The Sinus Maxillaris in Man. aaD 
RELATION OF THE SINUS MAXILLARIS TO THE TEETH. 
Since the sinus maxillaris varies greatly in size in different 
skulls, and on the two sides of the same skull, it at once becomes 
apparent that the relations of the teeth to the sinus cannot be 
constant. As stated before, the layer of spongy bone between 
S. Fron. 
S. Fron. 
Ge. Eth. 
Suoph, O.Sph, 
S: Sph. 
ean S. Max. 
Palatum M, C.N. Inf. 
Sep. Nasi 
Palatum D. 
Fic. 9 (X .64). Photograph of a dissection of the sinus paranasales from a 
dorsal view. The mucous membrane of the cavities is shown, the bony walls 
have been dissected away. The sinus frontalis and sphenoidalis, and the cellu- 
le ethmoidales of the right side have been opened. 
S. Fron., S. Sph., S. Max., = sinus frontalis, sphenoidalis, and maxillaris, 
respectively; Palatum M., Palatum D., = palatum molle and palatum durum, 
respectively; Cc. Eth., = cellule ethmoidales; O. Sph., = ostium sphenoidale; 
C. N. Inf., = concha nasalis inferior; Sep. Nasi., = septum nasi. 
the roots of the teeth and the floor of the sinus varies in thickness 
in different skulls, and the asymmetry on the two sides of the 
same skull is at times marked. When this layer of spongy bone 
is comparatively thin the projecting tooth fangs form elevations, 
of a greater or less degree, on the floor of the sinus. These eleva- 
tions at times aid in recess formation (fig. 16). Direet ecommuni- 
