Swollen gland in left side of throat under jaw for over 1 month. i had a tooth infection bottom left removed last week can this be serious?

Tooth issue: Taking care of the diseases tooth should take care of the swollen gland as it is on the same side and in same area as infected tooth. If gland does not change or get smaller over next 2'weeks, see your doc

Possible infection: May be an infection involving a lymph node. May also be an infected salivary gland. In either case, you should see a doctor. May need some antibiotics.