200 



HUMAN ANATOMY. 



This is a rough triangular surface articulating with the malar, often perforated, and 

 sending downward a smooth ridge separating the anterior and posterior surfaces ; 

 the former is in the front of the face, the latter in the zygomatic fossa. The lower 

 border of both is the alveolar process,^ which is simply a curved row of tooth 

 sockets made of very light plates of bone, which are absorbed after the loss of the 

 teeth. The palatal process ^ joins the inner side of the body like a sheli and supports 

 the anterior part of the alveolar process. The nasal process ^ rises from the anterior 

 inner part to meet the frontal bone. In certain parts of the description it is con- 

 venient to disregard these subdivisions. The anterior surface of the bone forms 

 the lower and outer boundary of the nasal opening, which is finished above by the 

 nasal bone. On the entire skull this aperture resembles an ace of hearts inverted. 

 The lower boundary of the opening is slightly raised and smooth. On the side it is 

 sharp. The pointed anterior nasal spine projects forward where the two bones meet 

 below the opening.* There is a slight depression — the incisor or myrtiforvi fossa — 

 over the lateral incisor tooth. External to this is a ridge caused by the socket of the 

 canine tooth. Farther outward is a well-marked hollow, the canine fossa. Above 



Fig. 224- 



Lachrymal groove 

 Lachrymal notch 

 Orbital surface 



Infra-orbital groovf 



Posterior dental canal 



Zygomatic surface. 

 Masseter 



Malar process 



Tuberosity 

 Buccinator 



Nasal process 



Orbicularis palpebrarum 



Lev. lab. sup. alixq. nasi 

 Orbicularis palpebrarum 



Infra-orbital foramen 



Lev. labii sup. 

 Canine fossa 



Incisor crest 



Lev. ang. oris 

 Compres. naris 

 Incisor fossa 



Depres. alee nasi 

 Alveolar process 



Right superior maxillary bone, outer surface. 



this, about five millimetres below the edge of the orbit, is the infra-orbital foramen, 

 transmitting the nerve and artery of the same name. This surface is bounded above 

 and externally by the malar process. 



The zygomatic surface is in the main convex, except for a smooth concavity 

 behind the malar process. The lower posterior portion, the tuberosity,^ is rough, 

 and presents at its upper part two or three minute /^,y/^r/^r dental foramina^ hy 

 which those nerves enter canals in the bone. The smooth superior or orbital 

 surface, slanting a little downward and outward, is triangular. The posterior 

 border is free, forming the lower limit of the spheno-maxillary fissure, and running 

 obliquely forward to the malar process. The anterior border passes outward and 

 backward to the same. The inner border is in the main antero-posterior. The 

 hind end slancs outward, articulating with the little triangular orbital surface of the 

 palatal. Anterior to this, the border joins the os planum of the ethmoid ; and anterior 

 to the latter, at the base of the nasal process, lies a semicircular indentation, the lachry- 

 ynal notch,' the posterior border of which touches the lachrymal bone. The deep infra- 

 orbital groove^ runs more than half across the orbital surface from behind, and then 

 * For a more detailed account, see the section on the Nasal Cavity. 



'Processus alvcolaris. -Processus palatinus. 

 'incisura lacrimalis. 'Sulcus infraorbitalis. 



Processus frontalis. 



'Tuber maxillare. "Foramina alveolaria. 



