[The diagnostic importance of different imaging technics in temporomandibular joint dysfunction]

Various imaging techniques enable to explore the Temporo-mandibular joints (T.M.J.). The physicians prescribing them, must be perfectly aware of the informations they provide as well as their costs, for a judicious formulation of their indications. Conventional radiography is absolutely necessary and, most of the time, sufficient, since it simply permits to evaluate the bony structures. An orthopantomogram and modified Schüller views of each T.M.J., "open mouth" and "closed mouth" will be performed. Conventional tomograms are no longer indicated. They will be abandoned for Computed Tomograms. This examination permits, at a relatively low cost, to analyse a bony abnormality and explore the muscular soft tissues. It may also be possible to assess the meniscus, its position and displacement when the mouth is opened. In fact, if a meniscal or articular pathology is considered, which could result in surgical or endoscopic procedure, it is absolutely necessary to perform: -either an arthro-tomography, with contrast material, -or a magnetic resonance examination. The latter provides perfect anatomical and pathological informations of the joint and meniscus, in an atraumatic fashion for the patient. Its only contraindication is in the cost of the examination. It will be possible to look for a dislocation, a malformation or a structural alteration of the meniscus which could result in a perforation, a rupture of the posterior frenulum, adhesions or joint extravasation. A necrosis or early osteochondritis of the condyle will be ruled out.