MR OF 732 TMJS - ANTERIOR, ROTATIONAL, PARTIAL AND SIDEWAYS DISC DISPLACEMENTS

Objective: The purpose of this study was to determine the prevalence o f anterior, sideways, rotational and partial anterior disc displacemen ts, as well as degenerative changes in patients with clinical signs an d symptoms of internal disorders. Materials and methods: 732 MR Images of temporomandibular joints (TMJ) were produced for 366 symptomatic p atients. Image analysis included assessment of disc positions and mobi lity, as well as recapture in coronal and mediolaterally divided sagit tal planes in closed and open positions. Results: Of these images, 545 TMJ showed an internal derangement comprised of 52% anterior disc dis placements without reduction, 26% anterior disc displacements with red uction, 11% partial anterior disc displacement, 5% pure sideways displ acements and 3% stuck discs. Rotational disc displacements were observ ed in 34% of the anterior disc displacements without reduction group a nd in 53% of the anterior disc displacements with reduction group. A t otal of 97% of the partial anterior disc displacement occurred lateral ly. Degenerative changes increased with age, mainly in the anterior di sc displacements without reduction group. Conclusion: Magnetic resonan ce imaging (MRI) investigations show that the disc is subject to a gre at variety of displacements and that there is a need for further resea rch to refine the clinical therapy for TMJ internal derangements. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.