Inflammatory involvement of the temporomandibular joint. Diagnostic and therapeutic aspects and a study of individuals with ankylosing spondylitis.

The aims of this thesis were firstly to investigate the relationship between pain and tenderness to palpation of the temporomandibular joint (TMJ), radiographic changes of the joint and signs of inflammation in the synovial fluid and to compare the effects of intra-articular injections of a corticosteroid into the TMJ with occlusal treatment in patients with tenderness to palpation of the TMJ, secondly to study subjective, clinical and radiographic features in the stomatognathic system of individuals with ankylosing spondylitis (AS) in comparison with individuals without general joint symptoms or disease, and thirdly to study the observer variability of some variables used in the clinical examination of the stomatognathic system. Radiographic, cellular and biochemical signs of inflammation were frequently found in the TMJs of patients with longstanding pain and tenderness in this joint. Absence of radiographic changes of the TMJ did not, however, exclude the possibility of organic TMJ disease. Both intra-articular injections of corticosteroid combined with local anaesthetic and occlusal treatment showed a long-term palliative effect on subjective symptoms and clinical signs from the stomatognathic system. The clinical signs, however, showed a significantly better long-term response to the intra-articular injections than to the occlusal treatment. The prognosis for the intra-articular steroid injections was most favourable in patients without radiographic signs of TMJ remodelling or general joint symptoms. The ankylosing spondylitis study showed that subjective and clinical symptoms in the stomatognathic system and radiographic changes of the TMJ are more frequent in the individuals with AS compared to the other individuals. Most signs and symptoms in the stomatognathic system of the individuals with AS were correlated to the extension and severity of this disease. There was also a correlation between clinical and radiographic signs of inflammatory involvement of the TMJ and subjective and clinical symptoms from the stomatognathic system in the individuals with AS which was not found in the other individuals. Occlusal factors seemed to play a minor etiological role in the development of signs and symptoms from the stomatognathic system in both the individuals with AS and the other individuals. The methodological study showed that the intra-observer variability was generally lower than the interobserver variability. Maximal mouth opening capacity had the lowest observer variability in the clinical examination.