Palatal morphology: A systematic review of the association of palatal shape with genetic ancestry, sex and age

Abstract

Objectives

This study aims to review the literature regarding palatal shape variation, and its influence on estimating genetic ancestry, sex, and age.

Design

A literature search was performed using PubMed, Scopus and Embase databases, from inception up to January 2025. Original research articles in English examining variation in shape of human hard palate were included, irrespective of study type or publication year. Articles regarding craniofacial anomalies, pathologies and orthodontic treatment were excluded. The risk of bias was assessed independently by two reviewers using the Joanna Briggs Institute critical appraisal tool.

Results

Twenty-two studies fulfilled the selection criteria. Dental casts (n = 13) and crania (n = 8) were predominantly utilised in the studies. Geometric morphometrics emerged as the predominant method for palatal shape analysis, followed by fourth-order polynomial curve fitting, visual assessments and ratios. Five studies examined ancestral variation in palatal shape, with four reporting differences between population groups. These studies, however, utilised fixed landmarks only, offering limited insight. Sexual dimorphism of palatal shape was extensively investigated (n = 12), with large numbers of semi-landmarks employed in two studies, but association was reported in four studies only. Palatal shape was reported to change from birth to adulthood but remained unchanged after adulthood.

Conclusion

This review highlights that palatal shape may aid ancestry classification but remains inconsistent to classify sex. Palatal shape changes during growth are allometric and hence need to be considered in forensic investigations. More standardised and robust methods may better evaluate the effects of ancestry, sex and age on 3D palatal variation.