26 A MANUAL OF DENTAL ANATOMY. 



mainly at its free margin, near to the neck of the tooth. 

 Over very prominent roots a portion of alveolus is at times 

 wanting, so that in a macerated skull the root is exposed to 

 view. 



The upper maxilla serves to give form and support to the 

 soft parts of the face, and also to carry the upper teeth. 

 These have to be rigidly fixed, while the teeth of the lower 

 jaw are brought forcibly against them with more or less of 

 shock. And whilst these blows have to be received, and 

 resisted, and ultimately borne by the cranium, it is obviously 

 desirable that they should be distributed over a sufficiently 

 wide area, so as not to be felt unpleasantly. 



The ascending nasal process is very stout, and serves to 

 connect the maxilla strongly with the frontal bone, which 

 also in the region in question is powerfully developed ; the 

 thick malar process gives rigidity and resistance to lateral 

 movements of the jaws, and carries off the strains to the 

 lateral walls of the cranium ; it is buttressed at the back 

 by the pterygoid processes. 



Taking next the various surfaces of the bone, there are 

 four, or, if we include the palatine aspect, five : the external, 

 forming a large part of the face, the superior or orbital, the 

 internal or nasal, and the posterior or zygomatic. Upon the 

 external or facial surface we have to note the eminence 

 caused by the socket of the canine tooth (" canine emi- 

 nence"), and immediately behind this a depression, the 

 canine fossa, through which the antrum is sometimes punc- 

 tured. The alveolar border, from the situation of the third 

 molar to that of the second bicuspid, gives attachment to 

 the buccinator muscle ; while immediately beneath the 

 margin of the orbit is the infra-orbital foramen, whence 

 issues the infra-orbital nerve ; hence this is one of the situa 

 tions to which neuralgic pain really dependent on the teeth 

 may be referred. 



The orbital and nasal surfaces concern us only through 



