submandibular pain

I'm a 25 year old male and I've been getting pain in my submandibular area on and off for at least the past year.  It's only on the right side.  When it occurs, the gland itself becomes very tender and touching the nearby jaw bone hurts as well.  Swelling is only slight, if at all.  The pain is directly beneath my very back molar that I have had problems with, needing a root canal and eventually having it pulled 6 months ago.  I had initially thought the pain was due to this tooth but it still persists.  I am hoping the lack of swelling is a sign that I do not have any sort of growth there.  However, the pain in my jawbone is starting to worry me also.  Any help would be greatly appreciated.