Sex determination from fragmented human remains – hierarchy of the foramen magnum dimensions

Although the foramen magnum is often described in the context of sex determination, to date, it has not been studied in relation to the Polish population. Considering interpopulation variation of human skull dimensions and shapes, study of a Polish population is needed. The aim of this paper is to evaluate a hierarchy of selected measurements of the foramen magnum in terms of their usefulness for sex determination and provide reference data for Polish non-modern populations in order to propose an alternative method of sex determination for fragmented human remains. Adult skulls from skeletal collection from Poland (N = 101, males 46.5% and females 53.5%) were measured to derive statistical functions. The anteroposterior diameter, transverse diameter, and the circumference of the foramen magnum were found to be significantly larger in males. Mollison's index and discriminant function analysis were performed to derive models for estimation of sex from the foramen magnum measurements and the +/- 1 SD ranges of the dimensions were calculated. Each of foramen magnum dimensions was able to predict sex in above 90% of crania. Due to some limitations of this study and the need of population-specific standards, it is recommend employing the foramen magnum in sex determination only in cases of fragmented human remains and when no other method can be applied. Further investigation of possible factors influencing the variability of the foramen magnum size and shape should be conducted in larger and geographically more diverse samples, and this could contribute to forensic, clinical, anatomical, and anthropological studies of this anatomical structure.