REPULSION OF TEETH. 9 



Technic. Secure the animal in the lateral recumbent 

 position with the affected side up. The operating table 

 affords hy far the best means for securing for the conven- 

 ience and safety of operator and patient. If the sinuses are 

 so involved as to make possible the inhalation of pus, blood 

 or other injurious matter, perform tracheotomy in ample 

 time to avert danger. Anaesthetize locally or generally as 

 required. Shave and disinfect the operative area and 

 trephine according to the method described in the following 

 chapter, down through the alveolar plate immediately over 

 the fang of the affected tooth. Avoid dulling the trephine 

 by striking it against the tooth fang. 



If an external fistula exists the identity of the affected 

 tooth is best determined by passing a metallic probe through 

 it against the diseased fang while one hand is passed into 

 the mouth and the location of the probe more fully ascer- 

 tained. Care should be exercised in trephining to not injure 

 the adjoining teeth. 



After removing the disc of bone isolated by the trephine, 

 control all hemorrhage and then enlarge the opening and 

 remove the bony tissues till the tooth fang is bared its entire 

 width. Insert a scalpel or bone chisel between the external 

 face of the bone and the soft tissues at the oral margin of 

 the trephine opening and with one hand in the oral cavity 

 with the fingers resting upon the alveolar border on the 

 lateral side of the tooth to serve as a guide, push the scalpel 

 or chisel along between the bone and soft tissues until it 

 emerges from the gums alongside the affected tooth and 

 extend this separation backwards and forwards until the 

 soft tissues are completely detached from the alveolar wall 

 over the entire area of the diseased member. 



When operating upon the superior molars, the fangs of 

 which are covered by the zygomatic ridge, the chisel or 

 scapel cannot be pushed directly from the trephine opening 

 into the mouth between the soft tissues and the bone because 

 the line is concave instead of direct. In these cases it is 



