Department of Oral and Maxillofacial Radiology, Aichi Gakuin University School of Dentistry, 2-11 Suemori-dori Chikusa-ku, Nagoya, 464-8651, Japan.
Department of Oral and Maxillofacial Surgery, Aichi Gakuin University School of Dentistry, 2-11 Suemori-dori Chikusa-ku, Nagoya, 464-8651, Japan.
Oral Radiol. 2021 Apr;37(2):236-244. doi: 10.1007/s11282-020-00438-x. Epub 2020 Apr 18.
The present study aimed to clarify the characteristic computed tomography (CT) features that indicate synovial chondromatosis (SC) with a few small calcified bodies or without calcification on panoramic images, and to discuss their differences from the features of temporomandibular disorder (TMD).
Panoramic and CT images from 11 patients with histologically verified SC of the temporomandibular joint were investigated. Based on the panoramic images, the patients were classified into a distinct group (5 patients) with typical features of calcified loose bodies and an indistinct group (6 patients) without such bodies. On the CT images, findings for high-density structures suggesting calcified loose bodies, joint space widening, and bony changes in the articular eminence and glenoid fossa (eminence/fossa) and condyle were analyzed.
All 5 distinct group patients showed high-density structures on CT images, while 2 of 6 indistinct group patients showed no high-density structures even on soft-tissue window CT images. A significant difference was found for the joint space distance between the affected and unaffected sides. A low-density area relative to the surrounding muscles, suggesting joint space widening, was observed on the affected side in 2 indistinct group patients. All 11 patients regardless of distinct or indistinct classification showed bony changes in the eminence/fossa with predominant findings of extended sclerosis and erosion.
Eminence/fossa osseous changes including extended sclerosis and erosion may be effective CT features for differentiating SC from TMD even when calcified loose bodies cannot be identified.
本研究旨在阐明在全景图像上表现为少量小钙化体或无钙化的滑膜软骨瘤病（SC）的特征性 CT 表现，并讨论其与颞下颌关节紊乱（TMD）特征的差异。
对 11 例经组织学证实的颞下颌关节 SC 患者的全景和 CT 图像进行了研究。根据全景图像，患者分为具有典型钙化游离体特征的明确组（5 例）和无此类体的不明确组（6 例）。在 CT 图像上，分析提示钙化游离体的高密度结构、关节间隙增宽以及关节突和关节窝（突/窝）和髁突的骨改变。
所有 5 例明确组患者在 CT 图像上均显示高密度结构，而 6 例不明确组患者中有 2 例甚至在软组织窗 CT 图像上均未见高密度结构。患侧与健侧关节间隙距离存在显著差异。2 例不明确组患者患侧可见相对于周围肌肉的低密度区，提示关节间隙增宽。11 例患者无论明确或不明确分类，均显示突/窝骨改变，以广泛硬化和侵蚀为主。
即使不能识别钙化游离体，突/窝骨改变包括广泛硬化和侵蚀也可能是 CT 区分 SC 与 TMD 的有效特征。
