Hi,
I know a lot of people think children should follow a time table but I have to say each child is different. If your child isn't ready to give up that bottle and it is still taken away guess what they will turn to. Their thumb, their fingers, sucking a blanket, etc.... My daughter fell and knocked out her front top tooth. She had to go off the bottle cold turkey at 13 or 14 months. She sucked her two middle fingers on her right hand until she was nearly in Jr. High. Her jaw is compressed and from the side she looks weird, of course her teeth are crooked, her fingers are permanently crooked. When we went to check on braces for her the Dr. showed us all the damage she had from the sucking. He explained she had still had the urge to suck when she was little. It is a basic need they are born with for survival. She wasn't ready. I would always take her fingers out of her mouth every time I saw them in there and it was a constant battle for over 9 years. Habits like that are nearly impossible to break.
In all my years of Child Care I only saw a couple of kids with bottle mouth teeth. One was a 3 yr. old who carried a milk bottle around sucking on it ALL the time. The other was a little girl that had poor genetics. Both of her parents had really bad teeth, maybe she just had weak enamel.
If you really want to get your child off the bottle it will take a couple of weeks at most. Get all the bottles "out of site out of mind" and just be strong. Offer his favorite drink in the tippy cup and another drink in the bottle.
If you let the child go ahead and keep the bottle a bit longer but still have concerns then take them to a pediatric dentist, regular dentist's are not experts on baby teeth, ask the dentist for suggestions. I think using Nursery Water from Wal-Mart is a good idea when offering water or juice made from concentrate, brushing their little teeth with the Orajel toddler Training Toothpaste Tooth Paste, it has no fluoride and is safe to swallow. There are lots of things you can do to help protect them from getting horrid teeth.