A Comparative Evaluation of Smile Esthetics Characteristics Among Iranian Adults from the Laypeople and Dental Specialists Point of view

Objective: A pleasant smile creates a major part of dento-facial esthetics and smile esthetics is achieved through an accurate treatment planning which targets the components of smile with the highest degree of impact on appearance. The objective of this study was therefor to compare components of pleasant and unpleasant smiles among Iranian adults, from the laypeople and dental specialists point of view, in order to identify characteristics of an aesthetic smile and evaluate the significance of each component. Method: A total of 200 participants were randomly selected and frontal view photographs of their posed smile were obtained and shown to a group of judges (consisted of laypeople and professionals), who were asked to give each photograph a score of 1 to 10 based on the level of smile attractiveness. The most and the least pleasing smiles were determined and smile esthetic variables including gingival display, smile arc, midline deviation, buccal corridor, smile width, rotation and malposition of teeth, diastema, crowding and spacing, Upper and lower vermilion was measured and reported for each photograph. Two-way ANOVA analysis was used to determine the differences of each quantitative variable among the worst and the best group according to the scores, which was given by the judges. Results: Among quantitative variables, rate of occlusal plane canting was significantly lower in the best group. The excess buccal corridor in the unpleasant group demonstrated p value near the significance level but was not considered significant. Among the pleasant and unpleasant group differences of midline deviation, maxillary and mandible alignment, upper and lower vermillion show did not reach the significance level. Conclusion: The results of this study indicate that absent or lower rate of occlusal plane canting, as an obvious display of facial asymmetry, has the most impact on smile esthetics.