What is a Cleft?
A "cleft" is the medical term for a separation which can occur in the lip or the palate (roof of the mouth), or both. The cleft may be as minor as a notch in the upper lip or as extensive as a wide fissure extending through the lip and gum into the nose. The cleft may occur on one side of the lip (unilateral cleft lip) (Figure 1) or on both sides of the lip (bilateral cleft lip) (Figure 2). A cleft palate may occur in combination with a unilateral or bilateral cleft of the lip or may occur with a completely normal lip.

Fig I: Before Surgery

After Surgery

How Common are Cleft Lips and Palates?
Clefts of the lip and palate are the most common congenital deformity affecting the face. The overall frequency is approximately one in every six hundred births. It is more common in children of Asian descent, occurring in approximately one in every five hundred births, and least common in black children, occurring in approximately one in every two thousand births.

What is the Cause of Cleft Lip and Palate?

Clefts arise when the lip and mouth do not come together properly in fetal development. Actually, each of us had clefts of the lip and palate before birth which normally fuse so that the clefts are not present at birth. No one knows exactly why clefts occur, although they do run in families to some extent. If one parent or child in a family has a cleft, the chances of a subsequent child being born with a cleft increases from the usual one in six hundred to approximately one in twenty. Because there are some circumstances in which the risk is even higher, it is important to meet with a geneticist to find out the approximate risk in any particular family. Parents should also understand that they have done nothing wrong during the pregnancy to cause the cleft. Nothing a woman eats or drinks, no medications she may have taken, nor any activities she has participated in while pregnant have any known effect on this particular birth defect. Parents with the most carefully monitored, trouble free pregnancies give birth to children with clefts at the same rate as the rest of the population.