Association of Gene Polymorphism with Three-Dimensional Nasal Root Morphology.

Paired box gene 3 () plays an important role in craniofacial development. Mutations in this gene are associated with Waardenburg syndrome, which is a condition characterized by facial anomalies such as widely spaced inner corners of the eyes. gene polymorphisms are associated with the relative position of the nasal root (nasion), even among healthy individuals. Facial morphology has primarily been examined using three-dimensional (3D) facial scans of soft tissues, whereas studies focusing on hard tissues remain limited. Therefore, the present study aimed to analyze 3D craniofacial morphology in hard tissues using computed tomography imaging and investigate the influence of polymorphisms on the 3D morphology of the nasal root. The analysis was conducted on three populations: 201 healthy Japanese, 74 healthy Korean, and 142 healthy Egyptian individuals. DNA was extracted from saliva samples, and the genotypes of two single-nucleotide polymorphisms (SNPs; rs9288572 and rs7559271) were analyzed. A multiple regression analysis of the association between these SNPs and measurements related to nasal root morphology revealed a significant association between rs7559271 and the protrusion angle of the nasion. These findings suggest that gene polymorphisms influence the morphological development of the nasal root within the normal range of hard tissues.