86 SURGICAL APPLIED ANATOMY. [Chap. vi. 



of the nose is often found to be greatly depressed. 

 This depends upon no actual loss of parts, but rather 

 upon imperfect development from local mal-nutrition, 

 that mal-nutrition following upon a severe catarrh 

 of the mucous membrane. The deformity only 

 occurs, therefore, in those who have had " snuffles " 

 in infancy. 



The nasal bones are often broken by direct 

 violence. The fracture is most common through the 

 lower third of the bones, where they are thinnest and 

 least supported. It is rarest in the upper third, 

 where the bones are thick and firmly held, and where, 

 indeed, considerable force is required to produce a 

 fracture. Since no muscles act upon the ossa nasi, 

 any displacement that occurs is due solely to the 

 direction of the force. Union takes place after these 

 fractures with greater rapidity than perhaps obtains 

 after fracture of any other bone in the body. In one 

 case noted by Hamilton, "the fragments were quite 

 tirmly united on the seventh day." If the mucous 

 membrane of the nose be torn, these fractures are apt 

 to be associated with emphysema of the subcutaneous 

 tissue, which is greatly increased on blowing the nose. 

 The air in such cases is derived, of course, from the 

 nasal fossae. In fractures of the upper third of the ossa 

 nasi the cribriform plate may be broken, but it is ques- 

 tionable whether this complication can occur when the 

 fracture is limited to the lower third of the bones. The 

 root of the nose is a favourite place for nieningoceles 

 and encephaloceles, the protrusion escaping through 

 the suture between the nasal and frontal bones. Such 

 protrusions, when occurring in this place, are often 

 covered by a thin and vascular integument, and have 

 been mistaken for nsevoid growths. 



2. The nasal cavities. The anterior nares 

 have somewhat the shape of the heart on a playing 

 card, and the aperture as a whole measures about 



