Sexual Dimorphism and Sex Prediction using Auricular Morphometry among Selected Ethnic Groups in Delta State, Nigeria

Abstract

Introduction: Auricular morphometry has emerged as a reliable tool in forensic identification due to its uniqueness, stability, and sexual dimorphism. However, population-specific data among Nigerian ethnic groups remain scarce. Aim: This study was done to evaluate sexual dimorphism in auricular morphometric parameters and to determine the most reliable predictor for sex estimation among selected ethnic groups in Delta State, Nigeria. Methods: A cross-sectional study was conducted among 4,000 adults (2,000 males and 2,000 females) aged 18-65 years from five ethnic groups in Delta State, Nigeria. Standard anthropometric techniques using a digital vernier calliper were employed to measure total ear height (TEH), ear width (EW), lobule height (LH), lobule width (LW), tragus length (TL), conchal height (CH), and conchal width (CW). Independent sample t-tests and discriminant function analysis were used to evaluate sexual dimorphism and predictive accuracy. Results: From the results, males demonstrated significantly larger values in TEH, EW, CH, and CW compared to females (p < 0.05). Tragus length exhibited reverse sexual dimorphism. Conchal height showed the highest discriminative power for sex estimation. The discriminant model improved accuracy when multiple variables were combined. Conclusion: Sexual dimorphism exists in auricular dimensions among ethnic groups in Delta State. Conchal height is the strongest single predictor of sex, while multivariate models enhance classification accuracy. Auricular morphometry can serve as a supplementary forensic identification tool in Nigerian populations.