Lip thickness reaches maximum at what age in males?

Lip thickness reaches its maximum during adolescence, then decreases to the point that in their 20s and 30s, some women consider loss of lip thickness a problem and seek treatment to increase it. Mammandras evaluated the records of 32 untreated patients who represented a cross-sectional sample of ages 8 to 18 years and measured such variables as lip length, lip thickness, and soft-tissue chin thickness. Mammandras found that in women, the upper lip reached its maximum thickness by age 14 and remained the same until 16 years of age, with the lip thinning afterward. In men, maximum lip thickness was attained around age 16 but also began to thin thereafter. The horizontal thickness of the lower lip slowed dramatically but was close to its maximum in both men and women by age 15. Similar results were attained in a study by Nanda et al with mild differences but essentially similar trends. Ref: Mamandras AH. Linear changes of the maxillary and mandibular lips. Am J Orthod Dentofacial Orthop. 1988;94(5):405-410.