I have pain below the upper left cheekbone area. I would describe it as a dull, swollen ache feeling that is there all the time. I've had this pain since 2005. I've tried to figure out the source of the problem but to no avail. I had a root canal done in 2006/2007 (don't remember exactly) and I had hoped that maybe the cause was the tooth. However, the pain lingered and I've pretty much been living with the pain all these years. I went to different doctors but no one knows what's going on. Now recently, I went back to a dentist who claims to see signs of infection at the top of this old root canal. This is tooth #14. They are suggesting for me to clean and re-do the root canal.

After reading these posts by Bryana, I'm wondering if I should get the tooth extracted rather than re-doing the root canal. Basically some questions:
1) How likely is the pain I've been having all these years due to this possibly infected root canal? I mean if I've had an infection all these years, wouldn't it have gotten extremely bad by now? In other words, is it possible for this root canal infection to persist at a steady state, giving me this constant dull swollen achy sensation for all these years but not to the point where it was ridiculously painful?

2) Should I at least give the root canal option one more shot (making this the 2nd time) before considering extraction options?

3) What is the downside to extraction? From my point of view, half of the tooth is already gone from the root canal. Is there any risk or side effect from removing the tooth?