摘要：

目的：评价三维重建软件评估正颌手术术后髁突变化的有效性及骨性Ⅲ类错畸形双颌术后髁突三维变化及骨质重塑的情况。方法：本研究纳入18例患者，分别于术前（T0）、术后2周（T1）、术后6个月（T2）拍摄螺旋CT，通过Proplan CMF、mimics等三维重建软件行头颅模型重建、标点、计算，明确双侧髁突在三维方向上的角度、位移变化及髁突上表面的骨质改建情况，分析下颌后退程度与双侧髁突的旋转及位移之间的关系。结果：左侧髁突术后2周较术前表现为向后、上位移，在术后恢复时期（T1—T2），左侧髁突向外、下位移，术后6个月相比术前(T0—T2)，左侧髁突整体向外、向后、向下位移；右侧髁突术后2周较术前表现为向外、向后、向上位移，术后恢复期间（T1—T2），髁突在冠状面上继续向下位移，术后6个月相比术前，整体向后位移。左侧髁突在T0—T1期间出现向后、外、上旋转，术后恢复期（T1—T2）髁突长轴在冠状面及矢状面表现为一定的恢复，术后6个月相比术前仍然表现为向后、向外、向上旋转；右侧髁突术后向外、前、下旋转，术后恢复期（T1—T2）在水平面、矢状面、冠状面均有向原有方向恢复的趋势，术后整体（T0—T2）表现为向外、后、上旋转。术后髁突的骨质吸收主要在前内侧区，骨质生成主要在后内侧区。下颌的后退程度（B0-B1）与左侧髁突外极点T0与T2之间在冠状面之间的距离（MPLZ0-2）、右侧髁突外极点T0与T1之间在水平面之间的距离（MPRX0-1）、右侧髁突外极点T1与T2之间在水平面之间的距离(MPRX1-2)之间存在极显著的强相关关系。结论：三维重建软件可以有效地运用于正颌术后髁突变化方面的研究。骨性Ⅲ类错畸形双侧髁突术后出现旋转及位移，双侧髁突术后的旋转、位移及骨质重塑并不一致，同时下颌的后退程度与髁突的位移之间存在相关性。

关键词: 骨性Ⅲ类错畸形, 面部不对称, 三维重建, 髁突

Abstract:

Objective: To evaluate the effectiveness of three-dimensional (3D) reconstruction software in assessing condyle changes after orthognathic surgery and to clarify 3D changes of condyles and bone remodeling after bimaxillary surgery for skeletal class Ⅲ malocclusion. Methods: In this study, 18 patients were enrolled, and spiral CT was taken before surgery (T0), two weeks after surgery (T1), and six months after surgery (T2), respectively. 3D reconstruction softwares such as Proplan CMF and mimincs were used to perform skull model reconstruction, puncturing, and calculation of bilateral condyle angle and displacement changes in 3D direction as well as bone remodeling on the upper surface of the condyle in order to analyze the relationship between the degree of mandibular regression and the rotation and displacement of bilateral condyles. Results: The left condyle showed backward and upward movement shortly after the surgery. During the postoperative recovery period (T1-T2), the left condyle moved outwards and downwards, At six months after surgery (T2), the left condyle moved outwards, backwards, and downwards as a whole compared to the condition before surgery (T0-T2). Two weeks after surgery, the right condyle moved outwards, backwards, and upwards. During the postoperative recovery period (T1-T2), the condyle continued to shift downwards on the coronal plane, and moved backwards as a whole six months after surgery compared with that before surgery. The left condyle rotated backwards, outwards and upwards during T0-T1. The long axis of the condyle recovered in the coronal and sagittal plane during postoperative recovery (T1-T2), and still rotated backwards, outwards and upwards six months after surgery compared with that before surgery. The right condyle rotated outwards, forwards and downwards after surgery. Postoperative recovery (T1-T2) showed a trend of recovery to the original direction in horizontal plane, sagittal plane and coronal plane, and postoperative overall (T0-T2) showed outward, backward and upward rotation. The bone absorption of the condyle was mainly in the anteromedial region and osteosis was mainly in the posteromedial region. The degree of mandibular regression B0-B1 was strongly correlated with MPLZ0-2, MPRX0-1 and MPRX1-2. Conclusion: 3D reconstruction softwares can be effectively used in the study of condylar changes after orthognathic surgery. Bilateral condylar rotation and displacement occur after surgery for skeletal class Ⅲ malocclusion. The rotation, displacement, and bone remodeling after surgery for bilateral condylar are not consistent, and there is a correlation between the degree of mandibular retreat and the displacement of condylar.

Key words: skeletal class Ⅲ malocclusion, facial asymmetry, three-dimensional reconstruction, condyle

中图分类号: 

• R782