[Evaluation of radiographic diagnosis on osteoarthrosis of the temporomandibular joint].

84 cadavers' temporomandibular joints were used to compare the results shown in standard lateral tomographs and Schuller's position films with gross views on the bone and cartilage changes. The results and conclusions were as follows: (1) The positive rates of the radiographic evidences were associated with the degrees of the macroscopic lesions. The more severe the macroscopic lesion, the higher the positive rate of radiographic evidence. (2) The sensitivity of radiographic examination was positively correlated with the extent of the macroscopic lesion. So, the negative predictive value was. However, the specificity and the positive predictive value of the radiographic examination were negatively correlated with macroscopic change index. It has been found that the more the extent of osteoarthrosis changes, the higher the sensitivity of radiographic examination; the higher the negative predictive values, the higher the positive rate of radiographic evidence, and the lower the underdiagnosis rate was. Meanwhile, the more the extent of bone pathological changes in the joint, the lower specificity of the radiographic examination, and the lower the positive predictive values and the misdiagnosis is increased. (3) The radiographic diagnostic value based on the standard latreal tomographs of TMJ, Schuller's position films or based on the both methods was not satisfied. Its underdiagnosis rate was higher. Therefore, we suggest that multiple-layers lateral tomography should be widely used in clinical practice.