Prognathy

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Reconstruction of Homo habilis : prognathy of the upper and lower jaw in an evolutionary stage of hominization .

In vertebrates, prognathy is the shape of the dentition in which the dental arches of the upper jaw and lower jaw protrude clearly from the face, so that a so-called snout is formed.

In the course of human tribal history , the original prognathy of the early hominini was gradually reduced. The originally parallel rows of left and right molars were increasingly rounded, and the canines became smaller. The teeth of modern humans are therefore parabolic and hardly protrude from the face.

In orthodontics , prognathy describes an undesirable position of the upper jaw in which the upper incisors are so far forward or the lower ones so far back that the upper and lower rows of incisors do not form a scissor bite. A corresponding malbite occurs when the lower jaw is shortened ( mandibular retrognathia ).

A dental position in which a comparatively long lower jaw protrudes over a shorter upper jaw is called a mandibular prognathy ( prognosis ). Here the chin and lower lip protrude. The wrong bite, in which the tooth surfaces of the upper and lower teeth do not interlock harmoniously, but often stand edge to edge or shift each other as a result of incorrect pressure load, can damage the teeth and the tooth-holding apparatus .

Insects are called prognath when the head is aligned in the direction of the body axis and the mouthparts point forward accordingly.

  • Skull of a dog with a healthy scissor bite

  • Skull of a dog with an undershot lower incisor teeth

  • Charles II of Spain in a contemporary depiction by Claudio Coello (1642–1693)

  • View of the sagittal plane : above human skull without prognathy, below with prognathic lower jaw

literature

  • Michael Schmitt (editor): Lexicon of Biology , Volume 7. Herder, Freiburg im Breisgau 1986, page 15, article “prognath”, ISBN 3-451-19647-6
  • Duden: Dictionary of medical terms. 8th edition, Mannheim 2007, p. 641, article "prognath, Prognathie", ISBN 978-3-411-04618-8

Individual evidence

  1. ↑ see: Michael Schmitt: Lexikon der Biologie
  2. ↑ see: the Duden dictionary of medical terms.
  3. ↑ http://flexikon.doccheck.com/de/Mandibul%C3%A4re_Prognathie
  4. ↑ Stefan v. Kéler: Entomological Dictionary Berlin 1963