148 THE PATHOLOGY OF' THE TEETH. 



"When the disease has penetrated the roots, and 

 has induced the usual inflammation, the thin parti- 

 tions that separate them from the sinuses do not resist 

 very long. Destroyed by the dilatory effort of the 

 hypertrophied root and the influence of the caries, the 

 altered matters of the mouth have free access into the 

 sinuses. Under the influence of their contact, the 

 membrane of the sinuses irritates, vascularizes, and 

 thickens by a serous infiltration in the early stage. 

 Then, the primitive cause of this modification contin- 

 uing, the membrane hypertrophies somewhat, and in 

 a short time, owing to its vascular system being richly 

 developed by inflammation, large vegetations of the 

 nature of polypi are elevated upon it. These, on ac- 

 count of the incessant augmentation of their volume, 

 fill the sinuses and cause a swelling of their walls. 



"When the membrane of the sinuses has become 

 the seat of an abnormal vegetation, an abundant quan- 

 tity of purulent matter is secreted, the more liquid 

 part of which drains out through the conduits leading 

 to the nasal cavities, while the more concrete part 

 remains in the sinuses. It then, according as it loses 

 its serosity, undergoes a transformation, and finally 

 displays the aspect of cadaveric grease, which it also 

 resembles in its repugnant odor. There is a great 

 analogy between the disease that causes this particular 

 lesion and that of glanders. 



"Symptomatology. The first symptom that indi- 

 cates a derangement of the dental apparatus is a diffi- 

 culty in mastication. The animal, excited by hunger, 

 seizes the food with avidity. The motions of the lower 

 jaw, however, are made with a sort of hesitation, and 

 often only at one side. The imperfectly masticated 

 hay, which on that account will not pass through the 



