OP THE ADULT ANTRUM. 37 



Fig. 12. 



Fossa extending along the upper part of the anterior wall heneuth the orbital plate. 

 Bony canal ending in a cul-de-sac {posterior view). 



included in dental surgery. The accidents and 

 diseases to which this part is peculiarly liable 

 are also worthy of passing notice. Where the 

 cavity is divided by a plate or ridge of bone 

 (Figs. 8, 9) in the operation of tapping, fluid may 

 be removed from one compartment, and remain 

 in the other, or the instrument may impinge 

 upon the bony septum. In the former case the 

 treatment would be ineffectual, and in the latter 

 the septum might be mistaken for an osseous 

 growth. Foreign bodies, such as musket-balls 

 and fangs of teetli, often pass into the antrum, 



