Patients with juvenile idiopathic arthritis (JIA) often have involvement of the temporomandibular joint (TMJ) during their disease course. Active arthritis of the TMJ remains difficult to assess. Clinical signs and symptoms alone are unreliable, and active TMJ arthritis needs confirmation by gadolinium-enhanced MRI. In recent years, changes in treatment approach have occurred. This article discusses the latest evidence on diagnosis and treatment of JIA-associated TMJ arthritis.