Widespread pain as a risk factor for dysfunctional temporomandibular disorder pain

Widespread pain has been found to be a risk factor for onset and persistence of temporomandibular disorder (TMD) pain. The aim of this cohort study was to determine if widespread pain is associated with interference and disability related to TMD pain. Three hundred and ninety-seven TMD patients were interviewed at 1 and 2 years following enrollment. Dysfunctional TMD pain was defined as grades IV, III and II with any disability points on the graded chronic pain scale (GCPS). Widespread pain was defined by the number of pain sites (0-4: head, back, stomach, chest) outside the masticatory system. Multivariable logistic regression analysis, controlling for the effects of age, education, depression, baseline GCPS, and time since study enrollment, was used to examine the relationship between widespread pain and risk of onset or maintenance of dysfunctional TMD pain during follow-up. Among women without dysfunctional TMD pain at baseline, widespread pain was a risk factor for development of dysfunctional TMD pain (odds ratio (OR): 1.9, 95% confidence interval (CI): 1.2-2.8, P=0.003). However, there was no association between widespread pain and onset of dysfunctional TMD pain among men (OR: 1.0, 95% CI: 0.4-2.8, P=0.95) or maintenance of dysfunctional TMD among either women (OR: 1.0, 95% CI: 0.8-1.4, P=0.85) or men (OR: 0.4, 95% CI: 0.1-3.2, P=0.40). Widespread pain was independently and highly associated with risk of developing pain-related disability among women who did not have pain dysfunction at baseline, but was not predictive of risk of onset of dysfunctional TMD pain among men or maintenance of dysfunctional pain among either women or men.