Factors determining occurrence of cleft lip and cleft palate.

The modern care of newborn infants with oral clefts renders their survival possible. Since they will eventually reproduce, a slight increase in the incidence may be expected and genetic counseling will be requested on occasion. The cleft lip with or without cleft palate has a different genetic inclination from isolated cleft palate and the risk of recurrence is different. Drugs, such as antiepileptics, salicylates, benzodiazepines and cortisone, have a role in causing oral clefts. When an oral cleft is a part of a syndrome, the genetics of the particular syndrome must be outlined and genetic counseling is given accordingly. Oral clefts alone are usually multifactorial.