Went to dentist for re-treatment of root canal on tooth #30 done many, many years ago. 3 days after procedure, I wake up with a swollen jaw. I go back to the dentist that day he x-rays my mouth notices #29 tooth is infected, although he didn't see it it 3 days earlier. He then performed a root canal on #29 that same day. Today I went in and he performed an I&D (Incision and Drainage) on my jaw. It hurt like crazy! Could the swollen jaw be from the re-treatment of #30? The infection from #30 was not drained properly or given time to drain before he sealed me which led to the pus formulating in my jaw. Have any idea what is causing the swollen jaw?