Clefts of the lips are one of the most commonly seen conditions affecting the face in newborn babies. Clefts occur somewhere between 1 in 500 to 1 in 2000 births, depending on the race of the parents. Children can be born with just a cleft lip, a cleft lip and palate, or just a cleft palate. Most commonly, 50% of the time, the cleft patient has components of both cleft lip and palate. The cleft lip can be incomplete, complete or bilateral.
A cleft lip is a separation in the lip that results from a disturbance in lip growth during the first trimester of development. The parts of the lip that are separated vary from child to child. Some children can simply have a notching or cleft in the lip. This notching can vary in degree and is called an incomplete cleft. Other children have a complete separation of the lip that extends all the way up into the nose. This is called a complete cleft lip. This type of cleft often distorts the nose as well. Clefts of the lip can be on one side (unilateral) or on both sides (bilateral) of the lip.