Hemifacial Microsomia

Hemifacial microsomia (HFM) is a condition in which the lower half of one side of the face is underdeveloped and does not grow normally. The eye, cheek and neck may also be affected. It is estimated to occur in between 1 in 5,600 and 1 in 26,550 newborns.

This is the second most common facial birth defect after cleft lip and palate. It is sometimes also referred to as first and second brachial arch syndrome, lateral facial dysplasia, or otomandibular dysostosis.

The syndrome varies in severity, but always includes the abnormal development of the ear and the mandible.

Goldenhar syndrome is one type of HFM and also affects the development of the eye, ear and spine. 

Patients can be seen by Texas Children's experts in Craniofacial and Craniosynostosis Clinic.

Causes & Risk Factors

While the cause is still unknown, it does not run in families and is not the result of a disease process. It is believed that it develops during pregnancy at approximately 4 to 8 weeks, when some form of vascular problem leads to poor supply of blood and then development of half of the face.

Some cases of HFM are severe; therefore, the degree of deformity is considerable. Other cases are mild with a wide spectrum of manifestation. No genes have been identified as probable cause for the condition, but it is clear that HFM is not caused by anything the parent did or did not do.

Symptoms & Types

HFM involves the entire face, and not everyone is affected the same. Children affected with HFM may have varied signs and symptoms, including:

• Facial asymmetry
• Absence, reduced size (hypoplasia), and/or displacement of the outer ear and, occasionally, bilateral anomalous ears
• Facial bones on the involved side are reduced in size and flattened
• Deafness due to middle ear abnormalities and/or absence or deficiency of the outer ear in about 30-50% of cases
• Presence of ear tags that may occur anywhere from the tragus (small flap of cartilage just in front of the ear canal) to the angle of the mouth
• Deformities inside the mouth, including abnormal shape or number of the teeth, or delay of tooth development
• Narrowed or absence of half of the mandible (jaw) on the affected side (in about 50-70% of cases)
• Associated oral cleft, (in about 7% of cases)
• Abnormalities of the eyes (very small or absent)
• Bone alterations, including problems of the vertebrae and ribs
• Damage or absence of certain cheek muscles or nerves that supply those muscles that can result in an asymmetrical smile
• Cheek tissue (fat and muscle) is often underdeveloped which makes one side of the face fuller than the other 

Diagnosis & Tests

HFM is typically diagnosed after a complete medical history and physical examination, preferably done by a geneticist. There is not a blood test to diagnose HFM.

Because the spectrum of severity is so wide, the diagnosis should come from an experienced geneticist skilled in diagnosing craniofacial anomalies.

Computerized Tomography (CT) scans, and X-rays of the face may also be ordered for a more accurate diagnosis.

Treatment & Care

Specific treatment for HFM is extremely variable because there are so many differences in the types of HFM. Depending upon the treatment required, it is sometimes most appropriate to wait until later in life for a surgical remedy, because the childhood growth of the face may highlight or increase the symptoms. Early management early is usually required, when there is a severe disfiguration:

• The craniofacial surgeon performs the jaw surgery and ear reconstruction.
• The ophthalmologist evaluates vision and eye movements
• The orthodontist follows the jaw growth and alignment of teeth to assist the surgeon in an optimal result of jaw surgery
• The otolaryngologist (ear, nose, and throat) assesses hearing abnormalities and coordinates middle ear surgery or hearing aids, if needed
• The speech therapist evaluates speech development and coordinates speech therapy, if necessary
• The geneticist counsels you and your child about the recurrence risks of HFM
• The social worker assists in obtaining resources and referrals in your community 

Living & Managing

For most children, HFM is not inherited and it won't be passed on from a parent to a child. However, if a couple has had a child with HFM, there is about a 3% chance that they will have another child with HFM.

For children who have a family history of relatives with similar facial differences, a referral to a geneticist and/or a genetic counselor is recommended.

It is rare for children with HFM to have problems with their heart. An echocardiogram (ultrasound of the heart) to check for abnormalities may be needed. Some have a 10 to 15% chance of having kidney problems. Renal ultrasound is recommended.

Some have differences in the muscles in the back of the mouth and this can lead to differences in the way your child speaks. If there are concerns about your child's speech, your child will be referred to a speech pathologist.

All newborns should have a hearing screening, usually performed in the birth hospital or within a few days of birth. If problems are found, further testing will be done.

An audiologist (hearing specialist) will perform different types of hearing tests as your child grows, based on hearing status and ear health. 

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