A New Brunswick dentist says his research indicates mouthguards can improve the performance of athletes, and take away their aches and pains.

Dr. Patrick Girouard, of Cap-Pelé, has been testing the theory that the way teeth fit together can affect a person's posture and centre of gravity, helping better performance and minimize the risk of injury.

Girouard, who is conducting the research as part of his master's degree at Tufts University in Boston, recalls hearing about the theory during a lecture by one of his mentors about four years ago.

He didn't believe it. So Girouard, a marathon runner, decided to test it on himself. He got a mouthguard, anxious to see if it would cure a pain in his right knee.

"I basically took his challenge and went out running, and to my surprise, my knee didn't bother me at all during that run," he said. "It was just mind-boggling for me. It was a revelation at this point."

That run inspired the research project, said Girouard, who is specializing in craniomandibular pain — discomfort affecting the head and neck.

Moncton test results favourable

"I decided to test this theory after seeing how many athletes have to use pain medication on a regular basis. I want to find out how to maximize pain-free performance by an athlete's body using the guards."

Girouard fit 80 members of the men's and women's soccer and hockey teams at the University of Moncton with two types of customized mouthguards and used electrodes to track their muscular activity.

"The athletes are quite favourable. They're saying that they see a change, they feel a change…. I'd say 90 per cent of them have seen a positive change in their posture and their muscular strength," he said.

"There's a certain hockey player who had a lot of lower back pain. Once we fitted him with the mouthguard, his back pain went away."

Girouard said he has finished collecting his data on the dental appliances and is working on the statistical analysis for his thesis, hoping to develop the perfect mouthguard.

Meanwhile, he continues to use a mouthguard every time he runs and will be wearing one during the Boston Marathon on April 19, he said.

Mouthguards, which provide a cushion between the upper and lower teeth, are typically worn by athletes to prevent dental injuries during impact-risk sports such as hockey. They help absorb and dissipate force when the upper and lower jaws bang together.

Although it's widely believed the devices also protect against concussion, Toronto neurosurgeon Dr. Charles Tator, founder of the injury-prevention organization ThinkFirst Canada, has said there's no definitive scientific evidence to support that idea.

He said there's a good chance they do, particularly during hits to the front of the head, in the jaw area. But he doesn't believe they would have much effect on limiting force generated by blows to the side or top of the head.

To make a custom mouthguard, a dentist takes moulds of the upper and lower teeth, and does a bite registration test to ensure a snug, comfortable fit.

Over-the-counter stock models are sold at most sporting-goods stores.