Inter-population variation in facial sexual dimorphism: a review with implications for forensic anthropology and medicine.

Background: Understanding how human facial morphology varies across populations and what factors drive these differences is essential for both theoretical and applied biological and medical disciplines. This manuscript aims to present the dimorphic differences in facial morphology, discuss interpopulation variation in the degree of dimorphism and its potential causes, and highlight the significance of this knowledge for medical science.

Review methodology: A systematic review was conducted using the PubMed, Scopus, and Web of Science databases from January to March 2025, following PRISMA guidelines.

Main findings: The reviewed literature consistently shows that individuals of European and South American origin exhibit a higher degree of facial sexual dimorphism compared to those of African origin. Additionally, significant differences (p < 0.01) in morphological variation between the sexes have been reported in relation to population size, with smaller or more isolated populations exhibiting reduced dimorphism. Interpopulation variation in facial morphology results from multiple processes, primarily natural and sexual selection. At present, the influence of the natural environment on adaptive or adaptability-based changes in human morphology is diminishing, while cultural factors are becoming increasingly important.

Clinical relevance and future directions: This review clearly demonstrates that data on facial morphology and sexual dimorphism from one population cannot be considered representative of another, nor can it serve as a universal basis for developing methods in forensic anthropology. Effective algorithms for sex determination based on facial features or craniofacial structure should also take biogeographical ancestry into account. Similarly, in aesthetic and corrective medicine, the absence of a universal beauty standard necessitates culturally sensitive approaches.