Kids have 20 baby teeth, also called primary teeth. That’s 10 in the upper jaw and 10 in the lower jaw. This is notably fewer than the 32 teeth adults eventually have, and the difference comes down to simple anatomy: a child’s jaw is too small to fit a full set of adult-sized teeth.
The 20 Baby Teeth by Type
Those 20 teeth break down into three types, each with a specific job. In each jaw (upper and lower), your child will have four incisors (the flat front teeth used for biting), two canines (the pointed teeth next to the incisors), and four molars (the wider back teeth for grinding food). That gives you eight incisors, four canines, and eight molars total.
Spacing between baby teeth is normal and actually a good sign. Those gaps exist because the jaw is reserving room for the larger permanent teeth that will eventually replace them.
When Baby Teeth Come In
The first tooth usually appears between 6 and 12 months of age. Most babies start with the two bottom front teeth, followed by the two top front teeth. From there, teeth come in roughly in pairs, one on each side of the jaw, working from front to back. By age 2½ to 3, most children have all 20 baby teeth in place.
Some babies teethe earlier or later than this range, and that’s often perfectly normal. Premature birth is one common reason for delayed teething, since overall development tends to run on a shifted timeline. Nutritional factors also play a role. Deficiencies in vitamin D, calcium, vitamin A, or vitamin C can slow things down because these nutrients are essential for building the bone structure that teeth push through. Certain medical conditions, particularly hypothyroidism and other hormonal imbalances, can also delay eruption.
If your child has no teeth by 12 months, it’s worth mentioning at their next checkup, but isolated late teething rarely signals a serious problem.
The Mixed Dentition Phase
Around age 6, kids enter a transitional stage where they have both baby teeth and permanent teeth at the same time. This is called the mixed dentition phase, and it lasts until roughly age 12 or 13, when the last baby teeth fall out. During these years, the total number of teeth in your child’s mouth fluctuates constantly as old teeth loosen and new ones grow in.
Baby teeth fall out in approximately the same order they arrived. The bottom front teeth go first, then the top front teeth, followed by the lateral incisors, first molars, canines, and finally the second molars. This process is gradual. A 7-year-old might be missing a few front teeth while still having a full set of baby molars in the back.
Why Kids Have Fewer Teeth Than Adults
Adults end up with 32 permanent teeth, 12 more than the baby set. The extra teeth are premolars (which replace the baby molars and add additional grinding surface) and a third set of molars in the back, commonly known as wisdom teeth. Children’s jaws simply don’t have the space or structural development to support these additional teeth. As the jaw grows through childhood and adolescence, it gradually creates room for the full adult set.
This is also why orthodontic issues often become apparent during the mixed dentition phase. If the jaw isn’t growing fast enough to accommodate the incoming permanent teeth, crowding can develop.
Caring for Baby Teeth
Baby teeth matter more than many parents assume. They hold space in the jaw for permanent teeth, and losing one too early to decay can cause neighboring teeth to shift, leading to alignment problems later. They’re also essential for speech development and, of course, chewing.
The American Academy of Pediatric Dentistry recommends scheduling a child’s first dental visit within six months of the first tooth appearing, or by their first birthday, whichever comes first. Starting dental care early helps catch problems when they’re small and gets kids comfortable with the routine.
Even before teeth appear, you can wipe your baby’s gums with a clean, damp cloth after feedings. Once that first tooth breaks through, a soft-bristled infant toothbrush with a rice-grain-sized smear of fluoride toothpaste is the standard approach. By age 3, when the full set of 20 teeth is in place, you can increase to a pea-sized amount of toothpaste.