The word "cleft" simply means a crack or divide. A cleft lip is simply the body incorrectly or incompletely closing the facial structures during development. This incomplete closing leaves a cleft, or divide, in the lip and/or palate of the new born. Below is an ultrasound showing a cleft lip.
About 6,800 children in the United States are born with isolated cleft lip/palates each year. This number accounts for about 70% of all the clefts in children. The other 30% of clefts are associated with one of over 400 syndromes that include a cleft as part of the syndrome.
Clefts are normally very repairable and the scare can be almost unrecognizable.