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.

  • John Hunter
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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    time the tooth is fully formed, for the lower part of the membrane continues to adhere to the neck of the tooth, which has now risen as high as the edge of the gum.* Of the Ossification of a Tooth upon the Pulp. The beginning of the ossification upon the pulp is by one point, or more, according to the kind of tooth. In the incisores it is generally by three points, the middle one being the highest, and the first that begins to ossify. The cuspidatus begins by one point only; the bicuspis by two, one external, which is the first and the highest, and the other internal. The molares, either in a child or an adult, begin by four or five ossifications, one on each point, the external always the first. Where the teeth begin to ossify at one point only, that ossification gradually advances till the tooth is entirely completed; but if there is more than one point of ossifica- tion, each ossification increases till their bases come in contact with one another, and there all unite into one, after which they advance in growth as one ossification. The ossifications in their progress become thicker and thicker where they first began, but increase faster on the edges of the teeth; so as thence to become more and more hollow, and the cavity becomes deeper.f As the ossification advances, it gradually surrounds the pulp till the whole is covered by bone, excepting the under surface ; and while the ossifications advance, that part of the pulp which is covered by bone is always more vascular than the part which is not yet covered.^ The adhesion of the pulp to the new-formed tooth or bone is very slight, for it can always be separated from it without any apparent violence, nor are there any vessels going from the one to the other; the place, however, where it is most strongly attached is round the * [The statement that the bone of a tooth is produced from the pulp is errone- ous. This substance constitutes only the mould upon which the ossification is formed, between which and the pulp is placed a membrane of extreme tenuity, which I have termed the proper membrane of the pulp. It is slightly attached to the surface of the pulp, which it completely covers, and it is from the outer sur- face of this membrane that the bone is secreted. As the pulp recedes on the deposit of the successive laminae of bone, the ossific membrane continues to cover it, and ultimately forms the well-known membrane lining the internal cavity of the perfect tooth. The double investing membrane or sac which surrounds the whole rudiment as far as the neck of the tooth, and no further, has been proved, by repeated in- jections, to be vascular throughout, though Hunter states the internal, and Blake the external layer to be exclusively so. It is from the inner surface of this cap- sule that the enamel is secreted, as will be more particularly noticed hereafter. As soon as the enamel is secreted the capsule becomes absorbed, beginning at the edge or horizontal surface of the tooth, where the enamel is first deposited. It is, therefore, not perforated by the rising of the tooth, as inferred in the text, but absorbed as soon as it has performed its single function.] f PI. V. f. 14, a, b, c, d, two rows of incisors sawed down the middle, the highest of the child, the other of the adult: e,/, g, two rows of grinders showing the same circumstances. % PI. V. f. £, 6.
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