24 HUMAN ANATOMY. 



It articulates with four bones the frontal, sphenoid, tem- 

 poral, and superior maxilla. 



Its muscular attachments are five the masseter, temporal, 

 zygomaticus major and minor, and the levator labii superioris. 



It is developed from one ossific centre. 



THE SUPERIOR MAXILLA is the largest bone of the face, 

 excepting the lower jaw, and one of the most important, assisting 

 in the formation of three cavities, the mouth, nose, and orbit; 

 two fissures, the spheno-maxillary and pterygo-maxillary ; and 

 two fossae, the spheno-maxillary and zygomatic. It consists of a 

 body and four processes the nasal, the malar, the palatine, and 

 the alveolar (Fig. 11). 



FIG. 12. 



1, antrum; 2, nasal process; 3, superior turbinated bone; 4, 

 middle meatus; 5, inferior crest; 6, inferior meatus; 11, posterior 

 palatine canal; 15, anterior nasal spine; 16, anterior palatine canal; 

 18, palate process. 



The body is excavated to form the maxillary sinus or antrum 

 Higlimorianum, a large, irregular triangular cavity, with its 

 base directed inward, its apex upward and outward, projecting 

 into the malar process. 



Its posterior wall presents the posterior dental canals, trans- 

 mitting the posterior dental vessels and nerves. 



The external or facial surface (Fig. 11) of the body presents 

 the following points : 



Incisive fossa, or myrtiform fossa, for the origin of the 

 depressor alas nasi : 



Canine fossa, for origin of levator anguli oris; 



Canine eminence, over the position of the canine tooth ; 



Infraorbital foramen, for the exit of the infraorbital nerve 

 and artery. 



