My 21mo son has what looks like plaque along the gumline of his bottom front 4 teeth. i've tried brushing but it's hardened. is it from too much milk?

No: This is not due to too much milk. He should see a pediatric dentist.

No: It is from the milk staying on his teeth after he finish drinking you should rinse his mouth or let him drink some water instead , as far as the hardened part it became tartar deposit because it wasent brushed right away and you should take him to the dentist to take care of that.

No : It does not sound like something that would be caused by milk. You should have your child seen by a pediatric dentist to evaluate his teeth and also advise you on what you can do to avoid the build up in the future.

Not plaque: Plaque is soft, mostly bacteria mixed with some food debris. If bacteria die, calcium from saliva precipitates out into the plaque matrix and forms hard calculus (tarter). You can't remove it. See dentist for removal and instructions on preventing new accumulations. Both plaque and calculus can permanently damage gums, so seek rx soon.

Calculus: at the age of 21 months, your child should have already seen a pediatric dentist at least one time. If you haven't taken your child in yet, make an appointment for an exam and treatment if needed. If the plaque is hardened it could be calculus/tartar than needs to be removed with a professional cleaning. Your dentist will tell you.

Baby bottle decay: Baby bottle tooth decay is a condition caused by the frequent exposure of a baby's teeth to liquids containing sugars like milk. Parents should first bring their child to the dentist when the child is between 6 and 12 months old. Take care.