MASTICATORY PARALYSIS. 
101 
given. Under other circumstances, and especially where extensive 
atrophy and degeneration have set in, treatment is of no value. In 
Waltrup’s case in the horse, and Froliner’s in the dog, improvement 
occurred gradually. Frick records three cases in the dog ; all appeared 
suddenly without visible cause, and all recovered completely. 
Treatment calls for appropriate nourishment, food must be placed in 
the mouth, and the stomach tube is sometimes serviceable. The induced 
or constant electric current should be tried, the poles being applied to 
the masseter and temporalis muscles; Frohner states that by its daily 
use recovery occurs in one to two months. 
(6.) PERIOSTITIS AND EXOSTOSIS ON THE POSTERIOR 
BORDER OF THE LOWER JAAV. 
Circumscribed periostitis sometimes occurs in the horse on the posterior 
border of the lower jaw at the height of the first molar, and induces 
exostosis The most frequent cause is external violence, especially striking 
against narrow mangers while feeding. The periostitis seldom produces 
disturbance ; pain is sometimes indicated by careful mastication, but t e 
presence of exostosis usually first attracts notice. On the posterior border 
of the lower jaw a hard, sharply defined, round, sometimes knobby, 
painless swelling appears, firmly attached to the bone. Sometimes the 
swelling is flatter, and may then be mistaken for that produced by 
alveolar periostitis, in which, however, the rarefaction of bone and the 
swelling are on the lateral surface of the lower jaw, and mount upwar s. 
Periostitis caused by local injury, on the other hand, remains confine 
to the posterior edge. 
Prognosis is favourable, the mature exostosis only producing an 
unimportant blemish. . 
Treatment must conform to general principles. Prominent exostoses 
may be removed : a circular cut is first made through the skin and 
periosteum, and the chisel or saw then applied. Flat swellings are 
better left alone. 
(7.) TUMOURS ON THE LOAVER JAAV. 
True tumours of the lower jaw are much less common in animals than 
in men. Only enchondromata, carcinomata, and epitheliomata have 
hitherto been described, and these sparingly. Cadiot and Dollar 
describe a case of lobulated pavement epithelioma of the lower 
jaw in a horse, of which an illustration is given overleaf. “ ihe 
left branch of the lower maxilla opposite the first molars appeal ec 
