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Why Do Some Animals Have Multiple Sets of Teeth?

HomeMiscellaneousWhy Do Some Animals Have Multiple Sets of Teeth?

What do manatees, kangaroos, and crocodiles all have in common? If you guessed their teeth, you’re right! Each species replaces its teeth continuously throughout their life. So, why are some animals stuck with just one or two sets of teeth while others are able to regrow new teeth? Over time, all animals have evolved in different ways depending on their needs, diet, environment, and other factors. Today at Edgewater Dental Arts, we want to explain why certain animals have evolved to have multiple sets of teeth. To do so, we will introduce a few new vocabulary words: polyphyodont, diphyodont, and monophyodont.

Small herd of gray polyphyodont elephants in Kenya walking along the golden grassland


A polyphyodont is any animal whose teeth are replaced many times, until their tooth buds deplete. Most vertebrae, toothed-fishes, and reptiles are polyphyodonts. The only mammalian polyphyodonts are manatees, kangaroos, and elephants. For species with this unique characteristic, new teeth grow just behind the old teeth in the jaw and push them forward like a conveyor belt until the old teeth migrate to the front of the jaw and fall out. Generally, a tooth is replaced every few months. Scientists believe that the lifespan and continuous dietary wear on the teeth of polyphyodonts led them to develop multiple sets of teeth.

Closeup of a brown monophyodont beaver with big front teeth standing in a patch of green grass


A monophyodont is an animal with only one set of teeth that grows continuously throughout its life, such as platypuses, sloths, walruses, seals, narhwals, dolphins, and most toothed-whales. The Rodentia order (which includes over 2000 species) of the Mammalian class are also monophyodont, including beavers, guinea pigs, rats, mice, hamsters, and chinchillas.

Blonde girl missing multiple baby teeth stands next to her blonde brother at the beach, with their hands in pockets


Humans and most other mammals are diphyodonts, meaning we have two successive sets of teeth: baby teeth (otherwise known as deciduous, primary, or milk teeth) and adult (or permanent) teeth. Because we chew and grind our food, we have evolved strong, durable teeth that can last our entire lifetime with proper at-home oral hygiene and high quality dental care at Edgewater Dental Arts.

Let Us Help Care for Your 2 Sets of Teeth!

For human teeth to remain strong and functional, they require an excellent dental hygiene routine. This includes brushing twice daily, flossing every day, and visiting our office every six months to receive professional cleanings! These will help keep your smile healthy throughout your entire life. To ask our friendly team questions about caring for your teeth or to schedule your next visit, contact us today!

Written by

John Cutting, DMD is an Annapolis dentist experienced in all aspects of dentistry. He provides complete care from general dentistry to cosmetic and restorative dentistry in his conveniently located and comfortable office, Edgewater Dental Arts.