Hemifacial microsomia

What causes hemifacial microsomia?

Hemifacial microsomia (HFM) usually occurs by chance. However, it's thought to be inherited in some families, because there have been many cases reported where the condition occurs more than once in a family.

Observations made from families who have one child with HFM show that the overall chance for another child to be born with the condition is about 2 to 3 percent.

Parents and other family members should have a thorough evaluation to help give more definite recurrence information.

In addition, HFM is sometimes found in children with various types of chromosome abnormalities, which typically occur by chance.

What are the symptoms of hemifacial microsomia?

One of the most obvious problems your child may have is the underdevelopment of the upper and lower jaws on the affected side. It may appear that your child's mouth slants upward toward the involved side.

Often the forehead and cheek are flattened on the affected side with one orbit (eye socket) smaller than normal.

Other areas of your child's face that may be affected by hemifacial microsomia include the following:

• Your child may have unequal cheek fullness because of the underdeveloped fat and muscle. Some parts of the face may not move normally, which may cause a "crooked" smile.
• Your child may have a mildly misshapen ear or almost complete absence of the external ear (atresia). Small tags of skin may also be present in front of the ear(s).
• Occasionally, the central nervous system is affected, causing parts of the face to not move symmetrically.