A manual of dental anatomy : human and comparative / by Charles S. Tomes.
- Charles Sissmore Tomes
- Date:
- 1898
Licence: Public Domain Mark
Credit: A manual of dental anatomy : human and comparative / by Charles S. Tomes. Source: Wellcome Collection.
600/646 page 586
![a perfectly anomalous one ; but, just at the period that this layer of the dentine papilla is at its maximum, the amelo- blasts suddenly attain to an enormous size. Over the next younger tooth they are small, and over the next older tooth the}^ have again dropped down to a small size, have lost their distinctness of outline, and have otherwise changed. Without entering into detail, it seems obvious that they have a short period of great activity, after which they are spent, and the only plausible explanation would seem to be that they are concerned in the calcification of this peculiar layer, for it is just at this period that it does calcify. If this view is correct, then the elasmobranch fish, just as they show us the first introduction of specialised teeth, present the first differentiation of enamel as a separate tissue, in the form of a joint product of the epiblastic enamel cells and the mesoblastic dentine papilla; afterwards, as tooth development came to be a slower and more deliberate process, as happens in many other fish and in reptiles and mammals, the ameloblasts took upon themselves the whole work. Rose's paper, to which I have alluded, attempts a com- prehensive classification of all calcified tissues, and in so doing he proposes a slightly different classification of dentines from that to be found in these pages. (Cf. p. 81.) He does not admit plici-deiitiue into the list, and proposes the term trabecular-dentine instead of my osteo-dentine, my plici-dentines being for the most part or entirely relegated to this grou]D of dentines. However, I do not agree with the conclusions which he has drawn; and, although the classifi- cation of dentines is avowedly'not quite satisfactory, I do not think that proposed by Rose materially improves the position ; for, when tested by actual application, it seems to me to break down, and to lead to more inconsistencies than the old one ; the general question, however, is too large for discussion here, and my reasons for not accepting his conclusions will be found elsewhere. (“ Anat. Auzeig., 1898.)](https://iiif.wellcomecollection.org/image/b21501014_0600.jp2/full/800%2C/0/default.jpg)
