OBJECTIVE: To study the reliability of the Portuguese version of a questionnaire for psychologically and psychosocially diagnosing individuals with temporomandibular disorders (RDC/TMD). METHOD: Interviews were held with 109 individuals of both sexes who required care at the physical therapy clinic of the Araraquara University Center (UNIARA) from January to July 2006. The questionnaires were applied by a single examiner. Two weeks later, the same questionnaire was reapplied to 36 individuals. To evaluate the internal consistency of the method, Cronbach's alpha coefficient was used. The intra-examiner reproducibility was analyzed using the intraclass correlation coefficient (rho) for quantitative variables and Kappa (kappa) statistics for qualitative variables. RESULTS: The internal consistency for the dimensions of chronic pain intensity, disability, limitations relating to mandibular function, nonspecific physical symptoms with pain items included, and nonspecific physical symptoms with pain items and depression excluded, were 0.8479, 0.8971, 0.8673, 0.8080 and 0.9270 respectively, thus confirming the excellent internal validity of the method. The intra-observer agreement was found to be "excellent" for questions relating to pain duration and intensity and "good" for the question relating to current pain. The lowest kappa values were associated with items relating to physical symptoms and depression. The subjects' perception of clicking and creaking also had "satisfactory" agreement, as did the question on seeking professionals for pain treatment. The remaining questions showed "good" and "very good" reproducibility and most of them presented the maximum agreement. CONCLUSION: The Portuguese adaptation of the questionnaire was shown to be reliable for detecting psychological and psychosocial abnormalities relating to temporomandibular disorders.
Reliability; Internal consistency; Reproducibility of results; Temporomandibular joint dysfunction; Diagnosis
