The Sinus Maxillaris in Man. 329 
The adult sinus maxillaris, as we know it, is the large cavity 
within the body of the maxilla. It is the largest of the sinus 
paranasales, save in exceptional cases, when it is comparatively 
small and may be exceeded in size by the sinus frontalis and the 
Sinus Frontalis 
Cc. Ethmoidales 
Sinus Maxillaris 
Fic. 7 (0.9). Photograph of a dissection of the sinus paranasales of the 
left side. The mucous membrane is shown, the bony walls have been dissected 
away after first hardening the subject in formalin. 
C. N. M., C.N. Inf., = conche nasales, media et inferior; Sep. Nasi, = septum nasi; 
Cc. Ethmoidales, = cellulae ethmoidales; S. Sphenoidalis, = sinus sphenoidalis ; 
M. N.S.,M.N. M., M.N.I., = meatus nasi, superior, medius, et inferior, respect- 
ively. 
sinus sphenoidalis. It lies lateral to the cavum nasi and resembles 
in shape a three sided pyramid (fig. 7). It follows in the main 
the shape of the body of the maxilla; and may be described as 
having a roof, a floor, and three walls. The walls of the sinus 
vary in thickness, usually from 5 to 8 mm.; but they may be 
THE AMERICAN JOURNAL OF ANATOMY, VOL. 10, NO. 2. 
