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Generally, tooth development in non-human mammals is similar to human tooth development. The variations usually lie in the morphology, number, development timeline, and types of teeth. [8] However, some mammals' teeth do develop differently than humans'. In mice, WNT signals are required for the initiation of tooth development.
Tooth development is commonly divided into the following stages: the bud stage, the cap, the bell, and finally maturation. The staging of tooth development is an attempt to categorize changes that take place along a continuum; frequently it is difficult to decide what stage should be assigned to a particular developing tooth. [26]
A tooth (pl.: 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, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young.
An animal's dentition for either deciduous or permanent teeth can thus be expressed as a dental formula, written in the form of a fraction, which can be written as I.C.P.M I.C.P.M, or I.C.P.M / I.C.P.M. [10] [11] For example, the following formulae show the deciduous and usual permanent dentition of all catarrhine primates, including humans:
New, permanent teeth grow in the jaws, usually under or just behind the old tooth, from stem cells in the dental lamina. [5] Young animals typically have a full set of teeth when they hatch; there is no tooth change in the egg. Within days, tooth replacement begins, usually in the back of the jaw continuing forward like a wave.
Carnivores possess diverse carnassial teeth. The carnassials are specialized teeth for different diets of different animals. [12] These teeth are used to cut through flesh. [12] Either the molars or both the premolars and molars in combination may be adapted into shearing carnassials. Tooth roots can be great indicators of diets.
The tooth germ is an aggregation of cells that eventually forms a tooth. [2] These cells are derived from the ectoderm of the first pharyngeal arch and the ectomesenchyme of the neural crest. [1] [3] [4] The tooth germ is organized into three parts: the enamel organ, the dental papilla and the dental sac or follicle.
A toothcomb (also called a tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates (which include lemurs and lorisoids), treeshrews, colugos, hyraxes, and some African antelopes.