Self-reported awake bruxism (AB) has been associated with temporomandibular disorders (TMD). However, the daily amount of AB behavior has not been quantified in pain patients. Therefore, this study aimed to assess AB frequency in patients with myofascial pain and temporomandibular joint (TMJ) pain and compare it to a group of pain-free individuals. Eighty-four individuals belonging to either a TMD group (n = 54) or a healthy control group (n = 30) were selected. AB frequency was obtained by ecological momentary assessment with a dedicated smartphone application that sent sound alerts at random intervals during the day for one week. Upon receiving the alert, the volunteer reported the current muscular condition and/or the teeth position, i.e., relaxed jaw muscle, jaw bracing, teeth contact, teeth clenching, or teeth grinding. Data were evaluated by independent t-test (α = 0.05). During the seven days, AB frequency was 62.1% ± 26.8% for TMD patients and 36.2% ± 27.3% for pain-free subjects (p < 0.001). Mandible bracing was most common in the TMD group (p < 0.001), while teeth contact, clenching, and grinding did not differ between groups. Moreover, no differences were found in AB frequency between myofascial pain and TMJ pain patients. Therefore, TMD patients have higher AB frequency characterized by jaw bracing, irrespective of pain location.
Keywords: bruxism; ecological momentary assessment; pain; temporomandibular joint disorders.