Friday 28 July 2017

What is a cleft lip and palate?


Causes and Symptoms


Cleft palate is a congenital defect characterized by a fissure along the midline of the palate. It occurs when the two sides fail to fuse during embryonic development. The gap may be complete, extending through the hard and soft palates into the nasal cavities, or may be partial or incomplete. It is often associated with cleft lip or “harelip.” About one child in eight hundred live births is affected with some degree of clefting, and clefting is the most common of the craniofacial abnormalities.




Cleft palate is not generally a genetic disorder; rather, it is a result of defective cell migration. Embryonically, in the first month, the mouth and nose form one cavity destined to be separated by the hard and soft palates. In addition, there is no upper lip. Most of the upper jaw is lacking; only the part near the ears is present. In the next weeks, the upper lip and jaw are formed from structures growing in from the sides, fusing at the midline with a third portion growing downward from the nasal region. The palates develop in much the same way. The fusion of all these structures begins with the lip and moves posteriorly toward, and then includes the soft palate. The two cavities are separated by the palates by the end of the third month of gestation.


If, as embryonic development occurs, the cells that should grow together to form the lips and palate fail to move in the correct direction, the job is left unfinished. Clefting of the palate generally occurs between the thirty-fifth and thirty-seventh days of gestation. Fortunately, it is an isolated defect not usually associated with other disabilities or with developmental delays.


If the interference in normal growth and fusion begins early and lasts throughout the fusion period, the cleft that results will affect one or both sides of the top lip and may continue back through the upper jaw, the upper gum ridge, and both palates. If the disturbance lasts only part of the time that development is occurring, only the lip may be cleft, and the palate may be unaffected. If the problem begins a little into the fusion process, the lip is normally formed, but the palate is cleft. The cleft may divide only the soft palate or both the soft and the hard palate. Even the uvula may be affected; it can be split, unusually short, or even absent.


About 80 percent of cases of cleft lip are unilateral; of these, 70 percent occur on the left side. Of cleft palate cases, 25 percent are bilateral. The mildest manifestations of congenital cleft are mild scarring or notching of the upper lip. Beyond this, clefting is described by degrees. The first degree is incomplete, which is a small cleft in the uvula. The second degree is also incomplete, through the soft palate and into the hard palate. Another type of “second-degree incomplete” is a horseshoe type, in which there is a bilateral cleft proceeding almost to the front. Third-degree bilateral is a cleft through both palates but bilaterally through the gums; it results in a separate area where the teeth will erupt, and the teeth will show up in a very small segment. When the teeth appear, they may not be normally aligned. In addition to the lip, gum, and palate deviations, abnormalities of the nose may also occur.


Cleft palate may be inherited, probably as a result of the interaction of several genes. In addition, the effects of some environmental factors that affect embryonic development may be linked to this condition. They might include mechanical disturbances such as an enlarged tongue, which prevents the fusion of the palate and lip. Other disturbances may be caused by toxins introduced by the mother (drugs such as cortisone or alcohol) and defective blood. Other associated factors include deficiencies of vitamins or minerals in the mother’s diet, radiation from X-rays, and infectious diseases such as German measles. No definite cause has been identified, nor does it appear that one cause alone can be implicated. It is likely that there is an interplay between genetic and chromosomal abnormalities and environmental factors.


There are at least 150 syndromes involving oral and facial clefts. Four examples of cleft syndromes that illustrate these syndromes are EEC (ectrodactyly, ectodermal dysplasia, cleft lip/palate), popliteal pterygium syndrome, van der Woude’s syndrome, and trisomy 13 syndrome. EEC and trisomy 13 both result in intellectual and developmental disabilities as well as oral clefts. Popliteal pterygium has as its most common feature skin webbing (pterygium), along with clefts and skeletal abnormalities. Van der Woude’s syndrome usually shows syndactyly as well as clefting and lower-lip pitting.


Problems begin at birth for the infant born with a cleft palate. The most immediate problem is feeding the baby. If the cleft is small and the lip unaffected, nursing may proceed fairly easily. If the cleft is too large, however, the baby cannot build up enough suction to nurse efficiently. To remedy this, the hole in the nipple of the bottle can be enlarged, or a plastic obturator can be fitted to the bottle.


Babies with cleft palates are more susceptible to colds than other children. Since there is an open connection between the nose and mouth, an infection that starts in either location will easily and quickly spread to the other.
Frequently, the infection will spread to the middle ear via the Eustachian tube. One end of a muscle is affixed to the Eustachian tube opening, and the other end is attached to the middle of the roof of the mouth (palate). Normal contraction opens the tube so that air can travel through the tube and equalize air pressure on both sides of the eardrum. As long as the eardrum has flexibility of movement, the basics for good hearing are in place. Children with cleft palates, however, do not have good muscle contractions; therefore, air cannot travel through the tube. If the tube remains closed after swallowing, the air that is trapped is absorbed into the middle-ear tissue, resulting in a vacuum. This pulls the eardrum inward and decreases its flexibility, and hearing loss ensues. The cavity of the middle ear then fills with fluid, which can breed bacteria, causing infection. The infection may or may not be painful; if there is no pain, the infection may go unnoticed and untreated. The accumulated fluid can cause erosion of the tiny bones, which would decrease sound transmission to the auditory nerve. This conductive
hearing loss is permanent. Persistent and prolonged fluid buildup can also cause accumulation of dead matter, forming a tumorlike growth called a cholesteatoma.


Other problems associated with cleft palates are those related to dentition. In some children there may be extra teeth, while in others the cleft may prevent the formation of tooth buds so that teeth are missing. Teeth that are present may be malformed; those malformations include injury during development, fusion of teeth to form one large tooth, teeth lacking enamel, and teeth that have too little calcium in the enamel. If the teeth are misaligned, orthodontia may be undertaken. Another possible problem met by patients with a cleft palate is maxillary (upper jaw) arch collapse; this condition is also remedied with orthodontic treatment.




Treatment and Therapy

One of the first questions a parent of a child with a cleft palate will pose regards surgical repair. The purpose of surgically closing the cleft is not simply to close the hole—although that goal is important. The major purpose is to achieve a functional palate. Whether this can be accomplished depends on the size and shape of the cleft, the thickness of the available tissue, and other factors.


Cleft lip surgery is performed when the healthy baby weighs at least ten pounds; it is done under a general anesthetic. If the cleft is unilateral, one operation can accomplish the closure, but a bilateral cleft lip is often repaired in two steps at least a month apart. When the lip is repaired, normal lip pressure is restored, which may help in closing the cleft in the gum ridge. It may also reduce the gap in the hard palate, if one is present. Successive operations may be suggested when, even years after surgery, scars develop on the lip.


Surgery to close clefts of the hard and soft palate is typically done when the child is at least nine months of age, unless there is a medical reason not to do so. Different surgeons prefer different times for this surgery. The surgeon attempts to accomplish three goals in the repair procedure. The surgeon will first try to ensure that the palate is long enough to allow for function and movement (this is essential for proper speech patterns). Second, the musculature around the Eustachian tube should work properly in order to cut down the incidence of ear infections. Finally, the surgery should promote the development of the facial bones and, as much as possible, normal teeth. This goal aids in eating and appearance. All of this may be accomplished in one operation if the cleft is not too severe. For a cleft that requires more procedures, the surgeries are usually spaced at least six months apart so that complete healing can occur. This schedule decreases the potential for severe scarring.


At one time, it was thought that if surgery were performed before the child began talking, speech problems would be avoided. In reality, not only did the surgery not remedy that problem, but the early closure often resulted in a narrowing of the upper jaw and interference with facial growth as well. Thus, the trend to put off the surgery until the child was four or five years of age developed; by this age, more than 80 percent of the lateral growth of the upper jaw has occurred. However, most surgeons can perform the corrective surgery when the child is between one and two years of age without affecting facial growth.


Successful repair greatly improves speech and appearance, and the physiology of the oral and nasal cavities is also improved. Additional surgery may be necessary to improve appearance, breathing, and the function of the palate. Sometimes the palate may partially reopen, and surgery is needed to reclose it.


When the baby leaves the operating room, there are stitches in the repaired area. Sometimes a special device called a Logan’s bow is taped to the baby’s cheeks; this device not only protects the stitches but also relieves some of the tension on them. In addition, the baby’s arms may be restrained in order to keep the baby’s hands away from the affected area. (The child is fitted for elbow restraints before surgery; the elbows are encased in tubes that prevent them from bending.) A parent of a child that has just undergone cleft palate repair should not panic at the sight of bleeding from the mouth. To curb it, gauze may be packed into the repaired area and remain about five days after surgery. As mucus and other body fluids accumulate in the area, they may be suctioned out.


During the initial recovery, the child is kept in a moist, oxygen-rich environment (an oxygen tent) until respiration is normal. The patient will be observed for signs of airway obstruction or excessive bleeding. Feeding is done by syringe, eyedropper, or special nipples. Clear liquids and juices only are allowed. The child sits in a high chair to drink, when possible. After feeding, the mouth should be rinsed well with water to help keep the stitches clean. Peroxide mixed with the water may help, as well as ointment. Intake and output of fluids are measured. Hospitalization may last for about a week, or however long is dictated by speed of healing. At the end of this week, stitches are removed and the suture line covered and protected by a strip of paper tape.


An alternative to surgery is the use of an artificial palate known as an obturator. It is specially constructed by a dentist to fit into the child’s mouth. The appliance, or prosthesis, is carefully constructed to fit precisely and snugly, but it must be easily removable. There must be enough space at the back so the child can breathe through the nose. While speaking, the muscles move back over this opening so that speech is relatively unaffected.


Speech problems are the most likely residual problems in the cleft palate patient. The speech of the untreated, and sometimes the treated cleft palate patient is very nasal. If the soft palate is too short, the closure of the palate may leave a space between the nose and the throat, allowing air to escape through the nose. There is little penetrating quality to the patient’s voice, and it does not carry well. Some cleft palate speakers are difficult to understand because there are several faults in articulation. Certainly not all cleft lip or palate patients, however, will develop communication problems; modern surgical procedures ensure that most children will develop speech and language normally, without the help of a speech therapist.



Genetic counseling
may help answer some of the family’s questions about why the cleft palate occurred, whether it will happen with future children, and whether there is any way to prevent it. There are no universal answers to these questions. The answers depend on the degree and type of cleft, the presence of other problems, the family history, and the history of the pregnancy. Genetic counseling obtained at a hospital or medical clinic can determine whether the condition was heritable or a chance error and can establish the risk level for future pregnancies.




Perspective and Prospects

Oral clefts, as well as other facial clefts, have been a part of historical records for thousands of years. Perhaps the earliest recorded incidence is a Neolithic shrine with a two-headed figurine dated about 6500 BCE. The origination and causative agent of such clefts remain mysterious today.


Expectant parents are rarely alerted prior to birth that their child will be born with a cleft, so it is usually in the hospital, just after birth, that parents first learn of the birth defect. Even if it is suspected that a woman is at risk for producing a child with a cleft palate, there is no way to determine if the defect is indeed present, as neither amniocentesis nor chromosomal analysis reveals the condition. When the baby is delivered, the presence of the cleft can evoke a feeling of crisis in the delivery room.


The problems accompanying clefting may alter family morale and climate, increasing the complexity of the problem. A team of specialists usually works together to help the patient and the family cope with these problems. This team may include a pediatrician, a speech pathologist, a plastic surgeon, an orthodontist, a psychiatrist, an otologist, an audiologist, and perhaps others.


The cooperating team should monitor for the following situations: feeding problems, family and friends’ reactions to the baby’s appearance, how parents encourage the child to talk or how they respond to poor speech, and whether the parents are realistic about the long-term outcome for their child. The grief, guilt, and shock that the parents often feel can be positively altered by how the professional team tackles the problem and by communication with the parents. Usually the team does not begin functioning in the baby’s life until he or she is older than one month. Some parents have confronted their feelings, while others are still struggling with the negative feeling that the cleft brought to bear. Therefore, the first visit that the parents have with the team is important because it establishes the foundation of a support system that should last for years.


If the cleft were only a structural defect, the solution would simply be to close the cleft. Yet, problems concerning feeding and health, facial appearance, communication, speech, dental functioning, and hearing loss, as well as the potential for psychosocial difficulties, may necessitate additional surgical, orthodontic, speech, and otolaryngological interventions. In other words, after the closure has been made, attention is focused on aesthetic, functional, and other structural deficits.




Bibliography:


Berkowitz, Samuel, ed. Cleft Lip and Palate: Diagnosis and Management. 2d ed. New York: Springer, 2006.



"Cleft Lip and Palate" Medline Plus, May 4, 2012.



Clifford, Edward. The Cleft Palate Experience. Springfield, Ill.: Charles C. Thomas, 1987.



"Facts about Cleft Lip and Cleft Palate. Centers for Disease Control and Prevention, July 19, 2012.



Gruman-Trinker, Carrie T. Your Cleft-Affected Child: The Complete Book of Information, Resources, and Hope. Alameda, Calif.: Hunter House, 2001.



Kliegman, Robert, et al. "Cleft Lip and Palate." In Nelson Textbook of Pediatrics, edited by Robert Kliegman, et al. 19th ed. Philadelphia, Pa.: Elsevier, 2011.



Lorente, Christine, et al. “Tobacco and Alcohol Use During Pregnancy and Risk of Oral Clefts.” American Journal of Public Health 90, no. 3 (March, 2000): 415–419.



Stengelhofen, Jackie, ed. Cleft Palate. New York: Churchill Livingstone, 1988.



Wyszynski, Diego F., ed. Cleft Lip and Palate: From Origin to Treatment. New York: Oxford University Press, 2002.

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