Sex determination of human crania using Mastoid triangle and Opisthion–Bimastoid triangle

In the present study an attempt has been made to establish standards for sex determination from the various direct and indirect measurements of the cranium. A total of 100 cranium (50 of either sex) were measured for nine direct measurements pertaining to Mastoid triangle and Opisthion–Bimastoid triangle. These measurements were used further to calculate four indirect measurements pertaining to the calculation of Opisthion–Bimastoid triangle area and angles.Analysis of data reveals that the male crania exhibit greater values for all the measurements except the angle right Mastoidale–Opisthion–left Mastoidale. The sex difference has been observed to be statistically significant for all the measurements except for the angles of the Opisthion–Bimastoid triangle. Sectioning point was calculated for the diagnosis of sex based on the mean values of these measurements; the accuracy of sex determination varied from measurement to measurement. The highest value for determining sex was obtained for Asterion–Mastoidale length of right side i.e. 80%, followed by Bi-mastoid breadth i.e. 75%. This suggests that these measurements could be used with relatively high degree of accuracy in determining sex of the unknown crania.