Association between smile arc curvature and skeletal pattern in orthodontic patients: a retrospective cross-sectional analytical study

To evaluate the association between smile arc curvature, skeletal pattern, and maxillary incisor display among orthodontic patients attending King Khalid University College of Dentistry. This retrospective cross-sectional analytical study included 150 eligible orthodontic patients. Standardized pretreatment posed smile photographs and lateral cephalometric radiographs were analyzed. Smile arc curvature was classified as consonant, flat, or reverse. Associations with sagittal skeletal pattern (ANB), vertical skeletal pattern (SN–MP), and maxillary incisor display were evaluated using Pearson’s chi-square or Fisher’s exact test. Multinomial and binary logistic regression analyses were performed to explore adjusted associations. Consonant smile arc was the most prevalent pattern (63.3%). No significant associations were observed with sagittal skeletal pattern or maxillary incisor display. A significant association with vertical skeletal pattern was identified in the unadjusted analysis; however, this association was not maintained after multivariable adjustment. Smile arc morphology appears to be multifactorial. Although an unadjusted association with vertical skeletal patterns was observed, no independent statistically significant associations were identified after adjustment. Further prospective studies are needed to clarify the factors influencing smile arc morphology.