Resilient appliance therapy of temporomandibular disorders. Subdiagnoses, sense of coherence and treatment outcome.

Temporomandibular disorders (TMD) with orofacial pain with or without reduced jaw function, are frequent conditions in the general population. Different factors such as tooth clenching and grinding, sometimes due to enhanced psychosocial stress, and trauma to the jaws may be important as etiologic factors. Signs and symptoms of TMD are a common cause for general practitioners to use different intraoral appliances as pain and bite-force reducing devices and for improvement of a reduced jaw function. Intraoral appliances are often used parallel to other treatment modalities. Before treatment start a thorough history taking and clinical examination is necessary for a relevant diagnosis. Sometimes the diagnostic process has to be complemented with proper radiographic imaging in order to support the diagnostic process. The overall aim of this thesis was to compare magnetic resonance imaging (MRI) findings of the TMJ on the clinically assessed diagnoses and to evaluate short- and long-term treatment outcome of a resilient intraoral appliance, in patients with TMD pain. A further aim was to study Sense of Coherence as an influencing factor on treatment outcome, on these patients. In article I the aim was to compare findings on MRI in TMD pain patients with clinical diagnoses of myofascial pain or arthralgia/osteoarthritis in combination with myofascial pain according to the Research Diagnostic Criteria for TMD (RDC/TMD). The temporomandibular joints of 60 consecutive patients, 19 with myofascial pain and 41 patients with arthralgia/osteoarthritis in combination with myofascial pain were examined clinically and with MRI. The most common MRI findings were disc displacements with or without reduction and structural bone changes. These findings were found in both pain groups, however, disc displacements were found significantly more often in patients with arthralgia/osteoarthritis in combination with myofascial pain. Joint fluid was found in both pain groups. The clinical diagnoses for subdivision into myogenous only or combined arthrogenous and myogenous pain groups were not confirmed by MRI findings. In article II the short-term efficacy of a resilient appliance compared to a non-occluding control appliance was studied in a randomised, controlled trial with 80 recruited TMD pain patients. They were randomly allocated to one of two groups: treatment with a resilient appliance or treatment with a hard, palatal, nonoccluding appliance. After 6 and 10 weeks of treatment, characteristic pain intensity (CPI) decreased in both groups. There was no statistically significant difference found between the resilient appliance and the non-occluding control appliance in reducing TMD pain in a short-term perspective. In article III possible factors of importance for treatment outcome were studied as well as the association between Sense of Coherence and grade of depression, and grade of non-specific physical symptoms and general health, in the TMD pain patients. A total of 73 TMD pain patients participated; 36 were treated with a resilient appliance and 37 with a non-occluding control appliance. The findings indicated that none of the studied background variables (age, gender, SoC, depression, nonspecific physical symptoms or general health) seemed to influence the short-term efficacy of intraoral appliances. In the TMD pain patients, no associations were found between SoC and depression, non-specific physical symptoms or general health. In article IV the long-term efficacy was evaluated of the resilient appliance compared to the non-occluding control appliance in the TMD pain patients. Appliance wear was also studied in this article. As in the short-term follow-up, there was no statistically significant difference between the resilient appliance and the non-occluding control appliance in reducing TMD pain in the long-term perspective.