68 DISEASES OF THE JAWS. 



usually downwards, but sometimes to one side. The first 

 form is termed complete, and the second incomplete. 



Treatment. By pressing the thumb firmly against the' 

 neck of the. lower jaw, grasping the latter with the other 

 fingers, and then turning backwards and giving an upward 

 direction to the chin, the jaw snaps into its proper place. 

 Hertwig says: "One man holds the animal's four legs and 

 body still, and two assistants firmly fix the head. A bit of 

 wood from 10 to 16 inches -long, and from J to 1 inch thick, 

 must be pressed between the jaws as far back as possible, 

 and then the operator grasps the lower jaw and straightens 

 it, pressing it firmly upwards against the stick. In this 

 act a powerful' leverage is obtained, whereby the bones are 

 brought in apposition." The after-treatment consists in 

 keeping the animal as quiet as possible. 



Open Joint Both horses and oxen are liable to blows and 

 wounds over the temporo-maxillary joint. If the synovia or 

 joint-oil flows at once after the infliction of the injury, we 

 observe the part soon to swell, become hot and painful, and 

 the glutinous discharge very abundant. Whenever the ani- 

 mal moves the lower jaw, the discharge increases, and it soon 

 becomes turbid and purulent. This formation -of pus or 

 matter is attended with progressive destruction by ulceration 

 of the joint surface, and when a case has attained this point, 

 in the horse, it must be regarded as incurable. (See Kg. 32.) 

 The common result is a gradual diminution of the inflamma- 

 tion, with increase rather than diminution of the swelling, 

 and this is due to bony deposition. The joint may become 

 fixed or anchylosed, the animal cannot masticate, and death 

 is the inevitable result. The lateral action of the jaws in 

 herbivora renders the accident more dangerous in them than 

 in all the animals in which -a simple opening and closing of 

 the mouth is effected. 



