Esthetics and Smile Characteristics Evaluated by Laypersons: A comparison of Canadian and US data

Abstract

Objective: To collect data regarding Canadian laypersons perceptions of smile esthetics and compare these data to US data in order to evaluate cultural differences. Methods: Using Adobe® Photoshop® 7, a digital image of a posed smile of a sexually ambiguous lower face was prepared so that hard and soft tissue could be manipulated to alter Buccal Corridor (BC), Gingival display (GD), Occlusal Cant (OC), Maxillary Midline to Face Discrepancy (MMFD) and Lateral Central Gingival Discrepancy (LCGD). Adult Canadian laypersons (n=103) completed an interactive computer-based survey of 29 randomized images to compare smile preferences for these variable. The custom survey was developed to display fluid, continuously appearing modifiable smile variables using MATLAB® R2008 for presentation. These data were compared to previously published data for US laypersons. Statistical inference was determined using Wilcoxon Rank Sum tests. Results: Canadian laypersons were more sensitive in detecting deviations from ideal and had a narrower range of acceptability thresholds for BC, GD, OC, MMFD and LCGD. Ideal esthetic values were significantly different only for BC. Conclusions: It appears cultural differences do exist related to smile characteristics. Clinically significant differences in the preference of the smile characteristics were found between Canadian and US laypersons. Canadian laypersons, on average, were more discriminating to deviations from ideal and had a narrower range of acceptability.