My endodontist is the guy who looked and found and treated all infections. he is not the same guy who does extractions. That is a different kind of dentist who does oral surgeries. I don't know if that is different for you. The bloodwork (I think) will NOT show up the infection in your jaw. The pain you are having may be related to an infection that does not enter your bloodstream but causes swelling (pressure) which triggers the TN event you are having. For a longtime I'd have pain when I chewed on the right side top. We kept on adjusting the bite. It kept working for a while but then the TN returned. Part of the problem as well may be looking in the wrong spot! I had that problem because it is referred pain and showed up in the wrong tooth! All 3 of my TN nerve routes were triggered at different times! So we looked incorrectly at my sinuses as well.
The opening in your jaw bone is a problem I had in the front bottom. I had infection from my root canals and it bubbled to a place it could abscess. then 20 years later it did it again. The bone had not grown properly below the root canals. So we watch it over the years. When I had the worst pain of my life after my darling Endo Dentist cleaned out the root canals - (I had 3 Percocets and 2 martinis and didn't feel pain relief!) He took me back in the next day and BLEACHED it down into the jaw from the root canals. It didn't hurt, he had already removed any infection -- it just relieved the unbearable pressure and could begin healing.
I will take a guess that your nerve pain is caused by something in your teeth/jaw, left unresolved. Could be coming from a different tooth /jaw area not yet uncovered.
To rest your mind - your dentist may have said you could possibly have nerve pain as a liability measure or because he didn't address the "root" cause 😉 I kept flossing and tapping and seeing what I could figure out.
20 years ago I was recommended to an EXCELLENT dentist. Turns out he did not deal with complicated women's teeth. He did not know I had extra roots which could not be detected! He went on vacation and the covering dentist (who was an EXCELLENT dentist) suspected that I may have had extra roots left behind. He was not capable of seeing them without equipment for that purpose so he was smart enough to send me to the Endodontist. That horrible experience was handled once the extra root was located and removed. Hang in there! If you have pain MORE opinions and dentists who work together. My sprain on the top LEFT which triggered the TN on my right took 3 months to resolve the sprain and bite adjustments. Improper bites when teeth move also trigger TN.