Palatal Morphology in Artificially Modified Crania: Evidence for Limited Craniofacial Integration

Background: Artificial cranial modification (ACM) in pre-Hispanic Andean populations provides a natural model for investigating whether marked deformation of the cranial vault is associated with corresponding changes in palatal morphology and craniofacial integration. Methods: Three-dimensional geometric morphometrics was used to quantify neurocranial and palatal shape in 19 Peruvian crania (9 modified, 10 unmodified). Analyses included Generalized Procrustes Analysis, principal component analysis, Procrustes ANOVA, morphological disparity tests, directional asymmetry assessment, and two-block partial least squares (PLS) analysis of neurocranial–palatal covariation. Results: Modified crania showed significant neurocranial shape divergence from unmodified individuals, whereas palatal mean shape, principal component scores, and within-group disparity did not differ significantly between groups. Directional asymmetry was significant in both groups, but differences in mean asymmetry between groups were modest. Two-block PLS analysis yielded a first-axis correlation of r-PLS = 0.694; however, this association was not statistically significant (p = 0.488), and the RV coefficient indicated only low-to-moderate integration between neurocranial and palatal shape (RV = 0.341). Conclusions: These findings indicate that pronounced neurocranial deformation is associated with substantial changes in cranial vault morphology but limited alteration of palatal shape. The absence of significant neurocranial–palatal covariation suggests that the palate behaves as a comparatively constrained component of the craniofacial complex, supporting a model of partial craniofacial integration during growth.