My 1-year-old used to love having her teeth brushed, but now just clamps her mouth shut and refuses to let me do them. She's a bit better in the morning and late afternoon, but after her last bottle of the night she really kicks up a fuss when she sees the brush. I don't want to force it into her mouth and make her scared of the brush. How can I get her to clean them? And how worried should I be if she isn't brushing them every single night? I don't want her to ruin her teeth. Sometimes she'll chew on the brush for a minute or so. Is this enough?