Influence of chin prominence on esthetic lip profile preferences.

INTRODUCTION: The purpose of this study was to determine the influence of chin prominence on preferred lip position in profile. METHODS: Five "male" and 5 "female" silhouette profiles differing only in the degree of mandibular retrognathism or prognathism (-25 degrees, -18 degrees, -11 degrees, -4 degrees , and +3 degrees facial contour angles) were created. Using a computer animation program, the evaluators moved the upper and lower lips independently into the positions they deemed to be the most esthetic for each profile. The evaluators included white male and female adolescent orthodontic patients, parents of patients, and orthodontists. RESULTS: In general, no differences in preferred lip position were found between the -11 degrees and -4 degrees profiles or between the -18 degrees and +3 degrees profiles, but preferences for each of the 3 profile groupings (-11 degrees and -4 degrees, -18 degrees and +3 degrees, and -25 degrees) were different. Fuller lip positions were preferred for the more extreme retrognathic and prognathic profiles, whereas more retrusive lip positions were preferred for the more average profiles. No differences were found among the 3 evaluator groups or between male and female evaluators. Scattered differences were found among lip preferences for male and female profiles.