PATHOGENESIS OF BROMODEOXYURIDINE-INDUCED CLEFT-PALATE IN MICE

This study was designed to examine the pathogenesis of bromodeoxyuridi ne-induced (BrdU) clefts of the secondary palate in mice, Intraperiton eal injections of BrdU (500 mg/kg body weight) were given on days 11 a nd 12 to some pregnant mice and on days 12 and 13, and days 11, 12 and 13 to others. Evaluation of craniofacial relations and palate develop ment in BrdU-treated mice revealed inhibition of vertical development of the palatal shelves, mandibular hypoplasia which led to failure of downward displacement of the tongue and the creation of an obstacle to reorientation of the palatal shelves. The results of this study demon strate a strong correlation between induction of cleft palate and the presence of structural alterations in the mandible, and the mechanism of BrdU-induced cleft palate resembles the defect in the Pierre Robin anomaly.