184 ANIMAL DENTISTRY. 



erly speaking, a deficiency in the proper distance between 

 the inferior arcades, causing a beveling of the molars. 



Symptoms — The beveling is usually confined to but one 

 side. The molars of one superior arcade become beveled 

 from without inward entirely obstructing the lateral motion 

 toward the afifected side. The condition is frequently com- 

 plicated with decay of one or more molars, and mastication 

 is almost impossible in the advanced stage. Parvignathism 

 is one of the most serious irregularities of the horse's mouth. 



Treatment — With the large lever cutter (Fig. 92), the 

 beveled crowns of the entire superior and inferior arcades 

 must be trimmed almost to the level of the gums, beginning 

 with the first molars, and the decayed teeth, if any, must be 

 removed. This treatment, while placing one-half of all the 

 molars entirely "out of commission," will be met by prompt 

 relief to the patient. 



PROJECTIONS ON THE FIRST SUPERIOR AND 

 SIXTH INFERIOR MOLARS. 



Definition — A universal irregularity existing in the molar 

 arcades of all mature horses, consisting of sharpened points 

 of enamel at the anterior end of the superior arcades and the 

 posterior end of the inferior arcades. 



Etiology — The aggravated forms due to such gross de- 

 formities as brachygnathism or congenital or acquired de- 

 ficiency in the proper length of one or both arcades are not 

 included in this category. The large elongations occurring 

 at the extremities in either of the molar arcades are usually 

 due to a deficiency in the length of the opposing arcade, 

 but in this minor irregularity the lengths of the arcades 

 are equal. These points are caused by the position of the 

 muscles of mastication. The fixed attachments of all the 

 muscles of mastication except the masseter and external 



