A picture is worth a thousand words, and I can't see your mouth. So I'm shooting blind.
I assume all these dentists and doctors looked in your mouth and did not see anything wrong:
- No bumps
- No sores
- No areas of redness
- No areas of irritation
I also assume the dentist pushed on your teeth near the area of tingling, and that the pressure on the teeth didn't produce the tingling. If it did, there could be something wrong with the tooth and its root.
One possibility that comes to mind is herpesviruses. This family of viruses can cause infections of nerves that produce tingling and unpleasant sensations.
With shingles, which is caused by a herpesvirus called varicella-zoster virus, the unpleasant sensation can be accompanied by visible abnormalities of the skin. But sometimes it's just the unpleasant sensation, without any visible problems. This theory might be more likely if you also had similar unpleasant sensations elsewhere in your head.
If your doctor thinks the sensation might be caused by a herpesvirus, there are medicines that can reduce the ability of the virus to reproduce. This could possibly provide some symptom relief. Also, the sensation is likely to go away even without treatment, although it could come back periodically.
This is pretty speculative, I know, but it's hard to make a diagnosis based on a few words.