From Baby Teeth to Permanent Teeth: Learn How They Grow

An amazing amount of oral development occurs in a child as they’re growing up – and it even begins before they’re born. To help parents understand what to expect (including what to watch out for), this post describes the stages of dental development from baby teeth through eighteen years of age. As a family dentist, I provide dentistry for everyone from children to seniors. But I’m always amazed by the stages of tooth development, including the fact that it begins before a child is born. Let’s take a closer look at the different stages:

Stage One: Age 0 to 3

This stage of oral development takes up the largest section of this post, and no wonder. It actually starts before a child is born! The first tooth buds, or baby teeth, develop at 6 weeks of pregnancy. Our permanent or adult teeth actually form at 4 months of pregnancy. Naturally, these teeth don’t break through at this early stage, but they’ve already formed in utero.. After the baby is born, the fun begins. On average, teeth erupt between 4 and 6 months of age. The first baby teeth to appear are the bottom front two teeth, called the mandibular central incisors. The next to erupt are the matching pair for the upper jaw, called the maxillary central incisors.  The lower teeth tend to erupt before the upper teeth. This graphic from the American Dental Association shows the order in which teeth erupt, and their names. While the timing for these eruptions vary between children, by the age of three most children have a full set of primary (or baby) teeth. That’s a total of 20; 10 on the top and 10 on the bottom. Within this first stage, the ADA recommends a visit to the dentist at age 1 to check the development of mouth and teeth, and to discuss any concerns and questions. This visit is primarily to educate parents on the upcoming development and how best to care for their child’s teeth. In between that first baby tooth their and first dental cleaning (we’ll get to that in a minute) you may notice your baby drooling, and attempting to stick everything in their mouths. These are signs of teething. Teething tends to be uncomfortable for infants and toddlers. I usually recommend a teething ring, chilled but not completely frozen. You may also use gentle massage in the sore area. Infant Tylenol can also relieve teething discomfort, but be sure to check with your pediatrician before administering. Also during this first stage, your child should transition from a bottle to a cup. By the of age three, your child should receive their first dental cleaning. We recommend the age of three because at this point, most children have all their primary teeth, and perhaps even more importantly, most three year-olds can sit in the chair and have their teeth cleaned. Visiting a dentist for the first time can create some anxiety with your child. To set minds at ease (yours and theirs), think about bringing your child in the next time you or an older sibling have a dental cleaning. Seeing mom or dad in the dentist’s chair will reassure them. In fact, it may even make them excited to get a cleaning like their parents or older sibling. One last note about this stage of development: Be sure to brush those baby teeth and floss. Yes, floss, even if there are large gaps between the teeth. Good habits start early. Finally, use only a training toothpaste without fluoride at this stage. Children aren’t good at spitting, and you don’t want your child ingesting a huge amount of fluoridated toothpaste.

Stage Two: Age 3 to 6

The stages get much less eventful from this point forward, but there are definitely plenty of big moments. For example, the first permanent molars erupt during this stage. These molars don’t displace any baby teeth, instead they’ll erupt behind the primary molars in the back of the mouth. Two molars will erupt on the top and two on the bottom by the age of five or six. I’d strongly recommend at this point that you get sealants for these teeth. A sealant is a protective coating that fits over the pits and grooves of the teeth and helps prevent cavities. Your child will also experience the wiggles at this point, as those baby teeth start to become loose and fall out. The bottom central incisors, the first to erupt, are also the first to become loose and fall out. Losing teeth can be an anxious time for children, but fortunately the tooth fairy is on hand for bountiful cash rewards to “fill the gap.” Note: The average payout from the tooth fairy is around $1.32. In the event parents need to spot the tooth fairy a few extra bills when she’s short on cash, I’d recommend keeping some singles on hand. We recently had to spot the tooth fairy a small loan, and we had nothing smaller than a $20 on hand. You can guess what went under the pillow, to my husband’s dismay.

Stage Three: Age 6 to 9

More visits from the tooth fairy are on the way. The lower central and lateral incisors will fall out, and permanent incisors will erupt in their place. There is a bit of a lull during the period as the rate of teeth falling out and erupting slows. You’ll note a difference between baby teeth and permanent teeth. Baby teeth tend to be smaller, flatter, and are naturally whiter than adult teeth. Sometimes, as early as the age of 7 or 8, if we notice a shortage of room available for the erupting larger permanent teeth, we recommend an evaluation by an orthodontist for possible palatal expansion.

Stage Four: Age 9 to 12

By now, children will have a pretty even mix of baby teeth and permanent teeth. By the age of 12, children should be brushing on their own. Second permanent molars will erupt behind the permanent first molars, so once again, we recommend sealants for those grooves and pits.

Stage Five: Age 12 to 18

By the age of 12 or 13, most children have lost their baby teeth. Baby molars should have been replaced by adult premolars at this point. For some adults, but the age of 18, our last permanent molars will erupt: The third molars, otherwise know as our wisdom teeth. Once these have fully erupted, a child will have 32 teeth – 16 on the top and 16 on the bottom. Now that I’ve taken you through some of the highlights of dental development, let me conclude by saying that the key to keeping teeth healthy throughout these early years, and onto your adult years, is by practicing good oral health habits. That includes brushing twice a day, flossing daily, and getting regular dental cleaning and check-ups every six months.