and where can I find it, at a reasonable price?
Expect the numbness to wear off in about 2 hours. If the pain is severe call the dentist. He could have dislocated your jaw. If it is moderate, try ice and expect it to last 24-48 hours. (kind of like a pulled muscle in you jaw)
I might be able to help with question one Roller ball mice collect dust inside the area that the ball resides. So remove the ball cover and clean the rollers on the sides of the ball. Replace the ball and cover. Good luck
