The anterior dimensions of the pelvis in male and female Nigerians. 
A retrospective study on the anteroposterior X-ray films of the pelvis of 40 male, and 31 female Nigerians was undertaken to verify if there was any significant difference in the values of the transverse diameter of the inlet (TID), bicristal diameter (BCD), bituberal diameter (BTD), and subpubic angle (SA) between the male and the female, between the younger age group (21-45 years) and the older age group (46-70 years) in each sex, using the student's t-test.  Results showed that TID, BTD and SA each was significantly greater in the female than in the male (P < 0.001).  BCD showed no significant difference between the sexes (P > 0.05).  SA was significantly greater in the older age group than in the younger age group (P < 0.05) while the other variable showed no significant difference.  TID showed significant positive correlation with BCD, and BTD in the female (P < 0.05), and with BCD, BTD, and SA in the male (P < 0.05).  The value of SA in female is obtuse but overlaps between acute and obtuse in males.  Ninety-three per cent of the female pelvis had subpubic angle above the 111.3 degrees demarking point (DP) but none of the male or female pelvis was marked out by the lower or upper demarking points of BCD, suggesting a relevance of DP of SA in sex discrimination.  The mean ratio of TID to BTD was 1.5:1 in the male and 1.2:1 in the female suggesting a gynaecoid tendency in the latter.  This study provided data that can be useful for clinical and radiological pelvimetry for use in obstetrical care of Nigerian women, and normal values for Nigerian male and female.