My mother has recently had a filing and had an injection in the gum to numb the pain, while she was given the injection by the dentist she felt a sharp pain in her throat, a week later and she still has a sore throat and can hardly move her jaw and is in discomfort when talking, she has spoken to her dentist and he does not know what has caused it, my mother does have quite a few allergies, any ideas what it could be?