Treatise on the natural history and diseases of the human teeth : explaining their structure, use, formation, growth, and diseases, in two parts / by John Hunter ; with notes by Thomas Bell.

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

Licence: Public Domain Mark

Credit: Treatise on the natural history and diseases of the human teeth : explaining their structure, use, formation, growth, and diseases, in two parts / by John Hunter ; with notes by Thomas Bell. 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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    Of the Bicuspides. Immediately behind the cuspidati, in eaoh jaw, stand two teeth, commonly called the first and second grinders, but which, for rea- sons hinted at above, I shall suppose to constitute a particular class, and call them bicuspides. These (viz. the fourth and fifth tooth from the symphysis of the jaw) resemble each other so nearly that a description of the first will serve for both. The first indeed is frequently the smallest, and has rather the longest fang, having somewhat more of the shape of the cuspidatus than the second. The body of this tooth is flattened laterally, answering to the flat side of the fang. It terminates in two points, viz. one external and one internal. The external is the longest and thickest; so that on looking into the mouth from without, this point only can be seen, and the tooth has very much the appearance of a cuspidatus, espe- cially the first of these teeth. The internal point is the least, and indeed sometimes so very small that the tooth has the greatest resemblance to a cuspidatus in any view.* At the union of the points the tooth is thickest, and thence it loses in thickness, from side to side, to the extremity of the fang, so that the fang con- tinues pretty broad to the point, and is often forked there. All the teeth hitherto described often have their points bent, and more particularly the cuspidati. The enamel passes somewhat further down externally and upon the inside, than laterally; but this difference is not so considerable as in the incisores and cuspidati; in some, indeed, it terminates equally all round the tooth. They stand almost perpendicularly, but seem to be a little turned inwards, especially the last of them. In the upper jaw they are rather thicker than in the lower, and are turned a very little forwards and outwards. The first in the upper jaw falls between the two in the lower, the second falls between the second and the first grinder; and both project over those of the lower jaw, but less than the incisores and cuspidati. The bicuspides, and especially the second of them, in both jaws, are oftener naturally wanting than any of the teeth, except the dentes sapientiae; hence we might conjecture that they are less useful; and this conjecture appears less improbable when we consider that of the cuspidatus. The simple and obvious use of this tooth, in the human species, is to tear such portions of food as are too hard or touo-h to be divided by the incisores ; and we frequently find it even far more developed in animals which are known to be exclusively frugivorous. Not only is its structure wholly unadapted for such an object as that assigned to it in the text, but there is no analogous or other ground for supposing that man was originally constructed for the pursuit and capture of living prey. His naturally erect position and the structure of the mouth would render this impossible by the means inferred by Hunter and the possession of so perfect an instrument as the hand obviates the necessity of his ever employing any other organ for the purpose of seSinVor holding food of whatever description.! seizing or •>P1. II. f. 1,2, cc. V J