An epidemiologic evaluation of two diagnostic classification schemes for temporomandibular disorders.

Few diagnostic classification schemes for temporomandibular disorders (TMD) have been applied systematically to examine the prevalence of various subtypes of TMD in clinic or community populations. In this study, computer algorithms were developed for classifying subjects according to the scheme of Eversole and Machado (1985) and a classification scheme recently developed in our own research at the University of Washington. The diagnostic algorithms were applied to clinical examination data for (1) persons without TMD pain (community controls) and (2) persons reporting TMD pain in the prior 6 months (community subjects with pain), identified in a random sample survey of a health maintenance organization (HMO) population, as well as (3) clinic patients seeking treatment for TMD through the same HMO. Prevalence rates for myofascial pain dysfunction in clinic patients were much higher under the University of Washington approach, whereas rates of internal derangement (type I) and degenerative joint disease were similar under the two schemes. These similar prevalence rates were not, however, accompanied by high concordance between the two schemes. These results highlight the complexities of differential diagnosis of TMD in field research, and suggest that further evaluation of alternative diagnostic schemes is warranted.