Cleft lip and palate
|Clefts of the primary palate||Clefts of the secondary palate||Clefts of the primary and secondary palate|
|Unilateral (left or right)||Complete||Unilateral (left or right)|
Cleft lip and palate (CLP) is the most common congenital craniofacial deformity. Its incidence varies according to the ethnic group studied: American Indians (1/300 live births) > Japanese (1/400) > Chinese (1/500) > Caucasians (1/600) > black people (1/2500). Cleft lip (CL) ± cleft palate (CL(P)), forms a separate entity from isolated clefts of the secondary palate (CP), with a difference in incidence, gender bias and genetic contribution. CL(P) is approximately twice as common in males as females, whereas, isolated CP is twice as common in females.
CL arises from failure of fusion (at 7 weeks in utero) between the medial nasal, lateral nasal and maxillary swellings. CP arises from failure of fusion (8–9 weeks in utero) of the lateral palatal swellings.
CLP may be isolated or as part of a syndrome. The aetiology of isolated CLP is multifactorial with both genetic and environmental influences. There is a fami/>