The impact of orthodontic treatment on face and smile attractiveness: A cross-sectional study of longitudinal data.

Background Although esthetic concerns are a primary motivation for seeking orthodontic treatment, few studies with strong protocols have evaluated its impact on facial and smile attractiveness as perceived by laypeople. This study aimed to assess the effect of orthodontic treatment on facial and smile attractiveness compared with pretreatment and untreated controls.Methods The sample included 37 adults (aged 21-35 years): 29 treated and 8 untreated controls. A total of 132 photographs (full-face smiles and close-up smiles) were collected at pretreatment and posttreatment for treated patients and once for controls. Laypeople (n = 297) rated the images using a visual analog scale (VAS). The association between orthodontic treatment and attractiveness was analyzed through univariate regression models; confounders were controlled via analysis of covariance. Comparisons between study and control groups were performed using t tests. The effect of evaluators' demographics on attractiveness was tested using multivariate regression models. The association of the Aesthetic Component of the Index of Orthodontic Treatment Need with pretreatment attractiveness was explored with Spearman correlation.Results Orthodontic treatment had a significant effect on facial and smile attractiveness, with VAS scores improving by 15.6% (P <0.001) and 24.3% (P <0.001), respectively. Posttreatment ratings were higher than those of untreated controls (Pface = 0.029; Psmile = 0.010), with no significant differences at baseline. Higher Aesthetic Component of the Index of Orthodontic Treatment Need scores correlated with lower initial VAS ratings (r = 0.67; P <0.001). Age and treatment duration had no significant effect.Conclusions Orthodontic treatment improves facial and smile attractiveness as perceived by laypeople. These findings support its esthetic benefits and can enhance patient communication and treatment planning.