Since our daughter got teeth I've been brushing them in the morning and her father has been brushing them at night. Once she reached the stage of wanting to do it herself we would let her brush them for a bit and then finish up ourselves.
Recently she has been refusing to cooperate with us brushing her teeth, though she continues to "brush" her own quite happily. Unfortunately we can't just let her do it because while she will brush the very front teeth on the side that faces forward, she won't brush the other side of them or the back teeth at all. Which is to be expected, she's 2.
The problem is how to get her teeth brushed. Her father will turn her upside down and basically pin her arms in place and then just do it over her protests. I'm not really comfortable with that, but even if I was I can't physically do it.
I've tried a lot of "this is going to happen then this" talk ahead of time, and play where she brushes my teeth and then I do hers, letting her choose a toothbrush, even using Mama's toothbrush. The only thing she is interested in is using my electric toothbrush, and I am pretty sure that isn't designed for a little person's mouth.
We've tried a form of time in with her: we don't leave the bathroom until you let me brush your teeth. No yelling or anything, just calm sitting and cuddling and periodically asking if she is ready. It worked once. The second time she cried and railed and kept me there for 45 minutes until she started to fall asleep in my arms. She'd been asking to go sleep for about 20 minutes at that point and I was feeling pretty awful, so we just took her to bed. Sometimes she asks for one parent rather than the other, which would be fine with us, but she still doesn't cooperate with the parent she asks for.
We're basically united on the gentle discipline front and on the view that she is too young for anything other than redirection and modelling of correct behaviour. But her father has much less patience than I do and is a huge hygiene freak. So I am concerned that he will lose his temper over this if we don't find a solution. Also in general I would say he doesn't place as much value on respecting her autonomy and bodily integrity as I do. In short, while I might be tempted to let it go for a couple of weeks so that the built up patterns of resistance could dissipate, he's not going to agree to that.