Discriminant function analysis of craniometric traits for sexual dimorphism and its implication in forensic anthropology

Abstract

Introduction: Determination of sex from bony elements is the fundamental step to human virtue. Scholars agree highly accurate sex identification can be done from adult skulls. Direct assessment of the bones is not always the most appropriate or practical. Medical advances have provided cross-sectional slices of scanned individuals in the form of computed tomography (CT). The aim of the present study was to examine the reliability of cranial measurements for sex differences in CT head scan records of adult live subjects to the highest possible percentage in South Indians and to develop discriminant function equations. Material and Methods: Seventy head CT records were taken and 16 parameters were measured using RadiAnt DICOM viewer software. Statistical analysis was performed using descriptive statistics, Student's t-test, and discriminant function analysis. Results: The classification accuracy obtained by multivariate analysis of all 16 variables was 97.1%, multivariate analysis of nine most significant variables was 91.4% and by stepwise was 92.9% and that by univariate analysis for bizygomatic breadth, orbital breadth, basion-bregma height, and inter-orbital breadth was 81.4%, 74.3%, 72.9%, and 70%, respectively. Discussion and Conclusion: Multivariate analysis gave the highest classification accuracy and bizygomatic breadth, orbital breadth, basion-bregma height, and inter-orbital breadth were the most dimorphic variables in the study population and several other populations, and thereby should always be considered in the sex determination of humans. The study derived specific discriminant functions for sex determination in the South Indian population, providing a population-specific data for sex determination using craniometric parameters in the South Indian population and for future studies on skeletalized remains.