Some psychoactive drugs can cause jaw clenching. I had that problem. Taking gabapentin helped, especially for the clenching I did while sleeping.

There is a procedure where the doctor injects Botox into the jaw muscle to weaken it to reduce the power of the clenching thus reducing the wear and tear on the TMJ.

I was treated for lock jaw and other TMD/TMJ problems by a physical therapist who did 'in mouth' release techniques. They were very helpful.

What symptoms do you think may be due to your possible hypochondria ?