Hi Manesh,
This happened to me. I had a root canal re-treatment. Three days later, the left side of my face along the trigeminal nerve line...exploded with pain. Most of it is documented here in a thread. I thought my life was over. I lost over thirty pounds in about a month, I had to go live with my parents, because I was crippled and helpless with pain. My dentist and the endodontist--although very sympathetic insisted that it was not from the root canal. In desperation, I landed at my PCP's office. She had known what was going on because I went to her early on for help with the massive anxiety when this all started. I did not address the pain with her at first because the dentist and endo kept assuring me that the tooth would "quiet down". It never did. In the 6th or 7th week, I had the tooth extracted. I demanded this. My dentist wanted to crown it,while I was in all this pain. I refused. The oral surgeon took it out and we were both horrified at the smell. Like a dead body...and the gunk inside the tooth was multi colored... It was completely infected. Pain continued. I landed at my PCP basically having suffered a nervous breakdown. I couldn't stop crying, the pain was constant. She ordered an MRI to rule out osteomyelitis of my jaw. I had had a CTscan of my head/jaw around the 6th week when I fainted from pain and was taken to the ER> Both were clear, thank God. We then concentrated on a two prong approach--dealing with the nerve pain, pain management, and anxiety control. The up shot of all this is--is that there is help. My pain was nerve pain--a burning, firey burning pain along the trigeminal nerve of the left side of my face and back behind my ear. Also constant throbbing...some electrical feeling tingling in my tongue...and roof of my mouth. We finally settled on a cocktail of meds that began to quiet all of this down. It took another two to three weeks. I think during the RC the endo hit a nerve in my face...and also she was up in there with a lot of needles to numb me both during the procedure and then three days later when I went in for the exploding pain. I think there was a lot of trauma to the area and maybe the swelling had pushed upon the nerves in my face... I hope this helps you--there very well could be a nerve pain med out there, if that is the cause of your pain...I know how horrible this is for you...and the debilitating nature of this whole episode. There is hope.