顎関節症患者のMR画像による閉口位と開口位の関節円板形態分析

MR images of the temporomandibular joint in 302 patients who consulted the Clinic for Temporomandibular Disorders, Tokushima University Hospital, with temporomandibular symptoms between January 2007 and April 2013, and underwent magnetic resonance imaging (MRI) were examined. Articular disc morphology in closed and open mouth positions was investigated, and classified it into 3 types: no morphological change, change into another morphology, and anteroposterior compression. The morphology of folding was classified into 2 subtypes: superior and inferior convex types. The association between these and other MRI/clinical findings were examined.
(1) The morphology of the disc in the closed mouth position was evaluated as biconcave on 397 sides, biconvex on 5, even thickness on 32, enlargement of the posterior band on 54, folding on 82, and other types on 11. It was compared with that in the open mouth position. There was no morphological change on 369 sides, an altered morphology on 45, and anteroposterior compression was noted on 167. The most frequent morphological change was one from biconcave to folding (superior convex), which was observed on 16 of the 45 sides. In patients with no morphological change, the incidence of joint effusion was significantly lower than in those with an altered morphology or anteroposterior compression, and the glenoid fossa was deeper. Concerning clinical symptoms, crepitus was significantly more frequent in patients with anteroposterior compression. There were no significant differences in the incidences of the other symptoms among the 3 groups.
(2) There were significant differences in the presence or absence of joint effusion and reposition between patients with superior and inferior convex folding. Briefly, in these patients, joint effusion was more frequent than in those with the other disc morphologies. However, effusion of the superior articular cavity was observed in all patients with inferior convex folding, whereas effusion of the superior and inferior articular cavities was noted in those with superior convex folding. In patients with inferior convex folding, reduction was significantly more frequent than in those with superior convex folding. Concerning clinical symptoms, there were no significant differences between the two groups.
The results of this study showed that the condition markedly differed between joints with and without mouth opening-related changes in the morphology of the articular disc, suggesting that this parameter is useful for clarifying the pathogenesis of temporomandibular joint arthrosis, selecting treatment, and predicting the prognosis.

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内容要旨 : LID201404241013.pdf
審査要旨 : LID201404241014.pdf
論文本文 : LID201404241015.pdf