Adults have 32 permanent teeth, including four wisdom teeth. Children have 20 primary (baby) teeth. The actual number in your mouth at any given time depends on your age, whether your wisdom teeth have come in, and whether you’ve had any removed.
Adult Teeth: The Full Set of 32
A complete adult mouth contains 32 teeth, split evenly between the upper and lower jaws. Each jaw holds 16 teeth arranged in a specific pattern:
- 8 incisors (4 top, 4 bottom): the flat, thin front teeth that bite into food
- 4 canines (2 top, 2 bottom): the pointed teeth next to the incisors, used for tearing
- 8 premolars (4 top, 4 bottom): the mid-sized teeth behind the canines, used for crushing
- 12 molars (6 top, 6 bottom): the large, flat back teeth that grind food, including 4 wisdom teeth
Without wisdom teeth, the count is 28. That’s the number many adults actually have, since wisdom teeth are frequently removed or never erupt at all.
Children’s Teeth: 20 Baby Teeth
Most children have 20 primary teeth that emerge between about 6 months and 6 years of age. This smaller set includes incisors, canines, and molars but no premolars. The first teeth to appear are typically the lower central incisors, around 6 months. By age 3, most children have their full set of 20.
These baby teeth serve as placeholders. As the jaw grows, permanent teeth develop underneath and gradually push the primary teeth out. The transition starts around age 6 or 7, when the lower front teeth loosen, and continues into the early teens. During this mixed stage, a child has a combination of baby and adult teeth in their mouth at the same time.
When Permanent Teeth Come In
Permanent teeth don’t arrive all at once. The process spans roughly a decade. The first permanent teeth to erupt are the lower central incisors and the first molars, both appearing around age 7 to 8. The lateral incisors follow around age 9 to 10, with canines and premolars filling in between ages 11 and 12. The second molars typically arrive around age 13.
Girls tend to get their teeth slightly earlier than boys, though the difference is usually only a few months. By about age 13, most teenagers have 28 permanent teeth in place, with only the wisdom teeth left to arrive.
Wisdom Teeth and Why the Count Varies
Wisdom teeth, the third set of molars at the very back of the mouth, are the last to appear. They typically emerge between ages 17 and 25, though some never break through the gums at all. About 8 in 10 people have at least one wisdom tooth that doesn’t fully erupt.
Because human jaws have gotten smaller over the course of evolution, there’s often not enough room for these extra molars. When wisdom teeth come in at an angle or stay trapped beneath the gum line, they’re considered impacted and are commonly removed. This is why “32” is the textbook answer, but 28 is closer to what most adults actually have in their mouths.
Some People Have Fewer or More Than Expected
Not everyone follows the standard count. Some people are born missing one or more permanent teeth, a condition called hypodontia. It affects anywhere from 2.3% to 10% of the population worldwide, not counting wisdom teeth. The most commonly missing teeth are the upper lateral incisors (the ones next to your front teeth) and the second premolars.
On the other end, some people develop extra teeth. This affects roughly 0.1% to 3.8% of the population. Extra teeth most often appear near the upper front teeth or behind the molars. They’re usually detected on dental X-rays and removed if they crowd or displace other teeth.
How Many Teeth Adults Actually Keep
The number of teeth in your mouth changes over a lifetime, and tooth loss is more common than most people realize. According to CDC data from 2017 to 2020, adults aged 20 to 64 are missing an average of 2 teeth due to decay or disease, separate from any wisdom tooth removal. Among adults 65 and older, about 15.2% have lost all of their natural teeth entirely.
The causes are straightforward: gum disease and cavities account for the vast majority of tooth loss. Gum disease weakens the bone and tissue that hold teeth in place, eventually causing them to loosen and fall out. Cavities left untreated can destroy enough tooth structure that extraction becomes the only option. Injuries, grinding, and certain medications also contribute over time.
So while the biological answer is 32, the practical number for most adults sits closer to 28 to 30, once wisdom teeth and common losses are factored in.