A "cleft" is a term used to describe a separation that 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 can be 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) or on both sides of the lip (bilateral cleft lip) A cleft palate may occur in combination with a unilateral or bilateral cleft of the lip or may occur with a completely normal lip.


How Common are Cleft Lips and Palates?

Cleft Lips and Palates are the most common congenital deformity affecting
the face. One in every six hundred births a cleft occurs in some form. 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. Each human baby had clefts of the lip and palate before
birth, but they normally fuse together so that the clefts are no longer present at birth.

There is no clear reason 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. There is 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. In short, clefts are more or less a random event.