EVALUATION OF SEXUAL DIMORPHISM USING PALPEBRAL FISSURE DIMENSIONS IN ASARI-TORU LOCAL GOVERNMENT AREA

Sexual dimorphism in facial morphology plays a critical role in forensic identification, clinical assessment, and anthropometric research. This study examined sexual dimorphism in palpebral fissure parameters among adults in Asari-Toru Local Government Area, Rivers State, Nigeria. A total of 412 participants (192 males and 220 females) aged 18–60 years were assessed using standard anthropometric techniques. The mean palpebral fissure width (PFW) was 32.17 ± 2.79 mm in males and 32.04 ± 2.97 mm in females; palpebral fissure height (PFH) 9.48 ± 1.49 mm and 9.51 ± 1.56 mm; palpebral angle 16.47 ± 2.73° and 16.62 ± 2.88°; inner canthal distance (ICD) 34.69 ± 3.33 mm and 34.04 ± 2.89 mm; and outer canthal distance (OCD) 98.51 ± 6.07 mm and 97.75 ± 5.87 mm, respectively. Independent t-tests and ANOVA revealed that only ICD showed a statistically significant sex difference (p = 0.034), while other parameters showed no significant variation with sex or age (p > 0.05). Logistic regression analysis indicated limited predictive power of palpebral measurements for sex determination (Nagelkerke R² = 0.02; classification accuracy = 54.9%). These findings suggest that ICD may serve as an auxiliary marker in forensic and anthropometric evaluations; however, palpebral fissure dimensions alone are insufficient for reliable sex classification. The study highlights the importance of establishing population-specific reference standards for facial morphometry in African populations.