506 DISEASES AND INJUEIES OF THE FACIAL EEGIOK 



asperities and irregularities are to be smoothed down with a fine 

 file. 



"VVlien the projecting piece of tooth is situated at the back 

 of the mouth, it is to be cut to a level with the other teeth with 

 a concave-edged chisel, and separate guard, which may be made 

 in a few minutes by any smith, as it consists only of a piece of 

 iron bent at its extremity so as to grasp the back of the tooth, 

 and of sufficient length in the handle to protrude from the 

 mouth. The bent end is to be inserted by the operator behind 

 the tooth ; the handle is to be held by an assistant, who is to 

 pull towards himself, exercising firm but not inordinate pressure ; 

 this will prevent the tooth from splitting when the cutting 

 cliisel is struck with the hammer. In all the other teeth but 

 the last, the operation can be performed with " Gowing's sliding 

 chisel," which would be the best instrument for the last tooth 

 also, if it could be applied. 



DISEASES OF THE ALVEOLAR PROCESSES. 



These are extensively diseased, in some cases with enlarge- 

 ment of the gums, which are soft, spongy, and bleed easily. The 

 teeth may or may not be diseased. 



The causes are various, and not easily demonstrated. Mr. 

 Varnell, whose observations on diseases of the teeth and cranial 

 and facial regions are entitled to great respect, says : — " The 

 causes which give rise to this condition of the maxillary bones 

 are not easy to define. That a horse so affected is from certain 

 peculiarities predisposed to it, there can be no doubt. For 

 example, the teeth being placed at a distance from each other, 

 allowing thereby the food to accumulate between them, must be 

 looked upon as a predisposing cause. A strumous diathesis, 

 which I believe to be more common in the horse than is usually 

 supposed, must also, when it exists, be regarded as a predisposing 

 cause of this affection. The particles of food which become 

 impacted in these unusually wide interdental spaces after a time 

 decompose, and give rise to foetid compounds, which act preju 

 dicially upon the parts they are in contact ^\dth. The membrane 

 which covers the gums, and also that wliicli lines the alveoli, 

 and is reflected on to the fangs of the teeth, become inflamed. 

 The inflammation wiU extend to the bone, the blood-vessels of 



