What Causes Hemifacial Microsomia & How is it Treated?

Hemifacial Microsomia is a congenital pathological condition which is seen immediately at birth or within a few days of life in which a child is born with underdeveloped lower part of the face to include the ears, mouth, and jaw. The extent of the condition is variable in that in some cases only one side of the face may be affected whereas in some cases both the sides of the face may get affected. Due to this underdevelopment of the lower part of the face, the child with hemifacial microsomia may have problems with breathing apart from other cosmetic complications.

The exact cause for Hemifacial Microsomia is still a matter of ongoing research but it is believed to be caused due to lack of blood supply to the lower part of the face during the developing phase of the fetus. Some studies suggest a genetic link to this disorder primarily because of some family member being also affected by Hemifacial Microsomia along with the patient. A child with Hemifacial Microsomia will have to undergo a battery of surgeries and a multidisciplinary approach towards treatment.

As stated, there is no clear cut etiology for development of Hemifacial Microsomia but studies suggest some sort of vascular problem during pregnancy may result in development of Hemifacial Microsomia and hence because of reduced blood flow to the facial areas during pregnancy the face starts to develop irregularly resulting in Hemifacial Microsomia. In some cases a genetic link is suggested to be the cause of Hemifacial Microsomia and the pattern of inheritance are autosomal dominant and autosomal recessive traits. An autosomal dominant trait occurs when a copy of the defective gene is passed to the child from one parent and that is enough to cause the condition whereas autosomal recessive trait is one in which the child needs two copies from both the parents of the defective genere order to get the condition, although many studies suggest that if there is one child in the family with Hemifacial Microsomia then the chances of another child getting this condition is only about 3%. Certain chromosome abnormalities have also been related to the development of Hemifacial Microsomia.

Answering the question as to whether Hemifacial Microsomia is a common disorder then it must be said that after Down Syndrome this is the second most common congenital abnormality.

The classic presenting feature of Hemifacial Microsomia is abnormal appearing face of the child when he or she is born. There are some deformities of the face which are clearly visible but some deformities may not be that clearly visible. Some of the common deformities that can be seen in child with Hemifacial Microsomia are:

• One side of the face being smaller than the other
• Missing ear or one ear being smaller than the other
• Skin tags over the ear
• An underdeveloped ear canal making it tough for the child to hear anything
• A wide mouth
• Small bones of the cheek or jaw
• Abnormal growths around the eye.

There are also certain other complications that arise due to Hemifacial Microsomia and they are spinal malformations, abnormal kidneys, and heart defects. Some children with Hemifacial Microsomia may find it difficult to open their mouths and may have poor dental condition with poor alignment of teeth.

Hemifacial Microsomia can be diagnosed at birth easily by just looking at the facial deformities but to confirm the diagnosis the physician will take a close look at the ears, jaw, eyes, teeth, and face. Radiological studies may also be ordered to get a better knowledge as to how much deformed are the structures in the form of x-rays, CT or MRI scans. To check whether other parts of the body are also affected by Hemifacial Microsomia, the physician may order renal ultrasound to check the functioning of the kidneys and EKG to check the functioning of the heart as they both may get affected in children with Hemifacial Microsomia, although it is rare.

Treatment for Hemifacial Microsomia depends on the severity of the condition and the overall health of the child. The child will have to undergo a battery of tests and surgeries for reconstructive purposes but this might be kept on hold until the child is a bit older so that he or she can tolerate such complex surgeries. Surgeries are basically done to reconstruct the underdeveloped parts of the face for cosmetic reasons. The following are the treatments done for Hemifacial Microsomia:

Ears: To correct the ears in patient suffering from Hemifacial Microsomia, surgery will be done when the child is around 8 years of age when the ears are of adult size. The surgery may be preceded by a hearing test to check whether there is any defect in the internal structures of the ear.

Face: To correct the face in patient suffering from Hemifacial Microsomia, grafts of tissue or muscle may be used to fill out the cheekbones, either using the child’s own tissue or using synthetic tissue.

Feeding and Breathing: A small jaw resulting from Hemifacial Microsomia can cause difficulty eating and breathing and thus surgery may have to be performed to address this issue.

Hemifacial Microsomia may make it difficult for the child to eat and breathe normally and hence should be monitored very closely. Some children may have permanent difficulties with speaking, hearing, or facial movements. Despite all these hindrances, majority of children with Hemifacial Microsomia go on to live healthy lives if they are treated early and carefully monitored for any complications arising from Hemifacial Microsomia.