正常人开闭口位颞颌关节盘磁共振影像测量分析

Imagine Analysis of Temporomandibular Joints of Normal Subjects at Opening and Closing Positions with Magnetic Resonance Imaging Technique

目的 :探讨正常人颞颌关节开、闭口位关节盘的形态变化特点及意义。方法 :对 9名健康男性大学生 (2 1～ 2 3岁 ) ,用超导磁共振仪 ,小视野线圈 ,分别采用左右侧卧位 ,拍摄双侧TMJ矫正矢状位质子加权开口位和闭口位不同层面的MRI影像 ,层厚 3mm ,选取其中能清楚反映关节盘形态的 16 6张图像用电子测量尺测量其关节盘的断面面积和周长。结果 :正常人颞颌关节盘闭口位影像呈窄长形 ,开口位影像呈哑铃形 ;开口位影像断面面积明显大于闭口位面积 (P <0 0 1) ,断面周长二者间无明显差别 (P >0 0 5 )。结论 :正常人开口状态下颞颌关节盘形态较闭口时明显变粗 ,可能是该两种状态下关节内压变化的反映。

Objective:The aim of this study was to investigate the features of discs of temporomandibular joints (TMJs), during the joint was in the closing and opening positions.Methods: A total of 9 male university students, 21～23 years old, without TMJD symptoms were selected for this study, and their bilateral TMJs were examined separately with Siemens 63_SP4000 super conductive MRI system (Germany). The parameters of MRI were 10 cm surface coil, proton_weighted, oblique sagittal section with 3 mm thick. Totally 166 imagines were obtained including closing and opening positions. Both the area and circle length of the disc sections were measured with the electronic ruler.Results: The disc on the oblique section showed a narrow imagine in the closing position, while a dumbbell_shape in the opening position. The shape of the disc demonstrated larger in the opening position than that in the closing position (P<0.01). The circle length of the disc in the above positions didn't showed significant difference (P>0.05).Conclusion: The shape of the TMJ disc in normal subjects changed a lot in the oblique sagittal section from closing to opening positions, which might be related with the internal pressure changes between these two positions.\;