Contribution of Lip Proportions to Facial Aesthetics in Different Ethnicities: a Three-dimensional Analysis

Background: Lip augmentations are commonly performed procedures in the United States, with annual numbers surpassing 100 000. While lips contribute to facial beauty, the relative influence of this feature to whole facial appeal has not yet been established. What is also of increasing interest is the consideration of ethnic differences in the evaluation of beauty. However, most current anthropometric measurements refer to Caucasians, and their use in the treatment of Asian American patients would be inappropriate.

Methods: Three-dimensional models of 197 male and female Caucasian, Chinese and Korean subjects were created using surface-imaging technology. The lips and corresponding faces from these models were ranked according to subjective aesthetic appeal by 20 male and female raters of various ages, occupations and ethnicities. The raters' results were subsequently compared with individually measured lip parameters.

Results: Rankings between lips and their corresponding whole faces differed greatly. Lips that were rated as the most attractive were smaller than average in midline upper lip surface heights, bilateral paramedian lip surface heights, upper lip angles and volume in the lower lip. Both Asian groups exhibited significantly different lip parameters and lip-projection volumes from that of Caucasians.

Conclusions: The results from this study suggest that there are indeed measurable differences in the baseline Asian lip morphology as compared with Caucasians. Tailoring lip enhancement treatment to each individual's anatomy, ethnic background and personal goals can optimise outcomes. What is also of interest is that lips did not contribute as much to facial attractiveness as previously thought.