REPULSION OF TEETH 



and osseous tissues for the remainder of the distance and 

 the separation completed. 



The operator needs to use great care in making his way 

 through the zygoma down to the mouth. Just beneath the 

 ridge, the larger branches of the facial nerve (yth, cranial 

 nerve) run parallel to the ridge directly under the skin. If 

 the operator inadvertently cuts or injures the nerve 

 branches, the lips are paralyzed and drawn to the opposite 

 side. The paralysis may be permanent and greatly disfigure 

 the animal. The operator needs to be careful, also, in this 

 part of the operation to avoid wounding the subzygomatic 

 artery and vein, SZ, Figs. 8, 9, which run parallel to the 

 zygoma, deeply imbedded in the masseter and lying almost 

 immediately against the bone. In separating the soft tissues 

 from the bone, therefore, the operator must be careful to 

 keep immediately against the bony plate. 



The trephining for the repulsion of the superior molars 

 involves the invasion of the facial sinuses. In a majority 

 of cases, the sinuses are the seat of empyema, so there is 

 the double object of removing the diseased tooth and pro- 

 viding means for overcoming the empyema. This is de- 

 scribed in the following pages under trephining of the 

 sinuses. 



The repulsion of the inferior grinders is one of the most 



hazardous operations undertaken by veterinarians, unless 

 accurate anatomical knowledge and surgical technic are 

 brought to bear upon the operation. The inferior grinders 

 are wedge-shaped, the fang being the apex of the wedge. 

 The inner and outer alveolar plates rest directly upon the 

 tooth. If the punch slips by the fang of the tooth and 

 engages either internal or external plate, disaster follows. 

 The masseter muscle covers the fangs of the inferior molars 

 and the operator must avoid mutilating it as far as possible 

 in order to prevent unsightly blemishing. The best plan 

 for laying bare the alveolar wall over the fang of the tooth 



