Hemifacial microsomia (HFM) (or craniofacial microsomia, CFM) is a condition in which a child is born with the lower half of their face underdeveloped, most commonly their ears, jaw and mouth; eyes, cheeks and neck may also be affected. After cleft lip and palate, this is the second most common facial birth defect.
Other names for this condition are as follows:
- First and second branchial arch syndrome
- Oral-mandibular-auricular syndrome
- Lateral facial dysplasia
- Otomandibular dysostosis
What Causes Hemifacial Microsomia?
The defect develops when the fetus is 4-weeks-old when it is thought that some kind of blood vessel problem results in a poor supply of blood to the face. No one knows what causes the condition; it can be caused by physical trauma but in most cases, it seems to occur by chance. There is some evidence, however, that sometimes it may be hereditary. It has been reported that when parents have a child with HFM, there is a 2–3% chance that another child will also have the condition.
What Are the Symptoms of Hemifacial Microsomia?
The appearance of a child with hemifacial microsomia can vary a great deal. In some children, for example, an infant may have only a slightly smaller jaw than usual and a small “tag” of skin in front of an ear that appears normal. In other children, multiple parts of the face may be affected, such as:
- The jaw (upper and lower)
- The middle ear (inside)
- The side of the skull
- The teeth (a bite that does not come together well)
- The cheeks (their shape and thickness)
- Facial muscles, which may be paralyzed
If your child has HFM, they are at higher risk for hearing loss and should have their hearing tested. A few children also have abnormalities of the kidneys and cervical spine, which are important to detect early. In most cases, mental and physical development are otherwise normal.
How Is Hemifacial Microsomia Diagnosed?
A thorough examination of your child’s face and head is the first step toward diagnosis. Findings related to their ears, face, jaw and teeth will help the doctor determine whether they have HFM or another condition.
For more information, X-rays and computed tomography (CT) imaging can also be helpful.
How Is Hemifacial Microsomia Treated?
Treating each of the problems your child may have is likely to involve a number of specialists. However, because each child with HFM may have differing defects, not every child will have problems in all of the following areas.
If your child has skin tags in front of his ears (small bits of skin that are connected to the surface of the skin with a tiny stalk), you may decide whether or not to have them removed.
If your child has noticeably disfigured ears and you decide to have surgery to improve their size and shape, it is best to wait until they are 6- to 8-years-old when the ears are reaching adult size. Keep in mind that surgeries to improve ear shape usually involve at least three procedures over time, and though the repaired ear will look better afterward, it will not look completely normal.
If your newborn is found to have hearing problems, more detailed testing is recommended in the first few years of life. As they grow older, more tests will be done so that your ear, nose and throat doctor and audiologist can discuss the best management of their hearing problem. This includes issues such as the best place for your child to sit in the school classroom, whether they need hearing aids and how to prevent further hearing loss.
If your infant has a cleft lip, a surgical repair is most often performed at 3- to 6-months-old. If your child has cleft palate, our surgeons will talk with you about repairing the palate, usually between 9-months and 1-year-old.
Some children with HFM have weakness in the muscles of their face caused by poorly functioning facial nerves. Many children with facial palsy improve in the first few years of life, but if the facial problem is severe, surgical treatment may be offered.
Children born with a condition known as macrostomia (wide mouth) can have problems with eating and speaking. Usually, surgery is needed to make a complete ring of muscle around the mouth.
Jaw/Teeth/Soft Palate Muscles
If your child has a small or abnormally shaped jawbone, your doctor may recommend a bone graft (an extra piece of bone) to lengthen the jaw or to make a new jaw joint. This option may be considered when your child is between 4- and 7-years-old. A newer procedure, called distraction osteogenesis, may be another good option. Learn more about distraction osteogenesis.
Children with HFM need to be evaluated by a dentist and/or orthodontist to check the condition of the teeth and, if needed, treated with a dental appliance or braces for the best possible appearance and function.
If your child is found to have faulty closing of the soft palate muscle in the mouth that allows air to escape through the nose instead of the mouth (called velopharyngeal insufficiency), this condition can lead to differences in the way your child speaks. If you or your doctors have concerns about your child's speech, your child will be referred to a speech pathologist.