From Baby to Adult Teeth: Understanding the Transition and Its Impact on Health

The role of baby teeth:

Baby teeth are crucial to the development of the mouth and jaw, shaping the structure of the mouth that will allow for future chewing and speaking. The 20 baby teeth will begin emerging at around 6 months of age, serving as placeholders for future teeth, and ensuring that these future teeth are able to grow in when they are needed. These early teeth also play a useful role in serving as testers for the development of oral hygiene habits. Young children and infants are unable to brush their own teeth, not learning these skills until they are several more years old at around 4-6. With the permanent teeth not coming in until around 6 or 7 years old, this allows for time to pass so that children can learn and develop habits to preserve their teeth for as long as possible.

Beyond serving as placeholders, baby teeth play a key role in helping children pronounce words correctly and chew food efficiently, both of which are crucial for proper nutrition and speech development. Also, important to note, of the 20 baby teeth, there are no premolars or wisdom teeth, with the need for these teeth not coming into greater importance until later in life.

The role of adult teeth:

As baby teeth fall out, adult teeth will begin to take their place. These teeth are larger and stronger, with more of them, increasing in count from 20 baby to 32 adult teeth. Not all of these teeth begin to push through at the same time, with the original 20 being pushed out one at a time. By around the age of 13, one will most likely have 28 adult teeth. The 4 wisdom teeth tend to develop at around the age of 17-21 years old. While many end up having to get their wisdom teeth removed, they historically played a key role in earlier generations. In earlier times, they allowed for a larger diet of raw plants and animals, provided increased chewing power of tough foods, and supported the structure of the jaw. Since our modern diets have greatly changed, the need for wisdom teeth has reduced and the overcrowding caused by these teeth can be more of a nuisance than beneficial.

What are the roles of each of our teeth?

With adults having 32 teeth, it is fascinating to learn what each of them actually do and why we have them in the first place. First, we have 8 incisors, 4 on the top and 4 on the bottom. These teeth are the first to come in and are crucial in allowing us to cut into and tear off chunks of food when we are eating, The second type of teeth are the canines. These are the 4 sharp teeth on either side of the incisors, 2 on the top and 2 on the bottom. These teeth are the sharpest and are heavily involved in the ability to cut through and tear away food including meats and other chewy foods. The third type of tooth is the premolars, next to the canines. There are 8 of these teeth as well, 4 on the top and 4 on the bottom. These teeth are used for tearing, crushing, and grinding up food so that it can be more easily digested and absorbed throughout the body. Lastly, there are 3 sets of molars numbering 12 teeth in all, 6 on the top and 6 on the bottom. These are the flatter teeth all the way in the back of the mouth that handle the majority of chewing that an individual does. The first and second molars tend to be lifelong teeth assuming none are lost through time, but the third molars (wisdom teeth) are the ones often taken out in surgery if overcrowding is present in one’s mouth. All of these teeth are critical to the act of digestion and ensuring we are able to get the nutrients needed each and every day.

Do other mammals replace their teeth?

With humans having 2 sets of teeth, one may wonder if this is common among all animals or unique to humans.  Most animals follow one of two systems, termed monophyodonts or polyphyodonts. Monophyodonts have just one set of teeth for their entire life. Many animals with a short life span, like rodents, tend to have this system of teeth, not requiring multiple sets throughout their life. This can be a method of conserving energy and using that energy it might take to generate new teeth into something necessary for survival. Polyphyodonts are those that continuously replace their teeth. Sharks are an example of this and regularly have teeth falling out and being replaced by new teeth. Interestingly, some sharks can go through around 30,000 teeth over the course of their lives, highlighting the regular generation of teeth that these animals experience. Other species have even more unique patterns, for example, wallabies only replace their premolar teeth. These unique tooth replacement methods highlight the amazing adaptations in the animal kingdom, setting up individual species for what they need to survive.

Sources:

Brichford, Connie. “The 4 Types of Teeth and How They Function.” EverydayHealth.com, 28 Aug. 2017, www.everydayhealth.com/dental-health/basics/types-teeth-how-they-function/.

“Why Do We Have Two Sets of Teeth Dental Care Report.” Dental Care Report, 2025, www.dentalcarereport.com/why-do-we-have-two-sets-of-teeth/. Accessed 11 Nov. 2025.

Assessed and Endorsed by the MedReport Medical Review Board