THE TEETH 33 



should look carefully for the central rings of enamel, which, it will be 

 remembered, surround the infundibular cavity. However artistically 

 the imitation of the infundibular depression may have been carried 

 out, there is no known artifice by which even an expert can effectively 

 replace the ring of enamel which has disappeared through friction. 



Another device to give an old tooth a youthful appearance is to 

 shorten the crown and then bishop. In cases of " bishopped " and 

 " trimmed " teeth, evidence of the use of the rasp or file may frequently 

 be found if carefully sought for in the form of roughened markings 

 on the enamelled surface of the tooth. 



Irregular Edges of Molars 



One of the most common forms of irregularity is found in connection 

 with the edges of the molars, the outer edge of the upper row and the 

 inner edge of the lower being the edges affected. 



It was a common belief that serious injuries to the buccal wall were 

 frequent results of such irregularities, but the consensus of opinion at 

 present is opposed to this view, and is inclined to the belief that 

 wounding by irregular molars is extremely rare. 



An animal with such teeth, however, does not feed well, and for this 

 reason it is advisable that a level edge should be obtained by means of 

 the rasp. 



Overgrown Teeth 



It frequently happens that one or more molars or incisors appear to 

 be much longer than the remaining teeth. This is due to the fact that 

 the visible portion of the tooth is much longer. The length of the 

 whole tooth is not greater than that of those around it, but it appears 

 longer on account of its having been pushed a liltle further out of 

 its socket. 



The increased length of the exposed portion may be due to the 

 absence of the opposing tooth either through accident or extraction. 



