A system of dental surgery / by Sir John Tomes.

  • John Tomes
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: A system of dental surgery / by Sir John Tomes. Source: Wellcome Collection.

    117/808 page 101
    ing to the (Icvclopmcut of the lower may be a]i])He(l to those faciul bones which ;ire connected witli the ni;istic;\tory apparatus. The tuberosity is to tlie ujijier what tlie base of the coronoid process is to the h)wer jaw. J'roni this point tiie alveohir hue is lengthened. In the s])ecinien last men- tioned, the second molar is l)urieil high up in the tvdierosity. Soon after the expiration of tlie twelfth year, the distance between the pterygoid ])rocess and the first molar will have increased sutticiently to idlow the second molar to take its place in the dental line, and by the e.\i)iration of the twen- tieth year the third molar is usually found in its normal position. Up to this period, tlie facial liones are connected to each otlier and to the bones of the cranium b}^ sutures only ; and in tlie soft tissue within these, development (if bone takes place. The maxillary bones, while their jirocesses are increased in length, are moved liodily forward, the rate of growth keeping pace with the increase at the tuberosity. Coincidently with development, the modelling of certain parts by super- ficial absorjition is carried on. By this pr(K-ess, the anterior surfiice of the lower bonier nf the malar process is removed, and thus thrown backward. In the seven years' s])ecimen it lies immediately above the anterior third of the first molar; at twenty-one it holds a similar position with resjiect to the second molar, thus showing a recedence equal to the width of one tooth. x\s res[iects the changes of Ibi-m and jiositinn which the glenoid cavity undergoes dui'iug growth, but little need lie said. Here we have articular cartilage, beneath wliich the recpiired amount of tione is slowly developed in the same manner as the subarticular cartilage of the lowei'jaw. ^Ir. Siiaw some yeai's ago ])oiute(l out that the cranial poi-tion of the skull differs liut little in dimi'nsiinis e\eu if the comjjarison lie made between giants and ])ersiins of ordinary statui-e, whereas the face and all tlie iMines wliicli enter into its f<irniation differ much, and this is vei'y marked in the lower jaws. This is apt to give to tlie faces of such
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