Determination of sex from some pelvic measurements among Egyptians: a radiological study

ABSTRACT

The identity of the dead is an essential part of post-mortem examination. The establishment of the identity may be required upon mutilated and dismembered corpses and identification of sex in such medicolegal situations is frequently confronted with. The most useful bones for sex determination are pelvis and skull. In the pelvis, variables such as the subpubic angle [SPA], bicristal diameter [BCD], transverse diameter of the inlet [TDI], bituberal diameter [BTD], and Ischio-pubic Index [IPI] have been measured independently for sex verification. Little information is available on the concurrent measurement of these variables on the same pelvis for sex determination. The aim of the present study was to develop a method for determination of sex from pelvis among Egyptians using some radiological pelvic measurements. The study was carried out on one hundred plain X-ray of the pelvis [anteroposterior view] of healthy adults of both sexes [70 males and 30 females], aged from 25 to 65 years. These radiographs were done in the outpatient clinic of Diagnostic Radiology department at Alexandria Faculty of Medicine. The following measurements were used subpubic angle [SPA], bicristal diameter [BCD], transverse diameter of the inlet [TDI], bituberal diameter [BTD], pubic length [PL], ischial length [IL], and ischio-pubic index [IPI]. Regression equation was developed using combination of these measurements for prediction of sex from the radiographs of the pelvis. The regression equation was then applied to a test sample [20 radiographs of pelvis] to establish the degree of accuracy in assigning sex. Based on age, cases of each sex were divided into two groups which were a young age group [25-45 years] and an old age group [45-65 years], and the same measurements were done and compared. The present study revealed that the mean values of all measurements except IL for females were significantly greater than that for males. These differences were statistically significant except in case of BCD. The SPA and BTD showed the most sexual dimorphism whereas the BCD showed the least according to the discriminating index. The overall percentage of accuracy of correct sex determination calculated from the developed equation was 97.0% whereas it was 98.57% in males and 93.33% in females. On application of the developed regression equation for the pelvis on the tested sample radiographs [n=20] blindly, the overall accuracy of correct sex determination was 98.0%. There was no significant difference between the young and old age groups of males as regards all measurements except with SPA and BCD. On the other hand, there was a significant difference between the young and old age groups of females as regards all measurements. It is concluded that the developed method for sex determination using radiographs of the pelvis is simple, reliable, applicable, and with a high degree of accuracy