Just watched an item on TV where so-called Dentistry Experts recommend parents should clean their children's teeh themselves to ensure it's done regularly and properly. This should be continued until the child had its second teeth at age 14.
When I was that age (and many years previous) there would have been one hell of a row if I wasn't trusted to do something so obvious. I can understand staying with your child until it is obvious they have the right idea but to insist on doing it is going to affect self confidence and attitude and all sorts of things. Anyway who is to say the parent knows how to do it properly :-)