Hemifacial Microsomia

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

This condition often happens by chance. It commonly develops during the fetal stage of pregnancy at around four 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 one 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.

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.

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

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 healthcare providers 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
• Having surgeries to fix your child’s external ear, cheeks or jaw
• Removing or correcting the position of your child’s teeth

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.

Your child may have hearing loss or eating problems related to HFM. Your child will need to be under the care of 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 specialist) 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.

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