[Magnetic resonance imaging in oral medicine. Principle indications and contra-indications].

MRI is the most recent of diagnostic imaging possibilities. It completes the information provided by panoramic X-rays and scanner. The technique is based on proton excitation within an intense magnetic field and does not release any ionizing radiation, as opposed to conventional images (panoramic and CT scanner). This technique is harmless, provided that known and continuously updated contraindications be complied with. Its major advantages include imaging within different spatial planes without moving the patient and its excellent tissular discrimination capacities. The latter quality accounts for spontaneous visibility of the TMA disc. Currently, it is the golden standard in exploring painful TMAs (internal derangements).