Most if the body heals by scarring. Bone is unique because it can heal without scarring. Furthermore, bone can actually be stretched longer if completed in a slow manner. This technique was initially used to stretch the bones of the leg over one hundred years ago. In the last ten years, bone expansion or bone "distraction" has been applied to the facial skeleton, initially with the lower jaw and subsequently with the rest of the face. The advantage of stretching the bone slowly is that the skin over the bone can also stretch slowly. With traditional methods, the skin is always trying to push against the bone. Because distraction is slow, the forces that counter the advancement (skin, muscle) are much less and one can stretch the bone much further than previously done. This process lessens the chance of relapse (losing some of the advancement).

The technique requires the facial skeleton to be cut in a particular place. The device that stretches the bone is placed over the cut. Most of the devices are placed under the skin next to the bone (internal or buried devices). Occasionally, external devices are used if the jawbone is very small. After the initial operation, a callus is allowed to form for three to four days at the site of the bone cut. The distraction process begins after this waiting period and usually occurs at 1 or 2mm per day. The parents complete the distraction at home. Weekly visits are made to the office during this time. The movements are small but add up very quickly. Most advancement is around two centimeters. After the distraction is completed, the new bone is allowed to heal (4-6 weeks) and then the device is removed with an outpatient procedure.

This technique has been used very successfully in patients with small jaws, especially if there is a breathing problem because of the small jaw, or the patient has a Tacheostomy (Please see articles under bibliography). The lower jaw is expanded, making more room for the tongue. The technique is also very useful in patients with a small jaw on one side (hemifacial microsomia). Again, the jaw on one side is expanded so the chin is moved to the middle and the teeth have a better fit. The technique has been used in patients with severe Pierre Robin, Treacher Collins syndrome, Nagers, and bilateral small jaws.

Another very good application for this technique is to expand the middle portion of the face (nose, cheeks, and upper jaw). Patients with cleft lip and palate deformities often have small upper jaws and l lot of scarring which is difficult to advance. This technique is effective in countering the forces of the scar. Babies with breathing problems because of a small nasal passage can often undergo distraction of the midface to prevent a Tracheostomy. This technique is very effective in patients with other syndromes such as Apert's, Crouzon, and Binder's Syndrome.

Currently, distraction devices are made of biocompatible titanium similar to what is used in correcting facial fractures. Prototypes of distraction devices are available that use a resolvable polymer. The new technology will provide a way to further decrease the need for surgery when the devices are removed. Much work is also being done with growth actors to complement the bone healing. Soon, these products may be available to further shorten the distraction process. The technique is very effective and has replaced many of the traditional craniofacial surgeries as the standard of care today.

Over the last five years resorbable materials have been used in the manufacture of internal distraction devices. The safety and efficacy of resorbable materials has been widely reported and accepted in Craniofacial Surgery. The advantage of this class of distractors is that they are resorbable and do not require a second operation for removal, which is required with metallic distractors. The small metal drive screw is backed out in the Doctors office after complete healing of the distracted bone. Resorbable distractors can be used to distract the lower and upper jaw as well as the forehead.

For more information on resorbable distraction go to http://www.biometmicrofixation.com/product.php?item=29&cat=11