This is a symptom of a parasite infection. I had a dozen parasites, including Ascaris, (White worm), Still have Strongyles (Red Worm) and manage somewhat.
My teeth were blown apart with systemic strongyle infection, I lost 8 teeth, but posted 2. Massive Dental bills, but using moxidectin on jaws, drove them out and finally learned to control them, cept spring and fall.

Interestingly enough, dental clenching was one of my first symptoms.

I discovered many nests in the head, and sinuses, that took several years to clear.

One has no clue how bad your situation is, until you start to treat. Then parasites that were unchallenged, show up in the locations, and nests they have created. Most parasitic infections are not felt, your health goes down hill, you have not a clue why. Then and only when you try the right med, do you discover an infection.

Red worms can get into jaw bone, years of oregano oil, thyme oil, then finally moxidectin got them out, not without a battle. Red worms love calcium objects that can withstand the nitric acid they emit.

Fighting systemic infections can be a huge battle, that can take years to understand which species, what formula, can I cure, or do I have to manage this one. Bone pain, Joint pain, and rotate head side to side. These are red worms. Do you hear crunching or crackles? What species takes more challenges. One species can have 5 stages or more. Each stage will have its own location and symptoms. The problem can get complex.

More than one species? This is called a complicated infection.

One gal I helped, had barberpole worms, rare and scary. She got MOP and cleared them out, Cured. She had symptoms that indicated flat, white, and red worms. She still has something, but from her 5 or 7 infections, she is now down to one infection. She is at year 3, but we jumped on her infections fast to prevent a disaster.

Do not ignore the symptoms. Use it as a basis, along with other observations, and challenge tests, to identify and then cure infections.

Try Flax seed oil capsules, red pine needle oil capsules, Piperazine Citrate teaspoon, Fenbendazole half dose in yogurt. If jaw clamp reduces, you have a starting point.