Citrullination is when a protein undergoes a molecular change in structure, says Dr. Bingham. In RA, that change results in the immune system seeing the protein as a foreign body and mounting an attack against it by creating anti-cyclic cirtrullinated (anti-CCP) antibodies. (The presence of these antibodies is associated with more severe RA.) One of the oral bacteria involved in periodontitis has been found to induce citrullination.

Dr. Molitor’s study, which was presented at the 2009 scientific meeting of the American College of Rheumatology, found that people with periodontitis who tested positive for anti-CCP antibodies were more likely to have moderate to severe periodontitis and be a smoker, a risk factor for both RA and periodontal disease. These findings suggest that bacteria in the mouth could actually be a cause of RA or that existing periodontal disease could be triggering rheumatoid arthritis.

In people with a genetic susceptibility to RA, citrullination of particular proteins will cause an immune response against those proteins. “So everybody has citrullination,” says Dr. Bingham. “If you are unlucky enough to have citrullination occurring in the wrong place or against the wrong protein, your body will make an immune response against it and that can be one of the early markers events in the development of RA.”

Sharing Treatment

If oral bacteria are involved in the development or progression of RA, or inflammation in the mouth somehow fuels inflammation in the joints, one might reason that clearing up the periodontal disease would also help prevent or treat RA. 

At least one small study suggests that may be the case. In a study of 40 people with both RA and periodontal disease, researchers at Case Western University School of Dental Medicine and University found that those who received nonsurgical treatments for their gum disease reported significantly more improvement in their RA symptoms than those who received treatment for RA only.

Dr. Bingham says more research is needed to better determine whether treating periodontal disease improves or and if efforts to prevent periodontal disease might also help prevent RA.  In the meantime, he says, there is reason for people with RA and their doctors to pay particular attention to oral health.

“My bottom line is that we find such a high prevalence of periodontal disease in patients with rheumatoid arthritis and given that there is this highly plausible biological connection between these two disease processes, we need to pay attention to the oral cavity in patients with RA and refer people for dental and periodontal evaluation and treatment,”  says Dr. Bingham.

If you have RA, the message is to take care of your teeth.  Schedule regular dental exams, eat healthfully, brush and floss and, if you have trouble taking care of your teeth due to stiff, painful hands or jaws, speak to your dentist or occupational therapist about ways to make dental care easier, including the use of special assistive devices.

It’s also important to work with your doctor to get your arthritis under control. Doing so could potentially save both your joints and your teeth.