Labial Morphology: A 3-Dimensional Anthropometric Study

Purpose: To develop a noninvasive 3-dimensional method to evaluate labial morphology and to assess gender-related differences in healthy young adults. Materials and Methods: Dental and lip impressions of 11 men and 10 women aged 21 to 34 years, with sound, full, permanent dentition were obtained. The models were digitized and 3-dimensional virtual reproductions obtained. The labial thickness, vermilion area, and volume of the upper and lower lips were measured from the digital reconstructions. The male and female data were compared using Student's t test. Results: The mean lip thickness was significantly larger (P = .02) in men (14.3 mm) than in women (12.3 mm). The lower lip was thicker than the upper lip. The vermilion width was larger in men (75 mm) than in women (70 mm), and no differences were found for vermilion height (10 mm). In the upper lip, the height/width ratio was significantly larger in women (14.1%) than in men (12.3%). The vermilion surface area was slightly larger in men than in women (upper lip area: women, 467 mm²; men, 501 mm²; lower lip area: women, 491 mm²; men, 569 mm²). The labial volume was significantly larger in men (upper lip, 2,390 mm³; lower lip, 2,902 mm³) than in women (upper lip, 1,743 mm³; lower lip, 1,764 mm³; P = .021). The upper/lower lip area and volume ratios were similar in the 2 genders. Conclusions: Overall, men had larger lips than women. The inferior lip height/width ratio was similar in both genders, and men had a relatively thinner upper lip than women.