Epidemiological investigations about the prevalence of TMJ ID and osteoarthritis have largely reported the symptoms and signs associated with these disorders without specific criteria to establish the diagnosis. In this study, specific diagnostic criteria have been developed, using historical, clinical and tomographic items that are predictive of the presence and stage of TMJ internal derangement. The diagnostic criteria were compared to arthrotomography to assess their diagnostic accuracy. Overall, the percent agreement was 75%. The predictability of specific stages of TMJ ID varied. Overall, sensitivity and specificity of the criteria were acceptable. The diagnosis of osteoarthritis was predicted only with tomography. Utilization of these diagnostic criteria in epidemiological studies is valid due to their high overall predictiveness when applied to a large population.