Introduction: The existence of sexual dimorphism in human skeletons especially skull and its medico-legal importance had long been studied [3] [2,1]. This study has investigated the existence of sexual dimorphism in cranial dimensions of Nigerian population.

Methods: A total of 100 adult dry skulls, (78 males, 22 females) free from damage and deformity fully ossified from Departments of Anatomy in Nigerian Universities were used for this study. Spreading calliper, measuring tape were used to measure the following parameters, bregma-lambda, lambda- inion, nasion-bregma, nasion-inion, basion-bregma. Graph pad prism version 5.0 was used to analyze the data, coefficient of variation, correlation, linear regression, percentiles, sexual dimorphism ratio were computed. Student‘s T-test was used to compare male-female and right-left measurements.

Results: The results indicate that the male parameters were higher than female parameters and statistically significant at P<0.05 in all. The length of Bregma-Lambda of male and female were 126.3 ± 0.85mm and 118.1±1.54 mm respectively. The length of lambda -inion of male and female were 71.31± 0.82mm and 60.01± 1.53 mm respectively. The length of nasion -bregma of male and female were 135.8± 1.16mm and 128.8.1± 3.17 mm respectively. The length of nasion-inion of male and female were 170.7± 0.93 mm and 157.5±1.34 mm respectively. The length of basion-bregma of male and female were 140 ±0.73 and 132 ±1.73 mm respectively. Sexual dimorphism ratio was greater than unity in all.

Conclusion: The anthropometry of these cranial dimensions can be a guide in gender determination of unknown individuals and a guide to surgeons in face of surgical intervention.