Cleft lip and palate Health Article

Definition

A cleft is a birth defect that occurs when the tissues of the lip and or palate of the fetus do not fuse very early in pregnancy. A cleft lip, sometimes referred to as a harelip, is an opening in the upper lip that can extend into the base of the nostril. A cleft palate is an opening in the roof of the mouth.

Description

Infants born with cleft lips will have an opening involving the upper lip. The length of the opening ranges from a small notch to a cleft that extends into the base of the nostril. Cleft lips may involve one or both sides of the lip.

Cleft palates are openings in the palate, which is the roof of the mouth. The size and position of the opening varies. The cleft may only be in the hard palate, the bony portion of the roof of the mouth opening into the floor of the nose, or it may only occur in the soft palate, the soft portion of the roof of the mouth. The cleft palate may involve both the hard and soft palate and may occur on both sides of the center of the palate.

Cleft lips can develop with or without cleft palates. Cleft palates may also occur without cleft lips.

Genetic profile

Cleft lip and palates not associated with a syndrome are caused by a combination of genetic and environmental factors. Inheritance caused by such a combination is called multifactorial. The embryo inherits genes that increase the risk for cleft lip and or palate. When an embryo with such genes is exposed to certain environmental factors, the embryo develops a cleft.

The risk of a baby being born with a cleft lip or palate increases with the number of affected relatives and increases with relatives that have more severe clefts.

Environmental factors that increase the risk of cleft lip and palate include cigarette and alcohol use during pregnancy. Some drugs also increase the incidence of clefting, such as phenytoin, sodium valproate, and methotrexate. The pregnant mother's nutrition may affect the incidence of clefting as well.

Demographics

The incidence of cleft lip and palate not associated with a syndrome is one in 700 newborns. Native Americans have an incidence of 3.6 in 1,000 newborns. The incidence among Japanese newborns is two in 1,000. The incidence among caucasians is one in 1,000 newborns. African Americans have an incidence of 0.3 in 1,000 newborns.

Signs and symptoms

Babies born with a cleft lip will have an elongated opening in the upper lip. The size of this opening may range from a small notch in the upper lip to an opening that extends into the base of the nostril. The cleft lip may be below the right or left nostril or below both nostrils.

Babies born with a cleft palate will have an opening into the roof of the mouth. The size and position of the cleft varies and it may involve only the hard palate, or only the soft palate and may occur on both sides of the center of the palate.

In some cases the cleft palate will be covered with the normal lining of the mouth and can only be felt by the examiner.

Infants with cleft lips and palates have feeding difficulties, which are more severe in those with cleft palates. The difficulty in feeding is due to the baby being unable to achieve complete suction. In the case of clefts of the hard palate, liquids enter the nose from the mouth through the opening in the hard palate.

A cleft palate also affects a child's speech, since the palate is necessary for speech formation. The child's speech pattern may still be affected despite surgical repair.

Ear infections are more common in babies born with cleft palates. The infections occur because the muscles of the palate do not open the Eustachian tubes which drain the middle ear. This allows fluid to collect and increases the risk of infection and hearing loss.

Teeth may also erupt misaligned.

Diagnosis

Cleft lip and palate can be diagnosed before birth by ultrasound. After birth, cleft lip and palate are diagnosed by physical exam.