Asked to comment on the study, John Molinari, Ph.D., director of infection control and safety at the University of Detroit Mercy School of Dentistry, noted that finding bacteria on mouth guards doesn’t prove they are making people sick. “People assume the bacteria automatically cause infection,” he said. “You need to show us the cases.”
Dr. Glass and his colleagues say they do have evidence that mouth guards cause lesions in the football players’ mouths, and they will present it in a forthcoming article in Sports Health. “It’s actually causing disease,” Dr. Glass said.
For the study, the researchers analyzed the mouth guards of 62 Division 1 football players from the National Collegiate Athletic Association (NCAA). Before the study began, the 62 players had a collective total of 85 lesions (1.4 per player), Dr. Glass said. By the end of the season, the 53 who completed the study had 198 lesions (3.74 per player). In addition, the lesions increased in severity over the season.
The area of the mouth in which the lesions appeared further supported the idea that the mouth guards were causing them, Dr. Glass said. The number of lesions on the palate, which isn’t touched by a mouth guard, decreased. But the number of gingival, buccal, and tongue lesions increased.
Much of the research focused on the organisms on the athletic mouth guards. The researchers examined 84 mouth guards and found 164 gram-positive cocci, 158 gram-positive bacilli, 13 gram-negative cocci, and 23 gram-negative bacilli. Of the gram-positive cocci, 57% were methicillin-resistant (MRSA) and 5% were resistant to vancomycin, one of the antibiotics of last resort against methicillin-resistant bacteria, said Stan Conrad, Ph.D., an OSU professor of microbiology.
In addition, the researchers found 21 isolates of yeast and 108 of mold.
“Almost anyone who is breathing down large quantities of mold spores has the potential to develop exercise-induced asthma or other respiratory diseases,” Dr. Glass said.