Most adults have 32 permanent teeth, though the real number in your mouth right now could be anywhere from 28 to 32 depending on whether your wisdom teeth came in or were removed. Children start with a smaller set of 20 baby teeth that are gradually replaced between ages six and twelve. If you’re curious about animals, the tooth counts across the animal kingdom range from zero to tens of thousands.
Adult Human Teeth
A full set of adult teeth totals 32, split evenly between your upper and lower jaws. Each jaw holds four incisors (the flat front teeth for biting), two canines (the pointed ones for tearing), four premolars (for crushing), and six molars (the wide back teeth for grinding). The last molars in each row are your wisdom teeth, also called third molars.
Wisdom teeth are the most variable part of the count. Many people have them removed in their late teens or early twenties because there isn’t enough room in the jaw, leading to impaction or crowding. Some people are born without one or more wisdom teeth entirely. That’s why plenty of adults walk around with 28 teeth and a perfectly functional bite.
Children’s Baby Teeth
Children develop 20 primary teeth, sometimes called baby teeth or milk teeth. These typically start appearing around six months of age, beginning with the lower front incisors, and the full set is usually in place by age three. Each jaw holds four incisors, two canines, and four molars. There are no premolars or wisdom teeth in the baby set.
Between ages six and twelve, permanent teeth push out the baby teeth one by one. During this transition, kids have a mix of both, so a seven-year-old might have anywhere from 20 to 24 teeth in various stages of eruption and loss.
Dogs and Cats
Adult dogs have 42 permanent teeth, ten more than humans. That extra hardware includes additional premolars and molars designed for shearing meat and crunching bone. Puppies start with 28 baby teeth that fall out around three to six months of age.
Adult cats have 30 permanent teeth. Their mouths are built for slicing rather than grinding, so they have fewer molars than dogs. Kittens begin with 26 baby teeth.
Horses
A mature male horse carries 40 to 42 permanent teeth. Mares typically have 36 to 40 because canine teeth, which sit in the gap between the front incisors and the back grinding teeth, appear in only about 20 to 25 percent of females. When they do show up in mares, they tend to be smaller than a stallion’s canines. Horse teeth also continue to slowly erupt throughout the animal’s life to compensate for the constant grinding down from chewing hay and grass.
Sharks
A great white shark has roughly 300 teeth in its mouth at any given time, arranged in multiple rows behind the front cutting edge. The teeth aren’t rooted in bone the way yours are. Instead, they sit in the gum tissue and constantly move forward like a conveyor belt, replacing any that break or fall out. Over a lifetime, a single great white can produce more than 20,000 teeth.
Alligators
An alligator has about 80 teeth at a time, and like sharks, it replaces them continuously. Each tooth socket can cycle through a new tooth up to 50 times over the animal’s 35- to 75-year lifespan. That adds up to roughly 4,000 teeth in a lifetime. Researchers have studied the mechanism behind this regeneration in hopes of one day applying it to human dentistry.
Elephants
Elephants take a completely different approach. Instead of having a full row of teeth, an elephant uses just one or two large molars per side of each jaw at a time. New molars grow in from the back and slowly push forward, replacing worn-out teeth over the course of the animal’s life. This replacement cycle happens five times total, giving an elephant six sets of molars. Once the final set wears down, usually around age 60 to 70, the elephant can no longer chew effectively.
Opossums
The Virginia opossum holds the record for the most teeth of any land mammal in the United States, with 50 sharp teeth packed into its small jaws. That count is higher than any other North American mammal and part of why opossums flash such an impressive (and intimidating) grin when threatened.
Baleen Whales
Blue whales, humpbacks, and other baleen whales have zero teeth as adults. Instead, they filter food through 150 to 400 plates of baleen on each side of their mouth. Baleen is made of keratin, the same protein in your fingernails, and it acts like a giant strainer to trap tiny fish and krill. Interestingly, baleen whale embryos still develop tooth buds during early growth. The buds are reabsorbed before birth, a leftover from toothed ancestors millions of years ago.
Snails
If you want the extreme end of the spectrum, look to the garden snail. Snails eat using a ribbon-like structure called a radula, covered in thousands of microscopic teeth. They scrape this flexible band across food like a cheese grater. The teeth are too small to see without magnification, but they’re effective enough to chew through leaves, fruit, and even thin shells.