100 



SPECIAL ANATOMY OF THE SKELETON 



The external border is serrated, bevelled at the expense of the internal surface 

 above and of the external below, to articulate with the nasal process of the 

 maxilla. 



Nasal bone. 

 Nasal proc. 



Infra-orbital 

 foramen. 



Ant. nasal spine. 



Lacrimal bone. 



Orbital surface. 

 Infra-orbital 

 groove. 



Artie, tcith malar. 



\Pos. dental 

 canals. 



Maxillary 

 tuberosity. 



FIG. 67. Nasal and lacrimal bones in situ. 



With frontal bone. 



f\ 



With 

 'opposite bone. 



Outer Surface. 



FIG. 68. Right nasal bone. 



With 

 frontal spine. 



Crest. 



With 



perpendicular 

 plate of 

 ethmoid. 



Groove for nasal nerve. 



Inner Surface. 



FIG. 69. Left nasal bone. 



The internal border, thicker 

 above than below, articulates 

 with its fellow of the opposite 

 side, and is prolonged behind 

 into a vertical crest, which 

 forms part of the septum of the 

 nose; this crest articulates from 

 above downward with the nasal 

 spine of the frontal, the per- 

 pendicular plate of the eth- 

 moid, and the triangular septal 

 cartilage of the nose. 



Development. Of intramembranous origin and from one centre for each bone, which 

 appears about the eighth week. 



Articulations. With four bones two of the cranium, the frontal and ethmoid, and two of 

 the face, the opposite nasal and the maxilla. 



The nasal bone has no muscles attached to it. 



The Maxillae (Upper Jaw). 



The maxillae are the largest bones of the face, excepting the mandible, and 

 form, by their union, the whole of the upper jaw. Each maxilla assists in the 

 formation of the walls of three cavities, the roof of the mouth, the floor and 

 outer wall of the nasal fossae, and the floor of the orbit, and also enters into the 

 formation of two fossae, the zygomatic and sphenomaxillary, and two fissures, 

 the sphenomaxillary and pterygomaxillary. The bone presents for examination 

 a body and four, processes malnr, nasal, alveolar, i.?d palatal. 



