Cranial and facial hyperostosis results in a characteristic clinical and radiographic appearance. The diaphyses of the bones are generally expanded. Halliday (1949) and Stransky et al. (1962) reported isolated cases with similar findings. Facial and cranial thickening and ... Cranial and facial hyperostosis results in a characteristic clinical and radiographic appearance. The diaphyses of the bones are generally expanded. Halliday (1949) and Stransky et al. (1962) reported isolated cases with similar findings. Facial and cranial thickening and distortion are particularly striking in this form. Most cases have been mentally retarded. Unlike the situation in the craniometaphyseal dysplasias (e.g., 218400), the long bones do not show metaphyseal flaring but show diaphyseal endostosis and are shaped like a policeman's nightstick. Joseph et al. (1958), who first suggested the designation of progressive craniodiaphyseal dysplasia, described a patient with a picture they considered identical to that described by Halliday (1949). Brueton and Winter (1990) indicated the unsatisfactory state of the genetic understanding of this disorder. On review of the report by de Souza (1927), they concluded that the sibs most likely had Van Buchem disease (239100).