Most people have four wisdom teeth, one in each corner of the mouth. They sit at the very back of your upper and lower jaws, behind your second molars. But not everyone has all four, and some people have none at all.
The Standard Number
A full set of adult teeth includes 32 teeth, and the last four of those are your wisdom teeth (also called third molars). You’d have one on the upper left, one on the upper right, one on the lower left, and one on the lower right. They typically come in between the ages of 17 and 21, making them the last permanent teeth to appear. The process itself takes years: the tooth calcifies, the crown forms, the root develops, and then the tooth finally pushes through the gum.
Many People Have Fewer Than Four
Having fewer than four wisdom teeth is surprisingly common. Some people are simply born without one or more of them, a condition called third molar agenesis. Rates vary widely by population. Studies have found that about 10% of African Americans are missing at least one wisdom tooth, compared to roughly 25% of people in Chile, 30% in Malaysia, and as high as 41% in Korea. One study from India reported a 46.7% agenesis rate in its sample group.
Among those who are missing wisdom teeth, the breakdown isn’t even. In one large radiographic study, about 20% of patients were missing a single wisdom tooth, 21% were missing two, 3% were missing three, and just under 2% were missing all four. So having one, two, or three wisdom teeth is perfectly normal.
Can You Have More Than Four?
Yes, though it’s rare. Extra teeth beyond the standard set are called supernumerary teeth, and when they appear behind wisdom teeth, they’re sometimes called fourth molars. The prevalence of supernumerary teeth falls between 0.1% and 3.8% of the population. One five-year study in Japan found fourth molars in just 0.32% of patients. Most cases happen on their own without any underlying condition, though extra teeth can also be associated with certain genetic syndromes affecting the head and face.
Why Wisdom Teeth Exist at All
Wisdom teeth were useful to early human ancestors who ate tough, uncooked foods that wore down their teeth over time. A third set of molars arriving in early adulthood helped replace that lost chewing surface. But as humans began cooking food and eating softer diets, jaw size gradually shrank over thousands of generations. The result: many people still develop wisdom teeth, but their jaws no longer have enough room for them to come in properly. According to the Smithsonian Institution, the teeth may still form inside the jaw but simply can’t erupt into a useful position.
This mismatch between tooth count and jaw size is a big reason wisdom teeth cause so many problems today. A large meta-analysis found that about 37% of people have at least one impacted wisdom tooth, meaning it’s trapped beneath the gum or blocked by other teeth. When calculated per individual tooth rather than per person, roughly 46% of wisdom teeth are impacted.
How to Find Out Your Number
You can’t reliably count your wisdom teeth just by looking in the mirror, because some may be fully hidden beneath the gum line or still developing inside the jawbone. A panoramic dental X-ray, which captures your entire mouth in a single image, is the standard way dentists identify how many wisdom teeth you have, where they’re positioned, and whether they’re impacted. For more complex cases, a cone beam CT scan creates a 3D image of your teeth, jaws, and surrounding nerves.
Most people get their first panoramic X-ray in their mid-to-late teens, which is when wisdom teeth typically become visible on imaging even if they haven’t broken through the gums yet. If you’ve never had one, your dentist can take one at any age to give you a definitive count.