A.M.
My son is 15 months and teeth brushing is an ORDEAL. In the morning, I am only able to get a couple good swipes before he pries his mouth shut. Night time is easier as I do it while he's in the bath. I recently got the toothbrush that plays music when you brush and he seems to be distracted by it long enough to let me get a good brush of his teeth before he shoves my hand and toothbrush away. I also almost lost my finger when attempting the fingertip one as well. ;)
Sometimes, if he watches his Dad brush his teeth at the same time that I brush his teeth, I am able to get a good brushing as well.
Another reason the bath is good is b/c I can also distract him with his waterproof froggie book while I brush his teeth. Unfortunately,its all about the distraction for now. I long for the day when he can brush his teeth himself. :)