December 2007

Document Type


Degree Name



Dept. of Orthodontics


Oregon Health & Science University


Introduction: The purpose of this study was to assess and compare the esthetic lip preferences of orthodontists and the lay public in straight, retrognathic and prognathic Caucasian profiles. Methods: The profile images of two Caucasian subjects, male and female, having normal cephalometric values were digitally altered. The chin was moved to create straight, retrognathic and prognathic profiles for both subjects. The position of the upper and lower lips were then horizontally protracted and retracted in two millimeter increments in each profile to a maximum distance of six millimeters. The profile images were assembled into a booklet and distributed to 50 orthodontists and 100 lay people who evaluated the attractiveness of the profiles by marking a Visual Analogue Scale (VAS). Thirteen orthodontists and 18 lay people repeated the survey a month later to assess reliability. Factorial ANOVAs with repeated measures and Bonferroni multiple comparison tests were conducted to determine differences in attractiveness preferences. All tests were set at a significance level of .05 (]7=.05). Results and Conclusions: Lay people and orthodontists did not differ significantly in their preferred lip positions for both the male (]7=.058) and female profiles (]7=.134). The straight profiles for both sexes had the highest overall ratings. Lip retrusion was preferred for the retrognathic profiles, while greater lip protrusion for the prognathic profiles. Minimal lip retrusion was deemed more acceptable in the male profiles. Both rater groups were tolerant of changes in lip position between two and four millimeters from their original positions, depending upon on the facial profile. Lay people and orthodontists were reliable in their assessments of facial profile attractiveness.




School of Dentistry



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