The elements of anatomy / by Jones Quain.

  • Quain, Jones, 1796-1865.
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: The elements of anatomy / by Jones Quain. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    199/914 (page 161)
    THE TEETH CLASSES OF. 1G1 where it ends in a blunted point: the root is longer and sinks deeper into the alveolus than that of any other teeth; it is single, conical, compressed at the sides, and marked by a slight groove, running its whole length from its apex to its summit. This is a trace or a rudiment of that division into processes which obtains in the molar teeth. The small molar, or bicuspid teeth (dentes bicuspidati) four in number in each jaw, are so named from usually having a divided root. They are intermediate in size as well as in situation between the cuspidati and molares. Their crown, compressed laterally where it is in apposition with the other teeth, is rounded on the external and internal sides, so that its depth from without inwards is greater than that of the incisores or cuspidati, whilst its breadth from side to side is less. The cutting extremities present two tubercles, one internal, the other external; in the lower jaw the internal tubercle is but very slightly prominent. A section of the neck presents an oval form, the root is single till near the apex, where it is usually bifid, particularly in the posterior bicuspidati; the groove at its sides is deeper than in the cus- pidati. The large molar, or true grinding teeth (dentes molares), are larger and placed farther back than the others; the crown, or projecting part, is compressed from before back- wards, as well as at the sides, so as to assume a cuboid form ; its free surface, which is intended for trituration, is sur- mounted by four tubercles, separated by depressions, which so intersect one another as generally to assume a crucial form. There are six molares in each jaw when the set is completed : the first and second are the largest of all the teeth, and in the upper jaw are usually furnished with three roots, very seldom with four, whilst in the lower jaw there are but two. The disposition of the roots deserves attention. In the upper jaw two of the roots are placed external, and parallel in their direction, whilst the third projects inwards from them at a slight angle ; in the lower jaw the roots are placed one anterior, the other posterior. The last of these mo- lar teeth are the smallest, and as they appear at an advanced period of life, are named dentes sapiential. The root is often single and tapering, but marked by two grooves, indicating,