[Magnetic resonance in condylo-meniscal incoordination pathology of the temporomandibular joint. Indications, diagnostic accuracy and optimization of study techniques].

Up to 28% of the population is affected with pathologic conditions involving the temporo-mandibular joint (TMJ), most of them related to uncoordinated disk motion. To date, these pathologies have been evaluated by means of different diagnostic tools, the latest of which is MR imaging. The authors examined with low-field (0.2 T) MR imaging 15 normal volunteers and 20 patients suffering from temporo-mandibular joint disk dysfunction. The study was aimed at comparing the results obtained with low-field MR imaging with literature data on the subject. A standard technique employing low-field MR imaging was also assessed on normal subjects for the management of the patients with TMJ pathologies. The pathological TMJs were then evaluated, each of them examined with arthroscopy and/or surgery. MR imaging was capable of identifying the meniscus in all cases, together with its morphology, signal, location, and movements during opening and closure of the mouth. Disk dislocation were always correctly identified. The point of re-capture in the cases with spontaneous reduction was easily ascertained. The simultaneous imaging of both the right and the left TMJs allowed the joints to be compared at the same degree of mouth opening, so that motion asymmetries were easily detected. High agreement was observed between MR, arthroscopic and surgical findings. Our experience points to MR imaging as the examination of choice in the evaluation of TMJ diseases. The best results are obtained when both joints are simultaneously imaged, on the sagittal and coronal planes, during opening and closure of the mouth, and possibly in a cine-animation display format.