Comparison of perceptions of smile esthetics of orthodontists and laypeople

Objectives: The purpose of this study was to find out how the tilted incisal plane influences the smile esthetic perceptions of orthodontists and laypersons. Methods: A 20-year-old female was chosen with an esthetic smile, a normal occlusion, straight profile, symmetrical face, aligned and intact maxillary incisors with no tooth color problems or veneers. Raters included: 40 orthodontists and 56 laypersons.The digitized picture of ideal smile was manipulated using adobe Photoshop 9.0 software to create the smile variations: low smile width,medium smile width,high smile width. Using the midpoint of the line connecting the most gingival point of the upper lateral incisors as the centre, rotated the dentition from a parallel position to the upper lip margin in one degree increments from zero to five degrees in both clockwise (right side) and counterclockwise directions(left side). All statistical tests were performed with SPSS 13.0. Results: 1. Orthodontists recognized more the occlusal cants and perceived the detracting effects of tilted incisal planes to the smile esthetics severer than laypersons. 2. Orthodontists got smaller ranges of tolerance to the tilted incisal plane than layperson. 3. Varied smile width was a dynamic factor to influence the smile esthetic perceptions of orthodontists and laypeople to tilted incisal planes. Conclusions: This study suggested the tilted incisal plane is an asymmetric factor which can affect the smile esthetics. The varied smile width could play a dynamic role in the smile esthetic perceptions of orthodontists and laypersons to the tilted incisal plane.