Kids lose 20 baby teeth in total. These are all the teeth that grew in during infancy and early childhood, and every single one eventually falls out to make way for the 32 permanent teeth that replace them. The process starts around age 6 and typically wraps up by age 12 or 13.
The 20 Baby Teeth by Type
Those 20 primary teeth break down into three types: 8 incisors (the flat front teeth used for biting), 4 canines (the pointed teeth next to the incisors), and 8 molars (the wider teeth in the back used for chewing). Each type appears in matched pairs on the top and bottom of the mouth, giving kids a symmetrical set that serves them through early childhood.
The 32 adult teeth that eventually take their place include all of these types plus 8 premolars and 4 additional molars (the wisdom teeth) that have no baby tooth predecessors. So 20 of the 32 adult teeth directly replace a baby tooth, while 12 erupt into new positions where no baby tooth existed before.
Which Teeth Fall Out First
Baby teeth fall out in roughly the same order they came in. The two bottom front teeth (lower central incisors) are almost always the first to go, followed by the two upper front teeth. After that, the sequence moves outward and backward through the mouth: lateral incisors, then first molars, then canines, and finally the second molars at the very back.
Most children lose their first tooth around age 6, though some start as early as 4 or as late as 7. The last baby teeth to go are usually the second molars, which tend to fall out between ages 11 and 13. By age 13, most children have a full set of adult teeth in place, minus the wisdom teeth that come in later during the late teens or early twenties.
How Baby Teeth Actually Fall Out
A loose baby tooth isn’t just randomly detaching. Underneath it, the permanent tooth is pushing upward, and the body responds by gradually dissolving the baby tooth’s roots. Specialized cells break down the root material from the bottom up, essentially eating away at the anchor holding the tooth in place. At the same time, the soft tissue inside the tooth, including the nerve and blood supply, is slowly absorbed. This is why wiggling a loose tooth usually doesn’t cause much pain or bleeding: by the time it’s truly ready to come out, most of the living tissue is already gone.
The pressure from the erupting permanent tooth plays a key role in triggering this whole process. Cells in the surrounding bone and the baby tooth’s own root tissue respond to that mechanical force by ramping up the signals that drive root breakdown. It’s a coordinated demolition project that clears the path for the new tooth.
When a Tooth Falls Out Too Early
Sometimes a baby tooth is lost ahead of schedule because of decay, injury, or infection. This matters because baby teeth do more than chew food. They hold space in the jaw for the permanent teeth developing underneath. When one disappears too early, the neighboring teeth can drift into the gap, potentially crowding out the adult tooth that’s supposed to come in later.
Back teeth are the bigger concern here. Losing a molar early is more likely to cause spacing problems because molars help maintain the width of the dental arch. Front teeth are less of an issue since their permanent replacements usually erupt relatively quickly after the baby tooth is gone. If your child loses a tooth more than a year before the permanent tooth is expected, a dentist may recommend a space maintainer, a small device that keeps the gap open until the adult tooth is ready. If the replacement tooth is likely to come in within six months, a maintainer is often unnecessary.
X-rays can show how far along the permanent tooth is in its development and whether the surrounding teeth have started shifting. Kids with naturally spaced-out teeth are at lower risk of crowding problems, while those with already-crowded mouths are more likely to need intervention.
When Baby Teeth Don’t Fall Out on Time
The opposite problem, a baby tooth that refuses to leave, is also common. This is called over-retention, and it’s one of the most frequent reasons dentists end up extracting baby teeth, particularly the lower front teeth. Sometimes the permanent tooth erupts right behind the baby tooth rather than pushing it out, creating a brief “shark tooth” appearance that often resolves on its own as the tongue pushes the baby tooth forward.
Other reasons a baby tooth might need to be pulled include severe decay that has damaged the tooth beyond repair, orthodontic planning to prevent or correct alignment issues, or trauma from an injury. Canine teeth are especially likely to be extracted for orthodontic reasons, while molars are more commonly lost to cavities. In many cases, though, a slightly delayed timeline is perfectly normal. Kids develop at different rates, and a tooth that’s a few months “late” rarely signals a problem. A dental X-ray can confirm that the permanent tooth exists and is on its way.
What the Full Timeline Looks Like
Here’s a general picture of what to expect across the years:
- Ages 6 to 8: The eight incisors (four on top, four on bottom) loosen and fall out, starting with the bottom center pair.
- Ages 9 to 11: The first molars and canines come out. During this stage, kids often have a noticeable mix of small baby teeth and larger adult teeth.
- Ages 10 to 13: The second molars, the last baby teeth standing, finally shed. By the end of this window, most kids have 28 permanent teeth in place.
The remaining four adult teeth, the wisdom teeth, typically appear between ages 17 and 25, bringing the total to 32 for those who develop all of them. Many people never get all four, and plenty have them removed before they fully erupt.
Every child’s timing varies by a year or more in either direction, and girls tend to lose teeth slightly earlier than boys. The sequence matters more than the exact age. As long as teeth are falling out in roughly the expected order and permanent teeth are following behind, the process is on track.