What are cleft lip and cleft palate?

Cleft lip and cleft palate are malformations (defects) in the face and mouth that occur very early in pregnancy, while the baby is developing inside its mother. A cleft results when the tissues do not join together properly.

  • A cleft lip is a physical separation of the two sides of the upper lip, and appears as a narrow or wide opening or gap in all layers of the upper lip. This separation can include the gum line or the palate.
  • A cleft palate is a split or opening in the roof of the mouth. A cleft palate can involve the hard palate (the bony front portion of the roof of the mouth) and/or the soft palate (the soft back portion of the roof of the mouth), and can be associated with a cleft lip

Cleft lip and cleft palate can occur on one or both sides of the mouth. Because the lip and the palate develop separately, it is possible to have a cleft lip without a cleft palate, a cleft palate without a cleft lip, or both a cleft lip and cleft palate together (the most frequently occurring defect).

Cleft lip preopCleft lip postop

An infant with cleft lip. The same child, age 2, after cleft lip repair.

Who gets cleft lip and/or cleft palate?

Cleft lip and/or cleft palate affects 1 in 1,000 babies every year, and is the fourth most common birth defect in the United States. Clefts occur more often in children of Asian descent.

Twice as many boys as girls have a cleft lip, both with and without a cleft palate. However, twice as many girls as boys have cleft palate without a cleft lip.

What causes a cleft lip and cleft palate?

In most cases, the causes of cleft lip and cleft palate are not known, and these conditions cannot be prevented. Most scientists believe clefts are caused by a combination of genetic (inherited) and environmental (related to the natural world) factors. There seems to be a greater chance of newborn having a cleft if a sibling, parent or other relative has had the problem.

Another cause of a cleft lip/palate may be related to a medication a mother may have taken during her pregnancy, including antiseizure/anticonvulsant medications, acne treatment medications containing Accutane®, or methotrexate, a drug commonly used for treating cancer, arthritis and psoriasis.

Other factors that can contribute to development of a cleft include:

  • Vitamin deficiency (folic acid)
  • Smoking during pregnancy
  • Substance abuse

The condition may also occur as a result of exposure to viruses or chemicals while the baby is in the womb. In other situations, cleft lip and cleft palate may be part of another medical condition.

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