小臼歯 - Dens premolaris

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翻訳

説明

The Premolars or Bicuspid teeth (dentes præmolares) are eight in number, four in each arch. They are situated lateral to and behind the canine teeth, and are smaller and shorter than they.

The crown is compressed antero-posteriorly, and surmounted by two pyramidal eminences or cusps, a labial and a lingual, separated by a groove; hence their namebicuspid. Of the two cusps the labial is the larger and more prominent. The neck is oval. The root is generally single, compressed, and presents in front and behind a deep groove, which indicates a tendency in the root to become double. The apex is generally bifid.

The upper premolars are larger, and present a greater tendency to the division of their roots than the lower; this is especially the case in the first upper premolar.


This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).

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