Advanced technology such as virtual surgical planning (VSP) and 3D-printed implants are helping otolaryngologists treat patients with complex facial trauma with more accuracy for improved outcomes.
Explore this issue:April 2019
Oral and maxillofacial surgeons use computer-generated modeling to plan for complex reconstructive procedures and order custom implants from manufacturers for patients who have facial bone loss due to trauma, cancer, or congenital deformities, said Shaun C. Desai, MD, associate residency program director and assistant professor of otolaryngology–head and neck surgery at Johns Hopkins School of Medicine in Baltimore. “We use the 3D technology for more complex cases, such as patients with complex loss of the maxilla or mandible or the skull. For a more complex defect, you can create a shape using the technology, and use it as a guide to make the bone cuts,” said Dr. Desai. “You can be more precise as you take a straight, long bone like the fibula and cut it into the shape of a jawbone. Even now, we often eyeball this technique, and there is asymmetry as a result. It takes a lot of time and surgical expertise. This technology gives you a more precise cut. You basically create a plan for where you will make the cuts into bone before you begin the surgery.”
Scan-Guided Surgery and Custom Implants
First, computed tomography (CT) scans are taken of the damaged facial areas. The surgeon analyzes these images using software designed for virtual surgical planning, said Dr. Desai. The data may also be sent to an engineer at a manufacturer to 3D print customized implants.
“If a patient has a facial fracture, such as a cheekbone that has collapsed, if you don’t fix it quickly, it can heal like that,” said Dr. Desai. The patient may require multiple revision surgeries as a result. To avoid this outcome, “we can use CT scanning to mirror the bad, damaged side of their face to the good side, and repair those maxillofacial injuries.”
VSP is useful for collaboration with an oral surgeon to perform reconstructive surgery on the maxilla, where both specialists use 3D software technology to guide the dental procedure and 3D printing of customized dental implants, said Dr. Desai.
With his patient’s CT scan data on his computer screen, J. David Kriet, MD, director of facial plastic and reconstructive surgery at the University of Kansas Medical Center in Kansas City, can examine a malpositioned cheekbone and orbit (such as a zygomaticomaxillary complex fracture) and then measure the patient’s “good side.”
“We can take the right half of the CT in virtual space and flip it over to map out a mirror image. That becomes our plan,” he said. “We can create an orbital implant using the mirrored image. We could either take an implant off the shelf or work with an engineer at a manufacturer to design a custom, patient-specific implant. By doing this, there are a number of advantages. We can do planning and create the implant before we get to the operating room. The time saved often offsets the more expensive implant. The less time we have a patient under anesthesia, the better,” he said.
Dr. Kriet has been using these technologies to plan for many oral and maxillofacial reconstructive surgeries for seven years. While 3D printing and VSP using CT scans are not yet the standard of care, these tools improve accuracy in more complex surgical cases, and they lower the risk of long-term discomfort or deformity for patients, he said.