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Hemifacial microsomia

Other Names for this Disease

  • Craniofacial microsomia
  • First and second branchial arch syndrome
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What is hemifacial microsomia?

What are the signs and symptoms of hemifacial microsomia?

What is the cause of hemifacial microsomia?

What is hemifacial microsomia?

Hemifacial microsomia 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.[1][2] This is the second most common facial birth defect after clefts.[1] It is sometimes also referred to as first and second brachial arch syndrome, oral-mandibular-auricular syndrome, lateral facial dysplasia, or otomandibular dysostosis. The syndrome varies in severity, but always includes the maldevelopment of the ear and the mandible. Goldenhar syndrome is one type of hemifacial microsomia and mainly affects the development of the eye, ear and spine.[3]
Last updated: 8/8/2013

What are the signs and symptoms of hemifacial microsomia?

Individuals with hemifacial microsomia may have varied signs and symptoms, including:[1][2][3][4][5][6][7][8][9]

  • Facial asymmetry;
  • Absence, reduced size (hypoplasia), and/or displacement of the outer ear (pinna) with a variable degree of involvement on one side; occasionally, bilateral anomalous ears are noted;
  • Maxillary, temporal, and malar bones on the involved side are somewhat reduced in size and flattened;
  • Deafness due to middle ear abnormalities and/or absence or deficiency of the external auditory meatus has been noted in 30% to 50% of cases;
  • Presence of  ear tags may occur anywhere from the tragus (small flap of cartilage just in front of the ear canal near the face) to the angle of the mouth;
  • Intraoral deformities include abnormalities (in shape or number) of the teeth or significant delay of tooth development of the affected size;
  • The incidence of delayed tooth development with hemifacial microsomia is proportional to the extent of mandible deformity;
  • About 50% to 70% of patients have narrowed or absence of half of the mandible on the affected side;
  • Associated cleft lip and/or palate is found in 7% of  patients;
  • Reduced size of facial muscles and those of facial expression on the involved side have also been observed;
  • Narrowing of the palpebral fissure occurs on the affected side in about 10% of patients;
  • Abnormalities of the eyes (extremely small or absent) has been reported;
  • Skeletal alterations are other common anomalies including problems of the vertebrae and ribs.
  • The absence of certain cheek muscles or nerves which supply those muscles 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.
Last updated: 9/12/2012

What is the cause of hemifacial microsomia?

For most people with hemifacial microsomia, the cause of this condition is unknown. It is believed that something occurred 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.[10]

Some possible explanations when the cause of hemifacial microsomia is unknown include that there is a very small chromosome deletion or duplication that was not detected, a mutation in a yet to be identified gene, or changes in multiple genes associated with development of the face. It is also possible that a combination of having a genetic change and an environmental risk factor could cause hemifacial microsomia.[10]
Last updated: 5/1/2014

  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. Lacombe D. Orphanet. Goldenhar syndrome. 2005; Accessed 8/8/2013.
  4. Murray Je, Kaban LB & Mulliken JB. Analysis and treatment of hemifacial microsomia. Plast Reconst Surg. 1984; Accessed 8/8/2013.
  5. Hemifacial microsomia. University of California in San Francisco. 2012; Accessed 9/12/2012.
  6. 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.
  7. Fan WS. An association between hemifacial microsomia and facial clefting. J Oral Maxillofac Surg. 2005; Accessed 9/12/2012.
  8. Hemifacial microsomia syndrome. International Craniofacial Institute. 2011; Accessed 9/12/2012.
  9. Hemifacial Microsomia. Online Mendelian Inheritance in Man (OMIM). 2012; Accessed 9/12/2012.
  10. Heike C, Hing A.. Craniofacial Microsomia. GeneReviews. March 19, 2009; Accessed 11/3/2010.

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.