A diphyodont is any animal with two ss of

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, initially the ''

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

'' set and consecutively the ''

permanent Permanent may refer to: Art and entertainment * ''Permanent'' (film), a 2017 American film * ''Permanent'' (Joy Division album) * "Permanent" (song), by David Cook Other uses * Permanent (mathematics), a concept in linear algebra * Permanent (cy ...

'' set. Most mammals are diphyodonts—as to chew their food they need a strong, durable and complete set of teeth. Diphyodonts contrast with ''

polyphyodont A polyphyodont is any animal whose teeth are continually replaced. In contrast, diphyodonts are characterized by having only two successive sets of teeth. Polyphyodonts include most toothed fishes, many reptiles such as crocodiles and geckos, and ...

s'', whose teeth are constantly replaced. Diphyodonts also differ from ''

monophyodonts A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

'', which are animals who have only one set of teeth that do not change over a long period of growth. In diphyodonts, the number of teeth that are replaced varies from species to species. In

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

s, a set of twenty deciduous teeth, or "milk teeth", are replaced by a completely new set of thirty-two adult teeth. In some cases

hypodontia Hypodontia is defined as the developmental absence of one or more teeth excluding the third molars. It is one of the most common dental anomalies, and can have a negative impact on function, and also appearance. It rarely occurs in primary teet ...

hyperdontia Hyperdontia is the condition of having supernumerary teeth, or teeth that appear in addition to the regular number of teeth (32 in the average adult). They can appear in any area of the dental arch and can affect any dental organ. The opposite ...

occurs, the latter in

cleidocranial dysostosis Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close togethe ...

and

Gardner's syndrome Gardner's syndrome (also known as Gardner syndrome, familial polyposis of the colon, or familial colorectal polyposis) is a subtype of familial adenomatous polyposis (FAP). Gardner syndrome is an autosomal dominant form of polyposis characterize ...

. In the

hare Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The ge ...

the anterior incisors are not replaced but the posterior smaller incisors are replaced. Not much is known about the developmental mechanisms regulating diphyodont replacement. The

house shrew The Asian house shrew (''Suncus murinus'') is a shrew species native to South and Southeast Asia that has been listed as Least Concern on the IUCN Red List since 2008 because of its large population and wide distribution. It has been introduced i ...

, ''Suncus murinus'', and the Chinese

miniature pig Miniature Pigs, also called mini pig, or Pygmy pig, are small breeds of domestic pig, such as the Vietnamese Pot-Bellied pig, Göttingen minipig, Juliana pig, Choctaw hog, or Kunekune (and specimens derived by crossbreeding these breeds). Mini ...

Otevřít soubor. - Masarykova univerzita
. are currently being used to study the diphyodont replacement of the deciduous dentition by replacements and additional permanent teeth.

Manatees Manatees (family Trichechidae, genus ''Trichechus'') are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living species ...

elephant Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae an ...

s and

kangaroo Kangaroos are four marsupials from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern gre ...

s differ from most other mammals because they are polyphyodonts.

References

Zoology Dentition types {{zoology-stub

See also

References