顎関節症ＩＶ型の臨床的観察 顎関節円板前方転位との関係

Abstract

Thirty one TMJs with osteoarthrosis of 28 patients (3 males, 25 females) were investigated in relation to internal derangement. Oblique transcranial projection, multiple tomography and direct sagittal CT were used in order to detect condyle changes. Bilateral arthrotomographic examination was performed in those patients. The results were as follows:1. The mean age of patients was 45 years and the maximal intcrincisal distance ranged from 22mm to 47mm with an average of 36.6mm. Crepitus was palpated in 22 joints.2. The most frequent finding of the condyle was erosive bone change followed by flattening, and then both marginal proliferation and sclerosis of the condyle.3. Arthrographic examination revealed that discs displaced frontward without reduction accounted for 78% of the TMJs, and those with reduction was 11%. But discs were not displaced in the remaining 11% of the TMJ with bony changes.4. Structural changes of the disc, like perforation, thickening, and adhesion were observed in 18 joints (65%) accompanied by discs displaced frontward without reduction.5. 12 patients were able to be followed up over 12 months in the course of conservative treatment with occlusal splints. In 5 patients whose discs had been displaced frontward without reduction, erosive bone changes or sclerosis of the condyle changed into flattening. The joint of one patient changed its condyle shape from erosive bone change into normal shape and its disc was not displaced but was perforated.From these results, it seemed that the overloading of the joint alone ae well as the displacement of the disc are the pathogenesis of osteoarthrosis. The hard tissue of the joint thought to he influenced and altered by the environment of the intra-and extra-joint. It is considered that the longitudinal observation of hard tissue is necessary in the patients with osteoarthrosis.