Preliminary Evidence on Intra-Articular Autologous Conditioned Serum (ACS) in Temporomandibular Joint Disorders (TMDs): A Systematic Review with a Focus on Mechanisms and Potential Application in Clinical Practice

Intra-articular injections form a substantial element of the temporomandibular joint disorder (TMD) therapy. Given the role played by IL-1β in pathology, the use of autologous conditioned serum (ACS) is well-founded. Despite years of effective use in different locations, data regarding the intra-articular administration of ACS in TMD is scarce, and the strategy itself is not routinely applied. This study aims to provide preliminary evidence on the therapeutic efficacy of administering intra-articular ACS in treating TMD. Patients with TMD who received intra-articular ACS were included. More invasive co-interventions, such as arthroscopy, were excluded. Final searches were conducted on 17 June 2025, using five databases (ACM, BASE, DOAJ, PubMed, and SciELO). Risk of bias was evaluated using the RoB 2 tool. The results were tabulated. Only one study met the inclusion criteria. When compared to dextrose prolotherapy in internal TMD, ACS therapy resulted in greater improvement in mouth opening, pain, and joint-sound reduction. The small sample size, head-to-head design, and limited blinding suggest a highly cautious interpretation of the findings. ACS is a promising, but still experimental, therapeutic strategy addressing critical mechanisms in TMD. However, the currently available data is insufficient to confirm the effectiveness and safety of such an approach, and further high-quality studies are needed. This study received no funding. PROSPERO registration number: CRD420251069310.