Betsy,
I haven't tried this, but have read a lot about it.
I would be wary of anyone who says they can cure your Migraine and promise a pain free life. There just isn't a one-size fits all cure for Migraines.
However, the premise of the splints makes sense for people who have certain kind of symptoms. There is a branch of nerves that run along your face and down to your jaw called trigeminal nerves. These nerves can get inflamed during a Migraine attack. And if you clench or grind your teeth at all, these nerves are not happy. The splints, which I think are similar to wearing a mouth guard, are supposed to stop you from grinding or clenching at night.
One of our writers shared her thoughts on this treatment, although she never did try it in the end. Her article brings up some valid points. I don't want to dissuade you, but this is really the only personal info I could find on the subject. https://migraine.com/blog/surviving-latest-totally-effective-treatment/
I hope others share if they've tried this. Make sure you do your research on it and the doctor you use.
-Katie
Migraine.com Moderator