52 OSTEOLOGY, OR ANATOMY OF OSSEOUS SYSTEM 



orifices of small canals which subdivide on the vertical plate 

 and lateral mass. Anteriorly is a fissure close to the base of 

 the crista galli, and external to it a notch connecting with 

 the anterior internal orbital canal for the passage of the nasal 

 nerve and anterior ethmoidal artery from the orbit to the 

 cranium, and thence to the nasal fossa. 



THE BONES OF THE FACE 



The Superior Maxillary Bones 



The superior maxilla is the principal bone of the face, sup- 

 porting the upper teeth of one side, helping to form the hard 

 palate, floor of the orbit, floor and outer wall of the nasal 

 fossa. It articulates with nine or ten bones with its fellow, 

 with the nasal, frontal, lacrymal, ethmoid, palate, malar, 

 vomer, inferior turbinate, and sometimes with the sphenoid 

 at the outer extremity of the sphenomaxillary fissure. There 

 are a body and four processes for description. The body is ;i 

 hollow half-cylinder, presenting an external surface subdivided 

 into an anterior and a posterior, an internal and a superior; 

 the processes are nasal, alveolar, malar, and palatal. 



The body encloses the ant ruin of Highmore, which opens 

 into the middle meatus of the nose. The anterior or facial 

 surface is marked below by eminences corresponding to fangs 

 of the teeth. Internal to the eminence for the canine is the 

 incisor or myrtiform fossa; external to it is the deeper canine 

 fossa; above the latter, below the margin of the orbit, is the 

 infraorbital foramen. The inner margin of this surface is cut 

 by the nasal notch, the sharp edge of which is prolonged below 

 into the anterior nasal spine. 



The posterior or zygomatic surface looks into the zygomatic 

 and sphenomaxillary fossse; it presents two or more apertures 

 of the posterior dental canals; below and posteriorly is a rough 

 tuberosity, the maxillary tuberosity. At the junction of this 

 surface with the nasal and orbital is a small triangular space 

 on which the orbital process of the palate rests, the pahifhii- 

 trigone (Henle). 



The internal or naxal xurfaee (Fig. S) presents in front the 

 inferior turbinate crest; below it is the smooth concavity of 



