How can a hidden wisdom tooth cause tooth sensitivity?

[BrentM.Adams36]

Hi, I have a wisdom tooth that is still under the gum. It started causing me pain a while ago and the dentist told me it was because it had come out the jaw but was not yet through the gum. The gum was shallow over the top of it and it was literally impact pain on the soft tissue when I chewed something over the area. No part of the tooth is through the gum.
At the same time I was getting shooting pains at the front of my mouth and a hot sore cheek. My dentist told me this was because my sinuses were inflamed from a cold and it was pressing on the nerve because the wisdom tooth and the sinus cavity were very close. He said that would settle down and it did. However the impact pain has continued to be an issue until it took a turn for the worse recently.
Recently the gum/adjacent tooth area where the wisdom tooth is has started reacting to hot and cold and I am mystified by this. I get quite sharp and uncomfortable pain flooding over the area when anything not blood temperature touches it. As the tooth is still under the gum this can't be a decay issue and the only tooth nearby is root canalled and crowned so it can't be that either.
Does anyone have any idea how a hidden wisdom tooth could be causing sensitivity pain? The only other thing I'll mention is my sinuses seem a bit blocked as they stuff up during the night and I can hear/feel them ticking as they drain in the morning when I get up. So I did wonder if this was related to the sinuses again.
Anyone have any idea what might be happening here, or anything I could do to ease the pain?
Many thanks!

 

[MountainMama]

It is interesting that you just posted this. I am dealing with possibly a similar issue, but in reverse.

I had a deep filling in my upper last molar on the left side. It caused the tooth to become infected and I had a root canal a little over a month ago. The root canal did not help and the tooth is still hurting, along with some weird sinus issues (without congestion).

I have a supernumary impacted wisdom tooth right next to the root canal treated tooth. I had all four of my wisdom teeth out when I was in high school, and this is an extra one and is really tiny, like the size of an incisor.

My endodontist thinks that wisdom tooth may be causing my root canal tooth to fail (or resemble failing).

I just saw an oral surgeon for a consult last week. He explained that because the wisdom tooth is impacted, it has caused bone loss around the roots. The tooth itself is partly out of the bone. The roots of the wisdom tooth are touching the roots of the molar, possibly causing inflammation under the tooth, which causes pain and sensitivity.

It is admittedly just a theory. Both my endodontist and oral surgeon said that removing it may or may not relieve the pain and sensitivity of my molar. However, it has to come out due to the bone loss issue.

I am curious to see what happens with yours. When are you getting it removed?