Incisor

Incisor
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Permanent teeth of right half of lower dental arch, seen from above.
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The permanent teeth, viewed from the right.
Latin dentes incisivi
Gray's subject #242 1115
MeSH Incisor

Incisors (from Latin incidere, "to cut") are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.

Contents

Function

In many omnivorous mammals, such as the human, they are adapted for shearing sharply. In cats, the incisors are small; biting off meat is done with the canines and the carnassials. In elephants, the upper incisors are modified into curved tusks, just as is the case with Narwhals, where normally one of them develops into a straight and twisted tusk. The incisors of rodents grow throughout life and are worn by gnawing.

Number and types of incisors

In humans

Adult humans normally have eight incisors, two of each type. The types of incisor are:

Children with a full set of deciduous teeth (primary teeth) also have eight incisors, named the same way as in permanent teeth. Young children may have from zero to eight incisors depending on the stage of their tooth eruption and tooth development.

In non-human animals

Among other animals, some other primates, cats and horses have twelve. Rodents have four, while Foxes have nine. Rabbits and hares (lagomorphs) were once considered rodents, but are distinguished by having eight—one small pair, called "peg teeth", is located directly behind the most anterior pair. Incisors are used to bite off tough foods, such as red meat.

Additional images

See also


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Synonyms:

Look at other dictionaries:

  • Incisor — In*ci sor, a. Adapted for cutting; of or pertaining to the incisors; incisive; as, the incisor nerve; an incisor foramen; an incisor tooth. [1913 Webster] …   The Collaborative International Dictionary of English

  • incisor — (n.) cutting tooth, 1670s, from M.L. incisor a cutting tooth, lit. that which cuts into, from L. incisus, pp. of incidere (see INCISION (Cf. incision)). Inscisours as the name of a cutting tool is attested from early 15c …   Etymology dictionary

  • Incisor — In*ci sor (?; 277), n. [NL.] (Anat.) One of the teeth in front of the canines in either jaw; an incisive tooth. See {Tooth}. [1913 Webster] …   The Collaborative International Dictionary of English

  • INCISOR — idem cum Carptore Scissore, Structore, quas voces vide. In Gallia Incisoris Regis insigne furcilla est cum cultro decu ssata. Cultri vero Incisorii duo decussatim locati, laminisque argenteis et ex auro capulis instructi, Abbatiae Quedelinburgiae …   Hofmann J. Lexicon universale

  • incisor — |ô| s. m. Aquele ou aquilo que corta …   Dicionário da Língua Portuguesa

  • incisor — ► NOUN ▪ a narrow edged tooth at the front of the mouth, adapted for cutting …   English terms dictionary

  • incisor — [in sī′zər] n. [ModL < L incisus (see INCISE) + OR] a cutting tooth; any of the front teeth between the canines in either jaw: in humans there are eight incisors: see TEETH …   English World dictionary

  • incisor — UK [ɪnˈsaɪzə(r)] / US [ɪnˈsaɪzər] noun [countable] Word forms incisor : singular incisor plural incisors medical one of the sharp teeth at the front of your mouth, used for cutting and biting. The incisors are between four sharp teeth called… …   English dictionary

  • incisor — SYN: i. tooth. [L. incido, to cut into] central i. the first tooth in the maxilla and mandible on either side of the midsagittal plane of the head. Hutchinson incisors SYN: Hutchinson teeth, under tooth. lateral i. SYN: second i.. second i …   Medical dictionary

  • incisor — noun Date: 1666 a front tooth typically adapted for cutting; especially one of the cutting teeth in mammals located between the canines when canines are present see tooth illustration …   New Collegiate Dictionary

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