Assessment of the esthetic smile in young Japanese women

IntroductionThe aim of the present study is to evaluate an esthetic smile in young Japanese women, which is not yet clear.MaterialsThirty orthodontically treated female patients formed Group 1 and the same number of female models, Group 2.MethodsAll smile photos and slides were digitalized for analysis in an image-processing program. As the photos in Group 2 had a different size, the output image size was not considered. Five visual and four quantitative evaluations of a smile were studied for each subject. The smile arch and index, buccal corridor spaces (BCSs) and relationship between BCS and maxillary dental arch widths were studied.StatisticsStandard errors of the measurements were calculated. Independent student's t-tests were used to compare statistically the measurements of Group 1 patients and Group 2 model samples, and also those of BCS and the widths of the upper dental arch (UAW). Mean and standard deviation were calculated and p < 0.05 was significant.Results and conclusionThe average smile, smile curve arch line without touching the lower lip, parallelism of the upper incisal curve with the inner curvature of the lower lip, no display of the 1st molar, 1:1 ratio of the widths of nose and upper cuspid, a minimum buccal corridor with no significant relation in widths of the upper dental arch all corresponded to ideal smile.