MRI-based reevaluation of patients with disc displacement without reduction

Background: MRI is the gold standard in the diagnosis of internal derangement (ID). The aim of the study was to reexamine patients with MRI-verified disc displacement (DD) without reduction after conservative therapy by splints clinically and by MRI to control morphologic changes. Patients: Twenty-eight patients with DD without reduction underwent clinical and MRI examination at the beginning of conservative treatment and again a mean of 23.3 months later. The morphology of disc, condyle, fossa articularis, position of the condyle within the fossa and translation of the condyle were described in parasagittal T1-weighted images, and the presence of hyperintense signals in T2-weighted MRIs. Results: Clinical parameters such as muscle palpation, extent of mouth opening, and pain intensity improved significantly after therapy. The condyle showed significant degenerative changes, the translation of the condyle improved, and hyperintense signals disappeared. Changements of the disc, position of the condyle, and degree of internal derangement were not significantly different in a comparison of both MRIs. Conclusion: By conservative treatment, structural changes in joints with DD without reduction could not be prevented, but the clinical symptoms improved significantly nevertheless. Keywords: disc displacement without reduction, MRI, CMD, internal derangement