After consultation with our orthodontist the training with the original, tested JAWLINER is not dangerous for your TMJ.
There are a lot of other jaw trainers which are definitely harming your TMJ and your teeth.
For more information please read our article: JAWLINER really Dangerous?
But please follow our training recommendations: Do not train more than 5-15 minutes every other day!
If you are still not sure and you generally want to put less pressure on your jaw muscles and train more of your entire facial muscles, we recommend the JAWLINER Fitness Chewing Gum instead of the JAWLINER.