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As described by you, the redness on gums near to the decayed tooth might be a sinus opening due to a long standing Chronic Periapical abscess
. It is possible to experience numbness in your chin part because of such an infection.
It is advisable to consult a local dentist
atthe earliest who will tell you if a Root canal treatment
can be performed or in case of grossly destructed tooth, it can be extracted.
If Acetomenaphin is not releiving your pain try a combination of Aceclofenac
. Also Antibiotics should be used- Cap Amox 500 mg Thribe daily for 5 Days after food and Tab Metrogyl 400 mg twice daily for 3 days after food.
I assume you are above 12 years of age with body weight consistent with your age and sex.