Kids Health Info

Jaw distraction mandibular distraction osteogenesis

  • Mandibular distraction osteogenesis: pron.  man-dib-u-lar   dis-track-shon   osti-oh-jen-esis

    Jaw distraction is the name for a surgical method of lengthening a small or recessed (hollow or indented) jaw.  A small or recessed jaw can cause severe or ongoing difficulty with breathing. The procedure involves surgical insertion of distraction (lengthening) devices into the jaw.  These devices allow the jaw bone to be lengthened. In most cases, as the jaw is lengthened, the airway opens up and allows the child to breathe clearly.

    This procedure is only used in cases of severe, life-threatening breathing problems.  It has been very successful in easing airway obstruction and has prevented the need for tracheostomy (pron.track-e-os-tomi) in most cases.

    Signs and symptoms

    Some children are born with a very small or recessed lower jaw. In most cases this does not cause any problems at all, but in a small number of infants it can cause serious problems in the first few months of life. This is mostly due to the tongue moving back into the throat when the child breathes in.  The tongue then partly or completely blocks the airway. This is known as upper airway obstruction and can cause serious disruption to breathing and feeding. 


    If it it seems that your child may have upper airway obstruction, they will need to stay in hospital for a period of time in hospital so that further tests can occur and their breathing can be monitored and assessed. During this time, non-surgical methods of improving the airway obstruction will be tried.  These methods can include positioning or insertion of a nasopharyngeal (pron. nay-so-far-ran-jeel) tube.

    In a very small number of cases, these non-surgical methods are not successful and a child's breathing problems become life threatening.  Sometimes, the non-surgical methods may be required for extended periods of time, and this can be very difficult to sustain. If either of these things happen, jaw distraction might be the best treatment.


    If your child has severe or persistent upper airway obstruction, one or more of the following tests will be done to decide if the jaw distraction procedure is appropriate:

    • Overnight oximetry: will see if your child's oxygen levels drop, by how much, and how often.
    • A sleep study: measures how effectively your child is breathing. A sleep study is one of the most reliable methods of measuring how serious your child's airway obstruction is.
    • Endoscopy: a small tube that has a camera and a light at the end can look into your child's airway to see how serious the narrowing or blockage is.
    • A CT (computed tomography) scan: will help the surgeons see the size and shape of your child's jaw before the surgery. This allows the surgeons to decide if jaw distraction will be possible and, if so, helps them to plan the surgery.


    The decision to perform a jaw distraction procedure is made by a team of medical and surgical staff with a variety of specialist expertise. Each member has skills and experience in various aspects of airway obstruction. After considering the results of the tests, the team will decide if jaw distraction is appropriate for your child.  Jaw distraction will not be considered for an infant to correct facial dimensions alone, but is only used to improve airway obstruction.


    The surgery takes approximately two to three hours.  Your child will need to stay in hospital until their airway has opened up and they are breathing clearly and without assistance. 

    An incision is made through the skin under the jaw line, and then the jaw bone is carefully sectioned to enable a distraction device to be attached to either side of this separation in the bone. This happens on each side of the jaw.

    The distraction device is not visible after the operation except for two small rods that will protrude out from the chin or from behind the jaw line. These are called the distractor arms, and this method of distraction is called internal mandibular distraction (Figure 2).

    Jaw distractor pre expansion

    Figure 2.

    The day after surgery, each distractor arm will be turned a full 360°. This separates the pieces of bone by 0.5mm. This procedure is repeated every eight hours for approximately 10 days. During the eight hours between turns, your child's jawbone will grow to fill the space.

    This gradually makes the jaw bone longer, which will move the tongue away from the back of the throat.  This in turn makes the airway larger, and breathing will become easier (Figure 3).

    Jaw distractor post expansion

    Figure 3.

    The distraction device will stay in place for a period of time to support the new bone as it gains more strength.  This will occur over the six to eight weeks (approximately) following surgery. During this time your child can be at home and will be breathing and feeding normally.

    The distraction device is removed once the bone is strong enough.  This involves another surgery, and your child will need to stay in hospital for another one or two nights.


    The risks involved in a jaw distraction procedure are very small.  The risks of either a tracheostomy or leaving an airway obstruction untreated are much higher.

    There are potential risks in all surgery.  However, in our experience these have been rare or extremely minor.  The risks specific to jaw distraction include infection, sensory disturbance in the face, damage to molars or faint scarring.

    At home care

    Once jaw distraction is complete there should not be much disruption to daily life. You can still feed your child normally.  A little extra care taken to keep the area around the distractor arms clean will help prevent an infection. The distractors are made of flexible titanium and there should not be a problem if they are knocked or grasped by your child.


    Follow up appointments will be made with the various doctors and surgeons involved in the jaw distraction process during your child's stay in hospital.

    If you have any problems with the distraction device, or if you notice any signs of infection such as redness, pain or swelling, you should contact the hospital's Plastic & Maxillofacial Surgery department (T) 03 9345 5522.

    Key points to remember

    • Wherever possible, non surgical methods to ease airway obstruction are always applied to avoid surgery on a small infant.
    • Jaw distraction is proven to be a much safer alternative to tracheostomy in an infant with severe upper airway obstruction. However, it will not be undertaken to correct facial shape alone.
    • A multidisciplinary team will decide if jaw distraction is an appropriate treatment option in each case.

    For more information

    Developed by The Royal Children's Hospital Neonatal Unit, in consultation with Plastics and Maxillofacial Surgery, Respiratory Medicine and Neonatology. Illustrations: The Royal Children's Hospital Educational Resource Centre. First published: January 2012

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This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital, Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.