目的·应用磁共振成像（magnetic resonance imaging，MRI）的Dixon技术评估非结构错乱的颞下颌关节紊乱病（temporomandibular joint disorder，TMD）的咀嚼肌疼痛患者的肌肉改变，并评价MRI引导的物理手法治疗咀嚼肌疼痛的临床疗效。方法·连续纳入自2021年6月—2022年9月就诊于上海交通大学医学院附属第九人民医院口腔外科、首次诊断为TMD肌筋膜疼痛（不伴有盘移位）的患者共29例。收集到增强MRI的Dixon序列并进行手法治疗的患者9例。治疗前，利用DICOM Viewer工作站获得9例患者的Dixon图像咀嚼肌疼痛区域值（Z1）、同侧非疼痛区域值（Z2）和对侧对应咀嚼肌区域值（Z3）。依据工作站获得的咀嚼肌异常区域，针对性地进行手法放松治疗。治疗后1~4周进行随访，对比治疗前后主动最大张口度（maximum mouth opening，MMO）和疼痛视觉评分（visual analogue scale，VAS）指标，并评价临床疗效。结果·Dixon序列Z2均值为66.23±32.90，Z3均值为66.27±33.87；而咀嚼肌疼痛区域Z1为131.94±83.99，明显高于Z2和Z3。手法治疗在改善MMO、VAS等方面有明显效果，有效率达88.89%。结论·Dixon序列的影像表现与临床主诉的疼痛点具有很大的相关性，MRI引导的手法放松治疗对改善非结构错乱的颞下颌关节紊乱病的张口度和疼痛有明显疗效。

Objective ·To assess muscle changes of patients of temporomandibular joint disorder with nonstructural disorder by using the Dixon technique for MRI of masticatory muscle, and evaluate the clinical effect of manipulation on masticatory muscle pain guided by MRI. Methods ·A total of 29 patients with TMD masticatory muscle pain (without disc displacement) who were diagnosed for the first time in the Department of Oral Surgery, Shanghai Ninth People′s Hospital, Shanghai Jiao Tong University School of Medicine from June 2021 to September 2022 were included. Among them, 9 cases who were assessed with Dixon technique for MRI of masticatory muscle were collected and treated by manipulation. Before treatment, the DICOM Viewer workstation was used to compare the value of masticatory muscle pain area (Z1), the value of ipsilateral non-pain area (Z2) and the value of contralateral corresponding masticatory muscle area (Z3) in Dixon image. Manipulation therapy was performed according to the area of abnormal threshold. Follow-up was performed for 1-4 weeks after treatment, the active maximum mouth opening (MMO) and Visual Analogue Scale (VAS) before and after treatment were compared, and the value of masticatory muscle pain area in Dixon image after treatment was obtained again to evaluate the clinical efficacy. Results ·The mean value of Z2 and Z3 in Dixon was (66.23±32.90) and (66.27±33.87), while Z1 in masticatory muscle pain region was (131.94±83.99), which was significantly higher than Z2 and Z3. Manipulation therapy showed significant improvement in MMO and VAS, and the effective rate was 88.89%. Conclusion ·There is a significant correlation between the imaging findings of Dixon technique for MRI and the pain points of the masticatory muscle reported by the clinical complaints. The manipulation therapy guided by Dixon technique for MRI has a significant effect on improving the degree of mouth opening and pain.