The Discriminant Formula for the Determination of Sex of Adults in A Nigerian Population (Using Pelvic Radiographs)

Abstract

Identification of sex in human skeletal remains is an important component and frequently the starting point of many forensic anthropological investigations. This study was carried out to document the determination of sex by discriminant formula using the pelvic radiographs of Nigerian adults. Measurements were carried out on the pelvis. Pelvic radiographs of 500 adult Nigerians of known sex, age range 18-75 years (comprising 250 males and 250 females) were measured in the antero-posterior position using a digital vernier calliper. The data was analysed using z-test. The results showed that the mean values for the Ischial length and Pubic length in males were 86.82±8.25mm and 76.41±8.91mm respectively while in females the Ischial length and Pubic length were 80.62±7.66mm and 84.58±8.80mm respectively. 4% males and 19% females were identified for ischial length and 15% males and 42% females were identified for pubic length. The mean value for pelvic height in males and females were 236.70±12.51mm and 223.02±12.18mm respectively, the demarking points identified 29% males and 32% females, while the mean value for midpubic width in males and females were 25.94± 4.54mm and 30.09± 3.67mm respectively, the demarking points identified 40% and 65% females. The mean values for ischiopubic and pelvic height/midpubic width were statistically significant (P<0.05). The mean values of the pelvic height/midpubic index were 9.35 ± 1.38 in males and 7.49 ± 0.82 in females. The demarking points identified 72% males and 75% females. While the mean values of the ischiopubic index in males and females were 88.46±9.26 in males and 114.67±99.28 in females, the demarking points identified 56% males and 84% females. It was observed that the males had higher pelvic height and ischial length than females, while the females had longer pubic length and mid pubic width which contributed to the females having wider pelvis.

The accurate determination of sex and race are important tools to forensic Scientists and physical anthropologists.

Keywords: Pelvis, Radiographs, Sex determination, Nigerian population.