面部不对称畸形颞下颌关节盘的磁共振研究

Morphologic and positional assessment of temporomandibular joint disk in patients with facial asymmetry:A magnetic resonance imaging study

目的旨在探讨面部不对称患者两侧颞下颌关节盘的形态和功能是否存在差异及面部不对称与关节盘内部结构紊乱之间可能存在的相关关系。方法对37名面部不对称者(10男,27女)的74个关节应用高清晰度的磁共振技术在矢状位(开口和闭口)和冠状位(闭口)进行扫描。将关节盘移位的类型分为部分前移位、前移位、旋转及侧向移位五种类型。将关节盘的功能分为正常、可复性移位和不可复性移位三组。在矢状向闭口位影像上将关节盘的形状分为双面凹、双面平、烟囱状和严重变形五种。同时对关节盘的位置、开口运动中的移位和旋转进行定量测量。对偏斜侧和非偏斜侧的差异进行统计学分析。结果本样本中约70%的面部不对称患者存在一侧或两侧的关节内部结构紊乱;关节盘前移位,特别是旋转性前移位在偏斜侧较多见(P<0.01);偏斜侧和非偏斜侧的关节盘形态有显著的统计学差异(p<0.01),偏斜侧形态异常者较多;偏斜侧关节盘的位置明显靠前、靠下(p<0,01);非偏斜侧关节盘在开口过程中表现出较大的运动幅度。结论面部不对称患者其两侧关节盘的形态和功能存在不同程度的差异,关节内部结构紊乱与面部不对称畸形的关系有待进一步研究。

Objective To examine the morphology and function of the disk on both sides among patients with facial asymmetry （FA） and to elucidate plausible correlations between internal derangement （ID） and FA. Methods The sample was composed of 10 males and 27 females with FA. The disk status of all subjects were evaluated by bilateral high resolution magnetic resonance scans in the sagittal （closed and open） and coronal （closed） planes. Five types of disk displacement were identified accordingly. The disk function was diagnosed as normal disk function, disk displacement with reduction, and disk displacement without reduction. The disk shape on sagittal MRI in closed position was classified as biconcave, bi-planar, funnel and deformed. The disk position, translation and rotation during jaw opening movement were also measured. The difference between the shifted side and contralateral side was analyzed by statistical analysis. Results Approximately 70% of the patients in the present study showed unilateral or bilateral ID. It was found that anterior disk displacement （ADD）, especially rotational ADD, occurred more frequently in the shifted side, while normal disk position was observed mainly in the contralateral side （p〈0. 01）. The disk of the shifted side showed significantly deformed configuration and inferior-anterior disk position. However, the disk of the contralateral side showed hyper-mobility during jaw opening movement. Conclusions These results demonstrated that in patients with FA, the disks status of the shifted side was different from that of the contralateral side, further studies need to be done to elucidate the correlations between ID and FA.