External Ear Anthropometry and Sexual Dimorphism among Students of Bayelsa Medical University, Nigeria: A Cross-Sectional Study

External ear dimensions show population, age, sex and side-related variation, making auricular anthropometry relevant to forensic identification, reconstructive surgery, ergonomic design and biometric research. This cross-sectional study assessed selected external ear parameters among 308 students of Bayelsa Medical University, Yenagoa, Nigeria, comprising 160 males and 148 females. A digital vernier caliper was used to measure left and right ear length, ear width, lobular length and lobular width. Ear index was calculated as ear width divided by ear length multiplied by 100. Data were summarised using descriptive statistics and sex-based comparisons were performed with the independent samples t-test at a significance level of P < 0.05. Males had significantly greater left and right ear length than females, with both sides measuring 60.42 +/- 4.78 mm in males and 59.08 +/- 3.38 mm or 59.08 +/- 3.36 mm in females (P = 0.005). Ear width showed a larger sex difference, with males recording greater left ear width than females (35.78 +/- 2.16 mm versus 31.82 +/- 2.88 mm, P < 0.001) and greater right ear width than females (35.77 +/- 2.16 mm versus 31.84 +/- 2.89 mm, P < 0.001). Ear index was also significantly higher in males on both sides (P < 0.001), indicating broader auricular proportions. Lobular length did not differ significantly between sexes, while lobular width was significantly greater in females on both sides (P < 0.001). These findings demonstrate measurable sexual dimorphism in the external ear of the study population, particularly for ear width, ear index and ear length. The study provides population-specific reference values for young adult students in Bayelsa State and supports the use of auricular measurements as supplementary variables in forensic, anatomical and clinical contexts.