Baby teeth are the first set of 20 teeth that develop during infancy and early childhood. Also called primary or deciduous teeth, they begin appearing around 6 months of age and serve as placeholders for the 32 permanent teeth that will eventually replace them. Though temporary, baby teeth play a surprisingly important role in a child’s development, from eating and speaking to guiding adult teeth into their correct positions.
How Many Baby Teeth and What Types
Children develop 20 baby teeth total: 10 on the top and 10 on the bottom. These break down into three types. Eight incisors (the flat front teeth) handle biting. Four canines (the pointed teeth next to the incisors) tear food. Eight molars (the wider teeth in the back) grind it up. That’s fewer than the 32 teeth adults eventually get, since children don’t develop premolars or third molars (wisdom teeth) in their primary set.
When Baby Teeth Come In
The lower central incisors are almost always the first to appear, typically between 6 and 10 months of age. From there, teeth tend to arrive in a roughly predictable order:
- Upper central incisors: 8 to 12 months
- Upper and lower lateral incisors: 9 to 16 months
- First molars: 13 to 19 months
- Canines: 16 to 23 months
- Second molars: 23 to 33 months
Most children have their full set of 20 baby teeth by age 3. These timelines vary quite a bit from child to child. Some babies cut their first tooth at 4 months, while others don’t see one until closer to their first birthday. Both ends of that range are normal.
How Baby Teeth Differ From Adult Teeth
Baby teeth are not just smaller versions of permanent teeth. They have a distinct structure that makes them more vulnerable to decay. The enamel on a baby tooth averages about 0.5 mm thick, roughly half the thickness of enamel on a permanent tooth. That thinner protective layer means cavities can reach the inner layers of the tooth faster.
Baby teeth also have a more bulbous shape, with the enamel bulging outward near the gumline more prominently than in adult teeth. Their roots are thinner, shorter, and more spread apart, which is partly by design: those roots gradually dissolve (a process called resorption) to make way for the permanent teeth pushing up from below. The major structure of each tooth, whether baby or adult, is the same. A hard layer called dentin makes up most of the tooth, covered by enamel on the visible crown. Inside sits a chamber of soft tissue containing nerves and blood vessels, which is why a deep cavity can cause serious pain even in a “temporary” tooth.
Why Baby Teeth Matter
It’s a common misconception that baby teeth don’t need much care because they’ll fall out anyway. In reality, primary teeth serve several critical functions during the years a child has them. They allow children to chew a full range of foods for proper nutrition. They play a direct role in speech development, helping children learn to form sounds correctly. And they contribute to a child’s self-esteem as they interact with peers.
Perhaps most importantly, baby teeth act as space holders for permanent teeth. Each primary tooth reserves a specific spot in the jaw. When a baby molar is lost too early, whether from decay or injury, the surrounding teeth can drift into the gap. This shrinks the available space and can force the incoming permanent tooth to erupt crooked or become impacted. Losing a primary molar prematurely can reduce the overall arch perimeter of the jaw, setting the stage for crowding and alignment problems that may later require orthodontic treatment.
When Baby Teeth Fall Out
Baby teeth typically begin falling out around age 6, and the process continues until roughly age 12. They generally fall out in approximately the same order they came in. The lower central incisors go first, followed by the upper central incisors, then the lateral incisors, first molars, canines, and finally the second molars. As a permanent tooth develops beneath the gum, it gradually dissolves the root of the baby tooth above it. That’s why a loose baby tooth often comes out with little or no root attached.
If a baby tooth is knocked out or pulled well before its permanent replacement is ready, a dentist may recommend a space maintainer, a small device that holds the gap open so neighboring teeth don’t shift.
Caring for Baby Teeth
Oral care should start before the first tooth even appears. Wiping an infant’s gums with a soft, damp cloth after feedings helps keep bacteria in check. Once that first tooth breaks through, it’s time for a toothbrush.
For children under 3, use a soft-bristled brush with a smear of fluoride toothpaste about the size of a grain of rice. From ages 3 to 6, increase to a pea-sized amount and brush twice daily. Young children don’t have the coordination to brush effectively on their own, so parents should do the brushing or at least supervise closely until around age 6 or 7.
The thinner enamel on baby teeth makes them especially susceptible to cavities. Early childhood tooth decay is one of the most common chronic conditions in young children, and it’s largely preventable. Avoiding prolonged exposure to sugary liquids, especially putting a baby to bed with a bottle of juice or milk, significantly reduces risk. If decay does develop and a baby tooth is lost prematurely, permanent teeth can come in crowded and out of alignment.
The First Dental Visit
The American Academy of Pediatric Dentistry recommends that a child’s first dental visit happen within 6 months of their first tooth erupting, or by their first birthday, whichever comes first. That timeline surprises many parents, but these early visits are less about treatment and more about establishing a baseline. The dentist checks for early signs of decay, evaluates how the jaw is developing, and can offer guidance on brushing technique, fluoride use, and feeding habits that affect oral health.
What Teething Feels Like
As teeth push through the gums, most babies experience some discomfort. Common signs include drooling, irritability, swollen gums, and a strong urge to chew on things. Some babies run a very mild fever, though a temperature above 100.4°F (38°C) is not considered a normal teething symptom and points to something else. Teething discomfort tends to be worst right before and as the tooth breaks the surface, then eases off once the tooth is fully through. Chilled (not frozen) teething rings and gentle gum massage with a clean finger are reliable ways to ease the soreness.