U.S. Food and Drug Administration
FDA Consumer magazine
July-August 2001
Table of Contents

Growing Bones: Bone Expansion Treats Facial Deformities

by Michelle Meadows

As strange as it may seem, our bones can be stretched and lengthened. Surgeons used to apply the concept only to big bones such as in the legs. But now growing bone in the jaws has become one of the newest ways to correct facial deformities, especially in children.

The Food and Drug Administration approves devices used for bone distraction osteogenesis--a technique that involves cutting existing bone and inserting a bone distractor. The titanium device holds the two pieces of bone less than a millimeter apart and is inserted into the jaw with pins or screw attachments. The patient, or a parent in the case of children, turns the screws twice a day to activate the stretching process. This results in osteogenesis, the development of new bone and soft tissue. New bone grows at the rate of one millimeter per day.

Bone distraction has been a successful treatment for people with underdeveloped jaws, including children with cleft lip and palate deformities, those born with unilateral defects, in which one side of the face grows faster than the other, and other facial growth syndromes.

"It allows us to stretch the side that needs to catch up and not the other," says Richard Burton, D.D.S., an oral and maxillofacial surgeon and a consultant to the FDA's Dental Products Panel. He has used bone distractors to treat children as young as 6 months and up through adolescence. The technique also has been used to reconstruct the jaws of adults after cancer surgery or accidents.

"If the jaw is too small, it closes off the airway," Burton says. Bone distraction has helped patients like 5-year-old Lauren Moser, of Columbia, Md., breathe better and eat on their own. Lauren was born with a very small jaw and chin, and used to hate eating, says her mother Lisa, 38. "We couldn't really fit a spoon in her mouth, and she would push it away." Because of the success of bone distraction, Lauren no longer needs to be fed with a tube, and eats soft food three times a day.

Lauren underwent bone distraction at age 18 months and again a few months later. "We made her jaw bone four times thicker and longer, which is something we couldn't have done with surgery," says Craig Dufresne, M.D., a plastic and reconstructive surgeon in Chevy Chase, Md., who treated Lauren. Surgery can't stretch the bone and facial tissue as far, and because bone distraction is a slow process, there is less chance of relapse or loss of advancement. If the bone is stretched too quickly, it tries to bounce back like a rubber band. "We were able to both stretch her bone and thicken the muscle, moving her jaw 40 millimeters in 40 days," Dufresne says.

In addition to having a small jaw and chin, Lauren's tongue was about the quarter of the size it should have been, Dufresne says. Bone distraction didn't directly affect the size of Lauren's tongue, he says, but expanding her small jaw made more room for her tongue.

Bone distraction requires two surgeries, one to implant the device and another to remove the device after the desired bone growth is achieved. It takes about six weeks for the new bone to heal and consolidate, and the device usually leaves only small scars. Dufresne says it's considered a safer and less invasive procedure than bone grafting, which takes bone from another part of the body like the hip, and places it in the jaw. The risks with bone distraction are relatively minor, and include potential damage to teeth and sensory nerves.

"The surgery is quite simple," Burton says. "The bigger issue is learning how to handle the devices." Just in the last few years, though, the devices have become easier for surgeons and patients to use, he says. "They used to be pretty clunky and hard to handle, but they've gotten smaller, lighter, and more user friendly."

For patients with very small faces, surgeons sometimes must use external bone distractors that protrude from the jaw. "Lauren's face was so little, I found the sight of the device a little overwhelming at first," Lisa says, "the way it stuck out like a walrus." But many times, the device is implanted internally so that it isn't noticeable.

Lisa says she turned Lauren's device once in the morning and once at night and found it easy. "It doesn't hurt, but sometimes made Lauren uncomfortable," she says. "Sometimes we had to hold her down to turn it," Lisa says. "But then she was up running around and doing everything like always. It didn't stop her."

Most distractors are manipulated manually, but motorized distractors that turn automatically or by hydraulics may be on the horizon, Burton says. He estimates that about 2,000 people in the United States undergo bone distraction each year, and says the numbers will increase as the technology becomes more well known.

"The exciting thing about it," Dufresne says, "is that we're able to correct deformities that previously couldn't be corrected," which means giving hope to families who thought there were no options. Lisa calls the change in her daughter remarkable. "Lauren still can't pronounce some words and has a slight slur," she says. "But she loves to sing and talks non-stop. Pretty amazing considering we weren't sure she'd be able to talk at all." Lauren will undergo another bone distraction procedure this summer to further widen her jaw.

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