[摘要] 目的：用螺旋CT研究磁力Twin-block矫治器矫治骨性Ⅱ类错牙合患者的TMJ改建以及髁突在关节窝中位置的变化。方法：11名Ⅱ类骨性错牙合患者，经磁力Twin-block矫治器平均治疗7.4个月,在治疗前、中、后及结束1年后拍摄螺旋CT。结果：治疗中11位患者双侧髁突的后上部都出现了"新月形"影像， 5位患者的螺旋CT片可以看到关节窝的改建，治疗结束一年后髁突及关节窝的影像与治疗前相似。结论：磁力Twin-block矫治器能有效的刺激髁突的生长，髁突改建的部位主要在髁突的后上部，而关节窝的改建不明显。

    [关键词] 磁力 Twin-block矫治器 螺旋CT Ⅱ类错牙合

    Changes of TMJ during and after Magnetic Twin-block Appliance Treatment Observed by Helix CT.

    WU Jian-Yong, LIU Jian,LIN Jiu-xiang.

    Department of Orthodontics, School of dentistry, Beijing University, Beijing 100081

    [Abstract]Objective: To analyse condylar and glenoid fossa remodeling and condylar location change in glenoid fossa accompanied by magnetic twin-block appliance treatment observed by helix CT. Methods: 11 patients(average 12.7years) with class Ⅱ malocclusion were treated with magnetic twin-block appliance for an average period of 7.4 months. Four helix CT imagines were obtained in each patient: before treatment (T1)，during treatment (about 4 months after appliance placement T2)，after treatment (T3), and about one year after treatment (T4). Results: The helix CT imagines showed that a crescent shape imagine could be identified at the posterior-upper part of the condyle of all patients at T2 as a sign of adapative growth change of condyle. The glenoid fossa remodeling was noted in five patients also at T2. All signs of condyle and glenoid fossa remodeling disappeared at T3 and T4. The condylar location in glenoid fossa was not changed by magnetic twin-block appliance treatment. Conclusion: The growth of condyle can be stimulated by maganetic twin-block appliance. The area of remodeling is located at the posterior-upper part of condyle, and the glenoid fossa remodeling is not prominent. ......