I had dental work done today and had novacaine put in my left cheek (5 or so needles worth). It is now 8 hours later and I have a weird feeling in my left arm and would like to know if these two things are related and if it is something I should be worried about. My left hand, especially the knuckles, feel like I punched a wall, pain increases when I make a fist, and the feeling is beginning to spread up my arm.