Vittert L, Katina S, Ayoub A, Khambay B, Bowman A W
School of Mathematics and Statistics, The University of Glasgow, Glasgow, UK.
Institute of Mathematics and Statistics, Masaryk University, Brno, Czech Republic.
Int J Oral Maxillofac Surg. 2018 Dec;47(12):1587-1595. doi: 10.1016/j.ijom.2018.05.024. Epub 2018 Jun 19.
Studies of orthognathic surgery often focus on pre-surgical versus post-surgical changes in facial shape. In contrast, this study provides an innovative comparison between post-surgical and control shape. Forty orthognathic surgery patients were included, who underwent three different types of surgical correction: Le Fort I maxillary advancement, bilateral sagittal split mandibular advancement, and bimaxillary advancement surgery. Control facial images were captured from volunteers from local communities in Glasgow, with patterns of age, sex, and ethnic background that matched those of the surgical patients. Facial models were fitted and Procrustes registration and principal components analysis used to allow quantitative analysis, including the comparison of group mean shape and mean asymmetry. The primary characteristic of the difference in shape was found to be residual mandibular prognathism in the group of female patients who underwent Le Fort I maxillary advancement. Individual cases were assessed against this type of shape difference, using a quantitative scale to aid clinical audit. Analysis of the combined surgical groups provided strong evidence that surgery reduces asymmetry in some parts of the face such as the upper lip region. No evidence was found that mean asymmetry in post-surgical patients is greater than that in controls.
正颌外科手术的研究通常聚焦于手术前后面部形状的变化。相比之下，本研究提供了一种创新的方法，即对比手术后与对照组的面部形状。本研究纳入了40名正颌外科手术患者，他们接受了三种不同类型的手术矫正：Le Fort I型上颌前徙术、双侧矢状劈开下颌前徙术和双颌前徙术。对照面部图像取自格拉斯哥当地社区的志愿者，其年龄、性别和种族背景模式与手术患者相匹配。对面部模型进行拟合，并使用普洛透斯配准和主成分分析进行定量分析，包括比较组平均形状和平均不对称性。结果发现，接受Le Fort I型上颌前徙术的女性患者组形状差异的主要特征是下颌残余前突。使用定量量表辅助临床审核，针对此类形状差异对个体病例进行评估。对综合手术组的分析提供了有力证据，表明手术可减少面部某些部位（如上唇区域）的不对称性。未发现手术后患者的平均不对称性大于对照组的证据。
