Premolar

Premolar

The permanent teeth, viewed from the right.

Permanent teeth of right half of lower dental arch, seen from above.
Details
Identifiers
Latin dentes premolares
MeSH A14.549.167.860.150
TA A05.1.03.006
FMA 55637

Anatomical terminology

The premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth.[1][2][3] They have at least two cusps. Premolars can be considered as 'transitional teeth' during chewing, or mastication. They have properties of both the anterior canines and posterior molars, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars.[4]

The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar.[1][3]

There is always one large buccal cusp, especially so in the mandibular first premolar. The lower second premolar almost always presents with two lingual cusps.[5]

Molar teeth by definition are permanent teeth distal to the canines, preceded by deciduous premolars.[6] In primitive placental mammals there are four premolars per quadrant, but the most mesial two (closer to the front of the mount) have been lost in catarrhines (Old World monkeys and apes, including humans). Paleontologists therefore refer to human premolars as Pm3 and Pm4.[7][8]

Additional images

Medical animation showing Premolar teeth and its arrangement in the mouth of an adult human being. 
Mouth (oral cavity) 
Left maxilla. Outer surface. 
Base of skull. Interior surface. 

See also

References

  1. 1 2 Roger Warwick & Peter L. Williams, eds. (1973), Gray’s Anatomy (35th ed.), London: Longman, pp. 1218–1220
  2. Weiss, M.L., & Mann, A.E (1985), Human Biology and Behaviour: An anthropological perspective (4th ed.), Boston: Little Brown, pp. 132–135, 198–199, ISBN 0-673-39013-6
  3. 1 2 Glanze, W.D., Anderson, K.N., & Anderson, L.E, eds. (1990), Mosby's Medical, Nursing & Allied Health Dictionary (3rd ed.), St. Louis, Missouri: The C.V. Mosby Co., p. 957, ISBN 0-8016-3227-7
  4. Weiss, M.L., & Mann, A.E. (1985), pp.132-134
  5. Warwick, R., & Williams, P.L. (1973), p.1219.
  6. Warwick, R., & Williams, P.L. (1973), pp.1218-1219.
  7. Christopher Dean (1994). "Jaws and teeth". In Steve Jones, Robert Martin & David Pilbeam (eds.). The Cambridge Encyclopedia of Human Evolution. Cambridge: Cambridge University Press. pp. 56–59. ISBN 0-521-32370-3. Also ISBN 0-521-46786-1 (paperback)
  8. Gentry Steele and Claud Bramblett (1988). The Anatomy and Biology of the Human Skeleton. p. 82. ISBN 9780890963265.
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