196 



AMMAL l)i;\'riS'l'RV 



trmlc thr()Ui;li the left commissure. In this position the 

 anterior end of the arcade h'es between the tluimh and first 

 finger, and the wrist is kept Hat on the interdental space of 

 tlie lower jaw, to keep the tons^ue from slipping beneath it. 

 The float is worked with the riglit hand, and the shaft is 

 guided by the palmar surface of the base of the thumb. The 

 fioat head is kept flat against the internal border of the 

 arcade, and not (^n tlie tables. (See Fig. 135.) 



Fig. 136. 

 Position of tlie Hands to Float tlic Riglil Inferior Molar Arcade. 



For the right inferior arcade i)lace the right hand in the 

 same relative i)osition as the left was placed for the oppo- 

 site inferior arcade, and work the float with the left hand. 

 Although the left hand is the awdcward one, it is advisable 

 to train it to accomplish this feat, as it is the only position 

 that will give universal satisfaction. Another method con- 

 sists of placing the left hand upright into the interdental 

 space and guiding the shaft between the second and third, 

 or third and fourth lingers. Still another method consists 



