Topic Overview

Cleft palate and cleft lip may occur independently of each other or at the same time. The terms below are often used to describe and classify cleft lip and cleft palate and to describe a cleft more precisely.

Basic classification of cleft palate

A cleft palate is first categorized according to whether it affects the hard palate, the soft palate, or both.

• The hard palate is the front part of the roof of the mouth.
• The soft palate is the back part of the roof of the mouth. This description may include whether the uvula is affected.

See a picture comparing a normal mouth with two types of cleft palate.

Classification of cleft lip

Cleft lip is classified according to its location and severity:

• Unilateral (on one side of the lip). The unilateral cleft may cause the nostril on that side to be tilted and lower than the other nostril.
• Bilateral (on two sides of the lip). The bilateral cleft may cause the nose to be broader and shorter than normal.
• Complete (extends to the nose)
• Incomplete (does not extend to the nose)

See a picture comparing a complete cleft lip and an incomplete cleft lip.

Most clefts involve only one side of the upper lip. They rarely occur in the lower lip.

If cleft lip occurs with cleft palate, the upper alveolar ridges, which are where the teeth sit, are also involved.

Combination terms

Complete classification of a cleft palate combines all of the appropriate terms. For example:

• A cleft of the hard palate with an incomplete unilateral cleft lip is a cleft in the front of the mouth and a cleft in one side of the upper lip that doesn't extend to the nose.
• A cleft of both the hard and soft palate with bilateral complete cleft lip describes a cleft that extends from the soft palate to the hard palate, and includes the alveolar ridge. Both sides of the lip have clefts extending to the nose.