202 On a new application of Lever Power 



sometimes seen the most skilful dentists extract the molar 

 teeth with difficulty,, and at the expense of protracted suffer- 

 ing to the patient. This suffering might no doubt be 

 obviated by the use of chloroform, but the many fatal acci- 

 dents that have occurred in the use of this powerful agent, 

 renders it very undesirable to be used except on special occa- 

 sions, and when a medical practitioner is present for the 

 purpose of administering it. 



I trust, therefore, that I have shown that a new and 

 more effective application of power in the extraction of the 

 molar teeth is a very important desideratum. 



The principle on which this new instrument acts is that of 

 the lever, a fulcrum being obtained from a sound tooth, 

 at a convenient distance from the tooth to be extracted. 

 The lever can thus be used either on the adjoining tooth or 

 on any other within reach. The only objection that can be 

 urged against the principle of its action, is the possibility in 

 certain cases of a very strong pressure on a sound tooth 

 proving injurious to it. I do not anticipate any such in- 

 jurious consequence when the instrument is used with 

 ordinary care and judgment, but against such possible ac- 

 cidents with the lever we must bear in mind the rough 

 usage to which the jaws of patients have hitherto been sub- 

 jected both with the key and the forceps, and the many 

 serious injuries that have been caused by these instruments, 

 and especially by the common key ; and if the forceps has 

 been productive of less injurious consequences than the key, 

 I feel quite confident that the direct pressure of the lever 

 on a sound tooth will be much less injurious to the jaw, 

 than the violent shaking and twisting motion with which 

 the forceps is frequently used. If the principle of this lever 

 therefore be admitted to be correct, the great power which 

 it possesses must give it, in difficult cases, a very great 

 advantage over all other instruments for extracting teeth. 



There are two modifications of this lever power which I 

 shall now endeavour to describe : — 



The first (Fig. 1, Table 1) which will probably be found the 

 more easy of application, consists of a shaft and handle, being 

 similar in this respect to a common tooth key, the shaft termin- 

 ating in two short arms like a fork — on one of these arms is a 

 small plate or rest, which is moveable, and protected with 

 leather. This rest is that part of the instrument which is placed 

 on the tooth or teeth selected as a fulcrum ; the other arm of 

 the instrument being employed to raise the forceps when it 



