(Temporomandibular joint disorder) This is very often caused by clenching or grinding
, usually during sleep, but often while awake as well. (I am a very BAD teeth clencher!) Left undiagnosed and untreated, this can eventually lead to joint damage, sometimes very severe, but often the first clue is a sore, stiff jaw, especially in the morning, pain when we yawn or try to open our mouths wide. Sneezing could conceivably cause pain.