240 HEALTH AND DISEASE 



constantly being moved sharply up and down, and in gathering his food 

 the animal breaks off abruptly. If there is much displacement mastication 

 is interfered with, and the food is dropped from the mouth. The lips 

 remain somewhat separated from each other, and on opening the mouth 

 the mucous membrane will be found to be torn or placed on the stretch 

 by the parting pieces, or not, according to the presence or absence of dis- 

 placement and the extent to which it has proceeded. 



When the breakage occurs across the body of the bone behind the 

 incisor teeth, the chin is more or less depressed, the mouth remains open, 

 allowing a free escape of saliva and maybe more or less protrusion of the 

 tongue. Crepitation is perceived when the broken parts are moved one 

 upon the other. In consequence of the pendulous and disabled state of 

 the lower lip the patient fails to gather his food, or if he succeed it is 

 in a very small measure, and only accomplished with great difficulty 

 and at the expense of much suffering. 



In fracture of the coronoid process the angle of the jaw on the side 

 of the injury will be found to be slightly lower than the opposite angle. 

 Mastication is seriously interfered with, and the movements of the jaw 

 lose their natural swing and become restricted and irregular. The animal 

 cannot masticate hard food, and will only take aliment of a soft and sloppy 

 character. 



Fractures through the neck of the jaw between the molar teeth and the 

 tusk, without displacement, are sometimes difficult to identify at first, the 

 only symptoms observable being a marked shyness in feeding, in the act of 

 which the saliva becomes churned into foam. 



Presently, however, a diffused swelling appears around the bone over 

 the seat of the fracture. This may encroach upon the " mental " nerve as 

 it escapes through the foramen on the outer side of the bone at this part, 

 and for a time partial paralysis of the lower lip is likely to result. If 

 the broken parts are displaced a crepitus or rubbing sensation may be 

 excited by moving one part upon the other. 



Treatment. Where displacement exists the parts should first be 

 brought into their natural position and retained there by suitable means. 



If the body of the bone be split vertically through the centre and 

 the parts are displaced, they may be brought into position again by seizing 

 the corner incisor teeth between a pair of large pincers and steadily but 

 forcibly pressing them together. If they are raised one above the other, 

 they must first be brought into line by depressing one piece or raising the 

 other, as the case may be. If this cannot be effected by the hands, the 

 pincers properly padded must be employed. 



Should the teeth have undergone any displacement they must be 



