Baby bottle mouth happens when sugars from liquids in the bottle stay in your baby’s mouth behind her front teeth long enough for the sugars in those liquids to be converted into acid by the natural bacteria in her mouth. This acid then eats away at the fine layer of enamel on her new teeth and forms cavities. It can be hard to spot because it often starts on the backs of your baby’s teeth, and it's only visible once it has advanced to the front.
Luckily, it’s also very easy to prevent.
The first and best way to avoid baby bottle mouth is to avoid putting your baby to bed with a bottle. When she is sleeping, her mouth doesn’t make as much saliva as it does during the day, so if she falls asleep with a bottle, the sugars from whatever she is drinking will stay in her mouth for much longer than they normally would. Juice, milk, formula and even breast milk contain these sugars, so it’s best to avoid bringing the bottle to bed.
Nighttime isn’t the only time when sugars find their way into your baby’s mouth, though! It’s best to not let her have a bottle in the place of a pacifier, and to not dip pacifiers in any kind of sugary substance. The shape of bottles and sippy cups allows sugar to get trapped behind your baby’s front teeth. One way to avoid this is to introduce her to real cups instead of sippies when you think she is ready to move on to a more sophisticated drinking utensil. She might take a little longer to master an uncovered child's cup than she would with a sippy cup, but she will have to learn it eventually, so why not start early and protect her teeth at the same time?
Finally, it’s important to start cleaning your baby’s teeth as soon as she has them. New guidelines from both the American Dental Association and the American Academy of Pediatric Dentistry recommend starting babies on fluoride toothpaste as soon as their new teeth start to erupt, but the amount of toothpaste shouldn’t exceed more than a smear the size of a grain of rice. Excess toothpaste can be wiped out of your baby’s mouth when she is too young to spit on her own, but the ADA says that rinsing can take away from the benefits of fluoride. On the other hand though, more than the recommended rice-grain-sized smear of toothpaste could put your baby’s new teeth at risk of a chalky white discoloration. The ADA suggests brushing babies’ teeth twice a day. Continue to clean her gums the way you have been, until more teeth come in.
With a few precautions, there’s no reason for baby bottle mouth to be any part of your or your baby’s lives, so as those new teeth come in, try not to worry too much, and just enjoy her brand-new smile.