A full set of adult teeth contains 32 permanent teeth. That total breaks down into four types: eight incisors, four canines, eight premolars, and 12 molars (including four wisdom teeth). In practice, many adults have 28 teeth because their wisdom teeth have been removed or never came in.
The Four Types of Adult Teeth
Each type of tooth has a distinct shape built for a specific job in breaking down food.
- Incisors (8): The four front teeth on top and four on the bottom. These are your flat, thin-edged cutting teeth, the ones you use to bite into an apple or slice through a sandwich.
- Canines (4): The pointed teeth flanking your incisors, one on each side of both jaws. Their sharp tips are designed for gripping and tearing tougher foods like meat.
- Premolars (8): Sitting just behind the canines, two on each side of both jaws. They have a flatter chewing surface with two raised points, making them useful for both tearing and crushing food.
- Molars (12): The large, broad teeth at the back of your mouth, three on each side of both jaws. Their wide surfaces handle the heavy grinding that breaks food down into small, swallowable pieces. The last four molars in this group are your wisdom teeth.
When you chew, these groups work in sequence. Your front teeth cut or tear off a bite, then your tongue pushes the food back onto the flat surfaces of your premolars and molars for grinding. Your jaw moves side to side during this phase, guided by the shape of those back teeth, increasing the food’s surface area so your digestive enzymes can work more efficiently.
When Adult Teeth Come In
Permanent teeth don’t all arrive at once. The process takes roughly 15 years. The first permanent molars typically push through around ages 6 to 7, which is why dentists sometimes call them “six-year molars.” These are notable because they don’t replace any baby tooth. They simply emerge behind the existing primary teeth.
From there, the remaining permanent teeth gradually replace baby teeth through childhood. Most children have 28 of their 32 permanent teeth by age 13. The final four, the wisdom teeth (or third molars), don’t usually begin erupting until somewhere between ages 17 and 21. Some people’s wisdom teeth never develop at all.
Why Most Adults Have Fewer Than 32
While 32 is the textbook number, the reality looks different. CDC data from 2024 shows that the average number of teeth decreases steadily with age: adults aged 20 to 34 have about 27 teeth on average, and by ages 50 to 64, that number drops to around 23. Tooth loss from decay, gum disease, and injury accounts for much of this decline. Among seniors 65 and older, about 17% have lost all of their natural teeth.
Wisdom teeth are the most commonly missing or removed. Many people have them extracted in their late teens or twenties because they’re impacted (stuck below the gumline), growing in at odd angles, or crowding other teeth. After wisdom tooth removal, a full healthy set is 28.
Being Born With More or Fewer Teeth
Some people are genetically programmed to develop a different number of teeth. Congenitally missing teeth (not counting wisdom teeth) affect roughly 3 to 10% of the population, or about one in every 10 to 12 people. Women are affected slightly more often than men, at a ratio of about 3 to 2. The condition happens when a tooth simply never forms during development. When fewer than six teeth are missing, it’s considered a mild form. When six or more are missing, it’s a more significant condition that may affect chewing and bite alignment.
The opposite can also happen. Some people develop extra teeth beyond the standard 32, a condition called hyperdontia. These additional teeth most often appear near the upper front teeth or behind the molars and sometimes need to be removed if they disrupt the alignment of surrounding teeth.
How Tooth Count Differs From Children
Children start with a set of 20 primary (baby) teeth: eight incisors, four canines, and eight molars. There are no premolars in the baby set. When the permanent teeth come in, the 20 baby teeth are replaced and 12 additional teeth appear (eight premolars and four wisdom molars), bringing the potential total to 32. This transition period, when a child has a mix of baby and permanent teeth, is sometimes called the “mixed dentition” stage and typically lasts from around age 6 to 12 or 13.