MIDLINE MAXILLOFACIAL SKELETON IN HUMAN ANENCEPHALIC FETUSES

The purpose of this study was to describe the midline maxillofacial sk eleton (the axial skeleton anterior to the sella turcica) in 15 human anencephalic fetuses (14-19 weeks of gestation) by radiography and his tology, and to relate the findings to skeletal patterns in the remaini ng part of the axial skeleton. Four patterns in the maxillofacial skel eton were recognized: normal structures, slightly deformed (6 cases); cleft palate (3 cases); incomplete nasal septum (3 cases); multilocula r ethmoid cartilage (3 cases). No association was found between skelet al patterns in the different parts of the axial skeleton. The study de monstrates the existence of a developmental borderline in the anenceph alic axial skeleton in the region of the sella turcica. It is presumed that this borderline indicates the boundary between skeletal tissue d eveloped around the notochord (posterior axial skeleton) and the anter ior skeletal components derived from neural crest cells.