I've noticed my 16mo has bad breath. I don't notice it every day but have noticed it quite a bit. We do clean his teeth every morning and every night but he doesn't like it and just bites on to the toothbrush (any tips on how to get him to just let it happen properly?). He sucks his thumb a lot so I'm wondering if the excess saliva also doesn't help? He is also currently teething but wouldn't see how that would create bad breath. Any thoughts?