Influence of lips on the perception of malocclusion.

[INTRODUCTION] The purpose of the study was to determine the influence of variations in the size of the vermilion borders of the upper and lower lips on the perception of the attractiveness of various occlusal traits.

[METHODS] Ten occlusal traits and 3 upper and 3 lower vermilion variations, placed in combinations on a facial image, were used in a questionnaire. Statistical analyses for attractiveness and social and sex attributes were performed for various occupational groups.

[RESULTS] The occlusion, vermilion border of the upper and lower lips separately, and the raters' occupations were all highly significant in influencing attractiveness, social perceptions, and perceived sex of the images (P < .01). All occlusal traits were perceived as more attractive with a thicker vermilion border. Thin vermilion borders and more severe irregularity were associated with unattractiveness, aggressiveness, and masculine traits.

[CONCLUSIONS] This study demonstrates that the thickness of the vermilion border has a profound effect on how people rate the attractiveness of the dentition. Therefore, treatment plans that could affect lip vermilion might result in improved dental alignment but also deterioration in overall attractiveness. Orthodontists placed more emphasis on the teeth than other occupation groups; this demonstrated an occupational bias.