Volume 1

Odontography, or a treatise on the comparative anatomy of the teeth, their physiological relations, mode of development and microscopic structure, in the vertebrate animals / by Richard Owen.

  • Owen, Richard, 1804-1892.
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: Odontography, or a treatise on the comparative anatomy of the teeth, their physiological relations, mode of development and microscopic structure, in the vertebrate animals / by Richard Owen. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    to the mechanical conditions of the tooth, but to the nutrition of the dentine. Dentine, thus organized, is ‘ unvascular’: the teeth of most mammals and reptiles, and of a few fishes present this modification of their main constituent. But the dentine in the teeth of most fishes, of a few mammals, and of still fewer reptiles, is traversed by canals containing blood vessels or a vascular pulp; the tooth- substance, thus modified, I term ‘ vascular dentine.’ Both the ‘ vascular’ and ' unvascular dentine’ may he present in the same tooth, as in those of the sloth, the walrus, and the cachalot: the transition from the vascular dentine to true bone is gradual and close. ‘ Cement’ always closely corresponds in texture with the osseous tissue of the same animal, and wherever it occurs of sufiicient thickness, as upon the teeth of the horse, sloth or ruminants, it is also traversed, like bone, by vascular canals. In reptiles and mammals, in which the animal basis of the bones of the skeleton is excavated by minute radiated cells, forming with their contents the ‘ corpuscles of Purkinje’, these are likewise present, of similar size and form, in the ‘ cement’, and are its chief characteristic as a constituent of the tooth. The hardening material of the cement is partly segregated and combined with the parietes of the radiated cells and canals, and is partly contained in aggregated grains in the cells, which are thus rendered opake. The relative density of the dentine and cement varies according to the proportion of the earthy material, and chiefly of that part which is combined with the animal matter in the walls of the cavities, as compared with the size and number of the cavities themselves. In the complex grinders of the elephant, the masqued hoar and the