Obesity as a risk factor for temporomandibular disorders

We conducted a clinical cross-sectional study to evaluate the association between obesity and the presence of painful temporomandibular disorders (TMD), controlling for age, gender, presence of migraine, depression, non-specific somatic symptoms and obstructive sleep apnoea syndrome (OSAS) in an adult population. A total of 299 individuals (76·6% women) with a mean age of 36·8 ± 12·8 years were evaluated. TMD were classified using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Depression and non-specific somatic symptoms were scored by the Symptom Checklist-90, while pain and disability was rated by the Graded Chronic Pain Scale. Bioimpedanciometry (BIA) was used to assess obesity through total body fat percentage. Migraine was diagnosed according to the criteria of the International Classification of Headache Disorders-2 (ICHD-2). OSAS was classified according to the Berlin Questionnaire. We performed univariate and multivariate models, chi-square tests and odds ratios (OR) with 95% confidence intervals (CI). In the single regression analysis, TMD-pain was significantly associated with total body fat percentage (P = 0·01). In the multivariate analysis, migraine, age, non-specific somatic symptoms and OSAS showed to be stronger predictors of TMD-pain, and obesity did not retain in the regression model. The initial association found between obesity and TMD-pain is lost when it was corrected for gender, migraine, non-specific somatic symptoms and OSAS.