340 FRACTURES OF BONES OF THE FACE. 



V.— DISEASES OF THE FACE AND LOWER JAW. 



The face is here regarded as comprising that section of the head 

 whose base is formed by the upper jaw and the malar and lachrymal 

 bones. 



(1.) FRACTURES OF BONES OF THE FACE. 



On account of its sheltered position, the upper jaw is seldom 

 fractured. In horses fracture may be due to dental operations, and 

 in dogs to bites ; less frequently to such external violence as kicks, 

 or collision with fixed objects. During the progress of dental opera- 

 tions fractures result if the animal, especially when operated on 

 standing, suddenly moves, and the operator does not follow the 

 movement with his forceps. Incautious attempts to loosen the tooth 

 with the forceps may also produce fracture of the maxilla. In 

 compound fractures the broken ends or splinters of the bone are 

 found in the wound. When the facial plate of the superior maxilla 

 is thus affected the corresponding sinus is opened, and air passes 

 in and out during respiration. 



The symptoms consist of swelling, salivation, defective and 

 painful mastication ; the molars are found to be loose, and the gums 

 wounded ; crepitation may sometimes be detected. 



Diagnosis of fractures of the malar, caused by external violence, 

 is only difficult when much swelling exists. If not due to cellulitis, 

 to the presence of new growths, cysts or disease of the superior 

 maxillary sinus, such swelling should arouse suspicion of a fracture, 

 especially if there be any considerable difficulty in mastication. 

 Where the superior maxillary sinus is laid open, or the zygomatic 

 ridge injured, doubt can no longer exist. Damage to the alveoli 

 of the upper molars, or extensive tearing of muscular insertions, 

 give rise to difficulty in feeding. Subcutaneous fractures of the malar 

 bone, which are of rare occurrence, unite easily, and compound 

 fractures only cause difficulty when the alveoli of teeth are exposed, 

 and purulent alveolar periostitis results. 



Prognosis depends chiefly upon whether the fracture is subcu- 

 taneous or complicated. In the former instance, recovery generally 

 occurs in three weeks ; in the latter, a much longer time is required. 

 Complications result both from injury to the skin, and to the mucous 

 membrane of the mouth and gums. In compound fractures with 

 exposure of the superior maxillary sinus or alveoli of the teeth the 

 prognosis should be cautious. 



