclear Information System (INIS)

Abdel Malik, W.E.Y.; Youssef, S.K.; Ibrahim, A.S.

1993-01-01

The activity level of the γ-emitting radionuclides was measured in the different component of Ismalia Canal (bottom sediment, biota and water) by γ-spectrometry. The average activity level of the dry samples ranged from 12 to 89 Bq/kg for the detected natural radionuclides. The annual external γ-dose to the living organisms in the canal, close to the sediment beds, was found to be in the range of 1.21±0.24 mSv/y and does not present any significant hazards when compared with the natural γ-ray background around the Ismalia Canal(IC) environment which ranges from 0.80 to 1.73 mSv/y. (orig.)

Radiographic analysis of odontogenic cysts showing displacement of the mandibular canal

International Nuclear Information System (INIS)

Cho, Bong Hae

2003-01-01

To assess the radiographic findings of odontogenic cysts showing displacement of the mandibular canal using computed tomographic (CT) and panoramic images. CT and panoramic images of 63 odontogenic cysts (27 dentigerous, 16 odontogenic keratocysts, and 20 radicular cysts) were analyzed to evaluate the following parameters: the dimension and shape of the cysts, and the effect of the cysts on the mandibular canal and cortical plates. Of the 63 cysts examined in the study, 35 (55.6%) showed inferior displacement of the mandibular canal and 46 (73.0%) showed perforation of the canal. There were statistically significant differenced between CT and panoramic images in depicting displacement and perforation of the mandibular canal. Cortical expansion was seen in 46 cases (73.0%) and cortical perforation in 23 cases (36.5%). The radicular cysts showed cortical expansion and perforation less frequently than the other cyst groups. Large cysts of mandible should be evaluated by multiplanar CT images in order to detect the mandibular canal and cortical bone involvement.

Root and Canal Morphology of Mandibular Third Molars in an Iranian Population

Directory of Open Access Journals (Sweden)

Maryam Kuzekanani

2012-06-01

Full Text Available Background and aims. A through knowledge of the root canal morphology is required for successful endodontic therapy. The aim of this study was to investigate the root and canal morphology of mandibular third molars in Kerman, a province in southeast of Iran. Materials and methods. One-hundred-fifty extracted mandibular third molars were collected randomly from different dental clinics in Kerman. The root canal anatomy and morphology of each tooth was carefully studied using a clearing technique. Root number and morphology, number of canals per root, root canal configuration according to Vertucci classification, and incidence of dilacerated roots and C-shaped canals in mandibular third molars were evaluated under stereomicroscope with ×2 to ×3 magnifications. Results. From the total of 150 mandibular third molars studied, 21% had one root. The majority of teeth (73% had two roots. 5.5% of the teeth had three roots. The incidence of C-shaped canal was 3.5% in this study and 8% of the teeth had at least one dilacerated root. Conclusion. Although root canal anatomy and morphology of mandibular third molars is very variable having two roots seems to be the normal anatomy for these teeth.

Postural strategies and sensory integration: no turning point between childhood and adolescence.

Directory of Open Access Journals (Sweden)

Sophie Mallau

Full Text Available In this study, we investigated the sensory integration to postural control in children and adolescents from 5 to 15 years of age. We adopted the working hypothesis that considerable body changes occurring during these periods may lead subjects to under-use the information provided by the proprioceptive pathway and over-use other sensory systems such as vision to control their orientation and stabilize their body. It was proposed to determine which maturational differences may exist between the sensory integration used by children and adolescents in order to test the hypothesis that adolescence may constitute a specific phase in the development of postural control. This hypothesis was tested by applying an original protocol of slow oscillations below the detection threshold of the vestibular canal system, which mainly serves to mediate proprioceptive information, to the platform on which the subjects were standing. We highlighted the process of acquiring an accurate sensory and anatomical reference frame for functional movement. We asked children and adolescents to maintain a vertical stance while slow sinusoidal oscillations in the frontal plane were applied to the support at 0.01 Hz (below the detection threshold of the semicircular canal system and at 0.06 Hz (above the detection threshold of the semicircular canal system with their eyes either open or closed. This developmental study provided evidence that there are mild differences in the quality of sensory integration relative to postural control in children and adolescents. The results reported here confirmed the predominance of vision and the gradual mastery of somatosensory integration in postural control during a large period of ontogenesis including childhood and adolescence. The youngest as well as the oldest subjects adopted similar qualitative damping and segmental stabilization strategies that gradually improved with age without reaching an adult's level. Lastly, sensory

Effectiveness of Various Irrigation Protocols in Removing Calcium Hydroxide from Root Canals

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Hakan Göktürk

2018-04-01

Full Text Available Objective: The purpose of this study was to investigate the removal efficiency of calcium hydroxide (CH by CanalBrush, Vibringe, laser-activated irrigation (LAI, conventional syringe irrigation (CSI, XP-endo Finisher, and passive ultrasonic irrigation (PUI in the root canal walls. Materials and Methods: Ninety-eight human mandibular premolar teeth were prepared. Root canals were filled with CH. The roots were divided into six experimental groups (n=15/group according to the irrigation protocol used: group 1 (CSI, group 2 (Vibringe, group 3 (CanalBrush, group 4 (XP-endo Finisher, group 5 (PUI, and group 6 (LAI. The amount of residual CH in the canal walls for each canal third was scored. Data were analysed by using Kruskal-Wallis and Bonferroni-correction Mann-Whitney U tests. Results: None of the investigated protocols renders the root canal walls free of CH remnants. Significant differences were found between tooth regions in terms of CH removal (p<0.05, and all groups except group 6 (LAI showed more residual CH in the apical region. PUI and LAI eliminated significantly more CH than CSI from the middle and apical thirds of the root canal, respectively. Conclusion: The activation of sodium hypochlorite with various devices increased CH removal at the apical and middle part of the canal. LAI and PUI produce better results in the apical and middle thirds, respectively.

A central incisor with 4 independent root canals: a case report

NARCIS (Netherlands)

Aznar Portoles, C.; Moinzadeh, A.T.; Shemesh, H.

2015-01-01

The maxillary central incisor is the tooth with the least anatomic variations. Despite the fact that several studies have reported a prevalence of 100% for the presence of a single canal, root canal aberrations of maxillary central incisors with up to 3 canals have also been reported. Such cases

Two-rooted maxillary first molars with two canals: a case series.

Science.gov (United States)

Shakouie, Sahar; Mokhtari, Hadi; Ghasemi, Negin; Gholizadeh, Seddigheh

2013-01-01

Thorough understanding of the anatomic and internal morphology of a root canal system is absolutely essential for the success of endodontic treatment. Since permanent maxillary first molars have shown variation in internal anatomy, morphology, this tooth has been reviewed extensively. Presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. In this report, three cases are presented, which involve the root canal treatment of maxillary first molars with fusion of the two buccal roots.

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Lifescience Database Archive (English)

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Lifescience Database Archive (English)

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Lifescience Database Archive (English)

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Lifescience Database Archive (English)

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Lifescience Database Archive (English)

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Lifescience Database Archive (English)

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File list: His.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: Unc.CDV.10.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

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QUANTITATIVE SIZE ASSESSMENT OF THE LUMBAR SPINAL CANAL BY COMPUTED TOMOGRAPHY

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M. Midia Z. Miabi

2007-08-01

Full Text Available By determining normal ranges of spinal canal diameters we can make early diagnosis in persons who have lower diameters of spinal canal. These persons are predisposed to spinal canal stenosis that is a major cause of spinal radiculopathies. In different studies performed in several countries, minimum and maximum ranges of spinal canal diameters were different for each population. In this study, we tried to determine the mean values of normal spinal canal diameters and areas in Tabriz and its suburb. 39 healthy, young to mid-age cases were selected. Our study was focused on L3-L4 and L4-L5. The following parameters were measured: the area of cross-section of the vertebral body, the area of cross-section of the dural sac, interarticular diameter, interligamentous diameter, antero-posterior diameter of the lumbar canal, inter-pedicular diameter, and the area of cross-section of the vertebral canal. A correlation between the parameters studied and the height of subjects was significant for interligamentous diameter (for L3/L4 and L4/L5 and interarticular diameter (only at L3/L4, cross-section area of the vertebrae (both L3 and L4, cross-section area of vertebral canal (only at L5 level, area of dural sac (at L3/L4 and L4. It was suggested that these diameters and areas should be interpreted as a unction of height of the subject. Most of diameters studied had smaller means than those in previous studies. This can be attributed to differences between populations and it can be interpreted as predisposition to spinal canal stenosis in our population.

Canal configuration of mandibular first premolars in an Egyptian population

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Hatem A. Alhadainy

2013-03-01

Full Text Available The purpose of this study was to investigate canal configuration of mandibular first premolars in an Egyptian population. Two hundred fifty human extracted mandibular first premolars were collected from Egyptian patients and a small hole in the center of the occlusal surface of each tooth was made perforating the roof of the pulp chamber. Teeth were decalcified by immersing in nitric acid and dehydrated in ascending concentrations of ethyl alcohol. A waterproof black ink was passively injected from the occlusal hole into pulp system and stained teeth were immersed in methyl salicylate solution for clearing. Standardized pictures of the cleared teeth were obtained and anatomical features of the root canal were observed. The average length of the mandibular first premolar teeth was 22.48 ± 1.74 mm, one-rooted teeth were 96.8% and the two-rooted were 3.2%. Vertucci Type I canal configuration represented the highest percentage (61.2% followed by Type V (16.4%, Type IV (13.2%, Type II (5.6% and Type III (2.8%. Vertucci Type VI canal configuration represented the lowest percentage (0.4% and a complex configuration was found in one tooth. Accessory canals were detected in 22.8% and inter-canal connections were observed in 24.8% while 54% showed apical delta. Such knowledge is clinically useful for localization and negotiation of canals of mandibular first premolar, as well as their subsequent management in Egyptian population.

The 'Amstel Canal' in Amsterdam Canal construction as part of the medieval reclamation and drainage system of the Western Netherlands wilderness

Science.gov (United States)

Abrahamse, Jaap-Evert; Kosian, Menne; Weerts, Henk

2013-04-01

Usually, Amsterdam is presented as a river city, with the river Amstel as the trade route towards its hinterland, the IJ sea-branch as the portal to the world and its Dam as a focal point of transshipment and trade. Geomorphological, sedimentological, historical and historical-geographical evidence however, points towards the straight part of the Amstel, now located in Amsterdam, as a drainage canal that was dug in the aftermath of the 'Great Reclamation' of the 11th and 12th centuries. During this period, large parts of the wilderness in Utrecht and Holland were cultivated and put to agricultural use. Prior to the 'Great Reclamations', large oligotrophic (Sphagnum) peat bogs drained by small rivers were characteristic of the entire region. All along the straight Amstel canal, Sphagnum peat is found, which is indicative of the area's former peat bog conditions. The 'Amstel Canal' connected two natural meandering watercourses, one at the north and one at the south of the canal. The soil along both watercourses exists of eutrophic peat, which is indicative of repeated natural flooding. This is a strong indication of the anthropogenous origin of the straight part of the Amstel. The reason for digging the Amstel canal was not to create better trade links; it was a local component of a solution for major regional drainage problems in the provinces of Utrecht and Holland. These problems arose from the silting up of the Rhine rivermouth around 1100AD. Because of this, the precipitation surplus of the entire region could not be drained to the North Sea by this route anymore. This led to increased flooding and subsequently to conflicts between the rulers of Holland and Utrecht. In 1165AD, these conflicts reached a point where the Holy Roman Emperor intervened. The ruling of Barbarossa eventually led to a compromise: Utrecht and Holland redirected the entire drainage system of the region from the North Sea to the Zuiderzee in a concerted effort. This operation consisted of

Piquet Caroline, Histoire du canal de Suez, Paris, Perrin, 2009, 372 p.

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Claudine Piaton

2011-01-01

Full Text Available Les études sur l'histoire du canal de Suez connaissent un regain d'intérêt chez les historiens français. Nathalie Montel avait ouvert la voie en 1998 en publiant un ouvrage passionnant sur le percement du canal, Le chantier du canal de Suez, 1859-1869. Une histoire des pratiques techniques. L'étude s'arrêtait à l'ouverture du canal en 1869, laissant le champ libre à de futurs travaux. La publication en 2008 de l'ouvrage de Caroline Piquet, La Compagnie du canal de Suez, une concession françai...

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File list: DNS.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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File list: Pol.CDV.20.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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File list: DNS.CDV.20.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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Teacher's Guide to Canal. The Middlesex Canal: A Role Playing Exercise.

Science.gov (United States)

Holmes, Cary W.; Tedesco, Paul H.

The document consists of a role-playing game and related teacher's guide designed to illustrate decision-making processes leading to the building of the Middlesex Canal in Massachusetts in 1793. The primary educational objective is to involve students in the decision-making process through role play. The game is designed to facilitate…

Strategies of Coping With Stress During Root Canal Therapy

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Zare Jahromi

2015-12-01

Full Text Available Background Endodontic treatment is one of the stress producing situations. Objectives The purpose of this article was to determine the most stressful stage of root canal therapy among endodontists, endodontic residents, and undergraduate dental students and offering some strategies for reducing stress during this treatment. Patients and Methods This descriptive survey comprised three groups. Thirty-six endodontists, 41 endodontic residents, and 47 undergraduate dental students selected by convenience sampling. Participants were asked about age, sex, the most stressful stage of root canal therapy and stress reducing strategies during the procedure. Results The most stressful stage of root canal therapy was endodontic treatment for children in male endodontists and residents, preparing access cavity on crowns in female endodontists, obturation of apically root Resorped canals in female residents, obturation in female students, and preparing access cavity on molar teeth in male students. The most suggested strategy for reducing stress during root canal therapy was related to experience, knowledge, enough study, and technical mastery. Conclusions It is required to consider the strategies during student education in dental schools for both under and post-graduation dental students and better to follow them in workshops for other dentists and even endodontists.

Review of root canal irrigant delivery techniques and devices

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Yeon-Jee Yoo

2011-05-01

Full Text Available Introduction Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

Prominent central spinal canal on MRI - normal variant or pathology

International Nuclear Information System (INIS)

Dugal, T.P.; Brazier, D.; Roche, J.

2002-01-01

Full text: The sensitivity of MRI can make differentiation of normal from abnormal challenging.The study investigates whether a visible central spinal canal is pathological or a normal variant. We review eight MRI (mostly on a 1.5 Tesla unit) cases where there is a visible central cavity in keeping with a central canal and review the literature. The central canal is a space in the medial part of the grey-matter commissure between the anterior and posterior horns. Histopathological studies show that the canal is present at birth with the majority showing subsequent involution but is uncommonly imaged on MRI. The main differential diagnosis is syringomyelia which usually presents with deficits in pain and sensation corresponding to the appropriate level often with a demonstrable aetiology. Two thirds of our patients were female with an average age of thirty-six years (range 26-45). The patients were largely asymptomatic or their symptoms appeared unrelated to the imaging findings. Three patients had minor previous trauma and two others had non-bacterial meningitis up to twenty years earlier. No patient had known spinal surgery or trauma.The cavity corresponded tomographically to the expected site of the central canal. The canal was in the thoracic location. The canal diameter ranged from one to five millimetres and its length varied from one half a vertebral body height to extending over the entire thoracic region. Its configuration was either filiform or fusiform, with smooth contours. No predisposing features to suggest syringomyelia or other structural abnormalities were noted. Where Gadolinium was given no abnormal enhancement was observed. These cases add to the literature and suggest that these prominent canals are largely asymptomatic and should be viewed as normal variants. Copyright (2002) Blackwell Science Pty Ltd

Cases requiring increased number of repositioning maneuvers in benign paroxysmal positional vertigo

OpenAIRE

Korkmaz, Mukadder; Korkmaz, Hakan

2016-01-01

ABSTRACT INTRODUCTION: Benign paroxysmal positional vertigo (BPPV) is a clinical syndrome that is proposed to be caused by dislocated utricular debris into semicircular canals. Although the majority of patients are treated by one or two repositioning maneuvers, some of the patients need repeated maneuvers for relief. OBJECTIVE: The goal of this study was to investigate the factors associated with patients with benign paroxysmal positional vertigo who required multiple repositioning proced...

Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

Science.gov (United States)

Moura-Netto, Cacio; Mello-Moura, Anna Carolina Volpi; Palo, Renato Miotto; Prokopowitsch, Igor; Pameijer, Cornelis H.; Marques, Marcia Martins

2015-03-01

This research analyzed the quality of resin-based sealer adaptation after intracanal laser irradiation. Extracted teeth (n=168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd:YAG laser (1.5 W, 100 mJ, 15 Hz) diode laser (2.5 W in CW), and Er:YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis' test (p<0.05). Both adaptation and sealer penetration in root canals were not affected by the laser irradiation. Nd:YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd:YAG irradiation (p<0.05). It can be concluded that intracanal laser irradiation can be used as an adjunct in endodontic treatment; however, the use of hydrophilic resin sealers should be avoided when root canals were irradiated with Nd:YAG laser.

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File list: ALL.CDV.05.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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File list: ALL.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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Cervical spinal canal narrowing in idiopathic syringomyelia

International Nuclear Information System (INIS)

Struck, Aaron F.; Carr, Carrie M.; Shah, Vinil; Hesselink, John R.; Haughton, Victor M.

2016-01-01

The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7. (orig.)

Cervical spinal canal narrowing in idiopathic syringomyelia

Energy Technology Data Exchange (ETDEWEB)

Struck, Aaron F. [Massachusetts General Hospital, Department of Neurology, Boston, MA (United States); Carr, Carrie M. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Shah, Vinil [University of California San Francisco, Department of Radiology, San Francisco, CA (United States); Hesselink, John R. [University of California San Diego, Department of Radiology, San Diego, CA (United States); Haughton, Victor M. [University of Wisconsin, Department of Radiology, Madison, WI (United States)

2016-08-15

The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7. (orig.)

In-vitro evaluation of the effect of canal curvature on adaptation of gutta-percha in canals obturated with HEROfill system by CBCT

International Nuclear Information System (INIS)

Zarei, M.; Talati, A.; Mortazavi, M.; Zarch, H.H.; Javidi, M.; Bidokhty, H.A.

2011-01-01

A hermetic seal of the root canal space following canal preparation is important in endodontics. This study evaluated the effect of canal curve on adaptation of gutta-percha to dentinal walls of canals obturated using the Herofill system. For this in vitro study, 80 mesial roots of mature human first molars with length of 16 mm, curve between 5 deg and 45 deg, and no caries or resorption of the root surface were selected. A cone beam computed tomography system was used to evaluate the presence or absence of a gap in the samples. Photographs were taken in three sections: 2 mm above the curve, at the curve and 2 mm below the curve. The gap area was identified using Photoshop and AutoCAD software. Kruskal Wallis and Mann-Whitney tests were used to analyze the data mounted in a castcurve. There were significant differences between the two lateral condensation groups with various curves; roots with more curve had more gaps. When the Herofill and lateral condensation groups were compared without considering the sections and curve, there was a significant difference between these groups and the Herofill group had less gaps. The Herofill system is an alternative to the lateral condensation technique in severely curved canals. (author)

File list: Oth.CDV.05.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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File list: Oth.CDV.10.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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File list: Oth.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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First branchial cleft fistula associated with external auditory canal stenosis and middle ear cholesteatoma.

Science.gov (United States)

Abdollahi Fakhim, Shahin; Naderpoor, Masoud; Mousaviagdas, Mehrnoosh

2014-10-01

First branchial cleft anomalies manifest with duplication of the external auditory canal. This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection. It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear.

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.

Effectiveness of EDTA as the irrigation solution to remove smear layer in root canal

Directory of Open Access Journals (Sweden)

Kurniasri Amas Achiar

2009-07-01

Full Text Available One of the objectives of successful endodontic treatment is the hermetic obturation of the root canal system. To achieve this, the root canal filling must seal the canal space both apically and coronally to prevent the ingress of microorganisms or tissue fluids into the canal space. Apical leakage is reported a common reason for the clinical failure of endodontic therapy. Leakage through an obturated root canal is expected to take place at interfaces between sealer and dentin or sealer and gutta-percha, or through voids within the sealer. Hence, the sealing quality of root canal filling depends much on the sealing ability of the sealer. Therefore, anything that may influence the adaptation of the root filling to the canal wall is can determine the degree and the extent of leakage, and ultimately the prognosis of the endodontic therapy. In endodontic therapy, the smear layer formation results from root canal preparation and may influence the effective seal of the root canal system. The smear layer formation is mainly composed of inorganic components (dentin debris and organic materials, such as pulp tissue remnant, bacteria, and blood cells. Removal of the smear layer from the root canal walls before the obturation can reduce the leakage of root canal sealer. To remove the smear layer use 10 ml 17% EDTA followed by 10 ml of 5.25% NaOCl as irrigating solution. This paper discribe about how the effectivity of EDTA as irigating solution to remove the smear layer especially in the apical root canal with many lateral canal to reduce the apical leakage.

Magnetic resonance imaging anatomy of the anal canal

International Nuclear Information System (INIS)

Kashyap, P.; Bates, N.

2004-01-01

The anatomy of the anal canal is complex but well demonstrated by MRI. Understanding the anatomy is a prerequisite for determining the true site and the extent of pathology, especially for surgical workup. In this article, the MRI anatomy of the anal canal has been displayed using highlighted MRI images and line diagrams. Copyright (2004) Blackwell Science Pty Ltd

Nodular Fasciitis of External Auditory Canal

Directory of Open Access Journals (Sweden)

Jihyun Ahn

2016-09-01

Full Text Available Nodular fasciitis is a pseudosarcomatous reactive process composed of fibroblasts and myofibroblasts, and it is most common in the upper extremities. Nodular fasciitis of the external auditory canal is rare. To the best of our knowledge, less than 20 cases have been reported to date. We present a case of nodular fasciitis arising in the cartilaginous part of the external auditory canal. A 19-year-old man complained of an auricular mass with pruritus. Computed tomography showed a 1.7 cm sized soft tissue mass in the right external auditory canal, and total excision was performed. Histologic examination revealed spindle or stellate cells proliferation in a fascicular and storiform pattern. Lymphoid cells and erythrocytes were intermixed with tumor cells. The stroma was myxoid to hyalinized with a few microcysts. The tumor cells were immunoreactive for smooth muscle actin, but not for desmin, caldesmon, CD34, S-100, anaplastic lymphoma kinase, and cytokeratin. The patient has been doing well during the 1 year follow-up period.

The Assessment of Sediment Heavy Metal Pollution in Begej Canal (Serbia)

Science.gov (United States)

Krčmar, Dejan; Trickovic, Jelena; Grba, Nenad; Becelic Tomin, Milena; Pesic, Vesna; Varga, Natasa; Dalmacija, Bozo

2016-04-01

Accumulation of heavy metals in aquatic systems has received huge concern due to their toxicity, persistence and subsequent accumulation in aquatic sediments. One of the most crucial properties of the metals, which differentiate them from organic pollutants, is that they are not biodegradable in the environment. Metals are part of biogeochemical cycles with aquatic sediments acting as their ultimate sinks for longer periods of time. However, when environmental conditions change (pH, redox potential, etc.) sediments act as secondary sources of metal pollution. The toxicity and mobility of metals depend strongly on the way they are associated with sediments. Therefore, information on the total concentrations of metals in sediment alone should not be used to assess the environmental impact of polluted sediments. The Begej Canal is navigation canal between Romania and Serbia and it is a part of Danube-Tisa-Danube hydrosystem in Vojvodina (Northern Province of Serbia). Approximately, 500,000 m3 of sediment is accumulated in Begej canal which currently prevents canal's primary function - navigability. The objective of the present study was to assess the chemical quality of Begej canal sediments regarding heavy metals content. The concentrations of heavy metals were as follows: Cd - 2.4-4.9 mg/kg, Cr - 125-349 mg/kg, Cu - 65-124 mg/kg, Pb - 47-113 mg/kg, Ni - 45-88 mg/kg and Zn - 362-602 mg/kg. According to Serbian legislation (Official gazette, no. 50/12), sediment of Begej canal is the third class sediment which means that special measures should be taken in case of its removal from watercourse and final disposal in order to prevent contamination of other environmental compartments (soil, ground waters, surface waters, wildlife). Therefore, determination of third class has important economic and social implications. Additional tests to assess sediment quality included determination of contamination factor (CF), pollution load index (PLI) and enrichment factor (EF). In

Incisive canal deflation for correct implant placement: case report.

Science.gov (United States)

Spin-Neto, Rubens; Bedran, Telma Blanca Lombardo; de Paula, Wagner Nunes; de Freitas, Rubens Moreno; de Oliveira Ramalho, Lizeti Toledo; Marcantonio, Elcio

2009-12-01

This article is a case report of a patient in whom the prosthetic planning indicated the necessity of an incisive canal deflation for the correct installation of an implant that is to be osseointegrated. In the reopening phase after the bone graft installation, the incisive canal deflation (biopsy of its content) was done and titanium implants were installed with one of them invading the anatomical space occupied previously by the incisive canal. The biopsy analysis showed fragments of the incisive artery and nerve, which are responsible for the anterior upper-tooth pulp, the periodontium vascularization and the innervation. From the anastomosis present along with other structures allied with the absence of teeth in the region, there was no detriment to the patient caused by the deflation. Incisive canal deflation is a viable technique in implantology. It can permit ideal prosthetic planning with no detriment to the patient.

First Branchial Cleft Fistula Associated with External Auditory Canal Stenosis and Middle Ear Cholesteatoma

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Abdollahi fakhim, Shahin; Naderpoor, Masoud; Mousaviagdas, Mehrnoosh

2014-01-01

Introduction: First branchial cleft anomalies manifest with duplication of the external auditory canal. Case Report: This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection. Conclusion: It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear. PMID:25320705

First Branchial Cleft Fistula Associated with External Auditory Canal Stenosis and Middle Ear Cholesteatoma

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shahin abdollahi fakhim

2014-10-01

Full Text Available Introduction: First branchial cleft anomalies manifest with duplication of the external auditory canal.   Case Report: This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection.   Conclusion:  It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear.

Experimental circumferential canaloplasty with a new Schlemm canal microcatheter

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Mao-Song Xie

2018-01-01

Full Text Available AIM: To present a new, simple, inexpensive Schlemm canal microcatheter for circumferential canaloplasty in a rabbit model. METHODS: A rabbit glaucoma animal model was established by intravitreal injection of triamcinolone acetonide. Circumferential canaloplasty with a new Schlemm canal microcatheter (patent license number: 201220029850.0 was performed. The Schlemm canal microcatheter was composed of microcatheter wall and lumen. The wall was made of high refractive index plastic optical fiber that could be attached to an illuminant so that the whole lighted microcatheter was visible during circumferential canaloplasty. The lumen could be attached to an injector for injection of viscoelastic during catheterization. Rabbits were divided randomly into the control, model and treatment groups. Intraocular pressure (IOP was measured with a Tono-pen tonometer pre-operation and 3, 7, 14, 21 and 28d post-operation. Ultrasound biomicroscopy was performed to visualize the Schlemm canal microcatheter in the Schlemm canal and the sclera pool. RESULTS: The Schlemm canal microcatheter could be used to perform circumferential canaloplasty in the rabbit glaucoma animal model. IOP was lower in the treatment group than that in the model group 3, 7, 14 and 28d after operation. There were no significant differences in IOP between the control group and treatment group. The differences among the three groups were statistically significant (3d: F=41.985, P<0.001; 7d: F=65.696, P<0.001; 14d: F=114.599, P<0.001; 28d: F=55.006, P<0.001. CONCLUSION: Circumferential canaloplasty is safe and effective in control of experimental glaucoma model in rabbits.

Roentgenographic study of the mandibular canal

International Nuclear Information System (INIS)

Ahn, Hyung Kyu

1980-01-01

The mandibular canal must be considered carefully during the surgical treatment, especially surgical extraction of the impacted tooth and intraosseous implant, because it contains the important inferior alveolar nerve and vessels. The author investigated the curvature of the mandibular canal and its relation to the mandibular molars and positional relation between the mental foramen and the mandibular premolars in orthopantomogram. The materials consisted of 441 orthopantomograms divided four groups; Group I consisted of 56 males and 44 females from 1 to 6 years of age, Group II consisted of 58 males and 45 females from 7 to 12 years of age, Group III consisted of 65 males and 33 females from 13 to 18 years of age, Group IV consisted of 86 males and 54 females over 19 years of age. The results were as followings; 1. The curvature of mandibular canal was 144.50 .deg. in Group II, 148.11 .deg. in Group III, 147.33 .deg. in Group IV. 2. The curvature of mandibular canal was located most frequently on the area between mandibular 1st molar and mandibular 2nd molar in Group I (42%) and on the mandibular 2nd molar area in Group II (54%), Group III (59%), Group IV (53%). 3. The position of mental foramen was most frequently below the mandibular 1st premolar in Group I (58%), between the mandibular 1st premolar and the 2nd premolar in Group II (62%), Group III (47%), and below the mandibular 2nd premolar in Group IV (58%).

Root anatomy and canal configuration of the permanent mandibular first molar: a systematic review.

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de Pablo, Oliver Valencia; Estevez, Roberto; Péix Sánchez, Manuel; Heilborn, Carlos; Cohenca, Nestor

2010-12-01

The main goal of endodontic therapy is to prevent or heal apical periodontitis. However, root canal anatomy might present a clinical challenge directly related to the treatment outcome. The purpose of this study was to review published literature related to root anatomy and root canal configuration of the permanent mandibular first molar. An exhaustive search was undertaken to identify published literature related to the root anatomy and root canal morphology of the permanent mandibular first molar by using key words. The search of the MEDLINE database included all publications from 1966-May 2010. Selected articles were then obtained and reviewed. Data evaluated and summarized in the data sheet included methodology, population, number of teeth per study (power), number of root canals, type of root canal configuration, and identification of number of apical foramina. Forty-one studies were identified including a total of 18,781 teeth. The incidence of a third root was 13% and was strongly correlated with the ethnicity of the studied population. Three canals were present in 61.3%, 4 canals in 35.7%, and 5 canals in approximately 1%. Root canal configuration of the mesial root revealed 2 canals in 94.4% and 3 canals in 2.3%. The most common canal system configuration was Vertucci type IV (52.3%), followed by type II (35%). Root canal configuration of the distal root revealed type I configuration in 62.7%, followed by types II (14.5%) and IV (12.4%). The presence of isthmus communications averaged 54.8% on the mesial and 20.2% on the distal root. The number of roots on the mandibular first molar is directly related to ethnicity. Root canal morphology and configuration might present the clinician with a complex anatomy requiring more diagnostic approaches, access modifications, and clinical skills to successfully localize, negotiate, disinfect, and seal the root canal system. Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.

Measurement-based Monte Carlo simulation of high definition dose evaluation for nasopharyngeal cancer patients treated by using intensity modulated radiation therapy

International Nuclear Information System (INIS)

Yeh, C.Y.; Tung, C.J.; Lee, C.C.; Lin, M.H.; Chao, T.C.

2014-01-01

Measurement-based Monte Carlo (MBMC) simulation using a high definition (HD) phantom was used to evaluate the dose distribution in nasopharyngeal cancer (NPC) patients treated with intensity modulated radiation therapy (IMRT). Around nasopharyngeal cavity, there exists many small volume organs-at-risk (OARs) such as the optic nerves, auditory nerves, cochlea, and semicircular canal which necessitate the use of a high definition phantom for accurate and correct dose evaluation. The aim of this research was to study the advantages of using an HD phantom for MBMC simulation in NPC patients treated with IMRT. The MBMC simulation in this study was based on the IMRT treatment plan of three NPC patients generated by the anisotropic analytical algorithm (AAA) of the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA, USA) using a calculation grid of 2 mm 2 . The NPC tumor was treated to a cumulative dose of 7000 cGy in 35 fractions using the shrinking-field sequential IMRT (SIMRT) method. The BEAMnrc MC Code was used to simulate a Varian EX21 linear accelerator treatment head. The HD phantom contained 0.5 × 0.5 × 1 mm 3 voxels for the nasopharyngeal area and 0.5 × 0.5 × 3 mm 3 for the rest of the head area. An efficiency map was obtained for the amorphous silicon aS1000 electronic portal imaging device (EPID) to adjust the weighting of each particle in the phase-space file for each IMRT beam. Our analysis revealed that small volume organs such as the eighth cranial nerve, semicircular canal, cochlea and external auditory canal showed an absolute dose difference of ≥200 cGy, while the dose difference for larger organs such as the parotid glands and tumor was negligible for the MBMC simulation using the HD phantom. The HD phantom was found to be suitable for Monte Carlo dose volume analysis of small volume organs. - Highlights: • HD dose evaluation for IMRT of NPC patients have been verified by the MC method. • MC results shows

Unusual root canal morphology of mandibular second premolars: A case series and review

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Snehal Sonarkar

2017-01-01

Full Text Available Mandibular second premolars (MSPs have varied anatomy ranging from 1 to 3 roots and 1–5 canals. Successful endodontic treatment is achieved by proper access opening, cleaning, and shaping and three-dimensional obturation. This case series describes five cases in which MSPs have been diagnosed with aberrant canal system. The Case 1 and 5 has one root with Vertucci's Type V canal configuration. The Case 2 has two roots with two canals, the Case 3 has one root with Vertucci's Type IV canal configuration, whereas the Case 4 has three roots with three canals. This case series also describes a classification for describing the root configuration. The clinical implications of this paper are first to reach at appropriate diagnosis of canal system using diagnostic aids (angulated radiographs and dental operating microscope. Second, to use advanced endodontic instruments for achieving successful endodontic therapy (NiTi rotary instruments.

Diffusion of graphite. The effect of cylindrical canals

International Nuclear Information System (INIS)

Carle, R.; Clouet d'Orval, C.; Martelly, J.; Mazancourt, T. de; Sagot, M.; Lattes, R.; Teste du Bailler, A.

1957-01-01

Experiments on thermal neutron diffusion in the graphite used as moderator in the pile G1 have been carried out. The object of these experiments is to determine: - the intrinsic quality of this graphite, characterised by its diffusion length L or its Laplacian 1/L 2 - the effect of the canals, which modifies anisotropically the macroscopic diffusion equation and is characterized by two principal diffusion regions (or two principal Laplacian), valid respectively for the diffusion in the direction of the canals and in a perpendicular direction. In order to determine them two experiments are necessary, in which the second derivatives of the flux in relation to the space coordinates are very different. These experiments form the object of the first two parts. Part 1: Diffusion along the axis of a flux coming from the pile source, and limited radially by a quasi cylindrical screen of cadmium bars. This screen, or Faraday cage is designed to give to the thermal flux produced the same radius of extrapolation to zero as that of the pile source. The determination of L (with the graphite full) has been made under the same conditions. The measurements have been interpreted in two ways. The influence of the brackets holding the detectors is discussed. Part 2: Radial diffusion in the graphite surrounding the 'long' cylindrical pile. This is well described by a sum of Bessel functions. Part 3: Results (valid for d = 1.61 t = 17 deg. C). For the graphite without cavity L = 52.7 ± 0.4 cm. The effect of the canals on the diffusion area and its anisotropy are in excellent agreement with the theory of Behrens: L(parallel) = 64.6 cm and L(perpendicular) 62.2 cm. Appendix: Theory of the Faraday cage. (author) [fr

Root Canal Configuration of Maxillary First Permanent Molars in an Iranian Population

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Saeed Rahimi

2007-06-01

Full Text Available

Background and aims. It is critical to have a proper knowledge of the normal anatomy of the pulp and its variations for the success of endodontic treatment. The purpose of this study was to investigate variations in the root canal system of maxillary first permanent molars in an Iranian population.

Materials and methods. In this study, 137 maxillary first molars were decalcified, dye-injected, cleared and studied.

Results. The results demonstrated that 37.96% of the maxillary first molars under study had three canals, 58.4% had four canals and 3.64% had five canals.

Conclusion. According to the results of this study and considering variations in the root canal systems of maxillary first molars, it seems that great care should be taken in the root canal treatment of these teeth.

Anatomy and morphology of the nasopalatine canal using cone-beam computed tomography

International Nuclear Information System (INIS)

Thakur, Arpita Rai; Burde, Krishna; Guttai, Kruthika; Naikmasu, Venkatesh

2013-01-01

This study was performed to evaluate the general anatomy and morphology of the nasopalatine canal using cone-beam computed tomography (CBCT) and to determine the human anatomic variability of the nasopalatine canal in relation to age and gender. The study included 100 subjects aged between 20 and 86 years who were divided into the following 3 groups: 1) 20-34 years old; 2) 35-49 years old; 3) ≥50 years old. The subjects were equally distributed between the genders. CBCT was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the nasopalatine canal by two independent observers. The correlation of age and gender with all the variables was evaluated. The present study did not reveal statistically significant differences in the number of openings at the nasal fossa; diameter of the nasal fossa openings; diameter of the incisive fossa; shape, curvature, and angulation of the canal as viewed in the sagittal sections; antero-posterior dimensions and length of the canal in the sagittal sections; or the level of division of the canal in the coronal plane by age. However, males and females showed significant differences in the length of the canal in the sagittal sections and level of the division of the canal in the coronal plane. The present study highlighted important variability observed in the anatomy and morphology of the nasopalatine canal.

Anatomy and morphology of the nasopalatine canal using cone-beam computed tomography

Energy Technology Data Exchange (ETDEWEB)

Thakur, Arpita Rai [Dept. of Oral Medicine and Radiology, Faculty of Dentistry, Jamia Millia Islamia University, New Delhi (India); Burde, Krishna; Guttai, Kruthika; Naikmasu, Venkatesh [Dept. of Oral Medicine and Radiology, S.D.M. College of Dental Sciences and Hospital, Dharwad (India)

2013-12-15

This study was performed to evaluate the general anatomy and morphology of the nasopalatine canal using cone-beam computed tomography (CBCT) and to determine the human anatomic variability of the nasopalatine canal in relation to age and gender. The study included 100 subjects aged between 20 and 86 years who were divided into the following 3 groups: 1) 20-34 years old; 2) 35-49 years old; 3) ≥50 years old. The subjects were equally distributed between the genders. CBCT was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the nasopalatine canal by two independent observers. The correlation of age and gender with all the variables was evaluated. The present study did not reveal statistically significant differences in the number of openings at the nasal fossa; diameter of the nasal fossa openings; diameter of the incisive fossa; shape, curvature, and angulation of the canal as viewed in the sagittal sections; antero-posterior dimensions and length of the canal in the sagittal sections; or the level of division of the canal in the coronal plane by age. However, males and females showed significant differences in the length of the canal in the sagittal sections and level of the division of the canal in the coronal plane. The present study highlighted important variability observed in the anatomy and morphology of the nasopalatine canal.

Anomalous facial nerve canal with cochlear malformations.

Science.gov (United States)

Romo, L V; Curtin, H D

2001-05-01

Anteromedial "migration" of the first segment of the facial nerve canal has been previously identified in a patient with a non-Mondini-type cochlear malformation. In this study, several patients with the same facial nerve canal anomaly were reviewed to assess for the association and type of cochlear malformation. CT scans of the temporal bone of 15 patients with anteromedial migration of the first segment of the facial nerve canal were collected from routine departmental examinations. In seven patients, the anomalous course was bilateral, for a total of 22 cases. The migration was graded relative to normal as either mild/moderate or pronounced. The cochlea in each of these cases was examined for the presence and size of the basilar, second, and apical turns. The turns were either absent, small, normal, or enlarged. The CT scans of five patients with eight Mondini malformations were examined for comparison. The degree of the facial nerve migration was pronounced in nine cases and mild/moderate in 13. All 22 of these cases had associated cochlear abnormalities of the non-Mondini variety. These included common cavity anomalies with lack of definition between the cochlea and vestibule (five cases), cochleae with enlarged basilar turns and absent second or third turns (five cases), and cochleae with small or normal basilar turns with small or absent second or third turns (12 cases). None of the patients with Mondini-type cochlear malformations had anteromedial migration of the facial nerve canal. Anteromedial migration of the facial nerve canal occurs in association with some cochlear malformations. It did not occur in association with the Mondini malformations. A cochlea with a Mondini malformation, being similar in size to a normal cochlea, may physically prohibit such a deviation in course.

Comparative Study of Three Rotary Instruments for root canal Preparation using Computed Tomography

International Nuclear Information System (INIS)

Mohamed, A.M.E.

2015-01-01

Cleaning and shaping the root canal is a key to success in root canal treatment. This includes the removal of organic substrate from the root canal system by chemo mechanical methods, and the shaping of the root canal system into a continuously tapered preparation. This should be done while maintaining the original path of the root canal. Although instruments for root canal preparation have been progressively developed and optimized, a complete mechanical debridement of the root canal system is rarely achievable. One of the main reasons is the geometrical dis symmetry between the root canal and preparation instruments. Rotary instruments regardless of their type and form produce a preparation with a round outline if they are used in a simple linear filing motion, which in most of the cases do not coincide with the outline of the root canal. Root canal preparation in narrow, curved canals is a challenge even for experienced endodontists. Shaping of curved canals became more effective after the introduction of nickel-titanium (Ni-Ti) endodontic instruments. Despite the advantages of Ni-Ti rotary instruments, intra canal fracture is the most common procedural accident that occurs with these instruments during clinical use. It is a common experience between clinicians that Ni-Ti rotary instruments may undergo unexpected fracture without any visible warning, such as any previous permanent defect or deformation. Pro Taper Ni-Ti instruments were introduced with a unique design of variable taper within one instrument and continuously changing helical angles. Pro Taper rotary instruments are claimed to generate lower torque values during their use because of their modified nonradial landed cross-section that increases the cutting efficiency and reduces contact areas. On the other hand, the variable taper within one instrument is believed to reduce the ‘taper lock’ effect (torsional failure) in comparison with similarly tapered instruments. Nevertheless, Pro Taper

[Shaping ability of two nickel-titanium rotary systems in simulated S-shaped canals].

Science.gov (United States)

Luo, Hong-xia; Huang, Ding-ming; Zhang, Fu-hua; Tan, Hong; Zhou, Xue-dong

2008-01-01

To evaluate the shaping ability of two nickel-titanium rotary systems (ProTaper and Hero642) in simulated S-shaped canals. Thirty simulated S-shaped canals were randomly divided into three groups and prepared by ProTaper, Hero642, ProTaper combined with Hero642 respectively. All the canals were scanned before and after instrumentation, and the amount of material removed in the inner and outer wall and the canal width after instrumentation were measured with a computer image analysis program. There was significant difference in the amount of material removed at the inner side of apical curvature and outer side of apex between ProTaper combined with Hero642 and ProTaper files (P Hero642, and the taper of canals were better than those prepared by Hero642. ProTaper combined with Hero 642 had better shaping ability to maintain the original shape and could create good taper canals in the simulated S-shaped canal model.

Pollution of Lahore canal water in the city premises

International Nuclear Information System (INIS)

Hussain, Z.; Baig, M.A.

1997-01-01

Water contamination is one of the major environmental pollution problems facing Pakistan because it has a direct impact on the health of human beings and crops. Lahore Canal water is being used both for irrigation and a source of ground water recharge. For the best use of this water, extent of pollution and its effect on soil hydraulic properties needs to be studied. For this purpose, water samples from twenty three sites and soil samples from three sites were collected along the Canal within the city limits of Lahore. The survey of the area from Jallo Park to Mall Road, show that all the abadies/colonies and industries situated on both sides of the canal dump their waste water and garbage in to canal. This result in increase of salinity as well as BOD and COD values which were found maximum at the locations of Herbuns Pura, Mughal Pura Dharam Pura, and Thoker Niaz Baig. (authors)

CT of the external auditory canal: Correlation with clinical otoscopy

International Nuclear Information System (INIS)

Shankar, L.; Hawke, M.; Leekam, R.N.

1987-01-01

CT is the modality of choice in the assessment of external auditory canal abnormalities. Disorders of the complex structures within the ear that may be difficult to define clinically are well visualized on high-resolution CT. This exhibit illustrates various external auditory canal abnormalities and correlates these with color illustrations from clinical otoscopy. Congenital lesions of the external auditory canal - microtia, temporo-bandibular joint herniation, and fistulas - and various acquired lesions - traumatic, inflammatory, and neoplastic - are reviewed in this exhibit

Incidence of two canals in extracted mandibular incisors teeth of Saudi Arabian samples

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Khalid S Al-Fouzan

2012-01-01

Full Text Available Aim: The purpose of this in vitro study is to provide clinical data on the presence of the second canal in mandibular incisor teeth of Saudi Arabian Samples. Materials and Methods: Eighty extracted human mandibular incisors were collected from Saudi patients. The teeth were accessed by small round bur then placed in 5.25% sodium hypochlorite for 24 hours to dissolve the organic debris. Indian ink was injected inside the root canal systems under negative pressure. The teeth were decalcified in 5% nitric acid for three days then dehydrated in different concentrations of ethyl alcohol. Following the decalcification process, the teeth were cleared in methyl salicylate and evaluated according to Vertucci′s classification. Result: Fifty six of both mandibular central and lateral incisor teeth (70% had type I canal configuration (one main canal and one main apical foramen, while the remaining 30% of the sample (24 teeth had a type III canal configuration (two separate canals and merged into one canal before exiting the tooth through single apical foramen. Conclusion : The incidence of two canals in mandibular incisor teeth is about one third of the examined Saudi Arabian samples with no difference between the centrals and laterals. The clinician should deal with these teeth as if they have two canals unless it is proved otherwise.

AFSC/ABL: Lynn Canal Echo-Integrated Trawl Surveys, 2001-2004

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

EL TRANSPORTE DE CANTIDAD DE MOVIMIENTO EN CANALES

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Francisco Jaime Mejía

Full Text Available Este artículo tiene por objeto aplicar el transporte de cantidad de movimiento al flujo en canales como una metodología independiente de otros principios físicos. Así se subsana una carencia de la literatura técnica cuando aborda la interpretación adicional de fenómenos hidráulicos que habitualmente se tratan desde la conservación de la energía. Concluye acerca del comportamiento de la profundidad de flujo en un canal ante diversas condiciones de flujo o variaciones de la profundidad o en presencia de controles hidráulicos. Con la ayuda de la ecuación de transporte de cantidad de movimiento a lo largo de un canal se interpreta el comportamiento del tirante hidráulico en flujo uniforme, en flujo no uniforme con variación gradual y en algunos fenómenos locales de flujo rápidamente variado como ocurre en las transiciones y en el resalto hidráulico. Se obtienen las ecuaciones del resalto hidráulico para calcular la profundidad inicial y secuente, conocida una de las dos, en diversas secciones transversales del canal.

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

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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.

Direct Acoustic Stimulation at the Lateral Canal: An Alternative Route to the Inner Ear?

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Nicolas Verhaert

Full Text Available Severe to profound mixed hearing loss is associated with hearing rehabilitation difficulties. Recently, promising results for speech understanding were obtained with a direct acoustic cochlear implant (DACI. The surgical implantation of a DACI with standard coupling through a stapedotomy can however be regarded as challenging. Therefore, in this experimental study, the feasibility of direct acoustic stimulation was investigated at an anatomically and surgically more accessible inner ear site. DACI stimulation of the intact, blue-lined and opened lateral semicircular canal (LC was investigated and compared with standard oval window (OW coupling. Additionally, stapes footplate fixation was induced. Round window (RW velocity, as a measure of the performance of the device and its coupling efficiency, was determined in fresh-frozen human cadaver heads. Using single point laser Doppler vibrometry, RW velocity could reliably be measured in low and middle frequency range, and equivalent sound pressure level (LE output was calculated. Results for the different conditions obtained in five heads were analyzed in subsequent frequency ranges. Comparing the difference in RW membrane velocity showed higher LE in the LC opened condition [mean: 103 equivalent dB SPL], than in LC intact or blue-lined conditions [63 and 74 equivalent dB SPL, respectively]. No difference was observed between the LC opened and the standard OW condition. Inducing stapes fixation, however, led to a difference in the low frequency range of LE compared to LC opened. In conclusion, this feasibility study showed promising results for direct acoustic stimulation at this specific anatomically and surgically more accessible inner ear site. Future studies are needed to address the impact of LC stimulation on cochlear micromechanics and on the vestibular system like dizziness and risks of hearing loss.

Extracting Environmental Benefits from a New Canal in Nicaragua: Lessons from Panama.

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Richard Condit

2015-07-01

Full Text Available Biologists have raised objections to a new canal in Nicaragua, but in this Essay I argue that dire predictions of environmental catastrophe are exaggerated. I present an alternative view based on my research experience in Panama, where Canal operations foster forest conservation. Currently in Nicaragua, the rate of forest loss is so rapid that the canal cannot make it worse. Rather, I contend, adoption of international standards in canal construction could lead to net environmental and social benefits for the country.

Continuous Adductor Canal Blocks

DEFF Research Database (Denmark)

Monahan, Amanda M; Sztain, Jacklynn F; Khatibi, Bahareh

2016-01-01

on cutaneous knee sensation in volunteers. METHODS: Bilateral adductor canal catheters were inserted in 24 volunteers followed by ropivacaine 0.2% administration for 8 hours. One limb of each subject was assigned randomly to a continuous infusion (8 mL/h) or automated hourly boluses (8 m...

The width of the incisive canal and labial alveolar bone of the incisive canal: an assessment on CT images

International Nuclear Information System (INIS)

Roh, Yang Gyun; Jang, Hyun Seon; Kim, Byung Ock; Kim, Jin Soo

2006-01-01

To assess the width of the labial alveolar bone of the incisive canal and the width of the incisive canal on spiral computed tomographic images of the anterior portion of the maxilla. Study materials included 38 CT scans taken for preoperative planning of implant placement. Axial cross-sectioned image entirely showing the incisive canal at an orifice to the oral cavity, middle portion, and an orifice to the nasal cavity and the diameter of the incisive canal at the middle portion were determined by two specialist using Digora for Windows 2.1. The statistical analyses were carried out using SPSS 12.0.1. When the maxillary central incisors remained, the mean labial alveolar bone width were 6.81±1.41 mm, 6.46±1.33 mm, and 7.91±1.33 mm. When the maxillary central incisors were missed the mean width were 5.42±2.20 mm, 6.23±2.29 mm, and 7.89±2.13 mm. The labial alveolar bone width at middle portion and an orifice to the nasal cavity were of no statistical significant difference according to presence of the maxillary central incisors (P>0.05). The width between oral cavity and nasal cavity, middle portion and to masal cavity revealed statistically significant difference (P<0.05)

[Shaping ability of multi-taper nickel-titanium files in simulated resin curved root canal].

Science.gov (United States)

Luo, Hong-Xia; Huang, Ding-Ming; Jia, Liu-He; Luo, Shi-Gao; Gao, Xiao-Jie; Tan, Hong; Zhou, Xue-Dong

2006-08-01

To compare the shaping ability of ISO standard stainless steel K files and multi-taper ProTaper nickel-titanium files in simulated resin curved root canals. METHODS Thirty simulated resin root canals were randomly divided into three groups and prepared by stainless steel K files, hand ProTaper, rotary ProTaper, respectively. The amount of material removed from inner and outer wall and canal width after canal preparation was measured, while the canal curvature before and after canal preparation and canals aberrations were recorded. The stainless steel K files removed more material than hand ProTaper and rotary ProTaper at the outer side of apex and inner side of curvature (P ProTaper group (P ProTaper had no evident aberration. The shaping ability of ProTaper is better than stainless steel K files.

An experimental study on the computed tomography of the cervical spinal canal

International Nuclear Information System (INIS)

Wakabayashi, Tsuguru

1980-01-01

A study was carried out to investigate how accurately CT could delineate the vertebral canal, vertebral body, lamina, intervertebral foramen and transverse process, and which factor influences the size of the vertebral canal, using cervical vertebrae obtained from four cadavers and one skeleton. EMI CT 5005 scanner was used. CT picture depicted accurate shapes of the vertebral canal, body and transverse process. The sagittal diameter of the vertebral canal of CT picture varied by various conditions, such as difference of scanning chance, scanning angle, window width and level, but variations due to different absorption coefficients of the bone surrounding the vertebral canal were negligible. It was most significantly changed by scanning angle. Permissible scanning angle was within 5 0 , and morphological findings were not influenced up to 15 0 . The size of the vertebral canal was most accurately measured under the condition of 400 in width and 250 in level. The optimal condition for delineation of the spine seemed to be 400 in width and 100 - 150 in level. Under the condition at width 400 and level 100, the vertebral canal was delineated narrower by an average 0.6 mm and 0.2 mm in the sagittal and transverse diameter respectively. In CT picture of the imitational ossified posterior Longitudinal ligament made of plastic and alginate, the average narrowing rate of the vertebral canal was 4.4% greater than the one obtained by lateral view of radiograph, but both correlated well with each other. The narrowing rate of the vertebral canal by CT tended to increase in proportion to the increase in scanning angle. (J.P.N.)

Root canal debris removal using different irrigating needles: An SEM study

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Sheetal Ghivari

2011-01-01

Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by

Estresse crônico melhora a função miocárdica sem alterar a atividade do canal-L para Ca+2 em ratos

Directory of Open Access Journals (Sweden)

Thiago Bruder-Nascimento

2012-10-01

Full Text Available FUNDAMENTO: O estresse crônico está associado à remodelação cardíaca; entretanto, os mecanismos permanecem a ser descobertos. OBJETIVO: A proposta deste estudo foi testar a hipótese de que o estresse crônico promove disfunção cardíaca associada a depressão da atividade do canal-L para Ca2+. M MÉTODOS: Ratos Wistar machos com 30 dias de idade (70 - 100 g foram distribuídos dentro de dois grupos: controle (C e estresse crônico (St. O estresse consistiu na imobilização durante 15 semanas, cinco vezes por semana, 1 h por dia. A função cardíaca foi avaliada pela performance do ventrículo esquerdo por meio do ecocardiograma e pelo músculo papilar ventricular isolado. A função do músculo papilar foi avaliada em condição basal e com manobras inotrópicas, como: pós-pausa e elevação na concentração extracelular de Ca2+, na presença ou ausência de um bloqueador específico de canal-L para Ca2+. RESULTADOS: O estresse ficou caracterizado por hipertrofia das glândulas adrenais, aumento nos níveis de corticosterona circulante e por hipertensão arterial. Ainda, o estresse crônico gerou hipertrofia ventricular esquerda. O estresse crônico foi capaz de melhorar a resposta no músculo papilar para manobras inotrópicas positivas. A melhora de função não esteve associada com o canal-L para Ca2+. CONCLUSÃO: O estresse produziu hipertrofia cardíaca; entretanto, nos estudos de músculo papilar isolado, as manobras inotrópicas positivas potencializaram a função cardíaca em ratos estressados, sem o envolvimento do canal-L para Ca2+. Assim os mecanismos responsáveis permanecem incertos para alterações no influxo de Ca2+.

Spinal canal stenosis; Spinalkanalstenose

Energy Technology Data Exchange (ETDEWEB)

Papanagiotou, P.; Boutchakova, M. [Klinikum Bremen-Mitte/Bremen-Ost, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Bremen (Germany)

2014-11-15

Spinal stenosis is a narrowing of the spinal canal by a combination of bone and soft tissues, which can lead to mechanical compression of spinal nerve roots or the dural sac. The lumbal spinal compression of these nerve roots can be symptomatic, resulting in weakness, reflex alterations, gait disturbances, bowel or bladder dysfunction, motor and sensory changes, radicular pain or atypical leg pain and neurogenic claudication. The anatomical presence of spinal canal stenosis is confirmed radiologically with computerized tomography, myelography or magnetic resonance imaging and play a decisive role in optimal patient-oriented therapy decision-making. (orig.) [German] Die Spinalkanalstenose ist eine umschriebene, knoechern-ligamentaer bedingte Einengung des Spinalkanals, die zur Kompression der Nervenwurzeln oder des Duralsacks fuehren kann. Die lumbale Spinalkanalstenose manifestiert sich klinisch als Komplex aus Rueckenschmerzen sowie sensiblen und motorischen neurologischen Ausfaellen, die in der Regel belastungsabhaengig sind (Claudicatio spinalis). Die bildgebende Diagnostik mittels Magnetresonanztomographie, Computertomographie und Myelographie spielt eine entscheidende Rolle bei der optimalen patientenbezogenen Therapieentscheidung. (orig.)

Effects of irrigation solutions and Calcium hydroxide dressing on root canal treatments of periapical lesions

OpenAIRE

Nirmala, Vita

2006-01-01

The preparation of root canal in endodontic treatment plays an important role in treating non vital teeth with periapical lesion. Some factors influence the success of root canal treatment in short and long terms are the irrigation of root canal using antiseptic solution and the use of root canal medicament. The aim of this literature study is to determined the effect of irrigation solution and Calcium hydroxide dressing in root canal treatment of periapical lesions. The use of root canal med...

The Effects of NiTi Hand and Rotary Canal Master U and K-Flex Instrumentation of Root Canal Morphology

Science.gov (United States)

1992-09-01

Rotary Canal Master "U" and K-Flex Instrumentation of Root Canal Morphology 6. AUTHOR(S) Robert H. Haller 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES... endodontic failure. B. STATET OF THE PREL]2U Conventional endodontic instruments have re.nained basically unchanged since the introduction of the K-type...F;hcw"e that this nO𔃾 instruneent destim tended ti- produce rounder pr rMticns with • t!-rnnVortaticn than c rnvrnticnal 4 endodontic instruments

33 CFR 117.181 - Oakland Inner Harbor Tidal Canal.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Oakland Inner Harbor Tidal Canal. 117.181 Section 117.181 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Tidal Canal. The draws of the Alameda County highway drawbridges at Park Street, mile 5.2; Fruitvale...

File list: InP.CDV.05.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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File list: NoD.CDV.20.AllAg.Atrioventicular_canals [Chip-atlas[Archive

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Lifescience Database Archive (English)

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File list: NoD.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: NoD.CDV.10.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available NoD.CDV.10.AllAg.Atrioventicular_canals mm9 No description Cardiovascular Atrioventicular canals... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.CDV.10.AllAg.Atrioventicular_canals.bed ...

File list: NoD.CDV.05.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available NoD.CDV.05.AllAg.Atrioventicular_canals mm9 No description Cardiovascular Atrioventicular canals... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.CDV.05.AllAg.Atrioventicular_canals.bed ...

File list: InP.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.CDV.50.AllAg.Atrioventicular_canals mm9 Input control Cardiovascular Atrioventicular canals... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.CDV.50.AllAg.Atrioventicular_canals.bed ...

File list: InP.CDV.10.AllAg.Atrioventicular_canals [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.CDV.10.AllAg.Atrioventicular_canals mm9 Input control Cardiovascular Atrioventicular canals... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.CDV.10.AllAg.Atrioventicular_canals.bed ...

Evaluation of the anterior and posterior ethmoidal canal by computed tomography

International Nuclear Information System (INIS)

Cankal, F.; Apaydin, N.; Acar, H.I.; Elhan, A.; Tekdemir, I.; Yurdakul, M.; Kaya, M.; Esmer, A.F.

2004-01-01

AIM: To examine the anatomy, length and angulation of the anterior and posterior ethmoidal canals (AECs and PECs) using computed tomography (CT), and to determine the anatomical landmarks in which the canals are expected to be seen in transverse and coronal planes. MATERIALS AND METHODS: CT images of 150 patients were analysed. One, 2, and 3 mm thick sections were obtained separately in axial and coronal images. The frequency of visualization of the AECs and PECs, and if present, a third canal, was noted. The course and the angulation of the AEC and the PEC in transverse and coronal planes were recorded. On axial sections the distance between the AEC and PEC and the previously defined landmarks were measured. On coronal images, the distances were calculated from the thickness of the cross-section and the number of sections between the various structures. RESULTS: The AEC was identified as a separate canal in 84% of patients, and was embedded in the ethmoid roof in 16%. The PEC was seen as a separate canal in 8% and was present in the ethmoid roof in 92%. On the 1 mm thick coronal and transverse sections, a third canal was identified at the junction of the middle and posterior third of the AEC-PEC distance in both of the images. The average lengths of these canals were 4-12 mm (mean 8.2 mm) for the AEC, and 2-13 mm (mean 7.6 mm) for the PEC. CONCLUSIONS: To avoid the complications that can develop during endoscopic sinus surgery; the course, length and the angulations of the anterior and posterior ethmoidal arteries and their canals can be identified by CT in standard positions if a sufficiently thin section thickness is used. The present study has shown the exact CT localization of the AECs and PECS, which are frequently overlooked when evaluating para-nasal sinuses

[Quantitive study of interleukin 1beta in periapical exudates of chronic periapical periodontitis in the course of root canal therapy].

Science.gov (United States)

Yan, Pei-fang; Liang, Jing-ping; Chen, Wei-min; Gu, Shen-sheng

2007-06-01

To evaluate the relationship between IL-1beta and clinical findings of chronic apical periodontitis and to explore the function of IL-1beta during the endodontic interappointment flare-ups. Periapical exudates samples were obtained from 19 teeth suffering from endodontic flare-ups after root canal preparation and 20 teeth without any symptoms and signs at the second visit after root canal preparation. The levels of IL-1beta were determined by ELISA and the data was analyzed by SAS6.12 software package. Significantly higher levels of IL-1beta were found in periapical exudates from teeth suffering from endodontic flare-ups than that before canal preparation(Pendodontic therapy if there were no symptom at the second visit (Pendodontic interappointment flare-up.

Effectiveness of EDTA as the irrigation solution to remove smear layer in root canal

OpenAIRE

Kurniasri Amas Achiar; Endang Sukartini

2009-01-01

One of the objectives of successful endodontic treatment is the hermetic obturation of the root canal system. To achieve this, the root canal filling must seal the canal space both apically and coronally to prevent the ingress of microorganisms or tissue fluids into the canal space. Apical leakage is reported a common reason for the clinical failure of endodontic therapy. Leakage through an obturated root canal is expected to take place at interfaces between sealer and dentin or sealer and gu...

Magnetic Resonance Imaging Quantification of Lumbar Spinal Canal Stenosis in Symptomatic Subjects

Directory of Open Access Journals (Sweden)

Siddarth Ragupathi

2017-10-01

Full Text Available Introduction: Low backache is a common condition to occur in the middle age. It is mainly caused by the degeneration of the intervertebral disc which forms the main support to the vertebral column. Lumbar spinal canal stenosis results in the compression of spinal cord and nerves at the level of lumbar vertebra. Aim: The purpose of this study is to measure the spinal canal dimensions and correlate with the clinical symptoms to establish a radiological criterion based on MRI for diagnosis of lumbar canal stenosis. This study is done to improve the diagnostic accuracy of lumbar spinal canal stenosis. Materials and Methods: Two hundred subjects with complaints of low backache without a traumatic history underwent Magnetic Resonance Imaging (MRI after assessment of pain by two methods: 1. Oswestry Disability Index (ODI scoring and 2. Wong Baker Facial Expression scale. All the images were qualitatively analyzed to obtain the MRI grading for central canal at various levels from L1 to S1 vertebra after making sure that the neural foramina is not involved. Anteroposterior (AP and transverse diameter of spinal canal at intervertebral disc and upper part of vertebral body levels and spinal canal area are measurements that are taken. Descriptive and inferential statistical analysis has been carried out in the present study. Results on continuous measurements are presented on mean±SD (min-max and results on categorical measurements are presented in number (%. Significance is assessed at 5% level of significance. Results: The spinal canal diameter measured along its AP and transverse direction is found to be correlating with the severity of low backache complained by the patient. Comparing the two methods of clinical assessment, ODI scoring was found to be more significant. Conclusion: The spinal canal measurements can be used as a radiologic criterion for diagnosis of acquired lumbar spinal canal stenosis. This will improve the diagnostic accuracy. However

Cervical Cord-Canal Mismatch: A New Method for Identifying Predisposition to Spinal Cord Injury.

Science.gov (United States)

Nouri, Aria; Montejo, Julio; Sun, Xin; Virojanapa, Justin; Kolb, Luis E; Abbed, Khalid M; Cheng, Joseph S

2017-12-01

The risk for spinal cord injuries (SCIs) ranging from devastating traumatic injuries, compression because of degenerative pathology, and neurapraxia is increased in patients with congenital spinal stenosis. Classical diagnostic criteria include an absolute anteroposterior diameter of spinal cord, which varies across patients, independent of canal size. Recent large magnetic resonance imaging studies of population cohorts have allowed newer methods to emerge that account for both cord and canal size by measuring a spinal cord occupation ratio (SCOR). A SCOR defined as ≥70% on midsagittal imaging or ≥80% on axial imaging appears to be an effective method of identifying cord-canal mismatch, but requires further validation. Cord-canal size mismatch predisposes patients to SCI because of 1) less space within the canal lowering the amount of degenerative changes needed for cord compression, and 2) less cerebrospinal fluid surrounding the spinal cord decreasing the ability to absorb kinetic forces directed at the spine. Patients with cord-canal mismatch have been reported to be at a substantially higher risk of traumatic SCI, and present with degenerative cervical myelopathy at a younger age than patients without cord-canal mismatch. However, neurologic outcome after SCI has occurred does not appear to be different in patients with or without a cord-canal mismatch. Recognition that canal and cord size are both factors which predispose to SCI supports that cord-canal size mismatch rather than a narrow cervical canal in isolation should be viewed as the underlying mechanism predisposing to SCI. Copyright © 2017. Published by Elsevier Inc.

Evaluation of the root canal shaping ability of two rotary nickel-titanium systems.