Transcranial radiographs in the evaluation of craniomandibular (TMJ) disorders

To use a radiographic technique to evaluate patients, one must be aware of the limitations of the study. A TR can be used to show both structural and positional changes of the lateral third of the condyle and fossa. TR obtained at vertical angulations greater than 20 degrees will add significant distortion to the full open-mouth radiograph. The structural changes seen in the joints of patients with the TR who had further diagnostic studies were confirmed with tomography. The changes seen with tomography were either as severe or more extensive than those noted on the TR. Three patients who had extensive structural changes on both the condyle and fossa were shown by arthrography to have a perforation in the joint's soft tissues. While the lateral position of the condyle does not represent the entire joint, this study has shown that it may qualitatively serve as a positional indicator for the joint. The TR together with the rest of a patient's examination data can be used in the treatment. For the patient who has not responded to therapy or whose TR disagrees with the clinical examination, tomographic and arthrotomographic studies are suggested. In the group of 61 patients, 11 (18%) fell into this category. Further diagnostic studies were not felt to be necessary for the remaining 50 patients.