ORGANUM
Cleft lip and palate occur separately or together and affect approximately 1 in 700 infants. It is more common in Asians (1:500) and least common in Africans (1:2500). Clefting occurs with two possible patterns: isolated soft tissue cleft palate or cleft lip with or without associated clefts of the hard palate. Isolated cleft palate is associated with a higher risk of other male predominance. The combined cleft lip/palate type has a male predominance.
Cleft lip is due to hypoplasia of the mesenchymal tissues with subsequent failure of fusion. There is a strong genetic component; the risk is highest in children with affected first-degree relatives. Monozygotic twins are affected with only 60% concordance, suggesting other nongenomic factors. Environmental factors during gestation also increase risk:
Drugs (phenytoin, valproic acid, thalidomide)
Maternal alcohol and tobacco use
Dioxins and other herbicides
Possibly high altitude
Chromosomal and non chromosomal syndromes are associated with clefting, as are specific genes in some families.
Cleft lip can be unilateral or bilateral and associated with cleft palate and defects of the alveolar ridge and definition. When present, palatal defects allow direct communication between the nasal and oral cavities, creating problems with speech and feeding.
In many cases, prenatal diagnosis can be made via ultrasonography around 18 weeks, although this is highly dependent on technician experience and skill. With traditional 2D ultrasonography, a cleft lip is more accurately detected than a cleft palate. A significant advancement in diagnosing cleft palate has evolved with 3D ultrasonography, which has 100% sensitivity in detecting cleft palate in a fetus that has already been diagnosed with cleft lip.
Management includes squeeze-bottle feeding, special nipples, nipples with attached shields to seal the palate, and astronomy in severe cases. Surgical closure of the cleft lip is usually done by 3 months of age. Closure of the palate follows, usually before 1 year of age. Missing teeth are replaced by prosthesis. Cosmetic results are often good, as are defects of teeth and the alveolar ridge.
Speech is nasal as a result of cleft palate - surgical treatment is effective, but sometimes may not restore palatal function completely. Speech therapy, or occasionally, the use of a speech-assisting appliance may help. Frequent episodes of otitis media are common, as are defects of teeth and the alveolar ridge.