Juvenile idiopathic arthritis (JIA) is the most common cause of chronic inflammation of the joints in childhood. Currently, JIA is divided into 7 subtypes, distinguished on the basis of the symptoms present in the first six months of the illness. Pharmacological treatment is different for every subtype. With all forms of JIA, dental problems can occur. These can include an increasing incidence of dental caries, stomatitis with the use of methotrexate, oral candidiasis with the use of immunosuppressive medication and temporal mandibular joint (TMJ) arthritis. The detection of TMJ arthritis seems to be especially difficult in daily practice. Dentists could play a role in identifying the TMJ complication in children with JIA.