hello, my tooth cracked on the right side.. I would say its the 5th tooth, but I know dentist number the teeth differently, anyway half of the tooth is still in. There have been times when I ate something sweet and it hurt that tooth area alot. Now when I rub my face as if to wipe something from my cheek, using a downward swipe from my nose, I feel this pressure.. and when I feel my gums I do feel a knot or something. I feel pressure when I push on the knot. Is it dangerous? Will it cause a brain infection?