In patients with juvenile idiopathic arthritis (JIA) temporomandibular joint (TMJ) involvement is a common cause of severe growth disturbances. Extent of growth deviation depends on age of onset and duration of arthritis in the TMJ. TMJ arthritis is difficult to diagnose at an early stage since relatively few symptoms and clinical findings are related to this joint. The pathologic process can affect growth long before radiographic changes are seen. We investigated the relationship between TMJ arthritis and symptoms and clinical findings to suggest a clinical routine for diagnosing TMJ arthritis. We also describe the course of TMJ arthritis in relation to a commonly used radiographic method versus MRI.
Fifteen children with JIA were examined 4 times at 6 month intervals for TMJ involvement by clinical examination, MRI-scanning, and orthopantomograms (OPG). At baseline, 10 healthy children served as a control group.
Patients reported more inability to chew and open their mouth than the control group. Translation of the condyle and range of mandibular movements were diminished in the arthritis group. Decreased translation was correlated to condylar changes seen on both OPG and MRI. MRI was superior to OPG in following changes of the condyle over time, and inflammation was detected in nearly all joints.
OPG cannot be recommended for diagnosis or to follow the course of changes in the TMJ. We advocate recording condylar translation and mandibular range of motion as a current clinical routine to find early TMJ arthritis in contrast to the often used OPG performed in our study, which was an uncertain method.