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Hemifacial microsomia

Other Names for this Disease

  • Craniofacial microsomia
  • First and second branchial arch syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.


What is hemifacial microsomia?

What are the signs and symptoms of hemifacial microsomia?

What causes hemifacial microsomia?

How might hemifacial microsomia be treated?

What is hemifacial microsomia?

Hemifacial microsomia (HFM) is a condition in which part of one side of the face is underdeveloped and does not grow normally. The eye, cheekbone, lower jaw, facial nerves, muscles, and neck may be affected.[1][2][3] Other findings may include hearing loss from underdevelopment of the middle ear; a small tongue; and macrostomia (large mouth).[3] HFM is the second most common facial birth defect after clefts.[1] The cause of HFM in most cases is unknown. It usually occurs in people with no family history of HFM, but it is inherited in some cases. Treatment depends on age and the specific features and symptoms in each person.[4]
Last updated: 10/9/2014

What are the signs and symptoms of hemifacial microsomia?

People with hemifacial microsomia may have various signs and symptoms, including:[1][2][5][6][7][8][9][10]
  • Facial asymmetry
  • Abnormalities of the outer ear such as absence, reduced size (hypoplasia), and/or displacement
  • Small and/or flattened maxillary, temporal, and malar bones
  • Deafness due to middle ear abnormalities
  • Ear tags
  • Abnormalities (in shape or number) of the teeth, or significant delay of tooth development
  • Narrowed mandible (jaw) or absence of half of the mandible
  • Cleft lip and/or palate
  • Reduced size of facial muscles
  • Abnormalities of the eyes (extremely small or absent)
  • Skeletal abnormalities including problems of the spine or ribs
  • Absence of cheeck muscles or nerves supplying those muscles (resulting in an uneven smile)
Last updated: 9/12/2012

What causes hemifacial microsomia?

For most people with hemifacial microsomia, the cause is unknown. It is believed that something occurs in the early stages of development, such as a disturbance of the blood supply to the first and second branchial arches in the first 6 to 8 weeks of pregnancy.[1]

Studies have suggested multiple possible risk factors for hemifacial microsomia. Environmental risk factors include the use of medications during pregnancy such as Accutane, pseudoephedrine, aspirin, or ibuprofen. Other environmental factors include second trimester bleeding, maternal diabetes, being pregnant with multiples, or the use of assisted reproductive technology. A genetic cause is found in some families, such as a chromosome disorder or a genetic syndrome.[11]

Some possible explanations when the cause of hemifacial microsomia is unknown include a very small chromosome deletion or duplication that is not detected, a mutation in an unknown gene, or changes in multiple genes associated with development of the face. It is also possible that a combination of genetic changes and environmental risk factors could cause hemifacial microsomia.[11]
Last updated: 5/1/2014

How might hemifacial microsomia be treated?

Treatment of hemifacial microsomia varies depending on the features present and the severity in each affected person. Various types of surgeries may be needed in many cases.

Some children need breathing support or a tracheostomy soon after birth if the jaw is severely affected. However in most cases, airway problems can be managed without surgery. Those with a jaw deformity and/or clefts may have feeding problems and may need supplemental feedings through a nasogastric tube to support growth and weight gain. Babies born with cleft lip or palate can have surgical repairs done during the first year. Cleft lip repair is typically performed when the child is 3-6 months old, while cleft palate surgery is generally performed when the child is about a year old. A lateral facial cleft, one of the most severe abnormalities associated with the condition, also requires reconstruction in stages.

If eye closure is incomplete due to eyelid abnormalities or facial paralysis is present, a child may need eye protection or surgery. Surgery may also be used for eyelid differences to reposition the lower lids and corners of the eyes. Some children with abnormally shaped or missing ears may choose to have a series of reconstructive surgeries to make the ear appear more normal. Children with skin, cheek and other soft tissue deficiencies may need augmentation procedures such as fat grafting or tissue transfer. Severe bone abnormalities may require surgery as well.[12]

Because multiple body systems may be involved in hemifacial microsomia, affected people should continually be monitored for complications.
Last updated: 10/9/2014

  1. Hemifacial Microsomia. The National Craniofacial Association. 2011; Accessed 8/8/2013.
  2. Craniofacial Microsomia. Seattle Children's Hospital Research Foundation. 2013; Accessed 8/8/2013.
  3. Hemifacial microsomia (HFM). Foundation for Faces of Children. 2014; Accessed 10/9/2014.
  4. Carrie L Heike, Daniela V Luquetti, and Anne V Hing. Craniofacial Microsomia. GeneReviews. October 9, 2014; Accessed 10/9/2014.
  5. Murray Je, Kaban LB & Mulliken JB. Analysis and treatment of hemifacial microsomia. Plast Reconst Surg. 1984; Accessed 8/8/2013.
  6. Hemifacial microsomia. University of California in San Francisco. 2012; Accessed 9/12/2012.
  7. Kapur R, Kapur R, Sheikh S, Jindal S & Kulkarni S. Hemifacial microsomia: A case report. J Indian Soc Pedod Prev Dent . 2008;;year=2008;volume=26;issue=5;spage=34;epage=40;aulast=Kapur. Accessed 9/12/2012.
  8. Fan WS. An association between hemifacial microsomia and facial clefting. J Oral Maxillofac Surg. 2005; Accessed 9/12/2012.
  9. Hemifacial microsomia syndrome. International Craniofacial Institute. 2011; Accessed 9/12/2012.
  10. Hemifacial Microsomia. Online Mendelian Inheritance in Man (OMIM). 2012; Accessed 9/12/2012.
  11. Heike C, Hing A.. Craniofacial Microsomia. GeneReviews. March 19, 2009; Accessed 11/3/2010.
  12. Scott Bartlett and Jesse Taylor. Hemifacial Microsomia. Children's Hospital of Philadelphia. February, 2014; Accessed 10/13/2014.

Other Names for this Disease
  • Craniofacial microsomia
  • First and second branchial arch syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.