[Study on radiographic examination in the temporomandibular joint. Comparison between tomographic and histological findings].

Radiographic changes in the temporomandibular joint (TMJ) generally mean structural bone changes. However, the TMJ has a complex structure and comparisons of histological and radiographic findings are seldom seen in the literature. The author examined 14 human cadavers, 21 TMJs, with lateral tomography and studied the areas of the radiographs histologically. The results were as follows. 1. Radiographic erosion observed in the depression for the lateral pterygoid muscle and in the posterior part of the condyle generally showed no histological changes. Only two erosions, one in the superior part of the condyle and the other in the anterior slope of the articular fossa, showed histological changes. 2. Radiographic sclerosis observed in the articular eminence and the posterior slope of the fossa revealed no histological changes. Four cases of sclerosis in the superior part of the condyle showed remodelling of the bone. 3. Radiographic osteophyte observed in the antero-superior part of the condyle, revealed remodelling and morphological changes corresponding to the radiographic findings. 4. Radiographic flattening observed in the articular eminence revealed histological remodelling changes that corresponded to the radiographic findings. 5. Radiographic concavity observed in the posterior part of the condyle showed no histological changes in this area. However, remodelling of the bone was observed in the superior part of the condyle. In conclusion, radiographic flattening and osteophyte indicated structural bone changes directly. However radiographic erosion and sclerosis must be interpreted with caution, because many cases showed no histological changes and the localization of these radiographic findings was important. Radiographic concavity also must be interpreted with caution, because most cases revealed no depression histologically, but showed proliferation of the bone in front of this region. It was also suggested that the technical terms that express radiographic findings must be questioned and discussed still more.