Hello James,
You are asking about a mouth guard.  Most people I work with use a night guard.  Preventing the grinding is important.  Teeth are bones as well...so you are impacting more than the jaw when grinding.  Also, stretch your feet, ankles, hips and low back,  Check out essentrics.com for some of their short videos.  Short intro videos are all you need to release fascial lines.  Presently working on
TMJ self help ebook.   Will keep you posted.  AND thanks for reading!!!!!!!  Annie