Assessment of sexual dimorphism in adolescent palatal size and shape: Implications for sex estimation

Sexual dimorphism of the human palate remains understudied in anthropological and forensic contexts. The palate may aid biological profiling when the cranium is fragmented or incomplete. Our study investigates sexual dimorphism in palatal size and shape across four populations.

Maxillary dental casts from European, Malay, Chinese, and Indian adolescents, with 50 males and 50 females sampled from each group (N = 400). Sixteen landmarks were identified per cast, comprising 14 gingival landmarks and 2 midline points. Palatal size was assessed using linear measurements of width, depth, and length, followed by multivariate analysis of covariance (MANCOVA) and discriminant function analysis (DFA). Palatal shape was assessed using geometric morphometrics, with dense semi-landmarks projected onto the palatal surface and analysed via Generalised Procrustes Analysis (GPA), Principal Component Analysis (PCA) and Canonical Variate Analysis (CVA).

Significant sex differences were observed in both palatal size and shape. Size showed significant population:sex interaction, indicating that the degree of size dimorphism varied among populations. Population-specific DFA classification accuracies ranged from 60% to 70%, with the highest accuracy observed in the Malay and Chinese populations. In contrast, shape-based analyses revealed a non-significant population:sex interaction, suggesting relatively consistent shape dimorphism across populations. The classification accuracy based on shape was 60%. Together, these findings suggest that size and shape capture complementary aspects of palatal sexual dimorphism, with size showing population-specific variation and geometric morphometrics capturing subtler differences in palatal shape.

Palatal traits demonstrate moderate sexual dimorphism and potential for sex estimation. Additional population-specific data remain essential for reliable forensic application.