Periodontal disease (PD) is more common in rheumatoid arthritis (RA), especially those with anti-citrullinated protein antibodies (ACPAs).  RA activity has been linked to the severity of PD and mucosal inflammation.

Researchers from Standfod have suggested a prominent role for PD in the pathogenesis of RA by showing PD related mucosal breaches leading to citrullinated oral bacteria, which activate inflammatory monocytes contributing to RA synovitis and flares while also activaing ACPA+ B cells.