Encyclopedia of Health and Medicine

16 The Ear, Nose, Mouth and Throat
cleft palate/cleft palate and lip Congenital
anomalies in which the bones of the face that
form the roof of the MOUTH fail to close properly in
the early stages of embryonic development. These
structures originate as separate entities and, in the
course of normal embryonic development, join
together by 10 weeks of gestation. Cleft defects,
known clinically as congenital craniofacial anomalies,
occur in varying degrees and combinations
that may include separations of the hard palate,
soft palate, upper gum, and upper lip. The most
common presentation is isolated cleft palate (the
defect involves only the roof of the mouth), or
cleft palate and lip (the defect extends from the
roof of the mouth to the external lip). These
anomalies are the fourth most common type of
birth defect in the United States, affecting about 1
in 1,000 infants born each year.
An intact palate is necessary for proper eating,
swallowing, and speech. An infant with a cleft
palate, and especially cleft palate and lip combination,
often cannot suck well enough to obtain adequate
nutrition. A complete cleft palate blends the
nasal and oral openings into a single chamber,
which interferes with BREATHING. Craniofacial
anomalies also occur among the deformities of
numerous other congenital syndromes. There is a
particular correlation between isolated cleft palate
and other congenital defects, notably HEART anomalies.
Because of these correlations, doctors evaluate
newborns with cleft palate defects for other
congenital disorders.
Symptoms and Diagnostic Path
Doctors detect most cleft palate defects shortly
after birth or in early childhood. Many clefts are
visible or palpable (the doctor can feel the defect
by running a finger along the roof of the infant’s
mouth). A missing or bifid (two-part) uvula, the
small flap of tissue that hangs from the soft palate
at the back of the THROAT, often though not always
indicates a cleft palate. Doctors may not detect
minor cleft palate disorders until the infant has
trouble eating or does not appear to be gaining
weight. X-rays, COMPUTED TOMOGRAPHY (CT) SCAN,
and MAGNETIC RESONANCE IMAGING (MRI) are among
the procedures that can confirm and define the
extent of the defect.
Treatment Options and Outlook
Nearly always surgery is the treatment of choice to
close the cleft, for functional as well as aesthetic
reasons. Surgeons generally prefer to do these
operations as early as the infant’s health permits,
typically between the ages of 3 and 18 months.
Mild to moderate defects often require only a single
operation. Extensive deformities may require
two or three operations done in stages, with follow-up
speech therapy. Severe deformities that
involve the upper gum and structure of the TEETH
may require ongoing orthodontic and dental
work, along with speech therapy, extending into
ADOLESCENCE. The outlook following surgical repair
is exceptional, with few complications for most
infants as they grow older. By adulthood there
generally is little apparent evidence of the cleft or
its repair.
Risk Factors and Preventive Measures
Cleft palate and cleft lip appear to be random
occurrences though are common with certain
genetic disorders such as DOWN SYNDROME. Some
studies suggest that these disorders are more common
among infants of mothers who take certain
antiseizure medications or ANTIANXIETY MEDICATIONS
in the benzodiazepine family. Cleft palate and cleft
lip are also more frequent among children of
women who drink ALCOHOL and smoke cigarettes
before and during pregnancy. Other studies show
that taking folic acid and vitamin B supplements
during pregnancy, which is a standard practice in
PRENATAL CARE in the United States to reduce the
likelihood of NEURAL TUBE DEFECTS, helps prevent
craniofacial clefts. When a woman gives birth to a
child who has a cleft palate, any subsequent children
are more likely than normal to have the
same kind of disorder.
See also CONGENITAL ANOMALY, CONGENITAL HEART
DISEASE; FETAL ALCOHOL SYNDROME; OPERATION; SMOK-
ING AND HEALTH; SURGERY BENEFIT AND RISK ASSESS-
MENT; SWALLOWING DISORDERS; VACTERL; X-RAY.
cochlea The organ of the inner EAR that converts
sound waves to NERVE impulses. Contained within
the bony labyrinth, the cochlea resembles a snail
shell. Thousands of specialized nerves, called HAIR
cells because of the fine fibers that project from