Source: www.eurekalert.org
Author: Cedars-Sinai Medical Center

Patients who lose a part of their jaw — whether from injury, infection, disease, or as a side effect of cancer treatment—can have the missing jawbone replaced through reconstruction. But most are left with a life-altering dilemma: Their new jaw is missing its teeth. That isn’t the case, however, for those treated by Cedars-Sinai’s “jaw-in-a-day” team.

The team—a partnership between Cedars-Sinai and the Los Angeles Center for Oral & Maxillofacial Surgery—is one of just a handful across the country performing a relatively new procedure where patients receive a jaw replacement complete with dental implants in one surgery.

“People who have a traditional jaw reconstruction get a new jawbone, but it isn’t very functional,” said oral/maxillofacial surgeon Steven Kupferman, DMD, MD. “The jaw is meant to talk and chew, and without teeth, it can’t do those things as well.”

A Tricky Reconstruction
In the traditional jaw-replacement procedure—called fibula free flap surgery—the surgeon replaces the damaged jawbone with a section of bone cut from the fibula, the outer bone in the lower leg, which can be removed without compromising the patient’s ability to walk.

It is possible for patients to have dental implants added to the jaw in a separate procedure, but head and neck surgeon Jon Mallen-St. Clair, MD, PhD, who has performed many fibula free flap procedures, said that rarely happens.

“The patient may be worn out from going through that major reconstruction operation,” Mallen-St. Clair said. “And the oral surgeon could be worried about damaging the transplanted fibula while placing the implants.”

Head and neck cancer patients often face additional challenges. If a cancer patient is treated with radiation after reconstruction, the new jawbone often is too weak to heal around dental implants. As a result, some cancer patients can have their disease treated and their jawbone reconstructed but will never have teeth again.

A Team Approach
For many patients, jaw-in-a-day offers an alternative.

The Cedars-Sinai team first meets with biomedical engineers to preplan each patient’s procedure. The engineers use CT scans of the patient’s jaw and fibula and an intraoral scan of the patient’s teeth. The scans are used to create 3D-printed custom guides to help surgeons cut the bones and place the dental implants. A titanium plate is custom fabricated for each patient to help hold the transplanted bone in place.

During the surgical procedure, which can last 10-15 hours, the surgeons use the custom guides to place dental implants in the fibula bone while it is still attached to the leg. They then remove the damaged jawbone, cut and move the section of fibula into place, and connect the blood vessels and nerves to the transplanted bone.

“Thanks to this custom planning, everything fits like a glove,” said oral/maxillofacial surgeon Jay Lee, MD, DDS, who also works on the jaw-in-a-day team. “Everything is precise to the millimeter. The other thing that makes this procedure possible is our collaboration among doctors of different specialties working closely together for the good of our patients.”

Preplanning also reduces the time the bone being transplanted is left without blood supply, called ischemia time.

“The longer the ischemia time, the greater chance the reconstruction will fail,” said Lee. “Without preplanning, it could take two to three hours to reshape the fibula bone to fit the jaw and shape a plate to hold it in place. During jaw-in-a-day, thanks to our cutting guides and prefitted plates, ischemia time is about 30 minutes.”

Recovery and Results
Following the procedure, the patient spends a few days in the intensive care unit, and a few more in the hospital.

“The bone graft takes about three months to fully fuse into place,” Mallen-St. Clair said. “Once that is complete, the patient can receive the final prosthetic teeth, which should function like any other tooth in the mouth.”

The Cedars-Sinai team has been doing about one jaw-in-a-day procedure a month, Lee said.

Virtually anyone needing a jaw reconstruction is a candidate for the procedure, and while some surgeons focus mainly on replacing the jawbone, Mallen-St. Clair said dental implants are too important to overlook.

“It’s like night and day, the quality of life afterward,” Mallen-St. Clair said. “It’s unbelievable how much difference the teeth make.”