The thickness needed in a protective mouthguard will depend on the type of sport being played and the level of play. High impact sports will require more protection. As the level of play increases from little league to high school, to collegiate, to Olympics and pro, the competition and hits become fiercer. The minimal amount of thickness needed for any protection is 3mm. Boxing and MMA mouthguard thicknesses can reach up to 7-8mm. We can even customize the thickness to be the minimal 3mm in the back and heavier thickness covering the front teeth. Please discuss with us the type of sport or activity and the competition level you are in so we can help customize the needed thickness of your mouthguard.