Temporo-mandibular joint dysfunction: pain and illness behaviour.

This study investigated prospectively the illness behaviour of 100 patients with temporo-mandibular (TMJ) dysfunction and 100 asymptomatic patients. It has previously been shown that a simple illness behaviour questionnaire (IBQ) can discriminate between patients with intractable facial pain and minor odontogenic pain [28]. The purpose of this study was to determine whether it was possible to prospectively identify those patients who may be resistant to conservative therapy. The results showed that the TMJ dysfunction patients had significantly increased levels of disease conviction (P less than 0.001), anxiety or depression (P less than 0.005), and were less likely to deny the existence of problems in their life (P less than 0.05) compared to control patients. However, the TMJ population was much closer to the control population than to a pain clinic population. In the small percentage (13%) of patients who failed to respond to conservative therapy, over half showed abnormal illness behaviour. Seventy-five percent of all the TMJ patients could be excluded from further assessment of abnormal illness behaviour at little risk of incorrect classification. Thus the illness behaviour questionnaire can be used as a screening device to identify those patients who require psychologic treatment rather than more aggressive surgical treatment.