Teeth brushing.... (10 pts for help!!)?

i have a 20 month old and she is stubborn. she wants to do it all by herself but of course isnt old enough yet. so i brush hers first,i praise her ridicuously for letting me brush them for her (kinda like you would when they first pee in the potty). then i let her hold it and i put my hand over hers to try to show her what to do,and lastly i let her do it on her own. she has learned that after she lets me help her that she gets to do it on her own. this may not work for every child but it has mine. good luck :)