Bifurcation of the mandibular canal according to sex, age, and facial skeletal pattern: a morphological and morphometric study of cone beam computed tomography.

PURPOSE: To assess the presence of mandibular canal bifurcation (BMC) and classify these variations by correlating findings with sex, age and facial skeletal pattern, measurements were made, including height, width, and distance from bifurcation to anatomical cortical bones. METHODS: BMC was identified in cone beam CT exams of 301 patients and classified according to its origin, location, direction, configuration and ending. The height and width of the MC before and after the bifurcation; height and width of the BMC; and distance from BMC to alveolar (C1), buccal (C2), lingual (C3) and basal (C4) bone cortices were measured. All data were correlated with sex, age, and facial skeletal pattern (class I, II, III). The significance level was 5%. RESULTS: 67 BMC (22.26%) were identified in 55 patients (18.28%). Bifurcations were more prevalent in females (p = 0.57), aged 18-39 years (p = 0.40), class I (p = 0.77). Single bifurcations, located in the posterior region of the mandible, originating in the MC, with a superior direction and ending in the retromolar foramen were more prevalent (p > 0.05). Mean cortical measurements were higher in male individuals, with significant differences only at C1 (p = 0.03). The mean height and width of BMC were 2.24 (± 0.62) and 1.75 (± 0.45) mm. There was no association between BMC classification and the variables studied (p > 0.05). CONCLUSION: Approximately 1/5 of the population studied had BMC. There were no associations of BMC presence or characteristics with sex, age, and facial skeletal pattern. The distance from bifurcation to alveolar (superior) cortical bone is greater in male individuals.

Comparison of different methods of analysis of maxillary sinus volume and validation of a new proposal using cone beam computed tomography.

PURPOSE: develop and validate a formula, through a discriminant analysis of sex estimation, evaluating maxillary sinus in cone beam computed tomography scans in a Brazilian population, comparing this formula with two other existing ones. METHODS: 190 cone beam CT scans of Brazilian adults were retrospectively evaluated by an independent examiner. Measurements were performed in the right and left MS region: height, width, length, distance between the breasts, distance between infraorbital foramina, and volume in the ITK software. The sample was divided into female and male. T test, ANOVA, Tukey test and the ROC Curve was performed (p > 0,05). RESULTS: statistically significant differences were found in relation to the maximum height of the MS both right (p = 0,001) and left (p = 0,026) between sexes and the maximum length in the right MS (p = 0,01). Regarding the comparison of MS volume according to the different analysis methods, statistically significant differences were found between sexes for the right MS when using the method by Bangi et al. (p = 0,012) and the volume of the left MS in females (p < 0,001). Comparing the three classification models, statistically significant differences were found between the proposed method and the classification by Bangi et al. (p < 0.007). The ROC curve showed greater accuracy in the classification proposed in this work. CONCLUSION: the new proposed formula obtained better predictions of sexual dimorphism, when compared to classifications already described in the literature.

Prevalence, morphology, and morphometry of anatomical variations of the clivus: a cone beam computed tomographic study.

The purpose of this study was to evaluate the prevalence and characteristics of 3 anatomical variations of the clivus: fossa navicularis magna (FNM), canalis basilaris medianus (CBM), and craniopharyngeal canal (CPC). Findings were correlated with sex, age, and facial skeletal pattern. A total of 602 cone beam computed tomography scans of Brazilian adults were retrospectively evaluated by 2 independent examiners. The presence of an FNM, CBM, or CPC was recorded, and length, depth, and width were measured. The CBM was classified according to type (3 complete and 3 incomplete varieties). All data were correlated with sex, age, and facial skeletal pattern. Results were tested using chi-square, Mann-Whitney U, and Kruskal-Wallis tests (P < 0.05). The prevalence rates for FNM, CBM, and CPC were 15.78% (n = 95), 6.64% (n = 40), and 0.17% (n = 1), respectively. No significant differences in the prevalence of the variations were found based on sex or facial skeletal patterns (P > 0.05). The median length, depth, and width of FNM were 5.55, 1.83, and 4.81 mm, respectively, with no significant differences (P > 0.05) between the variables. The prevalence of FNM was significantly higher in patients aged 18 to 33 years than in those aged 34 and older (P < 0.001). An incomplete variant of the CBM, presenting as an inferior recess, was more common (32.5%). The FNM is the most prevalent anatomical variation of the clivus, especially in young adults. The sex and facial skeletal pattern of the individual do not affect the frequency of FNM, CBM, or CPC. Because of their clinical relevance, recognition of these anatomical variations is essential, as they can be misdiagnosed as pathologies.