GOOD NEWS! NTI Safety, New Approaches, New Innovations for NTI wearers.
I too have TMJ, face pain, and Fibromyalgia issues and I wear a bottom teeth mouth splint in the daytime and a bottom teeth NTI splint at night. I ran into a critical safety issue and I'd like to share it with you at http://www.aglasshalffull.org/NTIimprovement.htm .
And you need to keep in mind that if you have a dentist and Osteopathic doctor work on you at the same time, with the Osteopath checking cranial stress and the dentist adjusting the NTI, you can end up with a relatively comfy NTI that will help you sleep with minimal grinding and stress. Once the NTI is adjusted to minimal cranial stress, you'll begin to learn why it is such a great invention. If you hate TMJ pain, grinding pain, clenching pain, face pain, and general head/teeth/jaw discomfort as much as I do, you owe it to yourself to heed my words. I got my NTI optimized with the use of an Osteopath-dentist team, and it really helped a lot.
But also check out my safety article mentioned above. I have nothing to sell but some good advice. Sooner or later someone will choke to death on their NTI, but it's NOT necessary, if people heed my advice, which is not theoretical, but comes from experience: the experience of nearly choking on my NTI.