Hi Cathy...I have severe TMJ to the point where the joints are disinigrated...I don't know if it's arthritis or what, but what a crunching noise I make when I chew! Anyway...I had an $800 appliance made ( I don't know if it's the same thing you are getting but I was supposed to wear it 24/7 for several months) because I grind my teeth when I sleep which only makes my condition worse. Anyway, it did not make me gag (I worried about that too) but no matter how I tried, I could not get used to sleeping with it in my mouth. I am prone to canker sores and even after all the adjustments I got too many sores where it rubbed against the roof of my mouth. Others have had great success with theses devices and I hope you are one of them! I don't think it will make you gag, especially since it is on your lower teeth.