Involvement of the TMJ joint is very common in JIA and is most often without symptoms like pain or stiffness. Most commonly, a pediatric rheumatologist notices changes in the movement of the TMJ or growth of the jaw bones which prompts an evaluation for TMJ disease with an MRI.  TMJ involvement does occur in oligoarthritis but would be more commonly seen in polyarthritis patients.  How to best diagnose, treat and monitor TMJ arthritis is an active area of research in pediatric rheumatology. At this time, our approach is to treat the TMJ if it is significantly inflamed with medications including DMARDs (e.g. methotrexate) +/- biologics to attempt to decrease the risk of long-term complications. This could include facial bone growth abnormalities, need for orthodontics, oral surgery, chronic TMJ pain and sleep apnea. We also often seek advice from our dental colleagues regarding the need for a splint or other specific dental care.