A dictionary of medical terminology, dental surgery, and the collateral sciences / by Chapin A. Harris.

  • Harris, Chapin A. (Chapin Aaron), 1806-1860.
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: A dictionary of medical terminology, dental surgery, and the collateral sciences / by Chapin A. Harris. 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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MIXTURE. Mistura. MNEME. Mvy/jiT]. Memory. MNEMONICS. From fivao/xai, I re- collect. The art of assisting the memory by signs. MOAN'ING. Audible expression of pain or sorrow in low plaintive groans. MOBILITY. Mobili'tas; from moveo, to move. Capability of being moved; susceptibility of motion. In Physiolocjy, great nervous susceptibility, complicated with a convulsive tendency. MOCH'LTA. From fiox^og, a lever. The reduction of a luxated bone. MOD'EL. Modu'lus ; from modus, a measure, rule, size, or bigness. A pattern of something to be made; any thing of a particular form, shape, or construction. A mould; something intended to give shape to castings. Something made in imitation of real life. An artificial form. Model, Plaster. In Mechanical Den- tistry, a fac-simile in plaster of a part or the whole of the alveolar border with the teeth which may be remaining in it, and if it be of the upper jaw, including the roof of the mouth. The manner of obtaining it is as follows :—An accurate impression, either in wax or plaster of Paris, having been procured, it is smeared with olive oil, and then filled with a batter or thin paste, made of the best calcined plaster and water. At first, it should be poured in while it is quite thin, until the indent- ations made by the teeth, if there were any in the jaw from which the impression was taken, are filled; after which the batter may be allowed to thicken a little before the remainder of the impression is filled, and it should then be poured on until the plaster is raised an inch, or an inch and a half above the impression. After the plaster has sufficiently har- dened, it should be trimmed, and the wax, after softening it in warm water or by the fire, removed from it. The same impression can sometimes be used a second or third time, but lest the shape of it should be altered in the removal of the model, a duplicate impression should be taken. The plaster should be shaped with a knife, so that a metallic casting obtained from it may be easily separated from the metal which may be cast upon it. After being thus trimmed, it should be thoroughly dried. It sometimes happens, when the alveo- lar ridge is very deep, that the lower edge of the arch inclines outward so much as to make the span of it here considera- bly greater than it is a quarter or half an inch higher up. In this case, if sand be used in procuring a metallic model, it would be difficult to remove the plaster without injuring the impression in the sand. To obviate this difficulty, the plaster model should be so constructed as to consist of three pieces or sections. After the three are put together, the model may be pressed in the sand until a good impression is made, and afterwards re- moved separately. Dr. A. Westcott, I believe, was the first to introduce the use of this description of plaster model, which may be procured by first filling the wax impression with the plaster, as in the manner before described; this is then re- moved, and about one-third from each side trimmed off, leaving the lower sur- face wider than the upper. This done, it is replaced in the impression, and filled up on each side with plaster, as in the first instance. After the last has consoli- dated, the model is trimmed and dried in the manner as before described. Model and Counter-Model, Metal- lic. In Mechanical Dentistry, a male and female casting made of lead, block- tin, zinc, or brass, used for striking up a plate to serve as a base for artificial teeth, or as a palatine obturator, or for chang- ing the position of a tooth which occupies a wrong place. They may be made in either of the following ways :—1. By pouring fused metal into an impression made with the plaster model in sand, and then placing this in, or pouring melted metal on it. 2. By placing the plaster model directly in, or pouring fused metal on it, and afterwards pouring into this some other melted metal. Model, Antagonizing, for Artifi-