The dental surgeon can feel inadequate when confronted with a rare disease: (a) difficult diagnosis, (b) therapeutic complexity, (c) and questioning by the parents, are three major obstacles that we have to overcome in order to carry out our therapy. Even if the field of genetics has made major advances during the last few years, it is clinical knowledge, above all, that leads us to a diagnosis. Certain syndromes present with very subtle signs which alone can appear trivial but which, taken together, defines a pathological entity. To know or to discover these signs and to recognize them is therefore the first challenge.
