Stomatology ›› 2022, Vol. 42 ›› Issue (1): 53-57.doi: 10.13591/j.cnki.kqyx.2022.01.009

• Clinical Research • Previous Articles     Next Articles

CBCT study on position changes of incisors and lips after orthodontic treatment in adult female patients with convex facial profiles

NI Jieli, WU Qingheng, HOU Wei, CAI Huayang, ZHANG Yang, GUO Shuyu   

  1. Department of Orthodontics, the Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China
  • Revised:2021-10-15 Online:2022-01-28 Published:2022-01-28

Abstract: Objective To evaluate the position change of incisor and lip after orthodontic extraction treatment in adult female patients with convex facial profiles and its correlation. Methods Thirty-nine adult female patients with convex facial profiles who received orthodontic treatment from 2017 to 2019 were selected. All subjects had undergone orthodontic tooth extraction. 3D superimpositions of CBCT scans before and after treatment, were analyzed for hard and soft tissue measurement. Results The study showed that SNA, U1-SN, UL-EP, LL-EP and naso-labial angle changed significantly after treatment. The retraction of the upper incisors was positively correlated with the degree of U1-SN and UL-EP before orthodontic treatment. There was a positive correlation between lower lip retraction and LL-EP before orthodontic treatment. Besides, the linear regression equation between the upper incisors and lip was y=0.174x+1.103(y, the retraction of upper lip; x, the retraction of upper incisors); the linear regression equation between the lower incisors and lip was y=0. 520x+1.590(y, the retraction of lower lip; x, the retraction of lower incisors). Conclusion Based on the study on superimpositions of 3D images, it is verified that orthodontists can effectively alleviate lip and facial protrusion, improve soft tissue profile, through orthodontic extraction treatment and by controlling the position of incisors in adult female patients with convex facial profiles.

Key words: lip change, convex facial profile, extraction, orthodontic treatment

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