THE SUPERIOR MAXILLARY BONE. 



51 



The nasal surface presents at the fore part a nearly horizontal ridge, the inferior 

 turbinate crest, for articulation with the inferior turbinate bone ; below the crest is 

 a smooth concave surface belonging to the inferior meatus of the nose ; and above 

 the crest a smaller surface, extending on to the base of the nasal process, and bound- 

 ing the atrium of the middle meatus. Behind the nasal process is seen the 

 lachrymal groove, nearly vertical, but inclined slightly backwards and outwards, about 

 half an inch in length, and leading into the inferior meatus ; the margins overhang 

 the groove in front and behind, and the small interval left is closed by the lachrymal 

 and inferior turbinate bones, thus completing the canal of the nasal duct. Behind 

 the lachrymal groove is the large opening into the antrum ; and above this there are 



ATRIUM OP 

 MIO. MCATUS 



INF. TURB. CREST 



Fig. 51. RIGHT SUPERIOR MAXILLARY BONE: INNER VIEW. (Drawn by D. Gunn.) 



often one or two small hollows which complete the middle ethmoidal cells. Behind 

 the opening of the antrum the surface is rough for articulation with the palate bone ; 

 and traversing the lower part of this roughness is a smooth groove, directed down- 

 wards and forwards from the posterior margin, and completing with the palate bone 

 the posterior palatine or palato-maxillary canal. 



The orbital surface is triangular, flat, and smooth ; anteriorly it reaches the 

 margin of the orbit for a short distance at the root of the nasal process ; externally 

 it is bounded by the rough surface for the malar bone. The internal border presents, 

 behind the nasal process, an excavation which receives the lachrymal bone, the 

 lachrymal notch, and then a nearly straight margin for articulation with the 

 ethmoid and palate bones. The posterior border is smooth, rounded and free, and 

 bounds the spheno-maxillary fissure ; the infraorlital groove commences here, and 

 leads forwards into the canal of the same name, which opens anteriorly by the infra- 

 orbital foramen. From the infraorbital are given off the anterior and middle dental 

 canals, which run down in the substance of the facial portion of the bone, and 

 convey the anterior and middle dental vessels and nerves. 



The nasal process, slender and tapering, has an external surface, smooth and 

 continuous with the facial surface of the body, and an internal surface, the hinder 



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