Premolar

First maxillary premolar from occlusal (above), buccal (outside) and palatal (inside)

X-ray overview:
canines (right edge of the image), premolars and molars (center of the image). The incisors are on the right outside the image section. The lower wisdom tooth has not yet erupted and its root growth is not yet complete.

Upper premolar with insufficient filling

A premolar ( Dens premolaris , Pl. Dentes praemolares ), also premolar tooth , is a molar tooth in the teeth of mammals . A synonym is the term bicuspid (from Latin to "twice" and cuspis "tip"). In contrast to the molars , premolars also have deciduous teeth that perform the grinding function before changing teeth .

In the mammalian ancestors there were originally four premolars in each half of the jaw , so a total of 16. This number is reduced in most modern mammals. In humans, only two premolars are formed , and in rodents (with the exception of the guinea pig relatives ) there are no more premolars. Ruminants have three premolars, they lack the first.

Premolars of Man

The human premolars have two to three cusps. Lower premolars have a very pronounced crown alignment . The number of tooth roots and root canals is shown in the following table, although deviations are possible:

teeth	Number of tooth roots	Number of root canals	Number of humps
14, 24	1 2 (> 60%) 3	1 (9.0%) 2 (85.0%) 3 (6.0%)	2
15, 25	1 (> 85%) 2	1 (75.0%) 2 (24.0%) 3 (1.0%)	2
34, 44	1 (74.0%) 2 (26.0%)	1 (73.5%) 2 (26.0%) 3 (0.5%)	2 (75%) 3 (25%)
35, 45	1 (85.0%) 2 (15.0%)	1 (85.5%) 2 (13.0%) 3 (0.5%)	3

The human dentition (scheme, each tooth in two views)

See also

• tooth
• Tooth scheme
• Tooth formula

Web links

Commons : Teeth  - collection of pictures, videos and audio files

Wiktionary: premolar  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ^ Gert-Horst Schuhmacher, Anatomie, Textbook and Atlas, 2nd edition 1991, Barth-Verlag. ISBN 3-335-00264-4 .
2. ^ John I. Ingle, Leif K. Bakland, Endodontics, Williams & Wilkins, Philadelphia, 4th Sub edition (1994), ISBN 0-683-04310-2 .
3. ↑ JR Strube, M. Stern, Curriculum Prothetik, Volume I, Quintessenz Verlag, 2011, pp. 32–33. ISBN 3-86867-026-2 .