Thanks for posting your query in health care magic forum.
I have read your concern.
Since the facial swelling occurs at the site of tooth infection
,the infection may have spread into Periapical area as well as into tissue spaces.
Yellow pus discharge occurs from an infected tooth also.
Tooth has to be either root canal
treated or extracted depending on severity of infection.
Usually in such cases,Metronidazole
as well as analgesics has to be administered.
Meanwhile,maintain oral hygiene
Hope this helps.