As I think I mentioned, we have added tooth brushing to our evening routine. While they both like the feeling of the bristles against their teeth and gums, they like to be in charge of the brushes. In order to ensure that teeth get brushed, we bought two sets of brushes: one for them to hold, and one for us to use. We used the same technique when we began using utensils to eat.
Emaline still likes to be in charge and would prefer holding both brushes.