Introduction

Cleft lip (cheiloschisis) and cleft palate (palatoschisis) (colloquially known as harelip), which can also occur together as cleft lip and palate, are variations of a type of clefting congenital deformity caused by abnormal facial development during gestation.

 

Note that harelip is now considered as a derogatory term. A cleft is a fissure or opening -- a gap. It is the non-fusion of the body's natural structures that form before birth.

Clefts can also affect other parts of the face, such as the eyes, ears, cheeks and forehead. In 1976, Dr. Paul Tessier described fifteen lines of cleft. These craniofacial clefts are rare and are frequently described as Tessier clefts using the numerical locator devised by Dr. Tessier.

A cleft lip or palate can be successfully treated with surgery soon after birth. Cleft lips or palates occur in somewhere between one in 600-800 births.