Tissue Response of TM-Joint to Arthritis Induction Methods in Rat

Abstract

Objective: Pathogenesis of rheumatoid arthritis (RA) related temporomandibular joint disorder remains unclear. Some studies investigated the change of condyle after Complete Freund's Adjuvant (CFA) injection which is similar to osteoarthritis. However, there were few studies to demonstrate effect of TMJ in CIA which mimics RA. The aim of this study was to investigate the TM-joint response of CFA and CIA group in rat model. Methods:24 Rats were divided into 4 groups. (1) Control group. (2) 50μl type I collagen injection group. (3) 50μl CFA injection group. (4) 25μl type I collagen + 25μl CFA injection group. Drug injection was performed on day 0 and day 14 and sacrificed on day 7, and day 35. After sacrificed, TMJ tissue was collected to do the H&E stain and investigated the inflammatory (IL-1β and MMP3) gene expression.Results: TMJ tissue of CFA group demonstrated adaptive bone growth. On the other hand, the subchondral bone of CIA group appeared degenerative process. The trend of IL-1β and MMP3 gene increased in CFA and CIA group compared to control group in synovial tissue and disc (p<0.05). Conclusion:Within limitation of this study, it's concluded that the CIA method can be used in RA related TMD mechanism research.