It has always been a struggle with my son, now 37 months. We had about 4 months recently where it was slightly less of a struggle because he became interested in a calendar/sticker reward system (the reward was just placing a sticker on his calendar). But he grew bored with that, and we're now back in toothbrush hell.
We brush twice a day. The routine doesn't vary, and it's not like I spring this task on him out of the blue, but he still fights it tooth and nail every.single.time. He has five different kinds of toothbrushes, three kinds of toothpaste, books about brushing, etc. We might spend 30+ minutes each time negotiating, threatening, discussing, trying to somehow convince him it's better to do it the 'easy' way, meaning cooperatively. (And honestly, at this age and size, the 'hard' way isn't really an option anymore because while I *may* be able to restrain him (something I completely loathe in concept and practice), I've found that you cannot make them actually open their mouths.)
We often now resort to taking away privileges like his one cartoon/show a day, threaten to remove toys, etc. I dislike this punishment approach, but we've simply run out of ways to handle the situation and we grow pretty frustrated with him, honestly. Please help. I don't want to punish, be forceful, or manipulative, etc. But he has some decay on his two front teeth...not that this task would be any less important otherwise, but that's always in my mind as well.