Hemifacial microsomia is a condition in which the structures on one side of the face are smaller or underdeveloped relative to the other side. The severity of hemifacial microsomia varies widely from person to person, but the ear and lower jaw are always affected.
When both sides of the face are affected to different degrees, the condition is called bilateral hemifacial microsomia.
The exact cause of hemifacial microsomia is unknown. The condition can occur by itself or as part of a syndrome such as Goldenhar's syndrome — also known as oculoauriculovertebral dysplasia — in which the spine and eyes are affected as well as the face.
The severity of hemifacial microsomia varies widely, but the ear and jaw are always affected. Some of the signs of the condition may include:
Hemifacial microsomia is diagnosed by physical examination at birth. A genetic evaluation helps determine if the hemifacial microsomia is isolated or is part of another syndrome or condition.
The goal of treatment is to balance the appearance of the two sides of the face as much as possible. Depending on the particular characteristics of each child's condition, we may recommend surgery, orthodontics or both.
If needed, ear reconstruction begins at about 6 to 7 years of age and involves three to four surgical procedures. Jaw reconstruction includes lengthening the lower jaw, sometimes using bone grafting or a distraction device. To fill out the cheek or other areas of the face, some children may benefit from soft tissue augmentation, which is done when the child has mostly finished growing.
In addition, routine hearing tests are important to detect any hearing loss that may require intervention.
A child with hemifacial microsomia may encounter social and emotional challenges unique to this condition. Support organizations and resources are available for children and their families.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.