The Role of Biomarkers in Temporomandibular Disorders: A Systematic Review.

Temporomandibular disorders (TMDs) impact quality of life and present diagnostic and treatment challenges. Biomarkers may serve as an additional tool to support diagnosis and monitor disease progression, offering supplementary information for treatment strategies in specific and selected patients. This systematic review aimed to assess the role of biomarkers in diagnosing TMD and guiding personalized treatment. It also examined key biomarkers linked to chronic temporomandibular joint (TMJ) pain and how therapies affect biomarker levels and clinical outcomes. A comprehensive search was conducted in PubMed, Scopus, and Web of Science to identify observational and interventional studies assessing the role of biomarkers in synovial fluid/tissue, saliva, and blood. The research was registered in PROSPERO, adhered to PRISMA guidelines, and employed Cochrane Risk of Bias tools. To assess the effect, only studies examining biomarker levels were considered. A total of forty-six studies met the inclusion criteria: three randomized controlled trials were rated as having some concerns, as were most of the observational studies. Elevated levels of interleukins (1ß and 6), tumour necrosis factor alpha, and prostaglandin E2 in synovial fluid were correlated with temporomandibular joint (TMJ) inflammation. Increased matrix metalloproteinases (2, 7, and 9) indicated cartilage deterioration, while oxidative stress markers such as malondialdehyde were higher in TMD patients. Treatments including hyaluronic acid, platelet-rich plasma, and low-level laser therapy effectively reduced inflammatory biomarkers and improved symptoms. Biomarkers show potential to contribute to the understanding of pathophysiological mechanisms in TMD and may support future diagnostic and therapeutic strategies for selected patients. After high-quality studies confirm these findings, this approach will enable personalized medicine by tailoring treatments to individual patient profiles, ultimately leading to improved outcomes and quality of life.