754 THE EXTERIOR OF THE HORSE. 



1st. The abnormal wear only involves the anterior face of the 

 incisors. 



2d. It bears upon their posterior face. 



3d. It exists upon their anterior and posterior faces at the same 

 time. 



4th. It affects the dental tables. 



5th. It takes place upon the lateral surfaces. 



In four of these cases, a bevel is formed at the expense of the faces ; 

 in the fifth, there is a simple shortening of the tooth, which leaves the 

 form of the dental tables absolutely intact. 



1st. The Abnormal "Wear only involves the Anterior Face of the 

 Incisors (Fig. 326 : A, B, C, D). The pincers and the intermediates are, as a 

 rule, worn at the same time ; more rarely only the corners are affected. The wear is 

 ordinarily more pronounced in the middle portion of the arcades, and often more 

 extensive from one side to the other. The bevel which results from it may be- 

 come two centimetres in length, and may even go so far as to open the external 

 dental cavity ; this- always diminishes to a great extent the surface of the dental 

 table. 



We have observed in this category the four following varieties : 



a. The bevel exists only upon the superior jaw (A). 



b. It is observed only on the inferior (It). 



c. It is seen in both jaws (C). 



In the first two cases, the contact takes place by the anterior part of the 

 dental table upon the foreign body ; in the third case, the horse seizes a round 

 border or a sharp edge, each jaw setting itself or cutting against one of the 

 adjacent faces of the foreign body. 



d. The two bevels are upon the same plane instead of being convergent 

 towards the interior of the mouth, D. This form results when the animal cribs 

 on a wide, flat surface, as the bottom of the manger, for example, by making to- 

 and-fro movements .with the jaws alternately from before to behind or from one 

 side to the other. 



2d. The Abnormal Wear only interests the Posterior Face of the 

 Incisors (Fig. 327, A, , C). This category is one of the most singular. If 

 the observer confines himself to a simple separation of the lips for the purpose 

 of examining the anterior face of the teeth, it is evident that nothing abnormal 

 can be seen ; if, on the contrary, he opens the mouth, it may happen that he still 

 may not recognize the accidental use, or that, even if recognized, it may not be 

 attributed to cribbing, but be considered simply as a dental anomaly. 



This wear is manifested in this variety by a bevel converging towards the 

 side of the lips, whose obliquity is directed in the same sense as the curve of the 

 posterior face of the incisors, while in the preceding cases the bevel was directed 

 in an inverse sense, which rendered it much more apparent. Nevertheless, the 

 observer who has been forewarned will never fail to perceive very easily the pos- 

 terior bevel of which we speak, but he will not forget that it is always less 

 apparent below than above, in consequence of the greater curvature of the supe- 

 rior incisors. 



It may be added that this sort of wear is more commonly observed in 



