Determination of Sex from Mastoid Dimensions among North Indians

Abstract

Introduction: Sex determination is the keystone of a biological profile and skulls of unknown provenance are best tested for race and sex using different variables. Determination of sex from the skeleton is vital to medico legalinvestigations. The mastoid region is analysed for determination of sex from fragmentary crania in Forensic Anthropology as it is one of the most protected region and resistant to damage due to its anatomical position at the base of the brain.Objective: The purposeof this study was to determine the existence of sexual dimorphism in the dimensions of mastoid process among North Indians.Material and Method: Material for the study consisted of 70 adult (above 18 years) human skulls (35 of either sex) of North Indians obtained from Anatomy and Forensic department of SGRDIMSAR, Amritsar. Mastoid measurements (Length, Breadth and A-P diameter) of both the sides were taken in millimeters with the help of sliding Vernier Caliper and size of mastoid process was calculated.Results: All four mastoidvariables showed significant sexual dimorphismp<0.001. Canonical discriminant function Coefficient using stepwise analysis was -3.142 in females and 3.142 in males.In statistical analysis using Canonical Discriminant Functions, Eigen value was 10.015 and Wilks’ Lambda was 0.091.Conclusion: Accuracy of determination of gender using all four variables was 97.1% original and 96.4% cross- validated. Therefore, mastoid process can be used as a tool fordetermination of sex in fragmentary skeletal remains.