The purpose of this study was to measure the amount of new information contributed by temporomandibular joint tomograms beyond that anticipated by the patient's clinical presentation.
The results of a clinical examination and history, including a video of patient interview, and dental casts of 105 patients with a temporomandibular disorder were presented to a panel of general dentist evaluators with some experience in temporomandibular disorders. These evaluators then described the radiographic findings they anticipated. Lastly they examined temporomandibular joint tomograms for each of the study patients and scored their findings.
The temporomandibular joint tomograms revealed unanticipated osseous changes in 61% of case judgments of condyles and 47% for the temporal bone or 34% and 22%, respectively, when subtle changes were excluded. Unexpected condyle positional findings were revealed in 31% of the patients. When stratified by clinical class, osteoarthritis and internal derangement, false-positive and false-negative interpretations were 12.1% and 25.5%, respectively, for osteoarthritis, and 12.2% and 17.3% for derangement.
The fairly high rate of unexpected new osseous and positional findings supports the need for tomograms in patients with a clinical diagnosis of derangement or osteoarthritis.