Hemifacial Microsomia

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Hemifacial microsomia is a condition in which one side of the face is smaller or underdeveloped or has parts that are missing. While the hallmark is unevenness (asymmetry) of the face, one or both sides may be affected. It is the second most common facial birth defect after cleft lip and palate. It happens more often in males than in females.

The condition usually affects the lower part of the face and may include the cheekbone, lower jaw, facial nerves, muscles, and ear. However, sometimes it affects the eye and forehead. Some babies born with hemifacial microsomia have minor facial changes, while others may have more severe changes to the face. The condition may also cause dental and speech problems along with difficulties feeding or eating, breathing, seeing, and hearing.

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Researchers do not know exactly why hemifacial microsomia happens. It is believed that poor blood flow to the baby’s developing face may be a cause. Experts also think that having diabetes, taking certain medications, smoking during pregnancy or being pregnant with more than one baby might play a role in developing hemifacial microsomia. Most of the time, hemifacial microsomia happens by chance, but there are some instances when it happens more than once in a family, leading doctors to believe it is sometimes inherited.

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The signs and symptoms of hemifacial microsomia vary; however, most of the time, the ear and lower jaw are affected. See the chart below for possible signs and symptoms of hemifacial microsomia and the areas that can be affected by the condition.

Affected Area Signs & Symptoms
  • Unevenness (asymmetry) of the face.
  • Underdeveloped facial muscles.
  • Damage to the facial nerves, which may make smiling or moving the face difficult.
  • Reduced quantity of fat in the face.
  • Cleft lip and palate.
  • Very small or missing eye.
  • Narrow or missing jaw joint or bones.
  • Unevenness of the dental arch that causes the smile and teeth to appear tilted.
  • Small, misshapen, or missing teeth.
  • Teeth that develop later than normal.
  • Ear that is missing, is smaller in size, or is misshapen.
  • Deafness due to a missing external ear canal and/or damage to the middle ear.
  • Growths on the ear and cheek (ear and skin tags).

Babies and children with hemifacial microsomia also may have medical problems involving the spine, ribs, heart, and kidneys that should be evaluated.

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Changes in the face can sometimes be seen in an ultrasound during pregnancy, and the physician may suspect hemifacial microsomia before birth. However, doctors usually diagnose hemifacial microsomia by examining the face after the baby is born. The doctor also may order x-rays and a CT scan to evaluate the bones, muscles, and tissue structures of your baby’s face.

The doctor may order genetic testing if there are others in the family with features of hemifacial microsomia, or if he or she wants to rule out other conditions that may be associated with some of the same symptoms.

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After diagnosis and testing, your child’s doctor may refer you to a craniofacial center for evaluation and treatment planning. These centers, which are usually part of children’s hospitals or university medical centers, have a team of health care professionals who will provide a complete treatment plan.

Specialist Area of Focus
Pediatrician Children’s health.
Pediatric Nurse or Patient Coordinator Alignment of patient’s treatment plan.
Geneticist or Genetic Counselor Genes and inherited disorders.
Dentist Teeth and mouth.
Orthodontist Alignment of the teeth and jaw.
Oral and Maxillofacial Surgeon Surgeries of face, mouth, and jaw.
Plastic and Reconstructive Surgeon Surgeries to repair physical deformities.
Otolaryngologist Ear, nose, and throat.
Ophthalmologist Eyes and vision.
Orthopedic surgeon Bones and joints.
Neurosurgeon Surgeries of the brain, spinal cord, and nerves.
Nephrologist Kidneys.
Cardiologist Heart.
Psychologist Behavior and mental health.
Social Worker Resources and counseling.
Audiologist Hearing.
Speech and Language Pathologist Speech, language, and swallowing.

Treatment depends on your child’s symptoms and overall general health. When your child is an infant, treatment focuses on making sure your baby is breathing and feeding well. When your child is older, the goal is to improve the evenness of the face, jaw movement, and bite. You will work with your child’s doctors to develop a specific treatment plan, which may include surgeries to repair, rebuild, and expand the upper and lower jaws, improve the evenness of the face, or reconstruct or repair the ear.

In addition to surgeries, your child may need other treatments, such as a feeding tube to provide nutrition, speech therapy, dental care and orthodontia, or hearing and vision aids.

Treatment may occur over many years to adjust the shape of your child’s face and to help him/her breathe, eat, speak, and hear. Overall, the goal remains the same: to help your child develop and thrive.

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Helpful Tips

  • Before visiting a doctor, write down questions or topics you would like to discuss at the appointment.
  • Ask your health care team questions and write down their answers. If you don’t understand something, ask them to explain.
  • After each visit, write down any tests, treatments, or instructions you received. This can help you remember them and communicate with other members of your child’s health care team.
  • Remember to take your child to the dentist for regular checkups. Discuss with the dentist the dental care and teeth cleaning routine your child should follow at home.
  • Ask your physicians for community resources or support groups in your area for both you and your child.
  • Ask for support from family and friends.
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Additional Resources

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Last Reviewed
December 2021