Baby teeth are the first set of 20 teeth that develop during infancy and childhood. They include 8 incisors, 4 canines, and 8 molars, split evenly between the upper and lower jaws. Every one of these 20 teeth will eventually fall out and be replaced by a permanent tooth, but they play essential roles in your child’s development long before that happens.
The 20 Baby Teeth by Name and Position
Children develop five types of teeth on each side of the mouth, mirrored top and bottom. Starting from the center and working outward, here’s what each jaw contains:
- Central incisors (4 total): The two front teeth on the top and the two on the bottom. These are the flat, thin teeth used for biting into food.
- Lateral incisors (4 total): Positioned just next to the central incisors on each side, these are slightly smaller and also used for biting.
- Canines (4 total): The pointed teeth sitting next to the lateral incisors. Sometimes called cuspids, they help grip and tear food.
- First molars (4 total): Broader, flatter teeth behind the canines, designed for chewing and grinding.
- Second molars (4 total): The furthest back teeth in a child’s mouth, also used for grinding food.
That’s 10 teeth per jaw, 20 in total. Notably, baby teeth do not include premolars or wisdom teeth. Those only appear in the permanent set. So if you’re looking at your child’s mouth and counting, any tooth behind the canines is a baby molar, not a premolar.
When Each Tooth Comes In
Baby teeth start erupting around 6 months of age, though there’s a wide range of normal. The lower central incisors usually appear first, followed closely by the upper central incisors. From there, the lateral incisors, first molars, canines, and second molars fill in over the next two years or so. Most children have their full set of 20 baby teeth by age 3.
The order can vary from child to child. Some babies get their first tooth at 4 months, others not until closer to 12 months. Both are perfectly normal, and the timing doesn’t indicate anything about overall health or development.
When Each Tooth Falls Out
Baby teeth fall out in roughly the same order they arrived. The process begins around age 6 and continues into the early teen years:
- Central incisors: 6 to 7 years
- Lateral incisors: 7 to 8 years
- Canines: 9 to 12 years
- First molars: 9 to 11 years
- Second molars: 10 to 12 years
The reason baby teeth loosen and fall out is a process called root resorption. The body gradually breaks down and absorbs the roots of the baby tooth from below, dissolving the anchor that holds it in the jawbone. As the root disappears, the tooth gets progressively looser until it falls out, typically making way for the permanent tooth pushing up underneath.
The 6-Year Molars Are Not Baby Teeth
This catches a lot of parents off guard. Around age 6, new molars emerge behind the last baby teeth in each corner of the mouth. These are permanent teeth, not baby teeth. They don’t replace anything. Instead, they grow into empty space at the back of the jaw that wasn’t occupied before.
Because these molars arrive around the same time the front baby teeth start falling out, it’s easy to assume they’re part of the same process. They’re not. The 6-year molars are meant to last a lifetime, which is why caring for them early matters. They won’t get a second chance.
How Baby Teeth Differ From Permanent Teeth
Baby teeth aren’t just smaller versions of adult teeth. They’re structurally different in ways that affect how quickly they can develop cavities and how they look compared to incoming permanent teeth.
The enamel on a baby tooth is about 1 millimeter thick, roughly half the thickness of enamel on a permanent tooth (which can reach 2.5 millimeters at the tip). That thinner protective layer means decay can reach the inner layers of the tooth faster in children. Baby teeth also have proportionally larger nerve chambers sitting closer to the outer surface, so a cavity that looks small can cause pain sooner than you might expect.
You may also notice a color difference once permanent teeth start growing in next to remaining baby teeth. Baby teeth have a milky white appearance, while permanent teeth tend to look more yellowish-white or grayish-white. This is normal and not a sign that the new teeth are stained or unhealthy. The contrast just looks dramatic when both types sit side by side during the “mixed dentition” years, roughly ages 6 through 12.
Why Baby Teeth Matter More Than You’d Think
It’s tempting to think of baby teeth as disposable since they’re all going to fall out anyway. But they serve several functions that directly affect how the permanent teeth come in. Baby teeth hold space in the jaw for the adult teeth developing underneath. When a baby molar is lost too early, whether from decay or injury, the neighboring teeth can drift into the gap. That shift narrows the available space and can force the permanent premolar into a crooked position or block it from coming in at all.
Beyond spacing, baby teeth are important for speech development. The front teeth help children form sounds correctly as they learn to talk. And of course, functional baby teeth let children chew a full range of foods during critical growth years.
Missing or Extra Baby Teeth
Fewer than 1% of children are born missing one or more baby teeth, a condition called hypodontia. Studies across different populations have found rates ranging from about 0.5% to 1%, with some Japanese studies reporting rates closer to 5%. When a baby tooth is congenitally absent, the corresponding permanent tooth is often missing as well, though not always. Extra baby teeth are even rarer. In either case, a dentist can track the situation with X-rays and plan ahead if spacing becomes an issue.