These removable appliances are mouthpieces that can prevent teeth grinding during sleep (nightguards) or prevent snoring and sleep apnea (snore guards). Nightguards are placed on upper or lower jaw but not both, and prevent teeth from grinding each other. Snore guards, however, are placed on both upper and lower teeth. They shift the lower jaw slightly forward so the back of the tongue doesn’t block the airway, eliminating the “snore” and sleep apnea.