Can I ask (maybe a dumb question) why we need to get rid of the bottle? Is there actually a medical/health reason, or is it more because they can't be 20 and drinking milk from a bottle, so at some point you have to phase it out?

Someone mentioned teeth- At some point soon-ish I will make sure DS has his teeth brushed after his bed-time bottle, so I'm not concerned about decay from milk sitting on them, but is there another teeth issue regarding bottles?

Sorry if this is a silly question!!