by David Douglas

Last Updated: 2008-05-13 17:54:58 -0400 (Reuters Health)

NEW YORK (Reuters Health) – Temporomandibular joint (TMJ) arthritis on magnetic resonance imaging (MRI), but not ultrasound, is often found at the onset of juvenile idiopathic arthritis (JIA), according to Pennsylvania-based researchers.

In fact, lead investigator Dr. Pamela F. Weiss told Reuters Health that "given the high prevalence of TMJ disease in new-onset JIA, pediatric rheumatologists should consider instituting universal screening for TMJ arthritis with MRI in newly diagnosed JIA patients."

As reported in the April issue of Arthritis and Rheumatism, Dr. Weiss of Children’s Hospital of Philadelphia and colleagues prospectively evaluated 32 children with newly diagnosed JIA. Both MRI and ultrasound were employed.

MRI identified acute TMJ arthritis in 24 of the patients (75%). Ultrasound did not identify any cases. Of patients with acute TMJ arthritis, 71% were asymptomatic and 63% had normal findings on jaw examination. Corticosteroid injection improved maximal incisal opening in 56% of the patients with acute disease.

MRI detected chronic TMJ arthritic changes in 69% of the patients, whereas only 28% were diagnosed by ultrasound.

"The next step," concluded Dr. Weiss, "is to determine how often and how physicians should screen for activity and resolution of TMJ disease."

Arthritis Rheum 2008;58:1189-1196.

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