Anatomical impact of neurocranial deformation on stomatognathic asymmetry.

Human craniofacial anatomy results from complex genetic, epigenetic, and environmental interactions, with the cranium and palatal arch being fundamental for brain protection and oral and respiratory functions. However, the in-uence of these factors on palatal arch morphology and asymmetry – especially in the presence of mechanical alterations of the cranium during growth – remains poorly understood, particularly with regard to the stomatognathic system. Arti!- cial cranial modi!cation (ACM) applied to the cranium, a common practice among pre-Hispanic Andean populations= and used as a marker of group identity>,?, provides a model for studying non-physiological mechanical alterations in the developing stomatognathic system. The comparative analysis of cranial and palatal morphology between adult individuals with ACM (applied during the prepubertal period of high bone plasticity) and unmodi!ed individuals allowed us to clarify the long-term e.ects of mechanical forces on craniofacial development. We analyzed 20 adult Peruvian skulls (19th–20th century) preserved at the Museum of Anthropology and Ethnology, University of Florence (Italy), divided into two groups: 10 with clear evidence of arti!cial cranial modi!cation (ACM) and 10 belonging to the unmodi! ed group. The skulls were digitized using high-resolution 3D scanning and analyzed with threedimensional geometric morphometric methods, applying 41 semi-landmarks to the palatal surfacej and 286 semi-landmarks to the cranium5, in order to observe morphological variation. Subsequently, directional asymmetry of the palatal archj was assessed to compare individuals with and without cranial modi- !cation.