[A rare dental abnormality: "the phantom tooth" or "odontodysplasia". Apropos of a case].

"Phantom tooth" or "odontodysplasia" is one of the most unusual and rare of dental abnormalities, being characterised: Clinically, by the topography of the lesions, the involvement of both sets of teeth and abnormalities in the size and form of the teeth which remain unrupted or only partially evolved. Radiologically, by transparency of the teeth to X-rays. Histologically, by disorganisation of the dental structures and a highly characteristic appearance of the enamel and, in particular, dentine. On the basis of one case, the authors review in detail each aspect of these characteristics, paying special attention to histology and the information obtained using the sweep electron microscope.