Here is a new system that uses LEDs on a special toothbrush with a webcam to track the movements during brushing.  The computer calculates what areas need additional attention.  They say it helps kids brush twice as good. I’m interested to find out when these systems will start showing up at dentist’s office.

Source: http://technology.newscientist.com/article/dn13598-computerised-toothbrush-makes-oral-hygiene-a-game.html