The aim of this study was to summarize and systematically review the literature on the prevalence of different research diagnostic criteria for temporomandibular disorders (RDC/TMD) version 1.0 axis I diagnoses in patient and in the general populations.
For each of the relevant papers, the following data/information were recorded for meta-analysis and discussion: sample size and demographic features (mean age, female-to-male ratio); prevalence of the assigned diagnoses; prevalence of the diagnoses assigned to the left and right joints, if available; prevalence of the diagnoses assigned to the 2 genders, if available; prevalence of the different combinations of multiple diagnoses, if available; and prevalence of TMD (only for community studies).
Twenty-one (n = 21) papers were included in the review (15 dealing with TMD patient populations and 6 with community samples). The studies on TMD patients accounted for a total of 3,463 subjects (mean age 30.2-39.4 years, female-to-male ratio 3.3), with overall prevalences of 45.3% for group I muscle disorder diagnoses, 41.1% for group II disc displacements, and 30.1% for group III joint disorders. Studies on general populations accounted for a total of 2,491 subjects, with an overall 9.7% prevalence for group I, 11.4% for group IIa, and 2.6% for group IIIa diagnoses.
Prevalence reports were highly variable across studies. Myofascial pain with or without mouth opening limitation was the commonest diagnosis in TMD patient populations, and disc displacement with reduction was the commonest diagnosis in community samples.