Sense of control modifies relationship between stress and temporomandibular disorder

While psychological stress is a risk factor for temporomandibular disorder (TMD), there are theoretical grounds to believe its effect might be modified by personal control, a psychosocial construct reflecting a person's global sense of control over their lives. Objectives: To identify contributions of personal control and stress as risk indicators for TMD in the Australian population. Methods: Cross-sectional survey of a probability sample of 3,828 dentate Australians aged 15-90 years who completed a questionnaire about TMD symptoms, previously validated as a screening method for clinical TMD (Locker and Slade, Community Dent. Oral Epidemiol. 1989;17:150-3). People who reported pain and dysfunction were classified as TMD cases. The questionnaire also included the 14-item Perceived Stress Scale, the 12-item Personal Control Scale and sociodemographic questions. Multivariable binary logistic regression was used to estimate separate and joint effects of stress and control on odds of TMD with adjustment for potential confounders. SAS survey estimation procedures were used to generate weighted estimates generalizable to the Australian population. Results: TMD pain and dysfunction was reported by 9.4% of Australians (95%CI = 8.0-10.9%). In the multivariate model, there was an interaction (P=0.04) between control and stress. After adjusting for age, sex, and means-tested eligibility for public dental care, higher stress was associated with increased odds of TMD in people with personal control scores in the lowest tertile (OR=1.6, 95%CI=1.2-2.2 per standard deviation [sd] of perceived stress). However, stress was not associated with odds of TMD in people with personal control scores in the middle tertile (OR=1.1, 95%CI=0.7-1.8 per sd of stress) or the highest tertile (OR=0.9, 95%CI=0.6-1.3 per sd of stress). Conclusion: In the Australian population, stress was a risk indicator for TMD, although only in the absence of personal control. Supported by: NHMRC, AIHW, ADA, State/Federal governments, Colgate Oral Care.