It is not at all normal to experience pain one year post extraction. Can i know which side of the tooth was extracted upper or lower? If you had upper tooth removed than there are chances of sinus infection but if the tooth removed was lower that it can be due to trauma to the jaw bone.
I would suggest you to visit the dentist from where you got the tooth extracted and get and X-ray done for the exact diagnosis of pain...for more info on tooth pain visit the link...http://www.identalhub.com/dental-pain-during-and-after-tooth-extraction-870.aspx
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