44 



BONES OF THE HEAD. 



THE SUPERIOR MAXILLARY BONE. 



This, the upper jaw, is one of the principal bones of the face ; it supports all 

 the teeth of the upper range, and takes part in the formation of the hard palate, 

 the floor of the orbit, and the floor and lateral wall of the nasal cavity. It 

 presents inferiorly a thick ridge, the alveolar process perforated with the 

 sockets for the roots of the teeth, and a horizontal palate plate ; exter- 

 nally, a convex surface corresponding with the anterior and lateral parts of 

 the face ; superiorly, an ascending or nasal process and an orbital plate ; 

 and internally, a nasal surface, opening from which is a large cavity or sinus, 

 hollowed out beneath the orbital plate in the body of the bone. The 

 superior maxillary bone articulates with its fellow, with the nasal, frontal, 

 lachrymal, ethmoid, palate, malar, vomer, and inferior turbinated bones, and 

 with the nasal cartilages. 



Fig. 38. 



Fig. 38. SUPERIOR MAXILLARY BONE OP THE 

 EIGHT SIDE. ^ 



A, from the outside; B, from the inside. 



1 to 2, alveolar process or arch 1 at the 

 middle incisor tooth, 2 marks the tuberosity, 

 and above it, in A, the posterior dental foramina ; 

 3, the nasal or ascending process ; 4, malar 

 tuberosity or process ; 5, oi'bital plate or process ; 

 6, placed in the nasal notch marks the nasal crest 

 terminating in the nasal spine ; 7, the incisor or 

 myrtiform fossa ; 8, is in front of the canine fossa ; 

 9, the infra-orbital foramen, and below 5, the 

 infra-orbital groove and canal ; 10, groove of the 

 nasal or lachrymal duct; 11, antrum maxillare, or 

 maxillary sinus; 12, on the inner surface of the 

 nasal process, marks the oblique ridge for the 

 attachment of the inferior turbinated bone ; 13, is 

 placed above the palate plate ; from 13 to 6, the 

 vomeric and septal crest ; from 13 to 14, the 

 incisor foramen ; 15, placed on the surface of arti- 

 culation of the body with the palate bone, points 

 to the posterior palatine or palato-maxillary canal. 

 These figures also exhibit a full set of the upper 

 teeth of one side as they occur in middle life, 

 little worn by use. 



The alveolar border or process, thick 

 and arched, is hollowed out into sockets 

 or alveoli, corresponding in number, form, 

 and depth to the roots of the teeth, 

 which are fixed in them. 



The palate plate, along with that of the opposite side, forms about three- 

 fourths of the hard palate. Its superior surface is smooth and concave from 

 side to side ; its inferior surface is vaulted and rough, and is marked laterally 

 with grooves for nerves and vessels, which reach the palate through the 

 posterior palatine canal. Its posterior extremity falls short of that of the 

 alveolar arch and body of the bone, and articulates with the horizontal 

 process of the palate bone, which completes the hard palate. The mesial 

 border rises into a serrated vertical ridge, upon which the vomer rests. 

 This border, or ridge, is interrupted at its anterior part by a canal, the 

 incisor foramen, which is completed on its mesial side by a slender lamina 



