Hemifacial Microsomia (HFM)

What is hemifacial microsomia?

Hemifacial microsomia (HFM) is a congenital problem. This means that your child is born with it. In this condition, 1 side of your baby’s face is underdeveloped (hemi means half). HFM usually only affects 1 side of the face. Sometimes both sides may be affected. This condition shares features with another condition called Treacher Collins syndrome.

What causes HFM?

This condition often happens by chance. It commonly develops during the fetal stage of pregnancy at around 4 weeks gestation because of vascular problems causing poor blood supply to the face. It may also run in some families. HFM may be passed on (inherited) in the following ways:

  • Autosomal dominant. This means that only 1 parent passes the gene on to the child. Each child has a 1 in 2 chance of having the condition.
  • Autosomal recessive. This means that both parents must have the gene to pass it on. Each child has 1 in 4 chance of having HFM.
  • Multifactorial. This means that many factors are involved. The factors are often genetic and environmental (such as trauma during pregnancy).

This condition may also occur in children with other chromosome abnormalities. Chromosomes are the structures in our cells that carry our genes. These types of abnormalities often occur by chance.

What are the symptoms of HFM?

Symptoms can occur a bit differently in each child. The deformities caused by HFM vary. They may range from mild to severe. Different areas of the face may be involved. The following may be underdeveloped in HFM:

  • Outside and middle ear
  • Side of the skull
  • Bone around the eye
  • Thickness of the cheek
  • Upper and lower jaws
  • Teeth
  • Some of the nerves involved in moving the face

In some babies, other parts of the body may also be affected by HFM.

How is HFM diagnosed?

Geneticists often diagnose HFM. A geneticist is a doctor with special training to diagnose and treat conditions passed down in families (genetic condition). Your child’s doctor will look at his or her health history. Your child will also have an exam. Your child’s doctor may also do imaging tests to make the diagnosis.

These tests may include:

  • X-rays of the head. X-rays will show the internal tissues and bones inside of your child’s head.
  • CT scan. A CT scan shows detailed images of any part of the body. Your child may need a CT scan of the head. This test will show his or her bones, muscles, and underlying tissue.

How is HFM treated?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

If your child has severe symptoms, he or she may need several surgeries. In this case, your child will be checked by a craniofacial anomalies team. This is a group of doctors who diagnose and treat face defects.

Your child’s treatment may include:

  • Fixing your child’s lower jaw. This is done using a bone graft taken from your child’s ribs.
  • Using a device to correct your child’s jaw
  • Surgeries to fix your child’s external ear, cheeks, or jaw
  • Removing or correcting the position of your child’s teeth

What are the complications of HFM?

If your child has a mild defect, he or she may not be at risk for complications. Children with more severe defects may be more likely to have issues. These can include hearing loss, eating problems, and trouble with self-image.

Living with HFM

Your child may have hearing loss or eating problems related to HFM. Your child will need to be under the care a team of craniofacial anomaly experts. This team may include:

  • A craniofacial surgeon who can do jaw surgery and ear reconstruction
  • An ophthalmologist to diagnose and treat eye and vision issues
  • An orthodontist to check and treat jaw growth and alignment
  • An otolaryngologist (ear, nose and throat doctor of ENT) to check hearing loss
  • A speech therapist to give speech therapy

HFM support groups can help you and your child. Ask your child’s healthcare provider about support groups in your area.

When should I call my child's healthcare provider?

Call your child’s healthcare provider if your child has any new symptoms. These can include trouble eating or gaining weight.

Key points about HFM

  • In HFM, 1 side of your baby’s face is underdeveloped. Your baby is born with this condition.
  • HFM often happens by chance. Sometimes this condition can run in families.
  • Children with HFM should be checked by a craniofacial anomalies team.
  • If your child has severe defects, he or she may need several surgeries to fix them.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.