THE MAXILLA 



joined to each other in the median line of the face and to the frontal 

 bone above. 



Lacrimal bones (os lacrimale, sing.). Right and left; small 

 and thin, situated in the walls of the orbits, just under the ex- 

 tremity of the supraorbital margin (Figs. 1 2 and 24). In this bone 

 is the beginning of the canal in which the lacrimal duct runs con- 

 veying the tears into the nose, thus preventing them from over- 

 flowing the eyelids and running down the cheek. 



Zygomatic bones (os zygomaticum, sing.). Forming the promi- 

 nences of the cheek (Fig. 12). They are especially noticeable 

 in certain races, as the Chinese, for example, who have high 

 " cheek bones." 



Maxilla (or upper jaw-bone). Situated in the front of the 

 face, and composed of the two superior maxillary bones joined 



Infraorbital foramen 



Canine fossa 



Nasal spine 



Incisive fossa 



Canine eminence 



Articulates with zygo- 



matic bone 

 Posterior dental canals 



Tuberosity 



FIG. 15. THE MAXILLA. (Morris.} 



together below the nostrils. It supports the cheeks, helps to form 

 the nose and also the floor of the orbits. It consists of a body and 

 several processes. 



The body is hollow, the space being called the maxillary sinus 

 or antrum of Highmore which opens into the side of the nasal 

 cavity. In the lower border of the body the teeth are imbedded, 

 the sockets of the large teeth being in the floor of the antrum, 

 which explains how a diseased tooth may lead to antrum trouble. 



The foramen on the surface of the body just below the orbit is called the 

 infraorbital foramen. It is on a line with the supraorbital foramen of the 

 frontal bone already mentioned. 



