As a foot note to this article...
http://www.medpagetoday.com/Neurolog...Neurology/7625
There is a great comment by Marc Picot (whoever that is) about the nature of concussions, and the results that the NE Patriots have had by requiring a specific type of mouth guard to be worn.
Here is an article about that mount guard...and the results...
http://sports.espn.go.com/nfl/news/story?id=2314899
...and their website...
http://www.mahercorlabs.com/mouthguard.htm
fascinating...