Objective: To test the null hypothesis that there is no effect of esthetic perception of smiling profile in three different facial types by a change in the maxillary incisor inclination and position.
Materials and methods: A smiling profile photograph with Class I skeletal and dental pattern, normal profile were taken in each of the three facial types dolichofacial, mesofacial, and brachyfacial. Based on the original digital image, 15 smiling profiles in each of the facial types were created using the FACAD software by altering the labiolingual inclination and anteroposterior position of the maxillary incisors. These photographs were rated on a visual analog scale by three panels of examiners consisting of orthodontists, dentists, and nonprofessionals with twenty members in each group. The responses were assessed by analysis of variance (ANOVA) test followed by post hoc Scheffe.
Results: Significant differences (P < 0.001) were detected when ratings of each photograph in each of the individual facial type was compared. In dolichofacial and mesofacial pattern, the position of the maxillary incisor must be limited to 2 mm from the goal anterior limit line. In brachyfacial pattern, any movement of facial axis point of maxillary incisors away from GALL is worsens the facial esthetics. The result of the ANOVA showed differences among the three groups for certain facial profiles.
Conclusion: The hypothesis was rejected. The esthetic perception of labiolingual inclination and anteroposterior of maxillary incisors differ in different facial types, and this may effect in formulating treatment plans for different facial types.
Keywords: Esthetics; face; goal anterior limit line; orthodontics; profile.