Sounds like she'd resist a mouth guard, but it sure will help. My husband can't be remember when I ask him to stop clacking his teeth. He has plants, crowns and soon partial plates.

I appreciate your reply. My mom would likely chew up a mouth guard and it would become a choking hazard. Fortunately, my dad can't hear my mom grinding her teeth, most of the time. For me, it is just a horrible sound and I know it isn't good for her teeth. My mom is on hospice, so intervention is minimal. A regular dentist is likely out of the question since we can't get her to an office plus, she won't necessarily open and keep her mouth open. Brushing her teeth is very challenging. I use an "Open wide" mouth rest I found on Amazon to keep her mouth open. I also use a rounded toothbrush so I can reach more surfaces in a shorter time. Both are marketed to children with special needs but work well for my mom.
I will need to stick with distraction to try to stop the grinding.
Thank you for letting me vent.
It is not an easy journey.