Cleft lip generally occurs at the junction between the middle and the lateral parts of the upper lip (lateral cleft lip). The cleft may be unilateral or bilateral. It may be restricted to the lip or also affect the primary palate. A rare form is the medial cleft of the upper lip.
Oblique facial clefts run along the line where the lateral nasal process normally fuses with the maxillary process. In this form of facial cleft, the nasolacrimal duct is usually found on the surface of the face. Oblique facial clefts are thought to be due to amniotic bands, which result from ruptures of the amnion.
Cleft palate results when the secondary palates fail to fuse completely or even partially. Bifid uvula is a less severe form of cleft palate.