INTRODUCTION: temporomandibular disorders (TMD) can be defined as a group of painful and/or dysfunctional conditions that involve masticatory muscles and/or the temporomandibular joints (TMJ). One of the methods used to the diagnostic is the "Research Diagnostic Criteria for Temporomandibular Disorders" (RDC/TMD). Parafunctional habits are those not related to the execution of normal functions of stomatognatic system. Bruxism is characterized by nocturnal involuntary parafunctional activity of masticatory muscles, while clenching is considered as a diurnal parafunction involving this musculature, although this may also occur at night. OBJECTIVE: the goal of the present study was to evaluate the frequency of relates of diurnal and/or nocturnal oral parafunctions in patients with TMD in different diagnostic subgroups of RDC/TMD. METHODOLOGY: it has been used data from 217 patients that seek for treatment at TMD and Orofacial Pain Clinic of Petropolis Medicine School, being evaluated through questionnaire and physical examination that compose RDC/TMD. RESULTS: from 182 TMD patients studied, 76.9% has related some kind of parafunction, that could be diurnal, nocturnal or both. Diurnal parafunction was the most frequent related among TMD subgroups, present in 64.8% of cases against 55.5% of cases with relates of bruxism. Relate of both parafunctions was verified in 43.4% of TMD patients. CONCLUSION: regarding each diagnostic subgroup, relates of diurnal and nocturnal parafunctions has been more frequent in patients of miofascial pain group.
TMD; RDC/TMD; Bruxism; Clenching
