It is likely you have two distinct problems.  It seems likely that
something is going on in that front tooth, and I'm afraid I have no
explanation for why no one can see a cause for that pain.  If it is
heavily restored I would suspect a pulpal problem or a fracture, but the
endodontist should certainly have been able to evaluate that.
    It is possible that you grind and clench, and that you are
over-stressing that tooth.  Pain to biting pressure or looseness of that
tooth would support that.
    I must say that some other factors must be considered--for instance
neuralgias.  I once did a root canal treatment on my mother (almost
certainly unnecessary, as it turned out) for facial pain that was
eventually determined to be a trigeminal neuralgia.
    If the pain is exacerbated by contact with some part of your mouth or
face, I would definitely pursue this possibility.

Good luck,
Steve

Hi, I'm 28 years old male. I have this pain in the right tooth of upper
front for about a year. The pain used be intermittent but now it seems
like it's continous and getting worse and worse. Not only that but now
I feel the pain in my jaws too. Last year my dentist told me to see a
root canal specilist. And since then I've been to 2-3 different
denists, root canal specialists and recently to a TMJ specialist. No
one seems to find anything wrong with the tooth except the person who
deals with TMJ pain told me the pain in the jaws seems like it's TMJ
but pain in the front tooth has nothing to do with it and he said maybe
I should see the oral sergeon and have the tooth extracted. If no one
sees anything wrong in the x-rays why tooth extration?
Is there anything else that could be related to this pain and anything
I can do to get rid of the pain?