Get an xray done (TM joint) it can be manually corrected
You probably have lockjaw. It’s when the muscles that connect your jaw to your skull having a spasm causing your jaw to lock. You should see a doctor for help
You should first have an X- ray of TM joint then you should further proceed any treatment.
Its good to visit dental clinic this will solve your both prblm that weather your jaw is troubling you due to dental prblm or due to locking of joints....but you should visit that dental clinic which have OPG machine, this xray machine will show your TM joint as well as dental abnormalities.