Objective: Literature implicates circulating inflammatory cytokines in pain and TMD. One anti- inflammatory adipokine, omentin-1, has decreased expression in inflammatory conditions. This study tested the hypothesis that circulating levels of omentin-1 were lower in individuals with TMD than healthy controls. Methods: A case-control design of chronic TMD cases (n=90) and TMD-free controls (n=54) were selected from the study named OPPERA. Omentin-1 levels were measured in blood plasma samples using an enzyme-linked immunosorbent assay (ELISA). Logistic regression estimated odds ratios (OR) and 95% confidence limits (CL) for the association between omentin-1 and TMD. Results: Mean omentin-1 concentration was lower in TMD cases (413.5 μg/ml) than controls (464.8 μg/ml), but the difference was not statistically significant. Odds of TMD decreased 36% per standard deviation increase in circulating omentin-1 (adjusted OR=0.64, 95% CL: 0.43, 0.96. P=0.031). Conclusion: Decreased omentin-1 in TMD cases supports the view that TMD pain is mediated by anti-inflammatory pathways.