Objective: To collect data regarding Canadian laypersons' perceptions of smile esthetics and compare these data to US data in order to evaluate cultural differences. Materials and 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 variables. The custom survey was developed to display fluid, continuously appearing modifiable smile variables using MATLAB R2008 for presentation. These data were compared with 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 that 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.

To evaluate changes in attractiveness on the basis of computerized variations of smile arcs and buccal corridors for male and female smiles judged by orthodontists and laypersons. Using a visual analog scale in a Web-based survey, orthodontists and laypersons rated the attractiveness of nine digitally altered smile arc and buccal corridor variations of male and female smiles. The variations were accomplished in a clinically relevant manner and based on standards set by experienced orthodontists in a pilot web-based survey. The results indicate that both laypersons and orthodontists prefer smiles in which the smile arc parallels the lower lip and buccal corridors are minimal. Significantly lower attractiveness ratings were found for smiles with flat smile arcs and excessive buccal corridors. Flattening of the smile arc overwhelms the deleterious effects of excessive buccal corridors on attractiveness ratings. On the basis of the results of this study, care should be taken not to produce an excessively flat smile arc during orthodontic treatment.