EXTRACTION OF TEETH 



passage of air bubbles to and fro through the blood and 

 lymph in the alveolus. Maintain the forceps in position 

 with one hand and with the other introduce the fulcrum to 

 a point where the depression on its superior surface will 

 receive the projecting rivet-head of the instrument or in an 

 otherwise secure position affording a safe support, while 

 the inferior surface rests evenly upon the crown of a tooth 

 anterior to that which it is desired to extract, as is shown 

 in Fig. I . The fulcrum needs to be held firmly in place in 

 order to prevent it from gliding away under pressure. 



In extracting the first premolars there is no opportunity 

 for resting the fulcrum on teeth anterior thereto and con- 

 sequently forceps have been made with fulcra beyond the 

 forceps jaws resting upon teeth more posteriorly situated. 

 This is not essential. If the tooth is thoroughly loosened, 

 as it should be, one hand placed in the interdental space 

 with the dorsal surface against the jaw and the volar grasp- 

 ing the instrument, will serve as an effective fulcrum. 



In other cases an iron or steel fulcrum is not essential, 

 but a stick of hard wood of proper size and form acts quite 

 as efiiciently and may even keep its position better because 

 the teeth upon which it rests sink into it somewhat'. On 

 the whole the fulcrum is not so important as some have 

 considered it, since, after a tooth is loose enough to be 

 drawn with its aid, a very trifling additional loosening will 

 permit it to be easily lifted from its alveolus without it. 



The tooth fang is extracted by forcing the handles of the 

 forceps toward the jaw in which it is located, so that as it 

 is gradually drawn out the forceps tend to pivot on the 

 fulcrum in a way to permit the tooth to emerge from its 

 alveolus in the direction of its long axis. By referring to 

 Fig. 2 it will be seen that the long axes of the different 

 teeth vary, that of the molars being obliquely forwards from 

 fang to crown towards the incisors, while the crowns of the 

 premolars are directed obliquely backwards toward the 



