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1. a fissure or longitudinal opening, especially one occurring during embryonic development.
2. having such a fissure.
branchial cleft
1. one of the slitlike openings in the gills of fish between the branchial arches.
facial cleft
1. any of the clefts between the embryonic prominences that normally unite to form the face.
2. failure of union of one of these embryonic clefts; depending on the site, this causes such developmental defects as cleft cheek, cleft mandible, or cleft lip. Called also prosoposchisis.
cleft lip (cleft palate) congenital fissure, or split, of the lip (cleft lip) or of the roof of the mouth (cleft palate); one or the other occurs in about one birth per thousand. Sometimes they are associated with clubfoot (talipes) or other anatomic defects. They have no connection with mental retardation. Although poor health of the mother during pregnancy may have some effect on the development of her child, the old superstition that psychologic experiences of the pregnant mother can cause cleft palate and cleft lip has no scientific basis. However, it is true that parents who were born with cleft palate or cleft lip are somewhat more likely than other parents to have children with these defects.

Cleft palate and cleft lip result from failure of the two sides of the face to unite properly at an early stage of prenatal development. The defect may be limited to the outer flesh of the upper lip (the term harelip, suggesting the lip of a rabbit, is both inaccurate and unkind), or it may extend back through the midline of the upper jaw through the roof of the palate. Sometimes only the soft palate, located at the rear of the mouth, is involved.

The infant with a cleft palate is unable to suckle properly, because the opening between mouth and nose through the palate prevents suction. Feeding must be done by other means, with a dropper, a cup, a spoon, or an obturator, a device inserted in the mouth to close the cleft while the baby is sucking. Cleft palate allows food to get into the nose, and it causes difficulty in chewing and swallowing. Later it will hinder speech, because consonants such as g, b, d, and f, which are normally formed by pressure against the roof of the mouth, are distorted by resonance in the nasal cavity. The cleft may also prevent movements of the soft palate essential in clear speech.
Treatment. Treatment of cleft palate and cleft lip is by surgery, followed by measures to improve speech. A cleft palate should be reconstructed by plastic surgery when the child is about 18 months old, before he learns to talk. The corrective work usually requires only one operation. After surgery, the child often needs special training in speech to facilitate communication and maintain self-esteem. Cleft lip usually can be corrected by surgery when the child reaches a weight of 12 to 15 lb (5.4 to 7 kg), generally at the age of 2 to 3 months. Successful surgery often leaves only a thin scar and a greatly improved ability to form the p, b, and m sounds. A child born with a moderate degree of cleft palate or cleft lip can look forward to a life normal in appearance, speech, and manner if proper action is taken early. This means consulting and carefully following the advice of competent specialists in medicine, surgery, dentistry, and speech.
Patient Care. The main concerns during the preoperative period are maintenance of adequate nutrition, prevention of respiratory infections, and speech therapy to prevent development of bad habits of speech. Postoperative care must be aimed at prevention of trauma to or infection of the operative site. The child is not allowed to lie prone until the incision is completely healed. Elbow restraints are used to keep the fingers and hands away from the mouth. The patient is usually fed with a special syringe with a rubber tip as long as only liquids are allowed. When a soft diet is prescribed, care must be taken that the spoon or other eating utensils do not damage the suture line. Mouth care is given frequently to keep the mouth clean and reduce the danger of infection. Dental caries often occurs in patients with cleft palate and regular visits to the dentist are needed. Tender loving care, always a part of pediatric care, is even more necessary when caring for these children. They must be reassured and kept quiet so that crying and restlessness do not undo the work done by the surgeon. (See Atlas 1, Part A.)
A, Severe and B, mild form of cleft lip/palate. From Mueller et al., 2001.


a fetus with a cleft face.