Cleft lip and/or palate (a gap or split in the upper lip and/ or a gap in the roof of the mouth) are the most common birth defects that affect the mouth or face. They occur when the tissues of the lip and/or the roof of the mouth (palate) do not properly fuse during fetal development. About 6,800 infants are born with cleft lip (with or without cleft palate) in the United States every year, according to the March of Dimes. Common complications include feeding problems, speech problems, ear infections and dental problems.

A cleft lip is a gap in the upper lip below the nose. It may occur beneath one or both nostrils. A cleft palate is a gap in the roof of the mouth, typically opening to the nasal cavity. It may extend through both the hard and soft palate, or through only one of these.

The actual cause of cleft lip and/or palate is not known, although there are many factors (e.g., genetics, maternal habits or illness during pregnancy) that may increase the risk of this birth defect. Clefting occurs in all racial groups, but is most common in children of Asian descent and is much rarer in children of African descent. Cleft lip with or without cleft palate occurs more often in boys while isolated cleft palate without cleft lip occurs more often in girls.

Feeding can be a major obstacle in infants with cleft lip and/or palate, especially before their repair surgeries. A physician can provide information on devices (e.g., special nipples for bottles, artificial palate) and on special feeding techniques for children with cleft lip and cleft palate. As children develop, speech therapy may be particularly important for some children with cleft palate.

Emotional support may become important during childhood and adolescence. Cleft lip and/or palate and the scars left by cleft repair surgery can make a child feel different and ostracized. The differences in physical appearance caused by cleft lip and/or palate can be particularly stressful for adolescents.

Cleft lip and palate are generally easy to diagnose. In some cases, the defects are detected before birth through the use of ultrasound. After birth, the defects are typically detected immediately. Whether or not clefting is diagnosed prenatally, treatment does not begin until the infant is born.