Children have 20 baby teeth in total. These primary teeth come in a predictable pattern starting around 6 months of age, and most kids have their full set by age 3. That number holds steady until around age 6, when the first baby teeth start falling out and permanent teeth begin taking their place.
The 20 Baby Teeth, Broken Down
Your child’s 20 primary teeth are evenly split: 10 on top and 10 on the bottom. Each half of the mouth contains the same types of teeth in the same arrangement. In total, kids get eight incisors (the flat front teeth used for biting), four canines (the pointed teeth next to the incisors), and eight molars (the wider teeth in the back used for chewing).
Baby teeth are noticeably smaller and whiter than adult teeth. They have thinner enamel and shorter, thinner roots, which is part of why they eventually loosen and fall out so easily when permanent teeth push up from below.
When Baby Teeth Come In
The first teeth to appear are usually the two lower front incisors, which typically break through the gums around 6 months. From there, teeth tend to arrive in pairs, roughly following this order: the upper front incisors come next, then the lateral incisors (the ones flanking the front teeth), followed by the first molars, canines, and finally the second molars in the very back.
Most children have all 20 baby teeth by age 2.5 to 3. There’s a wide range of normal, though. Some babies cut their first tooth at 4 months, while others don’t see one until closer to their first birthday. Late teething on its own is rarely a concern. The American Academy of Pediatric Dentistry, along with the ADA and AAP, recommends that all children have their first dental visit during the first year of life, which gives a dentist a chance to check that everything is developing on track.
When Kids Start Losing Teeth
Around age 6, the process reverses. Baby teeth begin to fall out in roughly the same order they arrived. The lower front incisors are usually the first to go, followed by the upper front incisors. From there, the lateral incisors, first molars, canines, and second molars shed over the next several years. Most children lose their last baby tooth between ages 11 and 13.
During this transition period, your child will have a mix of baby teeth and permanent teeth in their mouth at the same time. This “mixed dentition” phase is completely normal and can last six or seven years. It’s also the stage where teeth can look uneven or crowded, since permanent teeth are larger than the baby teeth they’re replacing.
The Jump to 32 Permanent Teeth
Adults end up with 32 permanent teeth: eight incisors, four canines, eight premolars, and twelve molars (including four wisdom teeth). That’s 12 more teeth than the baby set, and the extras don’t all come from replacements. Premolars are a new tooth type that take the place of baby molars, and the permanent molars in the very back of the mouth grow into empty space behind the existing teeth rather than pushing out a baby tooth.
This distinction matters because the first permanent molars, which arrive around age 6, are easy to mistake for baby teeth. They appear behind the last baby molars without anything falling out first, so parents sometimes don’t realize these are adult teeth that need to last a lifetime. Keeping them clean from the start is worth the effort.
Wisdom teeth are the last to arrive, typically between ages 17 and 21. But many people never get all four, and some never develop them at all. When wisdom teeth don’t fully emerge or don’t develop, the final adult tooth count lands at 28 instead of 32.
When the Number Varies
Not every child ends up with exactly 20 baby teeth or 32 permanent teeth. Some children are naturally missing one or more teeth, a condition called hypodontia. A large systematic review found that about 6.4% of children worldwide are missing at least one permanent tooth (not counting wisdom teeth). Rates vary by population, ranging from roughly 2.7% to nearly 10% depending on the study. Girls are affected slightly more often than boys.
On the other end of the spectrum, some children develop extra teeth beyond the standard count. This is less common than missing teeth but still something dentists see regularly. In most cases, whether your child has one too many or one too few, a dentist can spot the difference on a routine X-ray and plan accordingly well before it causes any spacing or alignment issues.