Three-dimensional analysis of lip soft tissue changes and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry

Article type: Research Article

Authors: Xu, Wenjie^{a; b; c} | Tan, Hao^{a; b; c} | Meng, Xuehuan^{a; b; c} | Ming, Ye^{a; b; c} | Wang, Tao^{a; *} | Zheng, Leilei^{a; b; c; *}

Affiliations: [a] Department of Stomatological Hospital of Chongqing Medical University, Chongqing, China | [b] Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China | [c] Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China

Correspondence: [*] Corresponding authors: Leilei Zheng and Tao Wang, Stomatological Hospital of Chongqing Medical University, 426 Songshibei Road, Yubei District, Chongqing 401147, China. Tel.: +86 23 88860108; Fax: +86 23 88860108; E-mails: zhengleileicqmu@hospital.cqmu.edu.cn (Leilie Zheng), taosan@126.com (Tao Wang).

Abstract: OBJECTIVE:To investigate three-dimensional soft tissue changes of lips and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry using cone-beam computerized tomography (CBCT). METHOD:This study included 46 CBCT scans of patients with aforementioned character before (T1) and 6–12 months after orthognathic surgery (T2). Subjects were divided into 2 groups according to two types of orthognathic surgery namely, the one-jaw surgery group who underwent bilateral sagittal splint ramus osteotomy (BSSRO) and the two-jaw surgery group who underwent Le Fort I osteotomy and BSSRO. Mimics 19.0 software are used for model reconstruction, landmark location and three-dimensional cephalometric analysis. Descriptive statistics and correlation analyses are used to investigate jaw hard tissue and lip soft tissue changes. RESULTS:In one-jaw group, the mandible shows changes in contour and position (p < 0.05), and the surgery causes changes of lip structure on the deviated side. While in two-jaw group, jaws only show changes in spatial position, and surgery changes contour of bilateral lips and nasolabial angle (p < 0.05). At the same time, lip symmetry increases significantly in both groups postoperatively. CONCLUSIONS:Orthognathic surgery can improve lip aesthetics in patients with skeletal class III malocclusion and facial asymmetry. However, changes induced by two surgical approaches are different. Surgeons should have a clear acquaintance with this difference to deal with different situations.

Keywords: CBCT, 3D cephalometric analyses, class III malocclusion, facial asymmetry, lip profile

DOI: 10.3233/XST-210903

Journal: Journal of X-Ray Science and Technology, vol. 29, no. 5, pp. 903-916, 2021