Indeed, recent studies reported that TLR4 elevated in the synovial membrane of temporomandibular joint (TMJ) synovitis induced by occlusal interference, and inhibition of TLR4 by TMJ injection of TAK‐242 could alleviate the level of synovitis, suggesting TLR4 participates in TMJ synovitis.20, 21. This evidence concerns the gene TLR4 and synovitis.