Developed at the U, wiring jaws without the wires

Alan Johnson was interested in getting his jaw wired shut because of the new technology involved.

The treating physician, Dr. Alan Johnson, hoped that his first-in-human test of a new jaw-fixation device would alleviate the pain and discomfort of traditional treatments for a busted mandible.

Johnson successfully installed the jaw-locking devices on his own teeth that day — merging his roles as facial-trauma doctor, medical device engineer and pioneering research subject, and launching his idea for the Minne Ties jaw-fixation system.

The idea went on to become, in 2017, the first invention out of the University of Minnesota's Earl E. Bakken Medical Devices Center's Innovation Fellows Program to be commercially marketed. Summit Medical, the Eagan manufacturer of the Minne Ties Agile system, has sold nearly 1,000 units and trained doctors at dozens of hospitals since then. The device took home silver this summer at the 20th annual Medical Design Excellence Awards in New York City.

"The first human who had these devices applied to them was me," said Johnson, the device inventor and head-and-neck surgeon who today practices at Altru Health System in Grand Forks, N.D. "I spent a Saturday afternoon in a room in the Mayo Building there on campus, applying these things to my own teeth, to make sure I had the right [design] and to see if they hurt, things like that. I took lots of pictures on my iPhone."

Many people ended up seeing those photos, including the folks at Summit Medical, which acquired rights to the idea from the U. Summit guided the device through the FDA's 510(k) clearance process, eventually selling the products to hospitals around the country, including the U's Medical Center and Hennepin County Medical Center.

"Overall, there were a few design challenges that our team was able to overcome. But the actual manufacturing process overall is quite straightforward," Summit Medical President Kevin McIntosh said. "We figured out how to make it manufacturable, and how to manufacture it. It was basically just a great idea when we saw it."

The basic idea at the heart of the device is to use specialized zip-ties instead of sharp metal wires to keep someone's jaw closed for several weeks.

The mandible is a tough bone, but it can be fractured by blunt-force traumas such as a punch or a kick to the face, a car crash, a sporting accident or a fall from a bike. Like any bone, the jaw has to be set and then kept immobile for two to six weeks to heal properly.

"You are putting everything through a blender and eating through a straw, pretty much. People are understandably really sick of smoothies when they get their jaw unwired," Johnson said.

Wiring and unwiring a jaw is a procedure that has been used since at least the 1940s. Johnson calls it "effective but really barbaric." The Minne Ties system eliminates the wires, arch bars and screws in traditional and "hybrid" systems, which can damage the patient's gums while they are in the mouth and injure a doctor's hands during removal.

"When you remove those wires, you numb up the mouth and try to do as little damage as possible," Johnson said. "You're just trying to get this out without literally having them bleed onto their shirt."

In place of wires and screws, Minne Ties uses "self-locking suture ties" made of medical-grade polyester. The ties have blunt ends (instead of a pokey wires) and are narrow enough to be threaded through the spaces between teeth.

During a Minne Ties procedure, several of the ties are inserted into the spaces where dental floss goes between back teeth in the upper and lower jaw.

The ends are slowly advanced through a hole in the locking head on the other end of the zip tie. Eventually, pulling the ties firmly forces the jaw closed, securing it from multiple points on both sides of the mouth.

Johnson said he saw the need to replace traditional metal wires and bars after having to unwire some gnarly jaws while working as a resident in ear, nose and throat (ENT) medicine at HCMC, one of the hospitals that residents rotate through during the U's multiyear program for training doctors.

Removing traditional wires in complex patients sometimes requires using general anesthesia and taking an hour or more in an operating room. "I'm not alone in despising wires and arch bars," Johnson noted.

Minne Ties can be removed in less than 20 minutes in an outpatient setting, instead of an operating room, making the experience a lot more comfortable for patient and doctor.

Johnson said the cost to patients will probably be the same whether for Minne Ties or traditional fixation because of how insurance works. For the hospital, Minne Ties cost more up front than a traditional wire-and-screw system, but the overall costs of using the system are lower.

"The hospitals gain an extra hour of operating room time," Johnson said. "Insurance companies [often] won't pay for the removal of wires, so the hospital really likes it, because the expense of going back to the operating room is eliminated. And insurance companies ... don't have to pay more for the operating room time."

Johnson and McIntosh said the U retains the patent and is licensing the device to Summit, which pays regular royalties. Johnson said he gets about 25 percent of the royalties paid by Summit to the U. So far the dental surgery device is available directly from Summit, not through dental-products distributors.

Summit Medical has long sold ENT devices, so the Minne Ties Agile maxilla-mandibular fixation (MMF) system fits well in its catalog, McIntosh said.

"It's unique and disruptive — I think that's a great word to describe it," McIntosh said. "And it is really catching the attention of surgeons. Every surgeon we show it to is excited to try it."

Joe Carlson • 612-673-4779