One of every 600 newborns is affected by cleft lip and cleft palate, making it the most common birth defect in the United States. Clefts occur very early in pregnancy due to a combination of genetics and environmental factors. Our upper lips are made from three parts, and the seams them fusing together are the “philtrum” – the vertical ridges in the middle of the upper lip. If these parts don’t fuse, on one or both sides, a cleft lip is the result. The separation will often continue back through the bones of the upper jaw and affect the teeth and gums. Our palates are formed later than the lip from two parts that fuse in the middle of the roof of our mouths. A cleft palate is an opening in the roof of the mouth into the nose. It is possible for a child to have a just a cleft lip, or just a cleft palate, or both cleft lip and cleft palate.