Hemifacial microsomia is a congenital condition where the tissues on one side of the face are underdeveloped. It is the second most common facial birth defect behind cleft lip and palate, and research has shown the process starts in the first trimester of pregnancy and may be caused by a vascular problem leading to poor blood supply to the fetus’s face during early development. The condition most often happens by chance.

Hemifacial microsomia is also known as craniofacial microsomia, first and second branchial arch anomaly, branchial arch syndrome, facioauriculovertebral syndrome, oculo-auriculo-vertebral (OAV) spectrum, and lateral facial dysplasia. When symptoms of hemifacial microsomia and spinal defects or narrow eyes occur together, the condition is referred to as Goldenhar syndrome, which is much rarer.


Hemifacial microsomia primarily affects the ear, mouth and jaw, though it may also involve the eye, cheek, neck and other parts of the skull, as well as nerves and soft tissue. Only 10 to 15 percent of cases result in symptoms present on both sides of the face.

The severity of symptoms associated with hemifacial microsomia can be barely noticeable to severe and are assessed by the OMENS classification system which determines the function and appearance of the orbit of the eye socket, the mandible, the ear, the nerves in the face, and the soft tissue. Symptoms in each area can appear as follows:

  • Orbit (eye socket): small and underdeveloped eyes with impaired vision; absent or unformed eye; growths on the eye; one eye appearing smaller than the other, but with normal vision
  • Mandible (jaw): underdeveloped upper and lower jaw on one side; crooked jaw; missing, misaligned or overcrowded teeth; cleft lip and/or cleft palate; limited opening or closing of the mouth
  • Ear: small skin tags; misshapen or missing external ear; absent or abnormal development of the ear canal resulting in partial or total hearing loss
  • Nerves: ranging from mild weakness to partial or full facial paralysis
  • Soft tissues (skin, muscle, fat, tendons and ligaments): flattened forehead or cheekbone, unequal cheek fullness, asymmetrical mouth with lateral cleft

Typically, there are no other major medical issues. In some rare cases, other health problems, such as malformed vertebrae, heart defects or abnormally shaped kidneys, may be present.


Diagnosis of this condition can be made before birth through ultrasounds, or after birth through a physical exam, X-rays and CT scans. Deformities in the jaw are key indicators of this condition and can range from mild to severe.


Due to the range of symptoms that a child with hemifacial microsomia can have, treatment is highly individualized. Respiratory support or a tracheostomy may be recommended if jaw deformities hinder breathing. A feeding tube can be used to support growth and weight gain if feeding is an issue. Surgery is an option for facial deformities, including eyelid abnormalities, cleft lip and/or palate, facial clefts and bone deficiencies. Treatment for hemifacial microsomia is done by our team of specialists at the North Carolina Cleft and Craniofacial Center who provide comprehensive care through reconstruction, surgery, therapy and future checkups.