The influence of maxillary incisor torque on the esthetic perception of the smile

Purpose: An esthetically pleasing smile is one of our patients' main goals. However, it is not always clear that the esthetic perceptions of patients and clinicians are the same. The purpose of this study was to evaluate and quantify the discrepancies in the esthetic perception of maxillary incisor torque among professionals, and between professionals and the general public. Materials and methods: A photograph of a 30-year-old woman was digitally manipulated to obtain nine smile images and nine full-profile images with various maxillary incisor torques, while maintaining the overjet. The images were evaluated in an online survey by three different groups: laypersons (LP, n = 21), orthodontists (OR, n = 20), and specialists in dental esthetics (SDE, n = 19). Results: From among the smile images, the LP group preferred the 80-degree option (the angle that forms the tangent between the crown of the maxillary incisor and the functional occlusal plane), the SDE group preferred the 75-degree option, and the OR group preferred the 70-degree option. From among the full-profile images, both the LP and the SDE groups preferred the 80-degree option, while the OR group preferred the 75-degree option. To analyze the data and verify or reject the hypotheses of normality and homoscedasticity, ANOVA and Kruskal-Wallis tests were used. Conclusions: The LP and SDE groups coincided, in contrast to the OR group, which preferred more protrusive torques and was less tolerant of retroclined maxillary incisors.