This happened to me when I had my "hidden" dying nerve in a back tooth.
The dentist had damaged the pulp by accident when he filled it last. It festered for a long time (I did not feel it) and drained into that sinus. I had several sinus infections, but no swelling in the tooth or gum itself.
One day the muscles on that side spasmed up and dislocated my jaw.
X-rays showed almost a 1/4 inch deviation.
I went to a specialist in TMJ and he evaluated the whole thing and put me on
muscle relaxants. After two weeks I could open my mouth (it was locked shut 3/4 of the way).
Muscle spasms can do this --yours might be due to other reasons.
Eventually I had the tooth root canaled and crowned. It took a LONG time isolating the cause.
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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