Distraction osteogenesis is the lengthening of bone by first making a cut in the bone and then slowly stretching the bone by expanding that cut over several weeks. This involves putting two specialize plates on the bone that have a mechanism that pushes the plates apart at the site of the cut bone. This commonly is performed in neonates or babies that have small jaws or micrognathia causing breathing issues shortly after birth. When this occurs the tongue sits very far back in the throat because there is not enough room for the tongue to sit forward. This is known as obstructive sleep apnea.
What is the advantage of performing distraction osteogenesis?
If a bone is anatomically short then lengthening the bone allows it to become longer. If used for lengthening the mandible, then this creates more room for the tongue to sit forward in the mouth relieving airway obstruction that can commonly occur while sleeping. This procedure can reduce the need for a tracheostomy in neonates.
What tests need to be performed prior to surgery?
The first tests obtained are x-rays of the jaw to confirm micrognathia. Then a sleep study will be obtained to determine if sleep apnea is occurring. This test is used to determine if the apnea is related to an obstruction such as the tongue or trachea versus a central sleep apnea caused by an abnormal connection from the brain. If the obstruction is related to the small jaw and tongue, then distraction osteogenesis will result in improved obstructive sleep apnea problems. This frequently leads to avoidance of a tracheostomy.
What is involved in the treatment with distraction osteogenesis?
After the initial tests are performed, surgery will be scheduled with an Ear-Nose-Throat (ENT) surgeon who specializes in airway management of neonates. At this surgery, the airway will be assessed with direct viewing of the mouth and trachea to determine if the obstruction is due to the tongue or the trachea. If the trachea is the true cause then a tracheostomy may be indicated and performed by the ENT surgeon.
If the obstruction is due to micrognathia and a tongue obstruction, then the distraction device is placed on both sides of the jaw. Our extensively trained craniofacial plastic surgeon will make an incision under the jawline with the device arm brought out behind the ear. The two distraction devices are placed after making cuts in the mandible bone. The distraction device arm is used to push the plates apart lengthening the bone. The metal device arm is turned once a day until the desired length of the mandible is achieved.