Hsu Li-Fang, Liu Yi-Jen, Kok Sang-Heng, Chen Yi-Jane, Chen Yunn-Jy, Chen Mu-Hsiung, Jane Yao Chung-Chen
Graduate Institute of Clinical Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Dentistry, National Taiwan University Hospital, Hsin-Chu Branch, Hsin-Chu, Taiwan.
Graduate Institute of Clinical Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan; Division of Orthodontics and Dentofacial Orthopedics, Dental Department, National Taiwan University Hospital, Taipei, Taiwan.
J Formos Med Assoc. 2022 Jan;121(1 Pt 1):98-107. doi: 10.1016/j.jfma.2021.01.018. Epub 2021 Feb 12.
BACKGROUND/PURPOSE: The nature of susceptibility to condylar resorption after orthognathic surgery can be different between skeletal Class II and Class III populations, which was addressed by few in the past. The aim of the present study was to use cone-beam computed tomographic (CBCT) images to investigate the displacement and morphological changes of temporomandibular joints (TMJs) in patients received orthodontic treatment combined with orthognathic surgery.
Both Class III (n = 34) and Class II (n = 17) patients were compared through overall and regional superimpositions of the initial and posttreatment CBCTs. Two-sample t-test was used to identify significance between group differences. Pearson's correlation coefficient was used to address changes of TMJ and the amount of setback or advancement.
The axial ramal angle increased significantly in Class III group and decreased in Class II groups after orthognathic surgery (p < FDR_p). For condylar dimensions, significant widths and lengths reductions were noted only in Class II group. However, no significant difference was found after comparing subgroup differences according to one-jaw and two-jaw options, nor any significant correlation found between the condylar changes and the amount of surgical movements.
The nature of condylar susceptibility could result more from different skeletal patterns than the amount of surgical movements. However, the direction of mandibular surgery may contribute to different changes of condylar angle in axial section.
背景/目的：正颌手术后髁突吸收易感性的本质在骨骼II类和III类人群中可能有所不同，过去对此研究较少。本研究的目的是使用锥形束计算机断层扫描（CBCT）图像来研究接受正畸治疗联合正颌手术患者的颞下颌关节（TMJ）的位移和形态变化。
通过对初始和治疗后CBCT进行整体和局部叠加，对III类（n = 34）和II类（n = 17）患者进行比较。采用两样本t检验确定组间差异的显著性。使用Pearson相关系数来分析TMJ的变化与后退或前移量之间的关系。
正颌手术后，III类组的下颌升支轴角显著增加，II类组则减小（p < FDR_p）。对于髁突尺寸，仅在II类组中观察到显著的宽度和长度减小。然而，根据单颌和双颌手术方式比较亚组差异时未发现显著差异，髁突变化与手术移动量之间也未发现显著相关性。
髁突易感性的本质可能更多地源于不同的骨骼类型，而非手术移动量。然而，下颌手术的方向可能导致轴向截面中髁突角的不同变化。
