[Observation of micrognathic development in mouse fetus induced by sulfadimethoxine].

The purpose of this study was to investigate the process of micrognathic development in mouse fetus induced by Sulfadimethoxine (SDM). SDM of 3,000 mg/kg was administered orally to pregnant ICR mice on days 8, 9, 10, 11, 12, and 13 of gestation. The fetuses were removed on day 15 to analyze the incidence of micrognathia. The incidence of micrognathia was the highest in the treated group on day 10. The fetuses, SDM-treated on day 10, were sacrificed on days 11, 12, 13, 14, 15, and 18 and prepared for histological and morphological analyses. Histomorphological analyses were performed by lateral and horizontal graphic reconstruction using serial frontal sections. It was also performed by clearing and alcian blue-alizarin red double staining. In the treated group, bilateral sigmoid buckling and shortening of Meckel's cartilage became evident after day 14, however, the nasal septal and capsule cartilage were less affected. It was concluded that remarkable hypoplastic and malformed Meckel's cartilage, caused by the administration of SDM, induced mandibular dysmorphogenesis.