From the Sun:
Athletes have been using mouth protective gear for years. Under Armour said its product is different because of its ArmourBite Technology, which prevents an athlete's teeth from clenching. Clenching triggers the production of stress hormones such as cortisol, which cause fatigue and can hurt an athlete's performance, the company said.
Check out the full story here: http://www.baltimoresun.com/business/bal-bz.underarmour14aug14,0,2903349.story