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Rady Children's Specialists

Hemifacial microsomia

Hemifacial microsomia is an underdevelopment of the tissues on one side of the face that occurs in approximately 1 out of 5,000 births.

Also known as Goldenhar syndrome when eye involvement is present, the condition affects both sides of the face in approximately 15 percent of patients. This condition results in an asymmetry of the face with malformation of the ear and an underdeveloped jaw on the affected side. The functional challenges of this condition include an abnormal bite, hearing loss and related psychosocial issues.

Characteristics of hemifacial microsomia include:

  • Short mandible canted to affected side.
  • Malocclusion with chin shifted to affected side.
  • Microtia (small ear).


Treatment consists of mandibular distraction, a technique where the lower jaw is cut after pins are placed in the bone on either side. Once the cut (osteotomy) is made in the bone, the pins are gradually moved apart (distracted), and new bone formation occurs in the gap by a process called distraction osteogenesis (see below).

Distraction osteogenesis was first used in orthopedic surgery and later adapted by surgeons to treat children with craniofacial conditions. Distraction is a less invasive and safer technique for correcting certain types of craniofacial deformities.

We offer a full range of distraction technology and techniques, including internal and external devices.