A manual of dental anatomy : human and comparative / by Charles S. Tomes.

  • Charles Sissmore Tomes
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: A manual of dental anatomy : human and comparative / by Charles S. Tomes. Source: Wellcome Collection.

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    tooth at an angle of 60 degrees; then, after passing throngh about half the thickness of the enamel, they turn up abruptly again, so that they are approaching to parallelism with the dentine, here making in fact an angle a little' less than 30 degrees with it. It follows from this that no transverse section can show very plainly the direction of the prisms in both parts of their course. The most instructive transverse section is one Fiq. 2('). cut parallel with the layers near to the dentine ; this will plainly show the successive layers passing to the right and to the left just as in the squirrel, but the yet more inclined fibres of the outer half of the enamel will then be cut across obliquely; and the figure may be regarded as {}) Transverse section of dentine and enamel of a left lower incisor of a beaver; in the inner half the prisms of contiguous layers cross each other at right angles, in the outer tliey are parallel. It is obvious that a transverse section, in order to show the decussation of superimposed layers clearly, must be parallel with the layers, i.c., oblique to the axis of the tooth. But this obliquity will not be right for the outer portion in which the fibres are yet more inclined upwards, so that in it several layers will be cut across somewhat obliquely.
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