Smile Attractiveness: Related to Buccal Corridor, Tooth Shape, Gingival Display

OBJECTIVES: Research has shown smiles rated as maximally attractive are individually characterized as having minimal buccal corridor width, minimal gingival display, and a width-to-height ratio between 70-85%. However, research to date has not examined the effect of these three variables simultaneously when rating overall attractiveness of a smile. The purpose of this research design is to see how these factors are related to laypersons' ratings of smile attractiveness. METHODS: Forty digital photographs of orthodontic patients smiles' post treatment (M=20, F=20) selected from the University of Iowa patient pool served as the sample population. These photographs were cropped showing only the smile and where incorporated into a slideshow for participants viewing. Participants (n=53) consisted of lay people in the College of Dentistry waiting room. Participants were asked to rate each of the 40 smile's attractiveness on a seven-point Likert scale (very unattractive to very attractive). They were asked a series of demographic questions and asked to rate characteristics they feel are most influential when determining overall facial and smile attractiveness. The average attractiveness rating for each photograph was then compared to the buccal corridor width, gingival display, and tooth height-to-width ratio for that individual photograph. RESULTS: Results indicated that average attractiveness score was significantly correlated with buccal corridor width (r=-0.58, p<0.0001) and marginally significantly correlated with tooth height-to-width ration (r=-0.31, p=0.0547). No significant relationship between attractiveness rating and gingival display was found. Additionally, photographs of female orthodontic patients obtained greater mean average rating scores than males did (p=0.0237). CONCLUSION: In general, the results of this study suggest that among lay people, maximally esthetic smiles are characterized by minimal buccal corridor width and increasing tooth height-to-width ratio, while gingival display does not play an important role in rating smile attractiveness. Additionally, overall, female smiles were found to be more attractive than males.