Cleft lip constitutes almost half of all major facial malformation its incidence ranges from 1:500- 2000 live births (dependent on race). We have developed a rat model of cleft lip that is caused by subjecting the developing fetus to hypoxic conditions. Hypoxia and subsequent rebound oxygenation is suspected of causes free radical release. It is suspected that these free radicals cause tissue damage. As well as examining the mechanisms of cleft lip development we are examining whether antioxidants can protect against cleft lip caused by fetal hypoxia. The Australia Society of Orthodontists (ASO) and the Australian Dental Research Fund (ADRF) support this research.