Orthodontia, or malposition of the human teeth : its prevention and remedy.

  • Guilford, Simeon Hayden, 1841-1919.
Date:
[1893]
Catalogue details

Licence: Public Domain Mark

Credit: Orthodontia, or malposition of the human teeth : its prevention and remedy. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    tioiis ill an alveolar arch of [)roper size to accommodate them, and this again rests upon a jaw bone of suitable amplitude. Thus jaw^ process and teeth are harmoniously correlated. As each deciduous tooth is lost it is succeeded by the corresponding permanent one, which, under normal conditions, will occupy the space created by the removal of its predecessor. In this way, one by one, the permanent set should make its appearance until all of the deciduous teeth have been supplanted by their permanent successors. The permanent teeth are all larger than the corresponding- ones of the deciduous set, with one exception,—the second bicuspid. This being the case, they require a larger alveo- lar arch and a correspondingly larger jaw bone for their accommodation. This nature furnishes by the slow pro- cess of enlargement by interstitial growth, which is hastened and stimulated by the lateral pressure of the teeth as they make their way into place, and afterward. When the first permanent molar makes its appearance it is obliged to provide sufficient accommodation for itself by forcing its way between the deciduous second molar and the strong maxillary tuberosity above or the equally resistant ramus below. This pressure is felt by all the other teeth in the arch. If, therefore, any of the deciduous molars should be extracted about the fifth or sixth year, for instance, as they too often are after having been impaired by disease, the permanent molar will move forward and occupy part of the space intended for the bicuspids. When the permanent lower central incisors erupt they make their a]3pearance inside of the deciduous ones, which soon loosen and drop out. Owing to the fact that the width of these new teeth is considerably greater than that of their predecessors, they naturally overlap to a certain extent the adjoining deciduous laterals. This over- lapping prevents the centrals from moving forward into line in the arch. When the permanent laterals erupt they ■assume a position by the side of the centrals, and to find