Age peaks of different RDC/TMD diagnoses in a patient population

AIMS: To evaluate the prevalence of different Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) diagnoses in a population of patients seeking for TMD treatment at a tertiary clinic in Northern Italy; to evaluate the pattern of age distribution of RDC/TMD diagnoses and to compare data with those from similar studies in the literature. MATERIALS AND METHODS: Two-hundred-forty-three (N=243) consecutive patients seeking TMD treatment at the TMD Clinic, Department of Maxillofacial Surgery, University of Padova, Italy, during the period from July 1st to December 31st, 2008, underwent a RDC/TMD axis I assessment by the use of a systematically translated Italian version of the RDC/TMD guidelines. RESULTS: One-hundred-ninety-nine (N=199) patients (female:male ratio 5:1, mean age 39.7+/-17.1 years, range 18-80) satisfied the RDC/TMD consortium inclusion criteria. Group I disorders (muscle disorders) were diagnosed in 49.7% of patients, group II disorders (disc displacements) in 57.3%, and group III disorders (arthralgia, osteoarthritis, and osteoarthrosis) in 81.4%. The majority of patients (64.3%) received RDC/TMD diagnoses of more than one group. On the basis of the age distribution of RDC/TMD diagnoses, two main distinct groups of TMD patients could be identified: a first group of patients showing disc displacement in the absence of degenerative disorders (any group II diagnoses alone or combined with group I diagnoses of muscle disorders and/or group IIIa diagnosis of arthralgia), and a second group of patients with signs and symptoms of inflammatory-degenerative joint disorders (group IIIb diagnosis of osteoarthritis and/or group IIIc diagnosis of osteoarthrosis). The former comprised 107 patients (20 males, 18.7%; 87 females, 81.3%) with a mean age of 32.7+/-14.5 years, while the latter comprised 46 patients (4 males, 8.7%; 42 females, 91.3%) with a mean age of 54.2+/-15.1 years, thus accounting for about 80% of the study population and being characterized by a significantly different age peak. CONCLUSIONS: Along with descriptive relative frequencies of the RDC/TMD diagnoses, which have been compared with other similar studies in the literature, the main findings of the present investigation were that at least two distinct age peaks are identifiable within this population of patients seeking for TMD treatment. These data might be useful to gather data on the specific epidemiologic features of each single RDC/TMD diagnoses. These findings have to be confirmed by means of multicenter studies involving many calibrated investigators.