Yes, humans lose their baby molars, but not their permanent ones. Children have eight baby molars (two in each quadrant of the mouth) that fall out between ages 9 and 12. These are replaced by premolar teeth, not by new molars. The permanent molars that arrive later are a separate set entirely, and once they’re in, they’re meant to last a lifetime.
Which Molars You Lose as a Child
Children grow 20 baby teeth, including eight molars, four on top and four on the bottom. These baby molars are the largest teeth in a child’s mouth and do the heavy lifting for chewing. They’re more bulbous than adult molars, with thinner, more spread-out roots.
Baby molars fall out in a predictable sequence. The first molars (closer to the front) shed between ages 9 and 11. The second molars (farther back) follow between ages 10 and 12. When each baby molar falls out, a permanent premolar tooth grows into its spot. So the replacement teeth aren’t actually molars at all.
The shedding process works through root resorption. Specialized cells, similar to the ones that break down and rebuild bone, gradually dissolve the roots of the baby tooth from below. This process is triggered by the developing permanent tooth underneath, which releases signaling molecules that activate the breakdown. As the root dissolves, the baby tooth loosens and eventually falls out, making room for its replacement.
Permanent Molars Grow In Without Replacing Anything
Your 12 permanent molars (three in each quadrant) are completely new additions. They don’t replace baby teeth. Instead, they erupt behind the baby molars as your jaw grows larger.
The first permanent molars come in around age 6 or 7, often before any baby molars have fallen out. Parents sometimes don’t notice them because they appear quietly at the back of the mouth. The second permanent molars arrive between ages 11 and 13. Wisdom teeth (third molars) emerge last, typically between ages 17 and 21, though many people never develop them at all. At least one in five people is missing one or more wisdom teeth entirely.
This means a child can have baby molars and permanent molars in their mouth at the same time. The first permanent molars sit just behind the baby second molars for several years before those baby teeth shed.
Why Adults Lose Permanent Molars
Permanent molars aren’t supposed to fall out, but they’re the teeth adults lose most often. The primary culprit is tooth decay, which accounts for roughly two-thirds of all permanent tooth extractions. Gum disease is the second leading cause, responsible for about 13% of cases. Trauma, impacted wisdom teeth, and orthodontic reasons make up the rest.
Molars are especially vulnerable because their chewing surfaces have deep grooves that trap food and bacteria. They’re also harder to clean thoroughly, sitting far back in the mouth where brushing and flossing tend to be less effective. Wisdom teeth are frequently extracted even when they haven’t decayed, because they often grow in at awkward angles or remain partially trapped beneath the gum line, causing pain or crowding.
What Happens When a Permanent Molar Is Missing
Losing a permanent molar sets off a chain of changes in your mouth. The jawbone in that area stops receiving the pressure signals it needs to maintain itself. Bone-destroying cells continue their normal work, but the bone-building cells slow down, so the jaw gradually loses density and volume at the extraction site.
Neighboring teeth begin to shift toward the gap over time. The tooth directly above or below the missing one can start to drift out of its socket, since it no longer has an opposing surface to press against. These shifts can change your bite alignment and make other teeth harder to clean, potentially leading to further problems down the line.
Some People Are Born Missing Molars
A small percentage of people never develop certain permanent teeth, a condition called hypodontia. Excluding wisdom teeth, this affects roughly 2% to 7% of the population depending on geographic background, with slightly higher rates in Europe and Australia than in North America. Most people with hypodontia are only missing one or two teeth, and the teeth most commonly absent are wisdom teeth, second premolars, and upper lateral incisors rather than the first or second molars. Still, congenitally missing molars do occur and may require orthodontic planning or prosthetic replacement.