Esthetic preferences of American and Japanese laypersons and dental students

Objectives: The objective of this study was to determine whether dental school training influences esthetic preferences for various lip profiles.

Methods: Four independent panels of 30 layperson judges (15 male, 15 female) viewed silhouette profiles of 10 Caucasian (5 male, 5 female), 10 Japanese (5 male, 5 female) and 10 African (5 male, 5 female) Angle Class I and II orthodontic patients. The judge panels comprised the following racial/ethnic groups: (1) Caucasian American laypersons (C), (2) 4th-year Caucasian American dental students (C4), (3) Japanese laypersons (J), and (4) 6th-year Japanese dental students (J6). Profiles were traced from lateral cephalograms and manipulated using Adobe Illustrator software so that the lip profile lay on Ricketts' E-line, 2mm anterior, 4mm anterior, 2mm posterior, 4mm posterior, 6mm posterior or 8mm posterior to the E-line. Judges selected the 1 profile they considered the most attractive, and then classified the remaining 6 profiles as either acceptable or unacceptable.

Results: The mean preferred lip position (mean±SD) was: -2.58±1.92mm for C, -2.92±1.76mm for C4, -3.45±1.92mm for J, and -3.03±2.00mm for J6. There was no significant difference between C4 and J6. There was a significant difference between the American and Japanese layperson (C vs. J) groups with respect to the most attractive profile (p<0.05) and the anterior limit of acceptability (p<0.001). Compared to the American dental students (C4) American laypersons (C) were more tolerant of protrusive profiles (p<0.01). But there was no significant difference between Japanese dental students (J6) and laypersons (J). There also was a significant difference between male and female judges with respect to the anterior limits of acceptability (p<0.05).

Conclusions: Dental school training may influence the esthetic preferences of Caucasian American dental students. No effect of professional training on esthetic preferences of Japanese dental students was found. Race of judge also may significantly influence esthetic preferences.