A baby tooth is one of the first set of teeth that grows in a child's mouth, starting around six months of age. These teeth are smaller and whiter than adult teeth, and they're temporary: they'll eventually fall out to make room for permanent teeth. Most kids have all 20 baby teeth by age three.

Baby teeth matter more than you might think. They help children chew food properly, speak clearly, and they hold space in the jaw for the adult teeth growing underneath. When a baby tooth gets loose and wiggly, it means the permanent tooth below is ready to push through. Kids usually start losing baby teeth around age six or seven, though the timing varies. The last baby teeth typically fall out around age twelve.

Baby teeth are also called primary teeth or deciduous teeth (deciduous means “falling off,” like leaves from a tree in autumn). You might also hear them called milk teeth because they first appear when babies are still drinking milk. Many families have traditions around lost baby teeth, like leaving them under a pillow for the tooth fairy.