Normal and abnormal midfacial development in the cadmium-treated hamster.

Clefts of the midface ranging in severity from a notched lip to complete facial disorganization were observed in the offspring of golden hamsters injected with cadmium chloride on the morning of the eighth day of gestation. Other malformations frequently observed were microphthalmia, anophthalmia, and diencephalic encephaloceles. Histologic examination of embryos on the 10th, 11th, 12th, and 13th days of gestation revealed a marked deficiency of mesenchyme in the frontonasal process, which led to a foreshortened and deformed nasal septum. These data confirm that the teratogenicity of cadmium is highly specific for the region of the anterior neural segment on the eighth day of gestation. The deficiency of mesenchyme in the frontonasal process may be the result of disruption in neural crest cell development in this region.