Sexual dimorphism of foramen magnum: An Egyptian study

Abstract

Background: Human identification is of a paramount forensic concern. It includes sex determination which becomes extremely complex and tricky especially in fragmentary remains. Purpose of the study: We aimed to evaluate the accuracy of ten dimensions of foramen magnum (FM) and occipital condyles in determination of sex among 367 subjects (204 females and 163 males), their ages ranged between 18-75 years. Multislice Computed Tomography images of skulls of the studied patients were obtained from the Radiology Department. Ten different anatomical variables of the FM were measured by two independent experienced radiologists blinded to the study. Results: FM dimensions are unique and show significant sexual dimorphism in the studied Egyptian population especially with application of discriminant function analysis. These landmarks include foramen magnum length and width (FML, FMW), FM index, FM area, length of the right and left occipital condyles (LROC, LLOC), width of the right occipital condyle (WROC), maximum bicondylar distance (MBD) and minimum intercondylar distance (MnICD). LROC and FMW are highly significant discriminating variables predicting sex. Conclusions: It is concluded that all the studied FM parameters showed significant differences between males and females except the left occipital condylar width with higher male values when compared to females. Additionally, the right occipital condylar length and FM width are highly significant discriminating variables which are strongly beneficial in prediction of sex. FM dimensions would provide a reliable additional tool for identification of sex among adult population and could be specific for Egyptians in case of fragmentary remains or damaged skulls.