Atlas of pathophysiology, 2 Edition

Part II - Disorders

Sensory Disorders

Cleft lip and cleft palate

Cleft lip and cleft palate—an opening in the lip or palate—may occur separately or in combination. Cleft lip and cleft palate are twice as common in males as in females; isolated cleft palate is more common in females.

Causes

·   Isolated birth defect: normal development of orofacial structures disrupted by a combination of genetic and environmental factors

·   Part of a chromosomal or mendelian syndrome (cleft defects are associated with over 300 syndromes)

·   Exposures to specific teratogens during fetal development

Clinical Tip

A family history of cleft defects increases the risk that a couple may have a child with a cleft defect. Likewise, an individual with a cleft defect is at an increased risk to have a child with a cleft defect. Children with cleft defects and their parents or adult individuals should be referred for genetic counseling for accurate diagnosis of cleft type and recurrence-risk counseling. Recurrence-risk is based on family history, the presence or absence of other physical or cognitive traits within a family, and prenatal exposure information.

Pathophysiology

Cleft deformities originate in the 2nd month of pregnancy, when the front and sides of the face and the palatine shelves fuse imperfectly. Cleft deformities usually occur unilaterally or bilaterally, rarely midline.

Signs and symptoms

·   Cleft lip may range from a simple notch in the upper lip to a complete cleft from the lip edge through the floor of the nostril.

·   Cleft palate may be partial or complete, involving only the soft palate or extending from the soft palate completely through the hard palate into the upper jaw or nasal cavity.

Clinical Tip

The constellation of U-shaped cleft palate, mandibular hypoplasia, and glossoptosis (downward displacement and retraction of the tongue) is known as Pierre Robin sequence, or Robin sequence. It can occur as an isolated defect or one feature of many different syndromes; therefore, a comprehensive genetic evaluation is suggested for infants with Robin sequence. Because of the mandibular hypoplasia and glossoptosis, careful evaluation and management of the airway are mandatory for infants with Robin sequence.

Diagnostic test results

Prenatal ultrasonography reveals the defect.

Treatment

Surgical correction (timing varies)

·   Cleft lip:

§  within the first few days of life to make feeding easier

§  or, delay lip repairs for 2 to 8 months to minimize surgical and anesthesia risks, rule out associated congenital anomalies, and allow time for parental bonding

·   Cleft palate:

§  performed only after the infant is gaining weight and is infection-free

§  usually completed by age 12 to 18 months

§  two steps: soft palate between ages 6 and 18 months; hard palate as late as age 5 years

Speech therapy

·   Palate essential to speech formation (structural changes, even in a repaired cleft, can permanently affect speech patterns)

·   Hearing difficulties common in children with cleft palate because of middle ear damage or infections

Other

·   Orthodontic prosthesis

·   Adequate nutrition

·   Use of a large soft nipple with large holes

P.399

VARIATIONS OF CLEFT DEFORMITY

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