Why Do We Have Two Sets of Teeth? Baby Teeth vs. Adult Teeth Explained

Discover why we grow baby teeth first, how they prepare us for our adult smile, and what dentists do to keep both sets healthy.
Posted on May 06, 2025
Side-by-side illustration of a baby tooth and an adult tooth isolated on a white background
A side-by-side visual showing the difference in size and root structure between baby and adult teeth.

Have you ever wondered why children grow a set of baby teeth only to lose them later? It might seem like nature’s redundancy, but there’s a smart reason for it. The transition from baby teeth to adult teeth is an important part of how our mouths grow and develop.

At Pecan Tree Family Dentistry, we love helping parents and kids understand the amazing design behind our smiles—starting from the very first tooth.

🍼 Baby Teeth: The First Set

Also called “primary” teeth, baby teeth begin to erupt around 6 months of age. By age 3, most children have 20 baby teeth. Though temporary, they play a crucial role in a child’s development.

Why Baby Teeth Matter:

  • They help children chew food properly
  • They assist in speech development
  • They hold space and guide adult teeth into the correct position
  • They support facial structure and confidence

Even though baby teeth eventually fall out, they deserve the same level of care as adult teeth. Routine brushing, flossing, and early dental visits help prevent decay and set the stage for a lifetime of healthy habits.

📌 Related: Establishing a Dental Home Early

😁 Adult Teeth: The Permanent Set

Between ages 6 and 12, children begin to lose their baby teeth as adult (permanent) teeth erupt. These larger, stronger teeth are built to last a lifetime—if properly cared for.

Adults typically have 32 teeth, including wisdom teeth. These new teeth require more space, which is why they appear only after the jaw has grown large enough to accommodate them.

Want to learn more about the last teeth to erupt? Read our blog: Why Do We Get Wisdom Teeth?

🦷 Why Not Just One Set of Teeth?

Babies are born with small jaws that simply can’t hold full-sized adult teeth. Baby teeth serve as a training set—helping kids eat, speak, and grow until they’re ready for the adult versions.

Think of it like learning to ride a bike with training wheels first—it’s all part of the process.

🧒 How Dentists Support Both Sets of Teeth

At Pecan Tree Family Dentistry, we offer age-appropriate care to protect teeth at every stage.

For young children, this includes:

  • Gentle cleanings
  • Fluoride treatments
  • Dental sealants for cavity prevention

For teens and adults, we offer full preventive and restorative care—tailored to every phase of life.

📞 Ready to schedule your family’s next visit? Book online today or call us at (972) 562-0767.

By Peter J. Kim, DDS

Dr. Peter J. Kim, DDS, is a highly skilled dentist in McKinney, TX. He earned his dental degree from the prestigious University of Michigan School of Dentistry and completed his residency in New York City. Dr. Kim is passionate about providing exceptional dental care and stays at the forefront of the field through advanced techniques and continuous education. Dedicated to serving the McKinney community, Dr. Kim offers a wide range of services, ensuring personalized care for every patient.