The natural history of the human teeth : explaining their structure, use, formation, growth, and diseases / by John Hunter ; with notes by Eleazar Parmly.

  • Hunter, John, 1728-1793.
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: The natural history of the human teeth : explaining their structure, use, formation, growth, and diseases / by John Hunter ; with notes by Eleazar Parmly. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    each edge, leading to the general cavity in the body of the tooth. T hese two cavities are formed by the meeting of the sides of the fang in the middle, thereby dividing the broad and flat cavity into two; and all along the outside of these (and all the other flat fangs) there is a corresponding longitudinal groove. These fangs at their middle, are generally bent a little backwards. The enamel covers the bodies of these teeth pretty equally all round. The first grinder is somewhat larger and stronger than the second ; it is turned a little more inwards than the adjacent Bicuspides, but not so much as the second grinder. Both of them have generally shorter fangs than the Bicuspides. There is greater difference between these grinders in the upper and lower jaw, than any of the other teeth. In the upper jaw they are rather rhomboidal, than square in their body, with one sharp angle turned forwards and outwards, the other backwards and inwards ; besides they have three fangs, which diverge, and terminate each in a point; these are almost round, and have but one cavity. Two of them are placed near each other perpendicularly, over the outside of the tooth ; and the other, which generally is the largest, stands at a greater distance on the inside of the tooth, slanting inwards. In this jaw these two grinders are inclined outwards, and a little forwards ; they project a little over the corresponding teeth of the lower jaw, and they are placed further back in the mouth, so that each is partly opposed to two of the lower jaw. The second in the upper jaw is smaller than the others, and the first and second are placed directly under the maxillary sinus. J once saw the second grinder naturally wanting on one side of the lower jaw. The third grinder is commonly called Dens Sapientice; it is a little shorter and smaller than the others, and inclined a little more in- wards and forwards. Its body is nearly of the same figure, but rather rounder, and its fangs are generally not so regular and dis- tinct, for they often appear squeezed together ; and sometimes there is only one fang, which makes the tooth conical ; it is much smaller than the rest of the grinders. In the upper jaw this tooth has more varie- ty than in the lower, and is even smaller than the corresponding tooth of the lower, and thence stands directly opposed to it; but for this circumstance the grinders would reach farther back in the upper jaw than in the lower, which is not commonly the case. In the upper jaw this third grinder is turned but a very little out- wards ; is frequently inclined somewhat backwards; and it projects over that of the under jaw. It oltener becomes loose than any of the other teeth. They are placed under the posterior part of the maxillary sinus, and there the parts which compose the sinus are thicker than in the middle. The variations as to the natural number of the teeth, depend commonly upon these Denies Sapienttcs. Thus from the Incisores to the first grinder, the teeth become gradu- ally thicker at the extremity of their bodies, and smaller from the 5