The only thing that helped my headaches
I suffer from moderate to severe chronic headaches, and I know it's from clenching my teeth at night.  This last bout of them lasted for weeks and the night guard I usually turn to (a cheaper brand) wasn't doing the trick for me.  All other night guards advertise how they protect your teeth from wear.  My dentist says mine are fine, so maybe I'm not so much grinding as I am clenching.  The Smart Guard was the only brand I could find that mentioned headaches, and indeed it helped my headaches tremendously!  It took about a week for the headaches to noticeably diminish.  It's been about 4 weeks now and I'd say the headaches are 95% better.  The instructions are a little intimidating, they make the formation process seem a little more complicated than it is, but I just followed the directions and formed it the first time no problem.  Definitely worth the extra money.
Rating: 5 stars