What is Hemifacial Microsomia?
Hemifacial microsomia (HFM), also called craniofacial microsomia (CFM), is a birth defect. It occurs when a part of the face, specifically the ear, jaw, eye, cheek, or neck, appears small or underdeveloped. The severity of the deformity varies greatly. HFM is the most common facial birth defect after clefts.

What Causes Hemifacial Microsomia?
The reasons for abnormal facial development during pregnancy are mostly unknown. Hemifacial microsomia doesn’t appear to be related to the behaviors or habits of the mother. It also does not appear to be hereditary. However, parents who have one child with HFM have an increased chance of having another.
What Are Symptoms of Hemifacial Microsomia?
The primary symptom of hemifacial microsomia is abnormal appearance. Some children have noticeable deformities. Others’ deformities are less noticeable. The most common deformities include:

  • one side of the face being smaller than the other
  • a small or missing ear
  • a small flap of skin over the ear
  • an underdeveloped ear canal
  • a cleft lip
  • an overly wide mouth
  • small bones of the cheek or jaw
  • growths around the eye

Some children also have limited muscle movements, difficulty opening the mouth, or poor alignment of the teeth (bite). Nerve problems or hearing difficulties are also common. Other complications from HFM include spinal malformation, abnormal kidneys, and heart defects.
How is Hemifacial Microsomia Diagnosed?
To diagnose hemifacial microsomia, your child’s doctor will first do a physical examination of the face and head. The doctor will look closely at the ears, jaw, eyes, teeth, cheek, and face. He or she might also order X-rays or CT scans to get a better look at the structure of the face and head.
How is Hemifacial Microsomia Treated?
Treatment for hemifacial microsomia will depend on the severity of the condition and whether the child suffers from other ailments as a result of the deformities. As children are still growing, treatments such as reconstructive surgery on the ears and jaw will often not be performed until the patient is an adult. In many cases, surgery is not necessary but is chosen for cosmetic reasons.
What is the Outlook for Hemifacial Microsomia?
Most children with hemifacial microsomia live normal lives, although the deformity sometimes causes accompanying problems. Some children have trouble eating or breathing and must be monitored closely. Others may have minor troubles throughout life, such as with speaking, hearing, or facial movement, especially if they don’t seek treatment. People with hemifacial microsomia have an increased risk of kidney problems.