A milk tooth is one of the first set of teeth that grow in a child's mouth, also called a baby tooth or primary tooth. These teeth start appearing when you're around six months old and eventually fall out to make room for your permanent adult teeth.

Most children have 20 milk teeth by age three: eight incisors for biting, four canines for tearing, and eight molars for chewing.

Starting around age six, milk teeth begin to loosen and fall out as the adult teeth growing underneath push them out. Many kids wiggle their loose milk teeth with their tongue until they finally pop free. The process continues until around age twelve, when the last milk teeth fall out.

Though milk teeth are temporary, they serve important purposes. They help children eat solid food, speak clearly, and hold space in the jaw so permanent teeth can grow in properly. That's why dentists say taking care of milk teeth matters, even though they won't last forever.

Some families celebrate lost milk teeth with traditions like the Tooth Fairy, who supposedly exchanges teeth left under a pillow for coins or small gifts.