A follow-up study on the relation of malocclusion and temporomandibular joint MRI and helical CT findings in temporomandibular disorder patients

目的：探讨颞下颌关节紊乱患者错颌畸形与颞下颌关节MRI及螺旋CT表现的关系。方法：根据MRI和螺旋CT的评估将受试者分为三组：椎间盘移位伴复位（DDWR）；无复位盘位移（DDWOR）；和正常受试者。所有受试者分别使用咬合配准条或黑色硅胶（咬合检查器）和Dental Prescale（压敏片）测定咬合接触量和咬合咬合力。结果：在牙尖间位，DDWOR TMD患者组的咬合接触次数和咬合总咬合力均低于正常对照组。在侧位下，DDWOR TMD患者组非工作侧磨牙的咬合力高于正常对照组。在边缘对边缘咬合位置上，磨牙的咬合力差异无统计学意义，但正常对照组磨牙有咬合接触的受试者比例低于患者组。根据收集到的数据，许多受试者的后续MRI结果与最初的MRI结果相比没有明显的变化。然而，一些DDWOR TMD患者的螺旋CT结果显示髁突有明显的糜烂改变。此外，与之前的检查相比，许多TMD患者在随访过程中表现出更大的咬合力（在牙尖间位置）。

Purpose : This follow-up study investigated the relation of malocclusion and temporomandibular joint MRI and helical CT findings in temporomandibular disorder patients.Methods : The subjects in this study were divided into three groups based on MRI and helical CT assessments : disc displacement with reduction(DDWR) ; disc displacement without reduction(DDWOR) ; and normal subjects. The occlusal contacts and occlusal bite force of all subjects were determined using occlusal registration strips or black silicone(bite checker)and Dental Prescale(pressure sensitive sheet), respectively.Results : In the intercuspal position, the number of occlusal contacts and total occlusal bite force of the DDWOR TMD patients group was lower than those of the normal control group. In the lateral position, the occlusal force in the non-working side molars of the DDWOR TMD patients group was higher than that of the normal control group. In the edge to edge occlusal position, the occlusal force in the molars was not significantly different, but the percentage of subjects who had occlusal contacts in the molars of normal control group was lower than those of the patients group.Based on the data gathered, the follow-up MRI results of many subjects showed no discernible change compared with their initial MRI results. However, some of the DDWOR TMD patients showed remarkable erosive change of the condyle as revealed in their helical CT results. Further, many TMD patients exhibited greater total occlusal bite force(in the intercuspal position)during the follow-up procedure compared with the previous examination.