THE MAXJ.LLM 



159 



tuberosity, especially prominent after the growth of the wisdom tooth; it is rough 

 on its lateral side for articulation with the pyramidal process of the palatine bone 

 arid in some cases articulates w r ith the lateral pterygoid plate of the sphenoid. 

 It gives origin to a few fibers of the Pterygoideus internus. Immediately above 

 this is a smooth surface, which forms the anterior boundary of the pterygopalatine 

 fossa, and presents a groove, for the maxillary nerve; this groove is directed lateral- 

 ward and slightly upward, and is continuous with the infraorbital groove on the 

 orbital surface. 



The orbital surface (Fig. 157) is smooth and triangular, and forms the greater 

 part of the floor of the orbit. It is bounded medially by an irregular margin which 

 in front presents a notch, the lacrimal notch; behind this notch the margin articu- 

 lates with the lacrimal, the lamina papyracea of the ethmoid and the orbital process 

 of the palatine. It is bounded behind by a smooth rounded edge which forms 

 the anterior margin of the inferior orbital fissure, and sometimes articulates at 

 its lateral extremity w r ith the orbital surface of the great wing of the sphenoid. 



With frontal 



Bones partially closing orifice of sinus 

 marked in red 



Ethmoid 

 Inferior nasal concha 

 Palatine 



With nasal bone 



Ant. nasal spine 



Bristle passed 

 through incisive 

 canal 



FIG. 158. Left maxilla. Nasal surface. 



t is limited in front by part of the circumference of the orbit, which is continuous 

 nedially with the frontal process, and laterally with the zyogmatic process. Near 

 middle of the posterior part of the orbital surface is the infraorbital groove, 

 or the passage of the infraorbital vessels and nerve. The groove begins at the 

 middle of the posterior border, where it is continuous with that near the upper 

 edge of the infratemporal surface, and, passing forward, ends in a canal, which 

 subdivides into two branches. One of the canals, the infraorbital canal, opens 

 just below the margin of the orbit; the other, which is smaller, runs downward in 

 the substance of the anterior wall of the maxillary sinus, and transmits the anterior 

 superior alveolar vessels and nerve to the front teeth of the maxilla. From the 

 back part of the infraorbital canal, a second small canal is sometimes given off; it 

 runs downward in the lateral wall of the sinus, and conveys the middle alveolar 

 nerve to the premolar teeth. At the medial and forepart of the orbital surface, 

 just lateral to the lacrimal groove, is a depression, which gives origin to the Obliquus 

 oculi inferior. 



