I have some pretty bad TMJ problems, and it seems to happen more when I vape. I know when I was sitting down at my mom's house talking to her, I was using my sentinel and a trident and vaping away. I would then notice my jaw would start to hurt more than it usually does. It's kind of like that feeling when you've been laughing so hard and your cheeks get sore, but in this case it actually hurts and is painful. Sometimes I just get the pain out of the blue, but I notice when I'm just sitting and chain vaping that it comes on full force. Anyone else have this kind of problem?
I've suffered TMJ. It is painful

I can't say vaping has made it worse. Mine got much better after I divorced my now ex. Stress will cause you to tighten the jaw. It is feasibly possible that as you withdraw from cigs, you subconsciously are doing that. Concentrate on relaxing your jaw. I find I had to do this ALL the time. I even have to make myself relax it when I'm trying to go to sleep. Even now as I type this I have to focus on relaxing it.
I clench my teeth a LOT. I've gotten in the habit of resting my tongue between my upper and lower back teeth.
I've actually had a dental tech tell me to loosen up cause I was starting to clamp down on her hand while she was cleaning my teeth.
ETA. It was so bad at one point it would pop

and I wouldn't be able to close my teeth together. That happened quite frequently when I was married to my ex.
This has happened only once since I started vaping.