The principles and practice of dental surgery / by Chapin A. Harris.

  • Chapin A. Harris
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of dental surgery / by Chapin A. Harris. Source: Wellcome Collection.

    815/836 (page 811)
    spring. The spiral spring must be made of such a length as will permit the valve to rest slightly upon the upper surface of the remnants of the lost velum. The slider has a pin in the posterior end, looking upwards to receive the other end of the spiral spring, before described. The anterior end of the slider has a small button looking downwards; the slider is attached to the plate by two small clasps, as represented in Fig. 226, b b. The plate may be made to cover the entire roof of the mouth, when necessary; or it may be made only sufficiently large to permit the mounting of the slider. These differ- ent plates, when put to- gether, particularly if the plate is to cover the whole roof of the mouth, makes a plate of the form represented by Fig. 249. Fig. 250 shows the attachment of the spiral spring to the valve and slider, c c. The staples confine the slider to the plate, b b.—and the but- ton on the end of the sli- der, d, by which the valve may be set back or for- ward, as desired by the patient, without removing the plate from the mouth. The palate should be made to fit the several parts for which it is intended, with great exactness. The plate must fit the roof of the mouth, and the teeth to which it may be secured, in a fault- less manner. The slider must be arranged so as to permit the valve to be drawn so closely against the posterior opening of the nar?s, as to close them; or to be pushed back so as to leave them-entirely unobstructed. The spiral spring, as I have before remarked, must be made of such a length as will allow the valve to rest slightly upon the upper surface of the remnants of the lost velum. The valve should be sufficiently wide at its base,