Effect of smile on facial attractiveness before and after orthodontic treatment in females with more attractive and less attractive facial background.

Introduction: One of the goals of orthodontic treatment is to improve facial esthetics. This study aimed to determine the effect of smile on facial attractiveness before and after orthodontic treatment in females with "more attractive" and "less attractive" facial backgrounds. In addition, changes in facial attractiveness after orthodontic treatment were examined.

Methods: Frontal rest and smile photographs of 60 female patients (mean age, 26.32 years) before and after orthodontic treatment were included in 4 separate online questionnaires. The link for each questionnaire was sent to 40 layperson raters (20 females, 20 males). They were asked to give a score from 0 to 100 on the basis of the visual analog scale for the attractiveness of each image. Then the data were collected and analyzed.

Results: The mean score of the pretreatment smile was significantly smaller than the frontal rest view, and the difference was significantly greater in the "more attractive" group (P = 0.012). After treatment, the smiling view was significantly more attractive than the frontal rest view, and the difference was significantly greater in the "less attractive" group (P = 0.014). In addition, the attractiveness of both smiling and rest views increased significantly after orthodontic treatment, and these changes were significantly greater in the "more attractive" group (P <0.001 and P = 0.011).

Conclusions: An unesthetic pretreatment smile negatively impacted facial attractiveness, and orthodontic treatment significantly improved facial attractiveness. These negative and positive effects were greater in more attractive facial backgrounds.