Expression of Interleukin-1 and temporomandibular disorder: Contemporary review of the literature

Objective: Temporomandibular disorders (TMD) are a group of conditions affecting the temporomandibular joint (TMJ), leading to jaw dysfunction, joint and muscle pain, and a decrease in quality of life. A communication network of pro- and anti-inflammatory mediators called cytokines maintains the homeostasis of the TMJ. This review will focus on the Interleukin (IL) family of cytokines, which have been quantified in TMJ synovial fluids in a variety of studies. IL-1α and IL-1β have pro-inflammatory effects, while the endogenous receptor antagonist (IL-1RA) inhibits the pro-inflammatory effects of IL-1. Methods: A literature search (2006–2016) to identify eligible studies was completed using the PubMed database. Studies identified used saline irrigation to quantify cytokine profiles in synovial fluid of healthy and/or dysfunctional joints. Results: The initial search yielded 111 articles, 5 of which met the inclusion criteria after inter-reviewer discussion. Conclusions: Articles that compared IL-1 concentrations in TMD vs. control groups found significant differences.