Cancer survivor Shirley Anderson keeps his lower face hidden under a surgical mask that covers up a missing jaw, the result of his battle with cancer that first began in 1998, but now a new technique developed by researchers at Indiana University will give him a realistic and comfortable prosthetic jaw.
Through digital modeling and 3D printing, researchers are able to prototype and create prosthetics quicker with a method that eliminates the claustrophobic and difficult process patients go through to create a mold of their face, resulting in lighter, more personalized facial prosthetics.
For Della Anderson, this new method is exciting. The intense radiation received targeting Shirley's cancer in 1998 and when it returned 15 years later destroyed his facial tissue, resulting in the disfigurement. She has spent years at her husband's side through chemotherapy, rehabilitation, and as a partner in the research that could transform and expedite the creation of prosthetics.
It is a difficult road for the couple married 50 years, but one she's confident will ultimately lead to improved care for other people with conditions similar to her husband's.
"It’s very hard for him, and his main concern was he did not want to scare little children. But little children seem to be the most accepting; they look and just go on," Della said in an interview with the Daily Dot. "I think my husband is a very brave person and with everything that he’s gone through, physically and mentally and emotionally, I sometimes wonder how he has made it through. He’s been through so much pain and anguish."
Indiana University's method is dubbed The Shirley Technique.
Shirley cannot speak due to his disfiguration, so he communicates through Della and by writing on a handheld board. The pair have spent the last few years working with Dr. Travis Bellicchi, a resident at the Indiana University School of Dentistry. Bellicchi says Shirley's case may be the most challenging he will have in his career working in facial prosthetics because of the sheer size of the prosthetic required.
Creating a prosthetic mold for the face traditionally requires patients undergo an uncomfortable hours-long process of getting a facial impression with a polyvinyl solution and layers of plaster. The solution covers the entire face and requires patients to modify their breathing, like by sticking straws through their nose. This process can be extreme and unsettling for many patients, and some stop the process before doctors can get a proper mold.
Shirley has a prosthetic created using this method that must be glued on, and Della said it's heavy and uncomfortable, especially in the Indiana heat. The couple hopes the newer method will provide a lighter option for Shirley to wear for a longer period of time in public.
"Our process takes that impression and reduces it to nothing more than sitting in a chair and essentially having photos taken of them," said Cade Jacobs, lead designer of the project and an undergraduate student at the School of Informatics and Computing.
Instead of a rigorous process of plaster, researchers take photos of the patient from all different angles, essentially creating a topographic map of their face. Once captured, Jacobs uses digital sculpting software to design a prosthesis from the patient's bust. Called ZBrush, the software is used in the entertainment industry to create movie monsters, Jacobs explained, and was never intended to be a tool in the clinic environment.
Once the mold of a patient's face is captured, it's sent to a Formlabs 3D printer that prints a negative of the facial map, which is then filled with silicone to create a prosthesis, perfectly formed to the person's face.
"This is the fun part of the process; you can experiment and prototype a bunch of different designs using the 3D printing and mockups of whatever it is you’re trying to work on," Bellicchi said. "That’s been the thing that’s freed me up the most—to take chances with the design and find a better solution."
There's no key to undo errors in a plaster cast. With a digital map of someone's face, it's much easier to modify and change things on the fly, and because it's possible to quickly print and prototype different molds, Bellicchi can create a variety of products to ultimately find what properly fits a patient.
Bellicchi said he expects a hollow prosthesis to be the best version of anything made so far, created from a set of molds with the help of the School of Mechanical Engineering. The idea is to print a hollow core and put a veneer of silicone around the core, he explained. Shirley and Della have not seen the latest iteration of the prosthesis, but they are expected to try it next month.
The prosthesis will connect to the face through acrylic hooks and magnets around the ears, and an elastic band with velcro will wrap around Shirley's neck. Creating a comfortable prosthesis was not the difficult part, but getting it to stay on securely was a challenge, Bellicchi said, because the prosthesis covers such a large surface area so adhesive doesn't work.
The digital scanning and 3D-printing method could make prosthetics more affordable and accessible to patients.
"It is dramatically more cost effective to reprint a mold rather than recreate a plaster mold," Bellicchi explained. "When working with traditional methods, you would have to go back and re-sculpt the prosthesis in clay or wax in order to make new molds. A digital workflow allows you to easily access your design data and recreate your work easily and efficiently."
Shirley is the team's first case, but Bellicchi said there are now over 10 patients in different phases of prosthetic prototyping and design, including prosthetics for ears, noses, and mouths.
Although Indiana University's method doesn't 3D print the prosthetic itself, rather the mold, a number of solutions exist for 3D-printed prosthetics using materials other than silicone. Access to this kind of 3D printing tech is so ubiquitous that some nonprofits enable students with upper and lower limb differences to design and build their own prosthetic creations.
Soon, however, directly printing silicone prosthetics may be possible. Fripp Design, a UK based research and design firm, developed Picsima, a process for 3D-printing synthetic polymers including silicone.
For Shirley, helping to develop a new way for doctors to iterate on and create prosthetics for future patients is the driving force behind his participation.
"He is mainly wanting to do this to help others," Della said. "Soldiers from Iraq and Afghanistan that have had their faces injured, burn victims, and any kind of accident that takes away something from the face."
Della says she is thankful her husband's cancer is gone, and the couple can enjoy life as much as they can, despite the challenges including disfiguration and diet that hinder activities like traveling during their retirement. There were times, she said, Della was unsure whether her husband would survive his cancer.
"We’re just taking life as it comes, and enjoying what we can have together," she said, like driving through Indiana in Shirley's Cadillac convertible.