Factors influencing the perception of profile beauty in Class III dental compensation: A comparative cross-sectional study according to three categories of assessors.

Introduction: The main objective of this study was to evaluate the different factors influencing the perception of female profile facial beauty in Class III patients with protruded mandible that can be treated with orthodontic dental compensation: (1)severity of the protrusion, (2) the upper incisors inclination and (3) the presence of jawlines. The secondary objective was to determine if the rater's gender and profession played a role in the assessment of the preferred profile.

Methods: A normal and smiling photographs of a female subject with normal facial and skeletal profile criteria were digitally manipulated to obtain 3 different mandibular sagittal positions: 0mm, +4mm and +8mm. Each position of the chin was evaluated with the presence or not of jawlines. In the smiling profiles, the same chin modifications were scored, and the maxillary incisor inclination was changed from 0 to +10 degrees with 5 degrees increments. A total of 320 raters (107 dentists, 103 orthodontists and 110 laypeople) scored the attractiveness of the different images using a Visual Analogue Scale. The limit of statistical significance was P<0.05. Generalized estimating equation (GEE) models were conducted to assess the predictors of variations in ratings within each set of photos, as well as the interactions of predictors where adjusted odds ratios (aOR) and their 95% confidence intervals were calculated and reported.

Results: In the profiles without a smile, image +4mm chin (Class III treated by compensation) and image +8-mm mandible (Class III not treated) were selected as the most and least attractive images, respectively, by almost all groups with no difference. The presence of jawlines has a positive role in facial attractiveness. In the smiling profiles, all the examiners showed a preference for image +4-mm chin and a slight protrusion of maxillary incisors (+5 degrees). No significant difference was found between genders in this study.

Conclusions: Class III treated by compensation (+4mm) are more attractive than non-treated Class III (+8mm) by almost all groups with no difference. The presence of jawlines has a positive role in facial attractiveness. In the smiling profiles, all the examiners showed a preference for image +4-mm chin and a slight protrusion of maxillary incisors (+5 degrees). Orthodontists older than 50 years old are aware of the difficulty to treat a skeletal Class III and tend to accept it due to their long career experience. No significant difference was found between genders in this study.