MSX1 and PAX9 Polymorphisms and Their Association With Lateral Incisor Morphology in Patients With Maxillary Canine Impaction

BACKGROUND Maxillary canine impaction is a common dental anomaly. Research suggests that genetics and the shape of lateral incisors are significant factors in the etiology of this anomaly. This study aimed to compare PAX9 (rs2073247) and MSX1 (rs12532) gene polymorphisms in buccal swabs of participants with and without maxillary canine impaction using real-time polymerase chain reaction (RT-PCR), and to analyze lateral incisor morphology on cone-beam computed tomography (CBCT). MATERIAL AND METHODS The study included 130 patients (50 males, 80 females; mean age 17.3 years), divided into an experimental group (EG, n=65) with maxillary canine impaction and a control group (CG, n=65) without impaction. Buccal swab samples were collected to perform RT-PCR analysis on the PAX9 and MSX1 genotypes. CBCT scans were assessed using Sidexis 4 and Galileos Viewer software to measure crown length, root length, total tooth length, and mesio-distal crown width. RESULTS All morphological parameters of the lateral incisors were significantly smaller in the EG than in the CG (P<0.001). Chi-square analysis revealed no significant difference in genotype distribution for PAX9 (P=0.130) or MSX1 (P=0.291). However, individuals carrying at least 1 mutant allele in both genes had a higher prevalence of canine impaction (P=0.019) and a significant reduction in lateral incisor crown width (P=0.038). CONCLUSIONS The presence of mutant alleles in the PAX9 (rs2073247) and MSX1 (rs12532) genes, combined with altered lateral incisor morphology, increases the risk of maxillary canine impaction.