Management of Polyarticular Course Juvenile Idiopathic Arthritis and Temporomandibular Joint Arthritis: A Systematic Literature Review and Meta‐Analysis Informing the <scp>APLAR</scp> Consensus Recommendations

INTRODUCTION: Juvenile idiopathic arthritis (JIA) is one of the most common chronic rheumatic diseases and requires coordinated and targeted treatment strategies to avoid long-term disability. Existing guidelines from Western countries may not address region-specific factors, including genetic heterogeneity, limited treatment availability, and limitations in healthcare infrastructure, in the Asia Pacific region. The aim of this systematic literature review (SLR) and meta-analysis was to provide up-to-date evidence for the Asia Pacific League of Associations for Rheumatology (APLAR) recommendations for managing polyarticular course JIA (pcJIA) and temporomandibular joint (TMJ) arthritis. METHODS: This systematic review followed PRISMA guidelines, with searches conducted on MEDLINE, Embase, Web of Science, Scopus, and CENTRAL through January 2025. Included studies addressed pharmacologic or non-pharmacologic treatments for pcJIA and TMJ involvement. Studies were limited to publications not already covered in existing guidelines. The Cochrane Rob2 tool and GRADE approach were used to assess quality and evidence certainty. Meta-analyses were performed where applicable. RESULTS: Of the initial 9424 records, 86 studies were included in the qualitative analysis. Methotrexate remains the csDMARD of choice, and subcutaneous administration may be more advantageous. Biological DMARDs, particularly abatacept and tocilizumab, have evidence for good efficacy and acceptable safety profiles. Emerging evidence supports the use of JAK inhibitors. Biosimilars were reported to have efficacy and safety comparable to those of originator biologics in observational studies. Limited evidence suggests that gradual medication tapering after achieving inactive disease status reduces the risk of flares. Evidence for physiotherapy, occupational therapy, and complementary medicine was of very low certainty due to methodological heterogeneity. CONCLUSION: This SLR offers new evidence to support region-specific clinical practice in JIA. While many findings support global recommendations, important evidence gaps remain, particularly in tapering, biosimilar use, TMJ management, and non-pharmacological therapies. These insights will directly inform APLAR's upcoming clinical practice guideline for pcJIA and TMJ arthritis.