Larheim Tore A
Department of Maxillofacial Radiology, Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Cells Tissues Organs. 2005;180(1):6-21. doi: 10.1159/000086194.
Temporomandibular joint (TMJ) abnormalities cannot be reliably assessed by a clinical examination. Magnetic resonance imaging (MRI) may depict joint abnormalities not seen with any other imaging method and thus is the best method to make a diagnostic assessment of the TMJ status. In patients with temporomandibular joint disorder (TMD) referred for diagnostic imaging the predominant TMJ finding is internal derangement related to disc displacement. This finding is significantly more frequent than in asymptomatic volunteers, and occurs in up to 80% of patients consecutively referred for TMJ imaging. Moreover, certain types of disc displacement seem to occur almost exclusively in TMD patients, namely complete disc displacements that do not reduce on mouth opening. Other intra-articular abnormalities may additionally be associated with the disc displacement, predominantly joint effusion (which means more fluid than seen in any asymptomatic volunteer) and mandibular condyle marrow abnormalities (which are not seen in volunteers). These conditions seem to be closely related. Nearly 15% of TMD patients consecutively referred for TMJ MRI will have joint effusion, of whom about 30% will show bone marrow abnormalities. In a surgically selected material of joints with histologically documented bone marrow abnormalities nearly 40% showed joint effusion. Disc displacement is mostly bilateral, but joint effusion seems to be unilateral or with a lesser amount of fluid in the contralateral joint. Abnormal bone marrow is also mostly unilateral. Many patients have unilateral pain or more pain on one side. In a regression analysis the self-reported in-patient TMJ pain side difference was positively dependent on TMJ effusion and condyle marrow abnormalities, but negatively dependent on cortical bone abnormalities. Of the joints with effusion only one fourth showed osteoarthritis. Thus, there seems to be a subgroup of TMD patients showing more severe intra-articular pathology than disc displacement alone, and mostly without osteoarthritis. It should, however, be emphasized that patients with TMJ effusion and/or abnormal bone marrow in the mandibular condyle seem to constitute only a minor portion (less than one fourth) of consecutive TMD patients referred for diagnostic TMJ imaging. The majority of patients have internal derangement related to disc displacement, but without accompanying joint abnormalities. In patients with rheumatoid arthritis and other arthritides TMJ involvement may mimick the more common TMDs. Using MRI it is possible, in most cases, to distinguish these patients from those without synovial proliferation.
颞下颌关节（TMJ）异常无法通过临床检查可靠地评估。磁共振成像（MRI）可以显示出其他任何成像方法都无法看到的关节异常，因此是对TMJ状态进行诊断评估的最佳方法。在因诊断成像而转诊的颞下颌关节紊乱（TMD）患者中，TMJ的主要发现是与盘移位相关的内部紊乱。这一发现比无症状志愿者中更为常见，在连续转诊进行TMJ成像的患者中发生率高达80%。此外，某些类型的盘移位似乎几乎只发生在TMD患者中，即开口时不能复位的完全性盘移位。其他关节内异常可能与盘移位相关，主要是关节积液（即比任何无症状志愿者中所见更多的液体）和下颌髁骨髓异常（志愿者中未见）。这些情况似乎密切相关。连续转诊进行TMJ MRI检查的TMD患者中近15%会有关节积液，其中约30%会出现骨髓异常。在经手术选择的、组织学记录有骨髓异常的关节材料中，近40%有关节积液。盘移位大多是双侧的，但关节积液似乎是单侧的，或者对侧关节中的液体较少。异常骨髓也大多是单侧的。许多患者有单侧疼痛或一侧疼痛更明显。在回归分析中，自我报告的住院TMJ疼痛侧差异与TMJ积液和髁骨髓异常呈正相关，但与皮质骨异常呈负相关。在有关节积液的关节中，只有四分之一显示骨关节炎。因此，似乎有一部分TMD患者表现出比单纯盘移位更严重的关节内病理改变，且大多无骨关节炎。然而，应该强调的是，下颌髁有关节积液和/或骨髓异常的患者似乎仅占连续转诊进行诊断性TMJ成像的TMD患者的一小部分（不到四分之一）。大多数患者有与盘移位相关的内部紊乱，但无伴随的关节异常。在类风湿关节炎和其他关节炎患者中，TMJ受累可能类似于更常见的TMD。在大多数情况下，使用MRI可以将这些患者与无滑膜增生的患者区分开来。
