Congenital malformations in the frontonasal area: their pathogenesis and classification.

The observation of 235 patients affected by abnormalities in the frontonasal area, has led the author to reinvestigate this complex chapter of the human congenital malformations. A complete critical review of the literature has been made in order to find the possible correlations between the available cases and those previously reported and to establish a simple morphogenetic classification that may embody them all, even transitional forms.