A cleft lip is a hole in the top lip that often develops between the fourth and seventh week of pregnancy if the tissue does not unite fully before delivery.
Additionally, the palate, or the roof of the mouth, develops during the sixth and ninth weeks of pregnancy. A cleft palate is a condition where the tissue that makes up the roof of the mouth does not completely fuse together. A Cleft lip and Palate surgery is done to treat this condition.