Teeth Grinding

Anthony has been grinding his teeth for a long time and he is actually starting to wear his teeth down.  We have to do something about it and I just ... I'm out of ideas.  This is when I need the help of professionals and I hope I can get it.  We have tried to give him a 'chewy', I have tried to teach him to chew gum, I try to do massage on his gums and jaw, nothing stops him.  It's not like he does it at night (although he might) and I can put a guard on his teeth, so I am feeling pretty helpless.  Today I decided, in all my spare time, to look on the internet about it and I found this link.  I sent it to his speech therapist and I'm hoping we can get going on it and maybe stop him from doing it before he gets his adult teeth.  So if anyone has any information about it, let me know and if not, just keep a good thought that we can get him to stop doing it before he becomes toothless.