Review on 🦷 Oral Mart Adult Sports Mouth Guard - Premium USA Flag & Vampire Fangs design for Football, Boxing, Karate, Martial Arts, Rugby, MMA, Hockey - 13 Colors available with Vented Case Included by Shane Jess

I followed directions exactly - 40 seconds in boiling water (mine was simmering), a quick dip in ice water, then put in mouth. The first time I had a crooked landing when the left side was higher than the right. The instructions told me to repeat the same steps if the fit wasn't perfect, so I re-immersed the tray in the boiling water for another 40 seconds. I got the perfect fit this time but found that there is now an ugly/slightly uncomfortable indentation on the inside right side. These were the tongs I used to transfer the guard from boiling water to ice water! I attribute the damage to user error, but would like to point out in the instructions that wearing the hot mouthguard must be very gentle. In addition to the extra recess, the mouthguard is great (for adults) and very comfortable.