THE NASAL CAVITY. 51 



ganglion in the spheno-maxillary fossa and pass through the spheno-palatine foramen as the 

 superior nasal and naso-palatine nerves to the lateral and median walls of the nasal cavity. The 

 naso-palatine nerve runs upon the septum as far as the foramen of Scarpa. When the surgeon, 

 operates in this deep region, he has other things to think about than this little nerve. 



The maxillary sinus or antrum of Highmore is the largest of the accessory cavities of the nose. 

 It is separated from the orbit by the orbital plate of the superior maxilla and extends posteriorly, 

 entirely filling the body of this bone. Upon the floor of the sinus the sockets of the molar teeth 

 frequently produce elevations, or the apex of the tooth-socket opens directly into the antrum so 

 that the tip of the root is covered only by the mucous membrane of the sinus. This is the situation 



Zygoma. 



Pterygoid fossa 

 Tuber maxillare 



Internal pterygoid plate 

 of sphenoid bone 



Hamular process of 

 sphenoid bone 



""Orbital plate of frontal bone 



-Nasal bone 



Os planum of ethmoid bone 

 Lachrymal bone 

 Nasal process of superior 

 maxilla 



Communication of maxillary 

 sinus with nasal cavity 



First bicuspid 



Inner socket of second molar 



Socket of second bicuspid 

 Inner socket of first molar 



FIG. 18. A portion of the skull in which the outer wall of the maxillary sinus has been removed in order to show 

 its communication with the nasal cavity and the relations of the dental alveoli to the floor of the sinus. The alveoli have 

 been perforated from below. 



in which diseases of the roots of the back teeth occasionally lead to inflammations and purulent 

 collections in the maxillary sinus. Since the orifice of the sinus is situated so high up (see Figs. 

 15 and 16) that it is inadequate for drainage, in such cases the sinus must be opened at its most 

 dependent portion. A tooth is extracted and the floor of the sinus perforated through the al- 

 veolus to allow of the evacuation of the contents of 'the sinus. Fig. 18 shows the relation of the 

 sockets of the back teeth to the floor of the maxillary sinus, the outer wall of which has been 

 removed by the chisel. It will be seen that the inner sockets of the first and second molar teeth 

 are the ones most favorably situated for the performance of this operation. 







