By Vishwadha Chander

(Reuters Health) – Youth ice hockey players who wear mouthguards to protect their teeth and jaws may also have significantly lower odds of concussion, a Canadian study suggests.

Concussions are the most common injury in youth ice hockey, and while Hockey Canada has a policy requiring mouthguard use, it’s not universally enforced, said senior study author Brent Hagel. The new evidence that mouthguards may reduce concussion risk adds to the case for making them mandatory, Hagel and his colleagues write in the British Journal of Sports Medicine.

“When we looked at both off-the-shelf and custom-fit mouthguards together in the analysis, we found their use lowered the odds of concussion by 64%,” said Hagel, a child injury researcher with the Cumming School of Medicine and Sport Injury Prevention Research Center at the University of Calgary.

Previous research has suggested that mouthguard use was associated with fewer concussions, but the findings have been inconsistent, the study team writes.

To explore this question, the researchers analyzed data from two injury surveillance studies in 2011-20212 and 2013-2016 that included child and youth players in Pee Wee (11-12 year-olds), Bantam (13-14 year-olds) and Midget (15-17 year-olds) divisions.

The researchers compared a total of 315 cases of concussion to 270 cases of non-concussion injuries, such as injuries to the trunk or a limb, to see if mouthguard use was tied to concussion risk.

Overall, 236 of the concussion cases (75%) were wearing a mouthguard when they were injured, as were 224 of the comparison group (83%). For youth wearing a mouthguard, the risk of concussion was almost two-thirds lower, the study found.

When researchers looked to see if the type of mouthguard made any difference, they found that off-the-shelf versions were tied to a 69% reduction in concussion risk compared with no mouthguard. Custom-fit mouthguards made by a dentist were linked to a 49% risk reduction – although that result was not statistically significant, meaning it could have been due to chance.

There were no dental injuries reported in the study groups, the authors note.

The study wasn’t designed to determine how a mouthguard may lower concussion risk, or whether mouthguard use is associated with safety culture or behavioral differences among players that might influence concussion risk.

Even so, the authors say it’s possible the mouthguard offers physical protection against concussion.

“The mouthguard may reduce the force of impact through the jaw bone to the skull, and may also activate neck muscles to reduce head acceleration,” Hagel said in an email, adding that the precise mechanisms require further research.

“I do feel mouthguard use can help lower the risk of concussion, specifically when the jaw hits something or something hits the jaw,” said Dr. Andrew Creighton, an assistant attending physiatrist at the Hospital for Special Surgery in New York City and an assistant professor of clinical rehabilitation medicine at Weill Cornell Medical College.

“However, I am not aware of anything that has definitively proven this in the literature,” said Creighton, who was not involved in the study but noted that he grew up playing travel hockey, always wore a mouthguard and was never diagnosed with a concussion.

“The current study is interesting from a cost standpoint too,” Creighton said. “Custom mouthguards, which are significantly more expensive, were not shown to be associated with a lower concussion rate compared to off-the-shelf mouthguards.”

The study also did not assess the quality and fit of the mouthguard, however, and whether the athlete wore it correctly while playing, Creighton said.

SOURCE: British Journal of Sports Medicine, online January 14, 2020.