Paek Seung Jae, Yoo Ji Yong, Lee Jang Won, Park Won-Jong, Chee Young Deok, Choi Moon Gi, Choi Eun Joo, Kwon Kyung-Hwan
Department of Oral and Maxillofacial Surgery, College of Dentistry and Dental Hospital, Wonkwang University, Iksan, South Korea.
Department of Oral and Maxillofacial Surgery, Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, 460, Iksan-daero, Iksan, Jeollabuk-do 570-749 South Korea.
Maxillofac Plast Reconstr Surg. 2016 Oct 5;38(1):38. doi: 10.1186/s40902-016-0082-0. eCollection 2016 Dec.
The aims of this study are to evaluate the lip morphology and change of lip commissure after mandibular setback surgery (MSS) for class III patients and analyze association between the amount of mandibular setback and change of lip morphology.
The samples consisted of 14 class III patients treated with MSS using bilateral sagittal split ramus osteotomy. Lateral cephalogram and cone-beam CT were taken before and about 6 months after MSS. Changes in landmarks and variables were measured with 3D software program Ondemand™. Paired and independent tests were performed for statistical analysis.
Landmarks in the mouth corner (cheilion, Ch) moved backward and downward ( < .005, < .01). However, cheilion width was not statistically significantly changed. Landmark in labrale superius (Ls) was not altered significantly. Upper lip prominence angle (ChRt-Ls-ChLt °) became acute. Landmarks in stomion (Stm), labrale inferius (Li) moved backward ( < .005, .001). Lower lip prominence angle (ChRt-Li-ChLt °) became obtuse ( < .001). Height of the upper and lower lips was not altered significantly. Length of the upper lip vermilion was increased ( =< 0.01), and length of the lower lip vermilion was decreased ( < .05). Lip area on frontal view was not statistically significantly changed, but the upper lip area on lateral view was increased and change of the lower lip area decreased ( > .05, < .005). On lateral view, upper lip prominent point (UP) moved downward and stomion moved backward and upward and the angle of Ls-UP-Stm (°) was decreased. Lower lip prominent point (LP) moved backward and downward, and the angle of Stm-LP-Li (°) was increased. Li moved backward. Finally, landmarks in the lower incisor tip (L1) moved backward and upward, but stomion moved downward. After surgery, lower incisor tip (L1) was positioned more superiorly than stomion ( < .05). There were significant associations between horizontal soft tissue and corresponding hard tissue. The posterior movement of L1 was related to statistically significantly about backward and downward movement of cheilion.
The lip morphology of patients with dento-skeletal class III malocclusion shows a significant improvement after orthognathic surgery. Three-dimensional lip morphology changes in class III patients after MSS exhibited that cheilion moved backward and downward, upper lip projection angle became acute, lower lip projection angle became obtuse, change of upper lip area on lateral view was increased, change of lower lip area decreased, and morphology of lower lip was protruding. L1 was concerned with the lip tissue change in statistically significant way.
本研究旨在评估Ⅲ类患者下颌后缩手术（MSS）后唇部形态及口角变化，并分析下颌后缩量与唇部形态变化之间的关联。
样本包括14例接受双侧矢状劈开下颌升支截骨术进行MSS治疗的Ⅲ类患者。在MSS术前及术后约6个月拍摄头颅侧位片和锥形束CT。使用3D软件程序Ondemand™测量标志点和变量的变化。进行配对和独立检验以进行统计分析。
口角处的标志点（口角点，Ch）向后下方移动（P<0.005，P<0.01）。然而，口角宽度无统计学显著变化。上唇唇峰（Ls）处的标志点无明显改变。上唇突度角（ChRt-Ls-ChLt°）变锐。口裂（Stm）、下唇唇峰（Li）处的标志点向后移动（P<0.005, P<0.001）。下唇突度角（ChRt-Li-ChLt°）变钝（P<0.001）。上、下唇高度无明显改变。上唇唇红长度增加（P≤0.01），下唇唇红长度减少（P<0.05）。正面观唇部面积无统计学显著变化，但侧面观上唇面积增加，下唇面积变化减小（P>0.05, P<0.005）。侧面观，上唇突出点（UP）向下移动，口裂向后上方移动，Ls-UP-Stm（°）角减小。下唇突出点（LP）向后下方移动，Stm-LP-Li（°）角增加。Li向后移动。最后，下切牙切端（L1）处的标志点向后上方移动，但口裂向下移动。术后，下切牙切端（L1）比口裂位置更高（P<0.05）。水平软组织与相应硬组织之间存在显著关联。L1的向后移动与口角的向后及向下移动在统计学上显著相关。
牙颌面Ⅲ类错合患者的唇部形态在正颌手术后有显著改善。Ⅲ类患者MSS术后三维唇部形态变化显示口角向后下方移动，上唇突出角变锐，下唇突出角变钝，侧面观上唇面积变化增加,下唇面积变化减小，下唇形态突出。L1与唇部组织变化在统计学上有显著关联。
