Blood Parameters and Feline Tooth Resorption: A Retrospective Case Control Study from a Spanish University Hospital.

Tooth resorption (TR; progressive destruction of hard dental tissues) varies in prevalence according to population, age, and country (29-66.1%). Our objective was twofold: describing the TR clinical presentation in Northeastern Spain, and studying 34 blood parameters to ascertain potential systemic effects associated with TR. Cases (29; presented from September 2018 to May 2019) and controls (58) were considered. Non-parametric tests were carried out to compare cases and controls for each blood parameter; those showing significant differences were chosen for multiple regression analysis (binomial logistic and hierarchical multiple regressions). In case TR was detected in 130/870 teeth (14.9%), TR stage and type were correlated (p < 0.001). Increasing CREA values (p = 0.034) and decreasing BUN/CREA and ALB/GLOB values were associated with TR presence (p = 0.029 and p = 0.03, respectively). Increasing GLOB was associated with increasing severity of TR (p < 0.01). Type 1 TR (highly related to inflammation and periodontal disease PD) was the most frequently observed type; the association of TR and inflammation biomarkers (ALB/GLOB, GLOB) are explained by this fact. The concomitant presence of PD and TR in old cats would cause TR association with kidney damage biomarkers (CREA, BUN/CREA). When affected by TR, special care in these aspects must be provided to cats.

Periodontal and Dental Status in Packs of Spanish Dogs.

While periodontal disease (PD) is the most common canine oral pathology, its prevalence varies according to diagnosis methodology, breed, and age. We intended to increase understanding of canine PD by studying dogs that are managed in a specific way: pack dogs in Spain. They received a mixed diet (home-prepared food, commercial dry food, stale bread and bones). Thirty-two conscious individuals from two packs of dogs in Northeastern Spain (30/32 crossbred hunting dogs and 2/32 Siberian Husky; 26 males and 6 females; 27.75 ± 5.807 kgs; 5.48 ± 2.818 years) received visual dental examination for assessment of absent teeth (AT), dental calculus (DC) grade, gingival recession (GR), periodontal disease (PD), tooth fracture (TF), and dental attrition (DA). DC was the most prevalent oral problem (75%), followed by TF/DA (68.75%), AT (34.37%), GR (31.25%), and, finally, PD (15.62%). Low individual affectation values were found for AT, GR, and PD (<1 tooth/individual); mean DC grade per individual was 0.06 ± 0.063; and TF and DA were found in 1.63 and 4.72 teeth/individual, respectively. Low prevalence and extent of PD was attributed to diagnosis methodology, bodyweight effect, breed, and, ultimately, diet. Individuals affected by DC remained under veterinary surveillance due to PD development.

Tooth Resorption in Spanish Domestic Cats: Preliminary Data.

The objective of this study was to collect preliminary data about tooth resorption (TR) from cats treated at the Odontology Service (September 2016-June 2018), part of a University Veterinary Hospital in Spain, with specific emphasis on TR distribution per tooth. Diagnosis was based on visual/tactile inspection and intraoral dental radiographs. This cross-sectional study was carried out on 59 adult cats (27 females, 32 males). TR occurred in 39/59 cats (66.1%; 95% CI: 54.0%-78.2%). The median number of lesioned teeth per TR-affected animal was 3. A highly significant but weak correlation was found for age and number of TR-affected teeth per individual (Spearman´s correlation ρ = 0.381, P = .003, power = 0.853; N = 59). No TR cases were detected in incisors (0/708, 0%) but TR occurred in canines (21/236, 8.9%; 95% CI: 5.4%-12.4%), premolars (78/590, 13.2%; 95% CI: 10.5%-15.9%), and molars (33/236, 14%; 95% CI: 9.7%-18.3%). A significant age influence on TR was found. The greatest TR occurrence corresponded to 307 (21/59; 35.6%; 95% CI: 23.4%-47.8%) followed by 409 (17/59; 28.8%; 95% CI: 17.2%-40.3%), 407 (16/59; 27.1%; 95% CI: 15.7%-38.4%), and 309 (16/59; 27.1%; 95% CI: 15.7%-38.4%). These teeth would be considered as TR-sentinels in the studied population. These findings are relevant for veterinarians working in dental clinics, where the TR prevalence may be high especially in older cats.

Interaction effect of tegmen tympani and superior semicircular canal statuses on the thickness of the roof of the glenoid fossa: a cross-sectional descriptive study.

PURPOSE: Homogeneous development of temporal bone structures is explained by their ontogenic origin; tegmen tympani (TT) and superior semicircular canal (SSC) are related with the glenoid fossa at the temporomandibular joint (TMJ). Therefore, our objective was to determine a possible relationship between TT status (dehiscence or integrity) and the roof of the glenoid fossa (RGF) thickness; SSC status has also been considered. METHODS: This cross-sectional descriptive study was conducted in two tertiary hospitals on 95 patients (109 ears) presenting hypoacusia, facial palsy, vertigo, tinnitus, and other single or combined symptoms, and submitted to a thin-section multidetector-row computed axial tomography (CT) scan. RESULTS: A significant interaction effect of TT × SSC statuses on RGF thickness was found (p = 0.049). A significant difference in RGF thickness was found only for SSC integrity status between TT integrity and TT dehiscence (p = 0.004). The TT dehiscence increased the risk for RGF dehiscence 12.047 times (p = 0.002). CONCLUSIONS: There is an interaction effect of the statuses of both TT and SSC on the thickness of the RGF, instead of an independent effect of the TT status. When RGF dehiscence is found, TT and SSC statuses should be assessed, to discard associated dehiscences.

Development of ossification in the vertical semicircular canals: tomographic study.

PURPOSE: To describe the ontogeny of vertical semicircular canals using computed tomography. MATERIALS AND METHODS: We have studied 39 human fetuses aged between 17 and 38 weeks of development through multi-helicoidal CT. RESULTS: The first signs of ossification in the semicircular canals, superior and posterior, are from 19 weeks of development, through two primary ossification centers in each canal, which will take part in the formation of the outer cover oriented towards the middle and posterior brain fossae, respectively. In this process it must be added the intervention of the common branch. Internal bone covers are formed by ossification of the fossa subarcuata in the superior semicircular canal, and from the compact center of the labyrinthine capsule into the posterior canal. The tomographic study has allowed us to demonstrate how ossification follows a variable rate, establishing a period between 21 and 26 weeks where there are completely closed canals with others still open to the brain fossae. CONCLUSIONS: The tomographic study of the semicircular canals has enabled us to establish a critical period in its ossification that could explain the etiology of the congenital-type dehiscence.

Influence of Sex and Age on Posterior Semicircular Canal Thickness.

OBJECTIVE: The aim of this study is to determine whether sex and age influence posterior semicircular canal (PSC) thickness. METHODS: This observational study was conducted in 3 tertiary hospitals. The minimal distance between the PSC and the posterior cranial fossa (PSC thickness) was estimated by thin-section multidetector row computed axial tomography (CAT) scan of the temporal bones. Nonselected consecutive patients of all ages (607 temporal bones) were considered. RESULTS: A significant effect was only detected for sex (F = 5.418, p = 0.020); PSC thickness showed a higher mean value in women (mean difference ± SE: 0.224 ± 0.096 mm). A significant and negative r value was detected for males aged >45 years (-0.173, p = 0.026); in that group of patients, PSC thickness decreased as age increased (0.018 ± 0.008 mm/year). For females aged ≤45 years, a significant and positive r value was found (0.198, p = 0.022); in that group, PSC thickness increased as age increased (0.020 ± 0.008 mm/year). CONCLUSIONS: PSC thickness did not significantly evolve with age in young males (≤45 years) but it decreased from age 45 years onwards. On the other hand, PCS thickness increased with age in women until the age of 45 years and it did not significantly change in older females.

Oral Disease and Microbiota in Free-Roaming Cats.

Oral health status was evaluated in 34 free-roaming cats that were submitted to a Trap-Neuter-Return program. Only 38.2% of individual cats showed oral disease. Periodontal disease (PD) was present in 6 cats ( 17.6%). Four cats (11.8%) showed feline gingivostomatitis, and clinical evidence of feline odontoclastic resorptive lesions was detected in only 3 animals (8.8%) by probing, but radiological studies would be necessary for reliable detection. Signs of PD occurred in 31.6% of teeth; only the less severe stages of PD were present. No retention of deciduous teeth, malocclusion, tumors, or dental fractures were found. Calicivirus was detected in 50% of the cats. The most frequent bacteria found were α-hemolytic Streptococcus (23.5%), Staphylococcus (17.6%), Neisseria (15.7%), and Pasteurella (11.8%). A significant association between age and oral disease was found (P = .001). The mean of bacterial strains/genus was higher in healthy mouths than in diseased mouths (4.5 vs. 2.1). In diseased mouths, Staphylococcus was the most frequently isolated genus (23.1%), whereas α-hemolytic Streptococcus was most prevalent in healthy mouths (33.3%). A significant association was detected between Porphyromonas and fungal isolation, with a fear concordance coefficient (κ = .334; P = .016).

Explicación ontogénica para la asociación entre dehiscencia del tegmen tympani y dehiscencia del canal semicircular superior / Ontogenetic explanation for tegmen tympani dehiscence and superior semicircular canal dehiscence association

Objetivos: Analizar la ontogenia del canal semicircular superior y del tegmen tympani y determinar si hay factores embriológicos comunes que expliquen la dehiscencia asociada de ambos. Métodos: Se han analizado 77 series embriológicas humanas de edades comprendidas entre las 6 semanas y recién nacidos. Las preparaciones estaban cortadas en serie y teñidas con la técnica de tricrómico de Martins. Resultados: La prolongación tegmentaria del tegmen tympani y el canal semicircular superior se originan de la misma estructura, la cápsula ótica, y poseen el mismo tipo de osificación endocondral; mientras que la prolongación escamosa del tegmen tympani se desarrolla desde la escama del temporal y su osificación es de tipo directa o intramembranosa. En la osificación de la prolongación tegmentaria colaboran los núcleos de osificación de los canales semicirculares superior, externo y accesorio del tegmen, los cuales por crecimiento se extienden hasta la prolongación tegmentaria, este hecho sumado a que ambas estructuras comparten una capa común de periostio externo podría explicar la coexistencia de falta de cobertura ósea en el tegmen y en el canal. Conclusión: El desarrollo del canal semicircular y tegmen tympani podrían explicar las causas de la asociación de ambas dehiscencias (AU)

Objectives: To analyze the ontogeny of the superior semicircular canal and tegmen tympani and determine if there are common embryological factors explaining both associated dehiscence. Methods: We analyzed 77 human embryological series aged between 6 weeks and newborn. Preparations were serially cut and stained with Masson's trichrome technique. Results: The tegmental prolongation of tegmen tympani and superior semicircular canal originate from the same structure, the otic capsule, and have the same type of endochondral ossification; while the extension of the squamous prolongation of tegmen tympani runs from the temporal squama and ossification is directly of intramembranous type. The nuclei of ossification of the superior and external semicircular canals and accessory of tegmen collaborate in the ossification of the tegmental extension and by growth extend to the tegmental prolongation. This fact plus the fact that both structures share a common layer of external periosteum could explain the coexistence of lack of bone coverage in tegmen and superior semicircular canal. Conclusion: The development of the semicircular canal and tegmen tympani could explain the causes of the association of both dehiscences (AU)

Ontogenetic explanation for tegmen tympani dehiscence and superior semicircular canal dehiscence association. / Explicación ontogénica para la asociación entre dehiscencia del tegmen tympani y dehiscencia del canal semicircular superior.

OBJECTIVES: To analyze the ontogeny of the superior semicircular canal and tegmen tympani and determine if there are common embryological factors explaining both associated dehiscence. METHODS: We analyzed 77 human embryological series aged between 6 weeks and newborn. Preparations were serially cut and stained with Masson's trichrome technique. RESULTS: The tegmental prolongation of tegmen tympani and superior semicircular canal originate from the same structure, the otic capsule, and have the same type of endochondral ossification; while the extension of the squamous prolongation of tegmen tympani runs from the temporal squama and ossification is directly of intramembranous type. The nuclei of ossification of the superior and external semicircular canals and accessory of tegmen collaborate in the ossification of the tegmental extension and by growth extend to the tegmental prolongation. This fact plus the fact that both structures share a common layer of external periosteum could explain the coexistence of lack of bone coverage in tegmen and superior semicircular canal. CONCLUSION: The development of the semicircular canal and tegmen tympani could explain the causes of the association of both dehiscences.

Association Between Tegmen Tympani Status and Superior Semicircular Canal Pattern.

OBJECTIVE: Detecting and quantifying the possible association between tegmen tympani (TT) status and superior semicircular canal (SSC) pattern. DESIGN: Observational study. SETTING: Study conducted in three tertiary Spanish hospitals. PATIENTS: Nonselected consecutive patients of all ages (607 temporal bones). INTERVENTIONS: Thin-section multidetector row computed axial tomography (CAT scan) of the temporal bones. MAIN OUTCOME MEASURE: Thickness of SSC bone coverture adjacent to the middle fossa, and TT status as a dichotomous variable: dehiscence (TTD) or integrity (TTI). RESULTS: The observed SSC patterns were dehiscence (3.79%), papyraceous or thin (11.20%), normal (76.77%), thick (4.94%), and pneumatized (3.29%). The observed TT statuses were TTD (10.87%) and TTI (89.13%). TTD was associated with SSCD and papyraceous patterns, and TTI percentages were higher in normal and thick patterns (χ2 = 11.102; p = 0.001). The TTD probability was estimated as a function of SSC pattern and age by a multivariate binary logistics regression model (χ2 = 45.939; p < 0.001). CONCLUSION: SSC pattern was significantly associated with TT status. Age influenced this association. The risk for TTD increased by 4.1% per each year of increasing age, did not differ significantly for normal and thick patterns, and increased 12 times and 20 times for papyraceous and SSCD patterns, respectively.

Peculiaridades en el desarrollo del canal semicircular superior / Peculiarities in the development of the superior semicircular canal

Objetivos: Realizar un estudio sobre la ontogénesis del canal semicircular superior con el fin de describir sus peculiaridades. Métodos: Para ello se han analizado 76 series embriológicas humanas de edades comprendidas entre los 32 días (6 mm) y recién nacidos. Las preparaciones estaban cortadas en serie y teñidas con la técnica de tricrómico de Martins. Resultados: En el desarrollo del canal semicircular hemos observado una serie de peculiaridades, como: secuencia cronológica definida de su osteogénesis con un ritmo de osificación variable, cada núcleo de osificación interviene en la formación de una de sus cubiertas, el superior de la superficial y el inferior de la profunda; la aparición de una dehiscencia transitoria, y el cierre del canal por hueso de tipo laminar con un grosor mínimo de 0,1 mm. Conclusión: Las peculiaridades en el desarrollo del canal podrían explicar las causas del origen de la dehiscencia patológica del mismo, ya sean congénitas o adquiridas (AU)

Objective: Our objective was to study the ontogeny of the superior semicircular canal in order to describe its peculiarities. Methods: We analyzed 76 series of human embryos aged between 32 days (6 mm) and newborns. The samples were cut serially and stained using Martin's trichrome technique. Results: In semicircular canal development there were a number of peculiarities, such as: a defined chronological sequence of osteogenesis with a variable rate of ossification; the fact that each nucleus of ossification was involved in the formation of one of its covers (the upper in the superficial and the lower in the deep); the appearance of transitory dehiscence; and canal closure by means of bone with laminar pattern, with a minimum thickness of 0.1 mm. Conclusion: The peculiarities in canal development could explain the origin of pathological dehiscence in the canal, whether congenital or acquired (AU)

[Peculiarities in the development of the superior semicircular canal]. / Peculiaridades en el desarrollo del canal semicircular superior.

OBJECTIVE: Our objective was to study the ontogeny of the superior semicircular canal in order to describe its peculiarities. METHODS: We analyzed 76 series of human embryos aged between 32 days (6mm) and newborns. The samples were cut serially and stained using Martin's trichrome technique. RESULTS: In semicircular canal development there were a number of peculiarities, such as: a defined chronological sequence of osteogenesis with a variable rate of ossification; the fact that each nucleus of ossification was involved in the formation of one of its covers (the upper in the superficial and the lower in the deep); the appearance of transitory dehiscence; and canal closure by means of bone with laminar pattern, with a minimum thickness of 0.1mm. CONCLUSION: The peculiarities in canal development could explain the origin of pathological dehiscence in the canal, whether congenital or acquired.

Radiological patterns of the posterior semicircular canal.

OBJECTIVES: The identification and definition of the radiological patterns of the posterior semicircular canal (PSC), with a view to obtain readily applicable conclusions. DESIGN: The parietal morphology of the PSC has been studied by multi-slice helical computed tomography (Philips Brilliance 6). We have determined the distribution of the different types of bone cover of the PSC, taking some previously notified, standardised measurements of normality as reference. RESULTS: 318 patients have been analysed (604 petrous bone) by CT and we have distinguished five different radiological patterns: type or normal, thick, thin, pneumatised and dehiscent. The first three patterns, normal, thick and thin, have in common the existence of a compact bone interposed between PSC and posterior fossa, being in the normal pattern has a thickness of between 0.9 and 2.5 mm (327 cases, 54.13%), in the thick pattern is ≥2.6 mm (99 cases, 16.39%) and in the thin pattern is ≤1.2 mm (158 cases, 26.15%). The fourth pattern, pneumatised, is characterised by having retro labyrinthine cells between PSC and media fossa (19 cases, 3.14%). Finally, a dehiscent pattern was observed in 2 cases (0.3%). CONCLUSION: We describe five different radiological patterns: type or normal, thick, thin, pneumatised and dehiscent. The thin type (<0.5 mm or papyraceous type) and the dehiscent type would be subject to producing pathology, and in some cases the latter could be a consequence of the former.

Influencia de la existencia de una dehiscencia en un canal semicircular en el espesor óseo de los canales contralaterales / Effect of semicircular canal dehiscence on contralateral canal bone thickness

Objetivos: Determinar si la existencia de un canal semicircular superior o posterior dehiscente se asocia con el adelgazamiento de la cubierta ósea en el resto de los canales verticales (superior o posterior). Métodos: Se estudia mediante tomografía computarizada y se compara estadísticamente el espesor de los canales semicirculares superiores y posteriores contralaterales a una dehiscencia. Resultados: Cuando un canal semicircular superior presentaba una dehiscencia, el canal contralateral mostraba un adelgazamiento significativo de su espesor con una media de 0,5mm (DE:0,3mm). No sucede lo mismo con los posteriores que no modifican su grosor de 2,1mm (DE: 1,2mm; p=0,49).Cuando un canal semicircular posterior presentaba dehiscencia no se observó adelgazamiento significativo en los canales semicirculares superiores 1mm (DE:0,4), ni en el posterior contralateral 1,3mm (DE:0,3). Conclusión: La existencia de una dehiscencia del canal semicircular superior se asocia al adelgazamiento del hueso del canal del lado contrario, pero no de los canales semicirculares posteriores. No ocurre lo mismo si la dehiscencia es del canal semicircular posterior, que no altera de manera significativa el espesor del canal del lado contralateral ni en los superiores (AU)

Objectives: Our objective was to determine if the existence of dehiscence in the superior or posterior semicircular canal was associated with the thinning of the bone roof in the rest of the vertical canals (superior or posterior). Methods: The thickness of the superior and posterior semicircular canals contralateral to a dehiscence was studied using computerized tomography and compared statistically. Results: When a superior semicircular canal had a dehiscence, the contralateral canal showed a significant mean decrease in its thickness of 0.5mm (SD: 0.3mm). This was not the case if the dehiscence was in the posterior semicircular canal, where the thickness of 2.1 mm remained unchanged (SD: 1.2mm; P=0.49).When a posterior semicircular canal showed dehiscence, no significant thinning was shown in the superior semicircular (1mm; SD: 0.4) or in the posterior contralateral (1.3mm; SD: 0.3) canals. Conclusion: The existence of a dehiscence in the superior semicircular canal is associated with bone thinning in the canal on the opposite side, but not with the posterior semicircular canal. In contrast, if the dehiscence is in the posterior semicircular canal, contralateral and superior canal thickness is not modified (AU)

Congenital dehiscence in the posterior semicircular canal.

HYPOTHESIS: Posterior semicircular canal dehiscence (PSCD) may be of congenital origin. BACKGROUND: PSCD is characterized by the lack of bone coverage, which results in its lumen being exposed to the meninges of the posterior cranial fossa or to the gulf of the jugular vein. It has an incidence of 0.2%. Its presence has been associated with several well-defined entities, although a congenital origin has not been proven. METHODS: We have analyzed, from a macroscopic, microscopic, and radiologic (computed tomography) viewpoint, the right temporal bone of a 32-week-old human fetus that presented a defect in the bone coverage located in the rear. RESULTS: The macroscopic study showed a solution of continuity in the posterior semicircular canal, with elliptic morphology and smooth edges. This defect was 3.4 mm long with a width that varied between 0.67 mm in its apical portion and 1.42 in the basal portion. The radiologic study (computed tomography) showed the absence of bone coverage of the posterior semicircular canal, which was open to the intracranial space in the posterior fossa. Its histologic study showed good bone coverage of this canal at the expense of compact bone tissue. However, at the medial end, there is a lack of bone coverage, resulting in the lumen of the canal being open to the intracranial space. The bone edges of the defect did not present any osteoclast activity. CONCLUSION: The lack of bone coverage (dehiscence) of the posterior semicircular canal in a 32-week-old fetus suggests a congenital component of bony dehiscences of this canal. Even so, this single finding does not conclusively prove the congenital component, and the dehiscence is a finding that can be part of and not by itself a syndrome.

Effect of semicircular canal dehiscence on contralateral canal bone thickness.

OBJECTIVES: Our objective was to determine if the existence of dehiscence in the superior or posterior semicircular canal was associated with the thinning of the bone roof in the rest of the vertical canals (superior or posterior). METHODS: The thickness of the superior and posterior semicircular canals contralateral to a dehiscence was studied using computerized tomography and compared statistically. RESULTS: When a superior semicircular canal had a dehiscence, the contralateral canal showed a significant mean decrease in its thickness of 0.5mm (SD: 0.3 mm). This was not the case if the dehiscence was in the posterior semicircular canal, where the thickness of 2.1 mm remained unchanged (SD: 1.2 mm; P=.49). When a posterior semicircular canal showed dehiscence, no significant thinning was shown in the superior semicircular (1 mm; SD: 0.4) or in the posterior contralateral (1.3 mm; SD: 0.3) canals. CONCLUSION: The existence of a dehiscence in the superior semicircular canal is associated with bone thinning in the canal on the opposite side, but not with the posterior semicircular canal. In contrast, if the dehiscence is in the posterior semicircular canal, contralateral and superior canal thickness is not modified.

Radiological patterns of the bony roof of the superior semicircular canal.

OBJECTIVES: To study the radiological patterns of the bony roof of the superior semicircular canal with a view for obtaining readily applicable conclusions. DESIGN: 84 patients (163 petrous bones) have been studied by Multi-slice Helical Computed tomography (Philips Brilliance 6). We have determined the distribution of the different types of bone cover of the superior semicircular canal, taking some previously notified, standardised measurements of normality as reference. RESULTS: During the analysis of the roof of the superior semicircular canal, we have distinguished five different types, depending on their thickness and tomodensitometric aspect. Normal pattern in 121 cases (74.2 %), with a thickness of between 0.6 and 1.7 mm, papyraceous pattern or fine thickness ≤0.5 mm that appears in 23 of our cases (14.1 %), thick pattern ≥1.8 mm that we have observed in 11 cases (6.7 %), and pneumatised pattern in 5 cases (3.1 %), which is characterised by having supralabyerinthine cells. Finally, a dehiscent pattern was observed in three cases (1.8 %). CONCLUSION: We describe five patterns of superior semicircular canal roofs: normal, thick, papyraceous, pneumatised and dehiscent. The papyraceous type and the dehiscent type would be subject to producing pathology, and in some cases the latter could be a consequence of the former.

Peculiaridades anatómicas del canal semicircular superior y su posible implicancia clínica / Anatomical peculiarities of the superior semicircular canals and its possible clinical implication

El objetivo fue estudiar las peculiaridades en la morfología apical del canal semicircular superior, a nivel de la eminencia arcuata con la finalidad de obtener conclusiones aplicativas. Se estudiaron 48 cabezas de cadáveres humanos (96 huesos temporales), con la intención de identificar la presencia de adelgazamiento o dehiscencia del canal semicircular superior, así como la existencia de surcos vasculares de la eminencia acuata que, discurriendo sobre el techo del canal, pudieran afectar a su integridad anatómica. El estudio incluye un análisis histológico (Tricrómico de Martins) y radiológico (Tomografía Computarizada) de los hallazgos positivos (dehiscencias y adelgazamientos), así como estudio tomográfico de los canales con surcos vasculares visibles. En un caso (1,04 por ciento hemos observado cómo el canal presentaba un defecto óseo completo (dehiscencia), en tres (3,12 por ciento) el canal presentaba una pared muy delgada cuyo grosor no excedía de 0,2 mm. En 12 casos (12,5 por ciento) la eminencia arcuata estaba recorrida por surcos por el que discurrían vasos colaterales meníngeos, que determinaron una concavidad entre 0,1 y 0,2 mm, mientras que el grosor medio de dicha pared en estos casos fue de 1,2 mm. De las tres peculiaridades estudiadas, la falta de cobertura ósea es la que produce el síndrome de dehiscencia del canal semicircular superior. Los canales que presentaban una cubierta adelgazada pueden estar predispuestos a una rotura y por lo tanto causar patología en el canal. En cambio la presencia de surcos vasculares que recorren la superficie apical del canal, no parece tener consecuencias al disminuir minimamente su grosor...

The aim was to study the peculiarities in apical morphology of the superior semicircular canal are studied at level of the arcuate eminence to obtain application conclusions. We have studied 48 heads from human cadavers (96 temporal bones), with the intention of identifying the presence of thinning or dehiscence in the superior semicircular canal, as well as the existence of vascular sulci of the arcuate eminence, which, traveling along the roof of the canal, may affect its anatomical integrity. The study includes a histological (Martin's Trichome method) and a radiological analysis (Computerized Tomography) of the findings (dehiscences and thinnings), and as well as tomographic study of the canals with visible vascular sulci. In one case (1.04 percent we have observed how the canal presented a complete bone defect (dehiscence), in three (3.12 percent), presented a very thin wall, which did not exceed 0.2 mm thick. In 12 cases (12.5 percent) sulci covered the arcuate eminence through which meningeal collateral vessels ran, which determined a concavity of between 0.1 and 0.2 mm, whilst the average thickness of this wall in these cases was 1.2 mm. Of the peculiarities studied, the lack of bone coverage is what produces the dehiscence syndrome of the superior semicircular canal. The canals that had a reduced coverage may be predisposed to breakage and therefore cause pathology in them. On the other hand, the presence of vascular sulci that ran along the apical surface of the canal seems to have no consequences to decrease their thickness...

Influence of aging and menopause in the origin of the superior semicircular canal dehiscence.

OBJECTIVE: Determine if aging and menopause, known to be associated with bone resortion, also are associated with superior semicircular canal dehiscence. DESIGN: Observational study. SETTING: Study conducted in 3 tertiary Spanish hospitals. PATIENTS: Nonselected consecutive patients of all ages. INTERVENTIONS: Thin-section multi-detector row computed tomographic scan of the temporal bones. MAIN OUTCOME MEASURE: The minimum thickness of the bone covering the roof of the superior semicircular canal (SSC) measured in each temporal bone. The outcome was studied both as a continuous and as a dichotomous variable: thin (<0.6 mm) and normal (≥ 0.6 mm). RESULTS: Five hundred eighty-two ears of 312 patients were included in the study. Fifty-five percent of the sample were women. Patient's age ranged from 2 to 88 years. A 40-year age difference between ears was associated with a decreased thickness of bone covering the SSC of 0.10 mm, which is 10% of the average thickness of such bone. The thickness of the bone overlying the SSC of subjects younger than 45 years was an average of 1.14 mm (SD, 0.52 mm), whereas that of the subjects older than 45 years was equal to 1.02 mm (SD, 0.45 mm; p = 0.006). The percentage of ears with thin bone coverage of SSC was 7.1% in subjects younger than 45 years and 13.8% in those older than 45 years (p = 0.013). CONCLUSION: Our data support the hypothesis that there is a slight osteopenia of the roof of the superior semicircular canal associated with aging, and this effect seems to be more pronounced in menopausal women.