Mandible: An indicator for sex determination - A three-dimensional cone-beam computed tomography study

Background: Mandible is considered as one of the stronger bones of skull available for gender identification. Mandibular measurements can be used for the identification of gender either on dry mandible or through panoramic radiography or cone-beam computed tomography (CBCT). Aim: To determine the gender from mandibular measurement using CBCT. Materials and Methods: The Morphometric analysis was performed on 200 CBCT scans of the subjects using OnDemand 3D software (Seoul, Korea). Morphometry of mandibular is measured by estimation of the angles formed at different locations on mandible to predict the gender. Statistical analysis was performed; independent samples "t-" test was used to compare the mean values between males and females. Discriminant function analysis was used for gender prediction. Results: The subject's age ranged from 18 to 60 years with an equal number of males and females. The mean angle formed by the intersection of lines from the left and right gonion to menton in males was 129.9 +/- 11.9 and it was 126.7 +/- 12.6 in females. The mean linear distances from the right gonion to menton in both males and females were 86.8 +/- 5.3 and 82.6 +/- 6.2, respectively. The mean linear distances from the left gonion to menton were 49.5 +/- 5.1 in males and 47.7 +/- 3.9 in females. The mean linear distance from the right gonion to left gonion was 47.7 +/- 4.4 in males and 46.6 +/- 4.2 in females. The Box's M statistics was applied to verify the applicability of mandibular measurements in gender prediction. The values indicate that gender can be predicted using these four variables, which is statistically significant (P = 0.000). The overall prediction accuracy of this model was 67%, with 66.7% in males and 67.3% in females being correctly classified. Conclusion: The angle formed by the intersection of lines from the left and right gonion to menton (Gn-M0) helps provide anthropological data, which can be used in dental and medicolegal practices.