26 HUMAN ANATOMY. 



Nasal crest for the vomer, and 



Anterior nasal spine projecting from the anterior extremity 

 of the crest. 



The alveolar process forms the curved, spongy portion for 

 the insertion of the upper teeth. It presents 



The alveoli or sockets of varying depths, eight in the adult, 

 five in the child. 



It articulates with nine (9) bones the ethmoid, frontal, 

 lachrymal, nasal, malar, inferior turbinated, palate, vomer, and 

 its fellow of the opposite side. 



Its muscular attachments are nine the levator labii supe- 

 rioris alagque nasi, levator labii superioris proprius, levator anguli 

 oris, compressor naris, depressor alas nasi, orbicularis palpe- 

 brarum, inferior obliquus, masseter, and buccinator. 



FIG. 13. 



1, horizontal plate; 2, vertical plate; 3, tuberosity; 4, crest; 5, 

 post-nasal spine; 6, inferior turbinated crest; 7, spheno-palatine fora- 

 men; 8, zygomatic surface; 9, sphenoidal surface. 



It is developed from four centres : one for incisive bone, or 

 pre-maxilla; one for palate process, or pre-palatine ; one for 

 the maxillary portion, including the orbital and facial portion; 

 and one for the malar portion. 



EACH PALATE-BONE is a thin, L-shaped bone, consisting of 

 an inferior or horizontal plate and a superior or vertical plate. 



Each bone assists in forming three cavities the outer wall 

 and floor of the nose, the roof of the mouth, and floor of the 

 orbit; two fossaB the pterygoid and spheno-maxillary ; and one 

 fissure the spheno-maxillary. 



The horizontal plate is quadrilateral. Its inferior surface 

 presents 



A ridge for the aponeurosis of the tensor palati muscle ; 



A groove entering into the formation of the posterior pala- 

 tine canal; 



Accessory palatine foramina for posterior descending pala- 

 tine nerves. 



