A couple more thoughts Harry;

many of our cancers were painless. This seems more often the case when in early stages.

Second, have you considered a neuralgia issue that might be causing this pain? http://en.wikipedia.org/wiki/Neuralgia paragraph 4 mentions glossopharyngeal neuralgia. I am no doctor so I am really not able to offer any more detail.

I can imagine that you want resolution to this but poking holes in your oral cavity willy nilly will cause additional pain. likely will come up negetive (because there is nothing to see). I really doubt cancer would go unnoticed by that many Docs and scans either. I am sorry that we have not been much more help to you so far.

Mark, 21 Year survivor, SCC right tonsil, 3 nodes positive, one with extra-capsular spread. I never asked what stage (would have scared me anyway) Right side tonsillectomy, radical neck dissection right side, maximum radiation to both sides, no chemo, no PEG, age 40 when diagnosed.