Sexual dimorphism of central midface skeleton: Geometric morphometrics approach on 3D models of human skull

Abstract

Morphological differences of the skeleton between the genders have long attracted the attention of disciplines concerned with sex determination, leading to the development of various approaches for gender assessment. In addition to traditional techniques, geometric morphometrics has recently been introduced as a method for identifying sex based on skeletal features. Geometric morphometrics allows quantification and evaluation of biological shapes, including skeletal material, through the application of statistical and mathematical tools. The study was conducted on 3D models of 210 human skulls (139 male and 71 female). Within the central midface skeleton, nine landmarks were selected and marked in the Landmark Editor software. After marking the landmarks, their spatial coordinates were extracted and then imported into the MorphoJ program to analyze shape and size variation between sexes. Principal component analysis, covariance matrix generation, and discriminant function analysis were carried out with sex as the classification variable. The findings indicated that sex estimation based on the size and shape of the central midface skeleton reached an accuracy of 73% for males and 70% for females. The shape of the central midface skeleton exhibited statistically significant sexual dimorphism independent of size. After excluding the influence of facial size and considering only shape variables, geometric morphometrics achieved predictive accuracy of 73% for males and 72% for females.