An infected tooth with an abscess (accumulation of pus) is a common cause of facial swelling (cellulitis). A deep cavity allows bacteria to enter the nerve of the tooth and travel through the tooth into the surrounding bone and tissues. If the infection remains localised an abscess will form next to the tooth. However where an infection spreads it can cause a facial swelling/cellulitis and appear on the skin as an area of redness and swelling which is hot to touch and often painful. Depending on which tooth is infected, the associated swelling can cause difficulty with swallowing, mouth opening or even swelling of the eyelids.
Often dental treatment is delayed until the facial swelling has resolved as local anaesthetics tend to be less effective. A course of oral antibiotics can be prescribed however for more severe cases IV antibiotics may need to be administered.