Hi.. Can understand your concern.. As per your complain it is very clear that you must have had a deeply infected tooth due to which you had pain and after taking tylenol the pain got suppressed and some inflammation was reduced but the infection was always present as no antibiotics or dental treatment was taken to clear off infection. In case when the infection is not treated it can lead to further spread of infection and causing pus formation as well as swelling and advanced case can lead to difficulty in opening the mouth and if left untreated it can lead to cellulitis. I would suggest you to consult an ENDODONTIST who will take an IOPAR (xray) and do a clinical examination to rule out the exact cause of your problem which most probably seems to be due to dental infection as per your explanation. If it is due to infection antibiotics , painkiller and steroids( if there is severe inflammation) can reduce your infection and can lead to improvement in your mouth opening. Attempts can be done to increase mouth opening manually by dentist under local anaesthetic if required. Once your mouth opening is improved you should get your tooth treated or removed depending on the condition of tooth that whether it can be saved or not. But firstly medication and if possible to start the treatment of tooth if it can be saved or removed can help in relieving faster. Hope you get well soon.. Thanks and regards.. Dr.Honey Nandwani Arora.