Jan Akervall was getting tired of knocking people's teeth out.

Akervall, an ear-nose-and-throat doctor in Farmington Hills, is used to conducting endoscopies in which a heavy instrument is inserted into a patient's mouth.

"They can harm and injure the teeth" even though the patient is wearing a mouth guard, he said. "That's when I started to think we might need something stronger, more durable."

Akervall collaborated with University of Michigan engineering professor Johannes Schwank to develop a perforated, non-compressible thermoplastic mouth guard.

"He hasn't knocked a single tooth out" in the 800 to 900 surgeries he's conducted since developing the new mouth guard, said Sassa Akervall, Jan's wife.

Since then, the mouth guard has turned into much more than a convenient surgical accessory. Jan Akervall and Schwank co-founded an Ann Arbor-based startup called Akervall Technologies — which is marketing the mouth guard to athletes and the military.

As chief operating officer, Sassa Akervall is leading the sales effort, which, she said, has already led to "tens of thousands" of units sold.

Akervall's product, called the Protech Dent mouth guard, is made of a customized polymer that can be soaked in hot water at home and custom-fit to the athlete's mouth.

At 1.6 millimeters thick, it's much thinner than typical commercial mouth guards that are 4 to 5 millimeters thick, Sassa said. The perforated material allows the mouth guard to oscillate and absorb the impact of a blow to the mouth. The company describes the Protech Dent mouth guard as 30 percent stronger than conventional mouth guards. It costs $40 for a two-pack or $25 for a single pack.

"Everybody who tries it loves it because it's thin, you can talk and breathe and you know you're safe," Sassa said. "Most (commercially available mouth guards) are so bulky and they're obstructive to breathing, but this is not."

Akervall launched in May 2009 with a website that "hardly drew any attention," Sassa said. But the company launched a redesigned website in January 2010, completed an Ann Arbor SPARK entrepreneurial training seminar called "Boot Camp" in May 2010 and secured a Phase 1 Small Business Innovation Research grant from the U.S. Department of Defense.

The company also secured a $15,000 low-interest microloan from SPARK's Michigan Pre-Seed Capital Fund — which Akervall recently paid off nine months early — to help get off the ground.

A market study helped Akervall decide to first target a small part of the sports market that is generally overlooked by major athletics equipment companies: roller derby.

"Obviously we're a startup with very limited funds, so we needed to find a market segment where we could create buzz," Sassa said. "We couldn't fight in the hockey, football arena, because it was too crowded, and we didn't have the money to fight it. We needed athletes interested in their health, interested in being hip and not afraid of spending money. They loved us immediately."

After securing a foothold in the roller derby market, the company has pursued sales in sports like rugby, field hockey and mixed martial arts.

Jan said the roller derby market was the right place to start.

It allowed the company to "learn from how we present the product and how we package it and how we educate the consumers and then build some momentum and then take it to the bigger markets," he said.

The product is being sold at 60 stores throughout the country — including Advantage Sports on Stadium Boulevard and Red Belly Boardshop on Plymouth Road — as well as the company's website. High-profile users include some Detroit Lions players, although Akervall did not identify them.

For now, Sassa is the company's only official employee — although the company expects to start hiring soon. She said Akervall has been funding its sales expansion through its revenue stream and wants to avoid accepting outside investment if possible.

Among the company's big opportunities is the military market. In fact, Akervall recently completed a study after receiving a Phase 1 SBIR grant from DOD. Now, Akervall is applying for a Phase 2 grant that would fund the design of an advanced version of the mouth guard for the military.

Some soldiers are already using the mouth guard on the battlefield in Afghanistan, the company said.

"The military has a lot of expenses because of chipped teeth," Sassa said. "They're interested in this, but our hope is that the next generation is going to be even better."

The product is currently being manufactured by a U.S. supplier, Sassa said. She said the company would like to eventually build its own manufacturing capacity in Michigan, though that would cost "millions of dollars."

"We're trying to be very smart about our efforts," she said.

Akervall, previously based at SPARK's business incubator on Liberty Street in downtown Ann Arbor, is temporarily based out of the Akervalls' home while the company finalizes a lease for space on South State Road in Pittsfield Township.

Contact AnnArbor.com's Nathan Bomey at (734) 623-2587 or nathanbomey@annarbor.com. You can also follow him on Twitter or subscribe to AnnArbor.com's newsletters.