CRANIOFACIAL SKELETAL DEVELOPMENT IN 3 HUMAN SYNOPHTHALMIC HOLOPROSENCEPHALIC FETUSES

In three human fetuses with synophthalmic holoprosencephaly (8, 14, 23 wks. p.c.) and two normal human fetuses (9 and 13 wks. p.c.) the anat omy of the cranial base, facial cranium and their relation to the noto chord was studied using serial histological sections and computer aide d three-dimensional reconstruction methods. Mesethmoidal cartilage dif ferentiation was variably deficient in all three holoprosencephalic ca ses. The premaxillary bones were rudimentary with missing tooth buds. The development of the sphenoid bone was defective in two of the holop rosencephalic cases (8, 14 wks. p.c.). The notochord terminated normal ly within the sphenoid body in all investigated cases. Our results ind icate that in holoprosencephaly there is a general defect in the midli ne cranial cartilage differentiation rostral to the notochord.