This document provides an overview of cleft lip and palate, including:
- Incidence rates are about 1 in 1000 live births globally. Risk increases with parental age and decreases in some populations.
- Clefts occur due to failure of facial prominences to fuse properly during embryonic development between 4-7 weeks.
- Clefts can be non-syndromic or associated with over 350 genetic syndromes. Both genetic and environmental factors contribute to clefting.
- Classification systems have evolved over time to better describe cleft types and guide multidisciplinary treatment planning. The document reviews several historic and currently used classification approaches.