目的:该研究旨在(1)评估III类患者双颌手术前后面部不对称的部位和严重程度,(2)确定初始严重程度和位置颌骨不对称对残余面部不对称的影响。
方法:对65例III级面部不对称患者行双颌手术的术前和术后锥形束计算机断层扫描进行了评估。确定了5个中线和14个旁正中面部软组织标志,以评估面部不对称性。将结果与由30名年龄和性别匹配的I类受试者组成的对照组进行比较。术后位置颌骨不对称(即,shift,roll,yaw)的每个截骨段(上颌骨,下颌骨,下巴,ramus)也进行了测量。
结果:手术前,下巴的不对称更严重,中间和下部轮廓。双颌手术有效矫正面部不对称,特别是在实现下巴偏差正常化方面。然而,术后中轮廓和下轮廓存在显著的不对称性(分别为p<0.001和p<0.01),受到滚动和移位中位置支流不对称性的影响。
结论:下巴的偏差,中,下轮廓对III类不对称中的整体面部不对称有重要贡献。尽管双颌手术后下巴偏离正常化,不对称在中间和下部轮廓上持续存在,主要是由于位置支不对称性校正不足。
结论:了解双颌骨手术后残留的不对称性对于最小化偏差和优化手术计划以进行矫正非常重要。
OBJECTIVE: The study aimed (1) to evaluate the site and severity of facial asymmetry in Class III patients before and after bimaxillary surgery, and (2) to identify the influence of initial severity and positional jaw asymmetry on residual facial asymmetry.
METHODS: Preoperative and postoperative cone-beam computed tomography of 65 patients with Class III facial asymmetry who underwent bimaxillary surgery were evaluated. Five midline and 14 paramedian facial soft tissue landmarks were identified to assess facial asymmetry. The outcomes were compared to a control group consisting of 30 age- and gender-matched Class I subjects. The postoperative positional jaw asymmetry (i.e., shift, roll, yaw) of each osteotomy segment (maxilla, mandible, chin, ramus) was also measured.
RESULTS: Before surgery, the asymmetry was more severe at the chin, middle and lower contour. Bimaxillary surgery effectively corrected facial asymmetry, particularly in achieving normalization of chin deviation. However, significant asymmetry persisted postoperatively in the middle and lower contour (p < 0.001 and p < 0.01, respectively), which was affected by the positional ramus asymmetry in the roll and shift.
CONCLUSIONS: Deviation of the chin, middle and lower contour contributed significantly to overall facial asymmetry in Class III asymmetry. Despite normalization of the chin deviation after bimaxillary surgery, asymmetry persisted at the middle and lower contour, primarily as the result of insufficient correction of the positional ramus asymmetry.
CONCLUSIONS: Understanding the residual asymmetry after bimaxillary surgery is important for minimizing deviation and optimizing the surgical planning for its correction.