Dear Music Man,
First who is reading the x-rays and panarexs? Radiographers or dentists. If you break a leg, by law only a radiologist is allowed to read it. There is a reason why; a very small percentage of the population can see enough shades of gray to read an x-ray properly. However, in the dental field, dentists and oral surgeons are reading x-rays. Why, do they as a group happen to see more shades of gray than the average doctor? So who is reading your x-rays may have a great deal to do with it. I live in the NYC area and I went to dozens of maxio doctors and to every dental school in this area and only one doctor was able to read what was so obvious to me.
Second, pulp testing is an inaccurate method for testing the viablity of a tooth. It can test for dead teeth, but usually you don't need pulp testing for that. Teeth can be alive and kill you. I know from experience. All the teeth that either almost killed me or caused me to flatline at the hospital were "living" teeth.
Third, can an infection in the jaw spread to the sinus cavity? Yes, is that what is happening. Can be, but probably not. I had major life-threatening sinus infections that went away once I had proper jaw surgery.
In conclusion, you have pain in tooth #14. This is not a good sign, but a sign the tooth is infected or the jawbone underneath, in which case the tooth will have to be removed anyway. The reason for this can be two-fold. Tooth #14 may have always been infected or the infection may have spread. The infection, however, doesn't have to be bacteria or fungal. It could be neurotoxins left over from the bacteria or fungus that infected site #15 & #16. Neurotoxins can also still be present in that area, too, if the doctor didn't properly debrie the area. Usually, doctors remove what they can see bacteria and fungus in an area, but not the toxins that are usually buried deep in the jawbone and can only be removed by literally cracking the jaw.
I am not a doctor and am not giving any medical advice,but I have suffered from this problem for many years and have done extensive research on the subject and I am just relaying to you what I have learned.