Morphological Simulation of Different Incisal Embrasures: Perception of Laypersons, Orthodontic Patients, General Dentists and Orthodontists

Abstract

This study aimed to evaluate how different forms of incisal embrasures influence the esthetic perception of the smile, the preferences of each group of evaluators, and the influence of gingival display. Two photographs of a broad male and female smiles were digitally manipulated to remove imperfections and asymmetries. A second manipulation was performed on the four maxillary incisors, creating 3 different forms of incisal embrasures: rounded, semi-rounded and squared. The lower region of the upper lip was shifted down to simulate a smile with and without gingival display, resulting in a total of 12 photos. A presentation in digital media was structured with instructions and the photos to be studied by 240 evaluators, who were divided into four groups: laypersons, patients undergoing orthodontic treatment, general dentists and orthodontists. The statistical analysis comprised the Multiple Factor ANOVA (SPANOVA), and the Tukey's post-test was applied at a 5% significance level. The semi-rounded form was generally preferred, with a score of 70.83 for the male smile, and 77.26 for the female smile. Gingival display generated a statistically significant influence on how the embrasures were perceived, with the semi-rounded being preferred when associated with gingival display. Orthodontists were the most stringent in their evaluations. Patients and laypersons exhibited different patterns of esthetic perception. The form of the incisal embrasures associated with gingival display influenced the evaluators' esthetic perception. There was a statistically significant difference between the groups of patients and orthodontists. Incisal embrasures play an important role in smile esthetics and influence the attractiveness perception. In general, the semi-rounded embrasure form is the most preferred. Different groups' perceptions on tooth morphology reinforce the importance of patient participation in treatment planning. (J Esthet Restor Dent 29:68-78, 2017).