About Cleft Palate

Cleft lip and cleft palate, which can also occur together as cleft lip and palate are variations of a type of clefting congenital deformity caused by abnormal facial development during gestation. This type of deformity is sometimes referred to as a cleft. A cleft is a sub-division in the body's natural structure, regularly formed before birth. A cleft lip or palate can be successfully treated with surgery soon after birth. Cleft lips or palates occur in somewhere between one in 600 and one in 800 births. The term hare lip is sometimes used colloquially to describe the condition because of the resemblance of a hare's lip. Interestingly, in Lun Heng (Chapter 6), the first century AD Wang Chong said, "If a pregnant woman eats rabbit, the baby will have a cleft lip." The Chinese word for cleft lip is tuchun, literally harelip.

A microform cleft is a very minor cleft where no surgery is required to correct it. A microform cleft can appear as small as a little dent in the red part of the lip or look like a scar.

Cleft palate is a condition in which the two plates of the skull that form the hard palate (roof of the mouth) are not completely joined. The soft palate is in these cases cleft as well. In most cases, cleft lip is also present. Cleft palate occurs in about one in 700 live births worldwide.

Palate cleft can occur as complete (soft and hard palate, possibly including a gap in the jaw) or incomplete (a 'hole' in the roof of the mouth, usually as a cleft soft palate). When cleft palate occurs, the uvula is usually split. It occurs due to the failure of fusion of the lateral palatine processes, the nasal septum, and/or the median palatine processes (formation of the secondary palate).

During the first six to eight weeks of pregnancy, the shape of the embryo's head is formed. Five primitive tissue lobes grow:

a) one from the top of the head down towards the future upper lip;

b-c) two from the cheeks, which meet the first lobe to form the upper lip;

d-e) and just below, two additional lobes grow from each side, which form the chin and lower lip;

If these tissues fail to meet, a gap appears where the tissues should have joined (fused). This may happen in any single joining site, or simultaneously in several or all of them. The resulting birth defect reflects the locations and severity of individual fusion failures (e.g., from a small lip or palate fissure up to a completely deformed face).

The upper lip is formed earlier than the palate, from the first three lobes named a to c above. Formation of the palate is the last step in joining the five embryonic facial lobes, and involves the back portions of the lobes b and c. These back portions are called palatal shelves, which grow towards each other until they fuse in the middle. This process is very vulnerable to multiple toxic substances, environmental pollutants, and nutritional imbalance. The biologic mechanisms of mutual recognition of the two shelves, and the way how they are glued together, are quite complex and obscure despite intensive scientific research. A comprehensive and easy to understand overview of palatal fusion with nice illustrations can be found in the March 2007 issue of Acta Histochemica.

The cause of cleft lip and cleft palate formation can be genetic in nature. A specific gene that increases threefold the occurrence of these deformities has been identified in 2004 as reported by the BBC.

Environmental influences may also cause, or interact with genetics to produce, orofacial clefting. Scientists have investigated seasonal causes (such as pesticide exposure); maternal diet and vitamin intake; retinoids, which are members of the vitamin A family; anticonvulsant drugs; alcohol; cigarette use; nitrate compounds; organic solvents; parental exposure to lead; and illegal drugs (cocaine, crack cocaine, heroin, etc.) as teratogens that increase the possibility of clefting.

If a person is born with a cleft, the chances of that person having a child with a cleft, given no other obvious factor, rises to 1 in 14. Research continues to investigate the extent to which Folic acid can reduce the incidence of clefting.

In some cases, cleft palate is caused by syndromes which also cause other problems. Stickler's Syndrome can cause cleft lip and palate, joint pain, and myopia. Loeys-Dietz syndrome can cause cleft palate or bifid uvula, hypertelorism, and aortic aneurysm. Many clefts run in families, even though there does not seem to be any identifiable syndrome present.

Within the first 2-3 months after birth, surgery is performed to close the cleft lip. While surgery to repair a cleft lip can be performed soon after birth, the oft preferred age is at approximately 10 weeks of age, following the "rule of 10s" coined by surgeons Wilhelmmesen and Musgrave in 1969 (the child is at least 10 weeks of age; weighs at least 10 pounds, and has at least 10 g haemoglobin). If the cleft is bilateral and extensive, two surgeries may be required to close the cleft, one side first, and the second side a few weeks later.

Often an incomplete cleft lip requires the same surgery as complete cleft. This is done for two reasons. Firstly the group of muscles required to purse the lips run through the upper lip. In order to restore the complete group a full incision must be made. Secondly, to create a less obvious scar the surgeon tries to line up the scar with the natural lines in the upper lip (such as the edges of the philtrum) and tuck away stitches as far up the nose as possible. Incomplete cleft gives the surgeon more tissue to work with, creating a more supple and natural-looking upper lip.

Often a cleft palate is temporary closed using a palatal obturator. The obturator is a prosthetic device made to fit the roof of the mouth covering the gap. Furthermore a tympanostomy tube is often inserted into the eardrum to aerate the middle ear. This is often beneficial for the hearing ability of the child.

Cleft palate can also be corrected by surgery, usually performed between 9 and 18 months. Approximately 20-25% only require one palatal surgery to achieve a competent velopharyngeal valve capable of producing normal, non-hypernasal speech. However, combinations of surgical methods and repeated surgeries are often necessary as the child grows. One of the new innovations of cleft lip and cleft palate repair is the Latham appliance. The Latham is surgically inserted by use of pins during the child's 4th or 5th month. After it is in place, the doctor, or parents, turn a screw daily to bring the cleft together to assist with future lip and/or palate repair.

If the cleft extends into the maxillary alveolar ridge, the gap is usually corrected by filling the gap with bone tissue. The bone tissue can be acquired from the patient's own chin, rib or hip.

Speech problems are usually treated by a speech-language pathologist. In some cases pharyngeal flap surgery is performed to regulate the airflow during speech and reduce nasal sounds.

Most children with a form of clefting are monitored by a cleft palate or craniofacial team through young adulthood. Care can be lifelong.

Note that treatment procedures can vary between craniofacial teams. For example, some teams wait on jaw correction until the child is aged 10 to 12 (argument: growth is less influential as deciduous teeth are replaced by permanent teeth, thus saving the child from repeated corrective surgeries), while other teams correct the jaw earlier (argument: less speech therapy is needed than at a later age when speech therapy becomes harder). Within teams treatment can differ from each individual case depending on the type and severity of the cleft.