Autosomal dominant endosteal hyperostosis is a generalized bone dysplasia characterized by a cortical thickening of the long bones, with no alteration in external shape, and a remarkable resistance of the bone to fracture. The skeleton is normal in childhood. Facial metamorphoses occur in adolescence, as the forehead flattens, the mandible becomes elongated, and the gonial angle decreases. An enlarging osseous prominence (torus palatinus) develops in the hard palate, which may lead to malocclusion or loss of teeth (summary by Van Wesenbeeck et al., 2003).