There are few long-term follow-up studies of treatment of temporomandibular disorders (TMD).The aim of this questionnaire study was to evaluate eight-year outcomes of appliance therapy in patients suffering from arthralgia/osteoarthritis and/or myofascial pain. The subjects comprised 120 patients, originally randomly assigned to treatment with an occlusal or a control (palatal) appliance. Eight years later, a questionnaire was sent to 118 eligible patients: 90 (76%) responded. The outcome measures were intensity and frequency of pain, physical and emotional functioning, and overall improvement of pain and headache. Maximum pain intensity had decreased by > 30% in 54 patients (60%); frequency of pain had also decreased significantly. A majority, 57/90, reported improved physical function. Fifty-nine patients reported moderate to severe depression and 61 reported non-specific physical symptoms. Sixty-eight patients reported an overall improvement in TMD pain and 61 perceived overall improvement in severity of headaches. In the intervening years, 57 patients had undergone further treatment, most frequently in the form of another occlusal appliance. The majority of respondents reported improvement in TMD pain and headache. However, it is difficult to evaluate the long-term outcome of appliance therapy as more than 60% of the patients had additional treatments during the eight years.