National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

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. HFM is part of a group of conditions known as "craniofacial microsomia". It is not known whether the conditions included in the group really are different conditions or part of the same problem with different degrees of severity. Treatment depends on age and the specific features and symptoms in each person.[4]
Last updated: 10/9/2014
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

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 42 |
Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Agenesis of corpus callosum 0001274
Anophthalmia
Absence of eyeballs
Failure of development of eyeball
Missing eyeball
No eyeball
[ more ] 		0000528
Anotia 0009892
Arnold-Chiari malformation 0002308
Atresia of the external auditory canal
Absent ear canal
0000413
Autosomal dominant inheritance 0000006
Blepharophimosis
Narrow opening between the eyelids
0000581
Block vertebrae 0003305
Branchial anomaly 0009794
Cleft palate
Cleft roof of mouth
0000175
Cleft upper lip
Harelip
0000204
Coarctation of aorta
Narrowing of aorta
Narrowing of the aorta
[ more ] 		0001680
Conductive hearing impairment
Conductive deafness
Conductive hearing loss
[ more ] 		0000405
Ectopic kidney
Abnormal kidney location
Displaced kidney
[ more ] 		0000086
Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face
[ more ] 		0000324
Hemifacial hypoplasia
Decreased size of half of the face
Decreased size of one side of the face
[ more ] 		0011332
Hemivertebrae
Missing part of vertebrae
0002937
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Hypoplasia of facial musculature
Decreased size of facial muscles
Deficiency of facial musculature
Underdevelopment of facial muscles
[ more ] 		0004660
Hypoplasia of the maxilla
Decreased size of maxilla
Decreased size of upper jaw
Maxillary deficiency
Maxillary retrusion
Small maxilla
Small upper jaw
Small upper jaw bones
Upper jaw deficiency
Upper jaw retrusion
[ more ] 		0000327
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Limbal dermoid 0001140
Malar flattening
Zygomatic flattening
0000272
Micrognathia
Little lower jaw
Small jaw
Small lower jaw
[ more ] 		0000347
Microphthalmia
Abnormally small eyeball
0000568
Microtia
Small ears
Underdeveloped ears
[ more ] 		0008551
Multicystic kidney dysplasia 0000003
Occipital encephalocele
Brain tissue sticks out through back of skull
0002085
Patent ductus arteriosus 0001643
Preauricular skin tag 0000384
Pulmonary hypoplasia
Small lung
Underdeveloped lung
[ more ] 		0002089
Renal agenesis
Absent kidney
Missing kidney
[ more ] 		0000104
Sensorineural hearing impairment 0000407
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ] 		0000486
Tetralogy of Fallot 0001636
Unilateral external ear deformity
Deformed external ear on one side
0008605
Upper eyelid coloboma
Cleft upper eyelid
Notched upper eyelid
[ more ] 		0000636
Ureteropelvic junction obstruction 0000074
Ventricular septal defect
Hole in heart wall separating two lower heart chambers
0001629
Vertebral hypoplasia
Underdeveloped vertebrae
0008417
Vesicoureteral reflux 0000076
Wide mouth
Broad mouth
Large mouth
[ more ] 		0000154
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Last updated: 7/1/2020
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
Hemifacial microsomia most often occurs in a single individual in a family and is not inherited.[12][13] If the condition is caused by a chromosomal abnormality, it may be inherited from one affected parent or it may result from a new abnormality in the chromosome and occur in people with no history of the disorder in their family.[12] In a very small number of cases, hemifacial microsomia is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder.[12][13] In rare cases, the condition is inherited in an autosomal recessive pattern, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The gene or genes involved in hemifacial microsomia are unknown.[12]

In some affected families, people seem to inherit an increased risk of developing hemifacial microsomia, not the condition itself. In these cases, some combination of genetic changes and environmental factors may be involved.[12]

Last updated: 8/8/2013
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.[14]

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

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Hemifacial microsomia. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Hemifacial microsomia. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • So I was wondering who do I consult about this? An orthodontist? And how do they treat this? See answer

  • I have hemifacial microsomia. What are the main causes of this condition? See answer


  1. Hemifacial Microsomia. The National Craniofacial Association. 2011; http://www.faces-cranio.org/Disord/Hemi.htm.
  2. Craniofacial Microsomia. Seattle Children's Hospital Research Foundation. 2013; http://www.seattlechildrens.org/medical-conditions/chromosomal-genetic-conditions/hemifacial-microsomia/.
  3. Hemifacial microsomia (HFM). Foundation for Faces of Children. 2014; http://www.facesofchildren.org/First%20and%20Second%20Pharyngeal%20Arch%20Syndromes.
  4. Heike CL, Luquetti DV, and Hing AV. Craniofacial Microsomia. GeneReviews. October 9, 2014; http://www.ncbi.nlm.nih.gov/books/NBK5199/.
  5. Murray Je, Kaban LB & Mulliken JB. Analysis and treatment of hemifacial microsomia. Plast Reconst Surg. 1984; http://www.ncbi.nlm.nih.gov/pubmed/6463144. Accessed 8/8/2013.
  6. Hemifacial microsomia. University of California in San Francisco. 2012; http://www.ucsfbenioffchildrens.org/conditions/hemifacial_microsomia/. 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; http://www.jisppd.com/article.asp?issn=0970-4388;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; http://www.ncbi.nlm.nih.gov/pubmed/15742282. Accessed 9/12/2012.
  9. Hemifacial microsomia syndrome. International Craniofacial Institute. 2011; http://www.craniofacial.net/syndromes-hemifacial-microsomia. Accessed 9/12/2012.
  10. Hemifacial Microsomia. Online Mendelian Inheritance in Man (OMIM). 2012; http://omim.org/entry/164210. Accessed 9/12/2012.
  11. Heike C, Hing A.. Craniofacial Microsomia. GeneReviews. March 19, 2009; http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=m-hfm-ov. Accessed 11/3/2010.
  12. Craniofacial microsomia. Genetics Home Reference (GHR). March 2012; http://ghr.nlm.nih.gov/condition/craniofacial-microsomia.
  13. Hemifacial Microsomia. Online Mendelian Inheritance in Man (OMIM). October 27, 2014; http://omim.org/entry/164210.
  14. Scott Bartlett and Jesse Taylor. Hemifacial Microsomia. Children's Hospital of Philadelphia. February, 2014; http://www.chop.edu/service/plastic-and-reconstructive-surgery/conditions-we-treat/craniofacial-conditions/hemifacial-microsomia.html. Accessed 10/13/2014.