MOUTHGUARDS, NOT ALL ARE EQUAL
It used to be that a mouth guard was a big rubbery blob. When inserted into the mouth it was nearly impossible to breathe and ensured at least one major drooling episode in front of teammates. Times have changed. The new style of mouthguard is made from a much thinner plastic that is heated in water and then molded to fit the mouth. That thinner plastic means far more room for inhaling oxygen on hard sprints or recovering from an epic battle. It also allows a closed mouth to prevent an embarrassing drool session.
Pro tip: keep a backup mouthguard in the gear bag because they do disappear. A player without a mouthguard is a spectator. All rules require a mouthguard to play and practice.
Sisu makes multiple versions of their thinner mouth guards. Below are videos on standard fitment and a useful tip on fitting for braces. We have tried the braces video and it works well.