A 2 year followup study of enhanced magnetic resonance imaging and clinical examination of the temporomandibular joint in children with juvenile idiopathic arthritis.

OBJECTIVE: Involvement of the temporomandibular joint (TMJ) in patients with juvenile idiopathic arthritis (JIA) can cause severe craniofacial growth disturbances if not treated in the initial stage. Magnetic resonance imaging (MRI) is an efficient method for detecting early inflammatory changes of the TMJ. We investigated correlation between findings from the clinical examination with MRI of the TMJ, and describe development of the MR image over time.

METHODS: Fifteen children with newly diagnosed JIA (mean age 12.0 yrs) were examined clinically and with MRI enhanced with Gd-DTPA 4 times at 6-8 month intervals. Clinical and MRI findings were scored. MRI variables included T1 weighted images before and after administration of Gd-DTPA with and without fat suppression.

RESULTS: A total of 115 joints were examined during the 2 year period: 93% showed enhancement, 71% condylar erosions, 26% pannus, and 23% joint fluid accumulation of the TMJ. In all except one child, one or both TMJ showed enhancement of the synovial membrane during the examination period. Symptoms were rare. All patients showing mild to severe findings by clinical examination also had pathological signs on the enhanced MRI, but not all patients without clinical findings had a normal MRI.

CONCLUSION: TMJ involvement in patients with JIA is very common, and MRI findings such as synovial enhancement, pannus, and joint fluid fluctuate over time. The clinical examination may be used as a filter, where children showing no clinical signs could be selected for enhanced MRI.