Mechanical dentistry, a treatise on the construction of artifical dentures

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1878 Excerpt: ...may remain of the soft palate communicates to the artificial velum such motion as enables the latter to perform the functions proper to the parts for which it is a substitute. Figs. 84 and 85 give a view of both sides of this instrument; it will be seen that it consists essentially of two wings which in the drawings are a certain distance apart along the Centre line; a third part is provided which covers the central slit, but which does not prevent the wings from closing when the edges of the fissure approach each other, as in the act of swallowing. Within the last few years an improved artificial palate has been introduced by Professor Kingsley. The principle adopted is the same as that worked out by Stearns, but the palate itself, which is made of soft rubber, is much more simple in its con. struction. Cases of palatal defect are divided into two classes, according to the immediate causes which may have produced them. First, those which are the result of arrested development---malformations--are called congenital; second, those which are produced by disease or otherwise are called accidental. A distinguishing feature in the two classes is, that the defect, so far as the palate is concerned, is in congenital cases always in the median line, whereas in accidental cases the defect is generally on one side or other of that line. When the cleft in congenital cases, however, proceeds in an anterior direction, involving the central portion of the jaw and teeth, and ending in fissure of the lip, it then may incline away from the median line in the direction of one or other nasal passage, or it may continue in the median line involving both nasal passages. Accidental defects vary much both as to locality and extent. There may be a simp...