Risk factors for onset of chronic oro-facial pain--results of the North Cheshire oro-facial pain prospective population study.

Due to the cross-sectional nature of previous studies, whether mechanical factors predict the onset of Chronic oro-facial pain remains unclear. Aims of the current study were to test the hypotheses that self-reported mechanical factors would predict onset of Chronic oro-facial pain and that any observed relationship would be independent of the confounding effects of psychosocial factors and reporting of other unexplained symptoms. About 1735 subjects who had completed a baseline questionnaire were assessed at 2year follow-up for the presence of Chronic oro-facial pain, psychosocial factors (anxiety and depression, illness behaviour, life stressors and reporting of somatic symptoms), mechanical dysfunction (facial trauma, grinding, phantom bite and missing teeth) and reporting of other unexplained symptoms (chronic widespread pain, irritable bowel syndrome and chronic fatigue). About 1329 subjects returned completed questionnaires (adjusted response rate 87%). About 56 (5%) reported new episodes of Chronic oro-facial pain at follow-up. Univariate analyses showed that age, gender, reporting of other unexplained symptoms, psychosocial factors and two self-report mechanical factors predicted the onset of Chronic oro-facial pain. However multivariate analysis showed that mechanical factors did not independently predict onset. The strongest predictors were health anxiety (Relative Risk (RR) 2.8, 95% CI 1.3-6.2), chronic widespread pain (RR 4.0 95% C.I. 2.2-7.4) and age (RR 0.2, 95% CI 0.1-0.7). The findings from this prospective study support the hypothesis that psychosocial factors are markers for onset of Chronic oro-facial pain. The efficacy of early psychological management of Chronic oro-facial pain to address these factors should be a priority for future investigations.