Functional magnetic resonance imaging of temporomandibular joint disorders

Fifty-eight temporomandibular joints (TMJs) from 40 patients with TMJ-relat ed symptoms were examined by means of magnetic resonance scans with modifie d gradient echo sequences and a special double coil. This technique yielded a good spatial resolution of the intra-articular soft tissues, especially the articular disc and the bone structure of the TMJ. In combination with a n incremental jaw opener, the disc-condyle complex was analysed in various closed and open mouth positions, depending an the clinical examination. Ope n mouth movement with differentiation of disc-condyle rotational and transl ation movement was demonstrated. Disturbances of TMJ motion showed interrupted condylar translation combined with mandibular deviation during open mouth movement (n = 8/58). Early pha ses of internal derangement of the TMJ with partial anterior disc displacem ent with (n = 12/58) or without (n = 2/58) reduction, total anterior disc d isplacement without reduction (n = 10/58), disc deformation (n = 10/58), di sc adhesion (n = 2/58), condylar hypermobility (n = 6/58), condylar displac ement (n = 8/58), and late phases of internal derangement of the TMJ with o steoarthrosis (n = 14/58) were clearly identified. Bilateral TMJ disorder w as found in 72.5 per cent of the patients. By using motion-adapted, semi-dy namic magnetic resonance imaging (MRI), it is possible to improve the under standing of the complexity of TMJ movements.