Craniofacial microsomia is a condition that affects the growth of the face and skull before birth. Infants may be born with a malformed and underdeveloped jawbone that can cause facial asymmetry and problems with the teeth.
In addition, they may have skin tags in front of the ear, an underdeveloped or missing ear and absent or closed ear canal. Eye involvement is less common but may take the form of an unusually small eyeball or other abnormality that affects vision.
The condition is also called lateral facial dysplasia, first and second branchial arch syndrome, oculoauriculovertebral dysplasia or Goldenhar's syndrome.
In the United States 1 in 3,500 babies are born with the condition.
Cause of craniofacial microsomia
Among most affected individuals, the cause of craniofacial microsomia is unknown. While there is no solid evidence of any specific genes causing the condition, some individuals have been found to have chromosomal abnormalities that are thought to be responsible for the abnormal development.
Some evidence suggests that the condition can run in families and point at inheritance of a causative gene. Certain medications are also thought to cause the condition if they are taken by a mother during pregnancy.
The most commonly accepted theory is that of vascular insult, with hematoma and hemorrhage occurring in the first and second branchial arches. This is thought to be caused by defects in the stapedial artery, a temporary vessel that connects to the pharyngeal artery but is later replaced by the external carotid artery.
Any resulting hemorrhage is thought to damage the developing branchial arches.
The clinical features of craniofacial microsomia include:
- Small, deformed jaw that may delay eruption of milk teeth due to overcrowding of teeth
- Abnormalities of the neck vertebrae, which may be fused
- Underdevelopment of the muscles used for chewing
- Underdeveloped ears causing hearing loss
- Skin tags in front of the ear of the affected side
- A cleft may also be present
Assessment and treatment
Diagnosis and treatment of this condition are important as the illness may be part of a syndrome that is also affecting other parts of the body such as the kidneys and heart. Imaging studies and blood tests are used to assess the degree to which other body parts are involved.
Treatment depends on the extent of the abnormality but usually involves surgery to reconstruct underdeveloped structures or prosthetic correction of the deformities.