Zhong Birong, Zhou Guilong, Yang Yong, Chang Shiping, Wang Jingfu, Zhao Kezhen, Zhao Jinlong, Tian Lei, Ma Qin
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Centre for Oral Diseases, Shaanxi Clinical Research Centre for Oral Diseases, Department of Trauma and Orthognathic Surgery, The Third Affiliated Hospital of Air Force Medical University, 710032, Xi'an, China.
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Centre for Oral Diseases, Shaanxi Clinical Research Centre for Oral Diseases, Department of Trauma and Orthognathic Surgery, The Third Affiliated Hospital of Air Force Medical University, 710032, Xi'an, China; Joint Logistics Support Force, Hospital 987, Baoji, China.
J Craniomaxillofac Surg. 2025 Mar;53(3):271-278. doi: 10.1016/j.jcms.2024.12.007. Epub 2024 Dec 13.
The purpose of this study was to investigate the effect of bimaxillary surgery on smile characteristics, including smile line, smile arc, smile index (SI), most posterior teeth displayed(MPTD), buccal corridor ratio (BCR), and smile symmetry. The study consisted of 87 patients with dentofacial deformity: Class II (30 patients), Class III (37 patients), and asymmetry (20 patients). Pearson's chi-squared test and ANOVA were used to analyze the differences in smile characteristics across the preoperative groups. Pearson's chi-square test and the paired-sample t-test were utilized to determine the differences in smile characteristics between the preoperative and postoperative periods. The results showed significant differences in lip thickness ratio (p = 0.021∗), smile line (p = 0.003∗∗), smile arc (p = 0.000∗∗), MPTD (p = 0.015∗), and BCR (p = 0.000∗∗) among the preoperative groups. After orthognathic surgery, in the Class II group there was an increase in the proportion of smile line that transformed from high to average and low (p = 0.001∗∗), an increase in the percentage of upper lip curvature that changed from downward to upward and straight (p = 0.011∗), and an increase in both postoperative SI and BCR (p = 0.007∗∗ and p = 0.002∗∗, respectively), while MPTD decreased (p = 0.031∗). For Class III, the postoperative change in upper lip curvature tended to be more upward and straight (p = 0.002∗∗), the smile arc became more parallel and straight (p = 0.000∗∗), postoperative SI and MPTD increased (p = 0.000∗∗), while BCR decreased (p = 0.000∗). Regarding asymmetry, both MPTD and BCS showed symmetry postoperatively (p = 0.038, p = 0.000∗∗). The findings of this study indicate that orthognathic surgery could enhance some smile characteristics.
本研究的目的是调查双颌手术对微笑特征的影响，包括微笑线、微笑弧度、微笑指数（SI）、最末位显示牙齿数（MPTD）、颊间隙比率（BCR）和微笑对称性。该研究纳入了87例牙颌面畸形患者：II类（30例）、III类（37例）和不对称畸形（20例）。采用Pearson卡方检验和方差分析来分析术前各组微笑特征的差异。使用Pearson卡方检验和配对样本t检验来确定术前和术后微笑特征的差异。结果显示，术前各组之间在唇厚度比率（p = 0.021*）、微笑线（p = 0.003**）微笑弧度（p = 0.000**）、MPTD（p = 0.015*）和BCR（p = 0.000**）方面存在显著差异。正颌手术后，II类组中从高微笑线转变为中等和低微笑线的比例增加（p = 0.001**），上唇弯曲度从向下变为向上和笔直的百分比增加（p = 0.011*），术后SI和BCR均增加（分别为p = 0.007和p = 0.002），而MPTD降低（p = 0.031*）。对于III类患者，术后上唇弯曲度倾向于更向上和笔直（p = 0.002**），微笑弧度变得更平行和笔直（p = 0.000**），术后SI和MPTD增加（p = 0.000**），而BCR降低（p = 0.000*）。对于不对称畸形患者，术后MPTD和BCS均显示出对称性（p = 0.038，p = 0.000**）。本研究结果表明，正颌手术可以改善一些微笑特征。
