Rheumatoid Arthritis and Orthodontic Treatment

Temporomandibular joint involvement in RA

The temporomandibular joints (TMJs) are synovial joints — the same type of joint predominantly affected in RA. Studies suggest TMJ involvement in 50 to 70% of RA patients, ranging from mild synovitis with pain and restricted mouth opening to condylar erosion and resorption that alters jaw position and bite. In adolescents with juvenile idiopathic arthritis (JIA, a related condition), condylar destruction can cause significant mandibular growth disturbance, leading to an open bite or severe retrognathia (recessed lower jaw). In adults with established RA, TMJ erosion progresses more slowly but can still cause bite changes over years of disease activity. An orthodontist treating a patient with RA must assess TMJ health before and during treatment — condylar changes during active treatment can destabilise the occlusal result that was planned.

How active RA affecting the TMJ complicates orthodontic planning

Active inflammation in the TMJs poses particular challenges for orthodontic treatment planning. If the condyles are actively resorbing, tooth positions established during treatment may shift as the jaw joint changes shape — a phenomenon sometimes called condylar resorption or idiopathic condylar resorption. Orthodontic treatment involving significant bite correction in patients with active TMJ RA should ideally be deferred until disease activity is controlled and the TMJs are stable. Imaging — typically an OPG (dental panoramic radiograph) or a CBCT (cone beam CT) — is used to assess condylar morphology before treatment begins. In some cases, a referral to an oral and maxillofacial surgeon is appropriate to assess whether surgical management of the TMJ is needed alongside or before orthodontic treatment.

Effects of methotrexate on tooth movement

Methotrexate is a cornerstone DMARD (disease-modifying antirheumatic drug) used in RA management. It inhibits folate metabolism and has anti-inflammatory and immunosuppressive properties. Its effect on orthodontic tooth movement is not fully characterised in human clinical trials, but animal studies and clinical case series suggest it may slow the rate of tooth movement by reducing osteoclast activity (the bone-resorbing cells necessary for tooth movement through bone). Orthodontists treating patients on methotrexate should be aware that treatment may take longer than typical estimates. There is no evidence that methotrexate at therapeutic doses causes permanent bone damage in the jaw, but any changes in medication should be communicated to the orthodontist. Methotrexate can also cause oral ulcers as a side effect, which may complicate brace wear.

Hydroxychloroquine and dental considerations

Hydroxychloroquine (Plaquenil) is used in mild to moderate RA and in systemic lupus erythematosus (SLE). It is generally well tolerated from a dental and orthodontic perspective. There are no clinically significant documented effects on tooth movement or bone metabolism at standard doses. However, hydroxychloroquine can cause dry mouth in some patients, which is relevant during orthodontic treatment because reduced saliva flow increases the risk of tooth decay around brackets and under aligner attachments. Any patient reporting dry mouth during orthodontic treatment should use a high-fluoride toothpaste (5000ppm if prescribed by their dentist) and consider a daily fluoride mouthwash.

Sjogren's syndrome overlap and dry mouth

A significant proportion of RA patients have concurrent primary or secondary Sjogren's syndrome — an autoimmune condition causing salivary and lacrimal gland dysfunction. Dry mouth (xerostomia) is the cardinal dental symptom. Saliva plays an essential role in protecting teeth: it buffers acid, remineralises enamel, and mechanically rinses bacteria. Patients with significant dry mouth are at substantially elevated risk of cavities during orthodontic treatment, where plaque control is already more difficult. Orthodontists should be informed of Sjogren's involvement. Management strategies include saliva substitute sprays and gels, sipping water regularly, sugar-free chewing gum, and intensified fluoride regimens. In severe cases, the decision to proceed with fixed braces versus clear aligners (which may be less cavity-promoting) should be discussed explicitly.

Corticosteroid use and bone effects

Long-term corticosteroid use — prednisolone and similar agents used in RA flares or as maintenance therapy — reduces bone density through several mechanisms, including reduced calcium absorption, increased bone resorption, and reduced bone formation. At high doses and with prolonged use, this can have effects similar to bisphosphonate therapy: reduced bone turnover that may slow tooth movement and raise theoretical concerns about osteonecrosis of the jaw, although the risk from corticosteroids alone is substantially lower than from intravenous bisphosphonates. Standard NICE RA guidelines (NG100) recommend using the lowest effective corticosteroid dose and duration. Orthodontists should ask about current and recent corticosteroid use as part of the medical history.

Appointment adaptations for hand and wrist pain

RA frequently affects the small joints of the hands and wrists, which can make placing and removing elastic bands (intermaxillary elastics used to correct bite relationships) extremely difficult or impossible for some patients. Orthodontists treating RA patients should discuss this early and consider alternatives: some patients manage better with placers or tools designed to hook elastics; others may benefit from appliance designs that reduce the need for patient-applied elastics. Appointment scheduling should accommodate the fact that RA patients may have worse symptoms at certain times of day (morning stiffness is a hallmark of RA) and may need longer or more frequent appointments during flares.

Timing treatment during RA remission

The ideal time to undertake comprehensive orthodontic treatment in an RA patient is during a confirmed period of remission, when disease activity is low, TMJ inflammation is absent or minimal, and medication doses are stable. Treatment undertaken during active disease carries higher risks of suboptimal outcomes due to condylar changes and variable bone turnover. Patients should discuss treatment timing with both their orthodontist and rheumatologist. A letter from the rheumatologist confirming current disease status, medication list, and TMJ stability is valuable before treatment is initiated. NICE guideline NG100 on RA management in adults provides the clinical framework within which rheumatologists will be operating.

Useful related pages

This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist.