Virtual Reality Expands UT-H Oral Surgery Capabilities

Young children with jaw deformities will now have greater hope of having normal facial function and appearance, thanks to a new kind of computer simulation process applied to oral surgery.

John Teichgraeber, M.D., (left), and Jaime Gateno, D.D. S., M.D.,
are combining computer technology and clinical knowledge
to enhance oral surgery capabilities.

Jaime Gateno, D.D.S., M.D., from the UT-Houston oral and maxillofacial services, and John Teichgraeber, M.D., from the UT-Houston Medical School's plastic surgery department, have created the idea of using software to further define "distraction osteogenesis" - a surgical procedure that lengthens jaw bone. They are combining new clinical knowledge and computer technology to enhance an older procedure.

Originated nearly half a century ago for lengthening bones in humans, distraction osteogenesis is now applied to the facial skeleton to correct an underdeveloped chin and jaw. Distraction osteogenesis is superior to the traditional procedure that involves taking bone from another region of the body and placing it in the jaw.

Since the spring of 1997, a selective number of centers in the U.S. have been using a new device for the procedure called the multi-guide distractor. This new device is different from devices used before because it allows for three-dimensional adjustments.

The multi-guide distractor, a metal device, is surgically placed into the jaw with pins. Bone is slowly lengthened daily by turning screws that are attached to the pins.

"The new device gives us more rotational control over how the jaw bone grows, whereas before the distractor could only move two-dimensionally. With the multi-guide we are not having to make gross adjustments later," says Dr. Teichgraeber.

And now with Dr. Gateno's new software, the multi-guide distractor is able to be used more accurately.

"Essentially what I have done is to use a software program that allows me to look at the person in virtual reality and have a blueprint as to the end result, " says Dr. Gateno, who has engineered the technology on his personal computer using the animation software 3-D Studio made by Autodesk. "When doctors go into surgery they usually don't have a recipe to follow, but by simulating first on the computer, I know from the very beginning just how much to turn the screws every day and all the possible outcomes.

"Because this is a three-dimensional deformity, drawing patients was not enough," Dr. Gateno explains. "Therefore, I tried many things; I bought models like architects use to build houses. But still I could not manipulate the design. The computer simulation is perfect. Because it is very dynamic, I can make fine adjustments along the way."

The patient wears the pins for about nine weeks - three weeks of daily adjusting and a six-week cast period. After the nine weeks, the patient goes back to surgery for one hour to have the pins removed and any cosmetic surgery necessary.

"Our goal is to make as normal looking a jaw as possible," Dr. Teichgraeber says.

The operation is best performed on children under 17. "We want to stimulate growth and it is easier to stretch a child's skin," explains Dr. Teichgraeber. Another advantage is that the initial surgery to implant the pins takes only three hours, as compared to as many as eight hours for implanting bone. This procedure also cuts down on infection, causes less pain and is more tolerable for parents.

The parental role is crucial, because they are the ones who turn the screws daily, depending on the doctor's orders. The patient visits the doctor weekly to monitor the fine tuning.

In the one year since Dr. Gateno designed the new software, it has been used successfully on nine patients.

- KRISTEN RIEGEL

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©2006 Texas Medical Center

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