Mouthguard Modification

[GregSchumacher]

Tonight we were officiating a 9th grade game where we noticed the quarterback had a mouthpiece much smaller than normal (back had been cut). Is there a rule that states the mouthguard shall not be modified? ... or, what prevents a player from basically cutting the mouthguard completely? Looking for actual location in rules for this. The only thing I see in rules book is that the color must not be clear and that

A tooth and mouth protector which shall include an occlusal (protecting and separating the biting surfaces) and a labial (protecting the teeth and supporting structures) portion and covers the posterior teeth with adequate thickness.