fascial pain after dental work

I had a filling placed between two back teeth and the numbness wore off around 4pm and later that night the whole right sidei of my face and neck started having severe pain.  Two days later when I called the denist he said the shot was placed through the fascial muscle and that it was normal to have spasms, but it is constant pain and spasms when I try to chew.  Is that normal and how long will it last???  I am taking about 9 Motrin a day ontop of Loratab 7.5, using a heating pad and still have pain.  Could it have caused a sinus infection???  Thanks

[Jerome Tsang, DDS]

Is there any swelling or increased pressure in the area?  It may be an infection if its progressively getting worse.  

There may have been some trauma (bruising) to the cheek if the fillings were done on the bottom teeth and a mandibular or inferior alveolar block injection was given.  If that is the case, definitely continue with the pain medications to help with the inflammation, stretch the muscles out every hour and apply an ice/heat pack every few hours to help relieve the soreness.  

If its in the upper area, usually this isn't a problem.  It'd be pretty rare for a sinus infection to develop on a filling.  That may happen with an extraction of an upper tooth.