THE USE OF A CINE-TECHNIQUE IN THE MRT INVESTIGATION OF THE TEMPOROMANDIBULAR-JOINT

A new cine-technique in a prospective study using rapid gradient echo sequences was evaluated for the MRT investigation of the temporo-mandi bular joint. A newly developed hydraulic apparatus was used to produce progressive opening of the jaw and MRT appearances were recorded duri ng predetermined points of mandibular movement. The investigation incl uded 16 normals and 34 patients. A modified gradient echo sequence was combined with an optimised surface coil or a special double coil and this provided good spatial resolution of the articular disc and of the muscular and bony structure. Amongst the abnormal findings were luxat ion of the disc (15 cases), tears in the disc (5 cases), late effects of internal derangements (12 cases) and condylar hypermotility (7 case s). The new cine-technique provides specific images in any chosen posi tion of the mandible depending on the clinical disability of the patie nt.