Hemifacial Microsomia

What is hemifacial microsomia?

Hemifacial microsomia (HFM), also called craniofacial microsomia or sometimes "Goldenhar syndrome," is a condition in which half of one side of the face is underdeveloped and does not grow normally. “Hemifacial” means one side of the face. “Microsomia” means smallness.

The deformity in hemifacial microsomia can range from mild to severe, and the areas of the face that are affected also vary greatly from child to child. However, HFM always includes some degree of underdevelopment of the lower jaw (mandible).

Areas of the face that may be underdeveloped in HFM include:

  • eye
  • external and middle ear
  • side of the skull
  • cheek tissue
  • upper and lower jaws
  • teeth
  • some of the nerves that allow facial movement

The degree to which area of the face is affected varies widely, and some areas may not be affected at all.

Hemifacial microsomia calls for advanced care from a collaborative team that typically includes plastic and oral surgeons and dentists and orthodontists, among other specialists. At Boston Children’s, our craniofacial team includes world-renowned specialists who are experts in treating HFM.

What are the symptoms of hemifacial microsomia?

If your child has hemifacial microsomia, the most visible signs of the condition are underdeveloped upper and lower jaws on one side of the face. It may appear that your child's mouth slants upward toward the affected side.

Often the forehead and cheek are flattened on the affected side and one eye socket is smaller than normal.

Other signs of hemifacial microsomia include:

  • Ear abnormalities: Small nodules of excess skin around the ear, underdeveloped or absent external ear, underdeveloped or absent inner ear structures, and hearing loss
  • Jaw abnormalities: A small or underdeveloped jaw, upward slanted mouth/jaw, appearance of a “crooked smile,” and inability to chew
  • Facial findings: Flat cheek and/or forehead, overall facial asymmetry (unevenness), weakness of muscles, and loss of sensation

Rarely, this condition can occur on both sides of the face. This is referred to as bilateral facial microsomia.

What causes hemifacial microsomia?

Experts do not know the exact causes of hemifacial microsomia. They believe that the condition occurs because of a disrupted process in your baby’s fetal development during the first six weeks of gestation. It is not known if environmental factors are involved.

Hemifacial microsomia is thought to be inherited in some families, because there have been some cases reported where the condition occurs more than once in a family. Researchers have not yet identified the genes involved in hemifacial microsomia.

There is nothing you (or your child’s other parent) did — or did not do — that caused the hemifacial microsomia.

How we care for hemifacial microsomia

Families seeking the very best care for their child come to the Craniofacial Program at Boston Children’s for our:

  • nationally recognized care: U.S. News & World Report ranks Boston Children's Hospital higher in more specialties than any other children's hospital in the country.
  • world-renowned facial reanimation program: Children with facial nerve paralysis are treated by team of doctors with extensive training and experience in restoring the greatest possible degree of sensation and movement in a child’s face.
  • research and innovation: Our clinicians are involved in research that moves us closer to a better understanding of — and treatment for — all deformities of the head and face.
  • customized treatment: Our team will develop a customized treatment plan that meets all of your child’s needs — one that involves you and your family at every step of the treatment. Learn more about our approach to craniofacial treatment and care.

Our Craniofacial Program includes some of the world’s most experienced craniofacial surgeons, plastic surgeons, oral and maxillofacial (jaw) specialists, dentistry professionals, psychologists, and social workers — all working together to address the many needs of your child and your entire family.

Meet our craniofacial team.

Make an appointment

For an appointment with the Cleft and Craniofacial Center, more information, or to obtain a second opinion for your child, please call us at 617-355-6309 or email samantha.hall@childrens.harvard.edu.

International patients

For families residing outside of the United States, please call Boston Children's Global Services at +01-617-355-5209.