Hi there Ashington1.
Take care chap - get your dentist to refer you double quick to maxillofacial at the hospital.
I have lots of spasms and cramps in my jaw now in areas which had lots of RT . The GP surgery don't give a flying f@@k!
Get yourself prescriptions of high fluoride mouthwashes and especially toothpaste if you can.
I had 2 wisdom teeth out last year at maxillo (they did mouth biopsies too) They were brilliant with me as I was suffering so much high anxiety (still do).
nearly 13 years on for me now - My motto is - be pro active! no one else (NHS etc (apart from maxillo facial) is bothered.
good luck - tony k