Some methods and appliances in operative and mechanical dentistry / By R. P. Lennox. With illustrations.

  • Lennox, Robert Proudfoot, 1843?-1902.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: Some methods and appliances in operative and mechanical dentistry / By R. P. Lennox. With illustrations. 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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    arch of the teeth of the upper jaw. This contraction is sometimes advocated in order to make room for springs when these cannot be dispensed with, but more generally it a]i]tears to be due to an idea that it is absolutely essential to place the teeth upon what remains of the alveolar ridge. In my view neither of these reasons can be justified, and I make it my practice to keep the arch as wide as possible. Springs. In the majority of cases, well-made plates need no special contrivance to keep them in position. Where any contrivance at all is necessary, I prefer to use springs. These are, in general, only necessary where a lower is difficult to keep in position, and even in such cases the use of them may sometimes be avoided by weighting the lower with Watt's or other metal. On the other hand, it sometimes happens that, in the case of very aged patients, the alveolar border is so far absorbed that even springs do not avail to keep the lower in place, and some additional contrivance becomes necessary. When springs are to be inserted, a question arises upon which authorities appear to differ, viz. as to the position of the bolts. If these are placed too far back, the springs must either be too short, or themselves go back too far and gall the mucous membrane. My rule is never to place the bolts in the lower further back than just below the centre of the second bicuspid, while in general I place them more forward, the room in the mouth, of course, determining the position in any given case. The bolts in the upper should go vertically over those in the lower, or rather just the least bit backward of that position. Whenever possible, I avoid vulcanising the bolts theni- selves into the positions intended for them, replacing them temporarily by pieces of knitting-needle (Fig. 7) taken back to a blue. These are afterwards readily withdrawn by heating the ends with a blow-pipe and using a strong pair of pliers. They are then replaced by the bolts, which should fit tightly into the holes prepared for them. The advantage of this method is that, when the swivels are worn out, the