Growth change in the lips of the adolescence (from 8 to 16 years old) / 대한치과교정학회지

ABSTRACT

This study was undertaken to assess the effect of growth on the lips. Not only does lip growth influence the stability of such orthodontic treatment it also directly influence facial profile, in which the lips have an important part. An understanding of the growth of lips is thus central to a consideration of profile change in orthodontics. By analyzing the serial lateral cephalograms of 15 male and 15 female of 8 years old to 16 years old who have normal occlusion. The result of this study were summerized as follows; 1. The largest growth increments in the length of the lips was occured age of 14 in both sexes. 2. The thickness of lips showed lager value for the male than that of the female in the most age group. The largest growth increments at A point was occured age of 14, while Ls, Li, B point decreased after the age of 10-11. 3. The largest increase in the interval between crest of lower lip and edge of upper incisors was occured between ages 9 and 11 in males. The interval decreased slightly from 8 to 16 years in females. 4. The nasolabial angle decreased slightly from 8 to 16 years in both sexes. 5. The mentolabial angle showed large variation.