The Osseous System 331 



filled with dense connective tissue. Ossification can, however, be 

 promoted by the practice of Osteoplasty. 



The Inferior Maxilla. Of all the head bones the inferior 

 maxilla is most commonly fractured. The lesion usually occurs 

 either at about the level of insertion of the second premolar imme- 

 diately posterior to the root of the canine tooth, or at the symphisis. 

 In the former position the fracture may exist simultaneously in both 

 halves or be confined to one side. This fracture is frequently com- 

 pound through laceration of the mucosa. It generally results from 

 direct violence, but in rare instances may be attributable to indirect 

 force exerted at a distant point. Such a case came under my notice. 

 A bullet shattered the bone posterior to the last molar and it was 

 concluded that the force of the missile exerted at this point had 

 tended to bend it downward or inward to the extent that it snapped 

 at its weakest spot, as a separate and distinct fracture also existed 

 just posterior to the root of the canine tooth and involved the second 

 premolar which was split into two distinct portions. This specimen 

 is in the Museum of the Army Medical Department. 



Chronic mercurial poisoning has a peculiar effect on the lower 

 jaw bones. There is an interesting specimen in the Pathologic 

 Museum at the Copenhagen School. It consists of the skull of an 

 aged hunting dog which had suffered from chronic mercurial poison- 

 ing through excessive dosing of the drug for a cancerous growth 

 of the mammae. The lower jaw is carious, some molars are missing 

 and the left ramus is broken across the middle (Stockfleth). 



Symptoms and Diagnosis. Characteristic are displacement of 

 the jaw so that the level of the teeth on one side is lower than on the 

 other, associated sometimes with lateral displacement, local tume- 

 faction and crepitation, salivation, difficult or suspended prehension 

 of food, and at times bleeding at the mouth. 



Treatment. This is beset with difficulty. For fractured sym- 

 physis interdental splinting should first be tried. This is accom- 

 plished by passing and securely binding a piece of silver wire round 

 the canine and incisor teeth as near to their necks as possible but 

 free from the gums. It is sometimes necessary to file a slight groove 

 in the postero-lateral aspect of the canines to retain the wire in 

 position. Should this method prove unsuccessful the two separated 

 rami must be wired together with silver wire, the latter operation 

 being performed externally with the animal under general anesthesia 



