MR成像在颞下颌关节可复性盘前移治疗方法选择中的价值

Clinical value of MRI in treatment choice of anterior disc displacement with reduction

目的 探讨MRI在颞下颌关节可复性盘前移治疗方法选择中的作用.方法 采用1.5 T超导MR,对连续选取的72例MRI确诊为单侧（66例）和双侧（6例）颞下颌关节可复性盘前移患者的双侧颞下颌关节,完成开口和闭口斜矢状面T2WI和质子密度加权像扫描,得到78侧可复性盘前移图像.根据临床症状将患者分为需要治疗的重症状组（45侧关节）和暂时观察的轻症状组（33侧关节）.由2名放射科医师完成两组关节盘前移程度的测量,评价关节盘形态（双凹形,双面形、双凸形、圆形、折叠扭转形和后带增宽形）和关节渗出（无渗出、少量渗出、中等量渗出、大量渗出）的情况.2名医师图像评价的一致性采用Kappa检验,两组关节盘前移程度的比较应用t检验,关节盘形变和关节渗出等计数资料的比较采用χ^2检验.结果 2名医生对关节盘形态和关节渗出评价的一致性较好（Kappa值分别为0.816和0.832,P值均〈0.01）.重症状组和轻症状组关节盘平均前移角度分别为（54.2±10.9）°和（46.4±9.0）°,重症状组关节盘前移程度明显大于轻症状组（t=3.37,P〈0.05）.两组关节盘形态改变发生率差异无统计学意义（χ^2=1.18,P=0.277）,重症状组关节盘形态改变以后带增宽形为主,轻症状组以双面形为主,差异有统计学意义（χ^2值分别为5.65和5.67,P值均〈0.05）.两组关节渗出发生率差异无统计学意义（χ^2=1.02,P=0.312）,但中等量以上关节渗出发生率在重症状组更高（χ^2=6.55,P〈0.05）.结论 MRI有助于客观判断颞下颌关节可复性盘前移的严重程度,帮助临床医师选择合适的治疗方法.

Objective To investigate the clinical value of MRI in treatment choice of anterior disc displacement with reduction. Methods 1.5 T superconducting MR was used to scan bilateral temporomandibular joints in 72 consecutive patients who were diagnosed by MRI as unilateral（66 patients）/bilateral（6 patients） anterior disc displacement with reduction at closed and open mouth. MRI sequences included oblique sagittal T2 weighted image and proton density weighted image, and 78 joints＆#39; images were acquired. According to the severity of clinical symptoms, all joints were divided into severe symptom group （45 joints） and mild symptom group （33 joints）. Treatment was performed in severe symptom group , while follow up was conducted in mild symptom group. Disk position（angle between posterior margin of the disc and the condyle vertical line）, disk morphology（biconcave, biplanar, biconvex, rounded, folded, thick posterior band）, and joint effusion （none effusion, mild effusion, moderate effusion, marked effusion） were evaluated by two radiologists. The observer agreement for image evaluation was calculated using Kappa statistics. Group difference in disk position was compared using t-test and Chi-square test was used to compare group difference in disk morphology and joint effusion. Results The Kappa value between two radiologists were 0.816 and 0.832 （P〈0.01） on evaluation of disk morphology and joint effusion. Statistical results indicated that the angles between posterior margin of the disc and the condyle vertical line in severe symptom group （54.2 ± 10.9）°; were larger than those in mild symptom group （46.4 ± 9.0）° （t=3.37, P〈0.05）. There was no significant difference in disc deformation incidence between the two groups （χ^2=1.18,P=0.277）. The common deformation in sever symptom group was thick posterior band （χ^2=5.65, P〈0.05）, and in mild symptom group was biplanar （χ^2=5.67, P〈0.05）. No statistical difference in joint effusion incidence was observed（χ^2=1.02,P=0.312）. Moderate and marked effusion were more common in sever symptom group than that in mild symptom group （χ^2=6.55,P〈0.05）. Conclusions MRI is a useful tool for making treatment choice in anterior disc displacement with reduction. Treatment should be given when the following occurred on MRI：moderate anterior disc displacement, disc deformation （excepting for biplanar）, moderate or marked joint effusion.