The Sinus Maxillaris in Man. 341 
THE SIZE OF THE SINUS MAXILLARIS. 
The sinus maxillaris varies greatly in size in different individ- 
uals. There may also exist considerable asymmetry on the 
two sides of the same individual. The statement that all old 
people have large sinuses is very fallacious, as is also the state- 
ment that all females have smaller sinuses than males (tables A, 
B,C.) 
The investigations of Zuckerkandl have shown that enlarge- 
ment of the sinus maxillaris may be produced by: 
a. Hollowing out of the processus alveolaris of the maxilla 
(recessus alveolaris) ; 
b. Exeavation of the floor of the nasal fossa by a pushing of 
the recessus alveolaris between the plates of the palatum durum 
(recessus palatinus) ; 
c. Extension of the sinus maxillaris into the processus fron- 
talis of the maxilla (recessus infraorbitalis) ; 
d. Hollowing out of the processus zygomaticus of the maxilla 
(recessus zygomaticus) ; 
e. Extension to, and appropriation of an air cell within’ the 
processus orbitalis of the palate bone; 
To these should be added, according to my findings: 
f. Extreme hollowing out of the body of the maxilla in all 
directions, thus causing the sinus walls to be thin and the recesses 
all markedly developed; 
g. The rarer condition when the lateral nasal wall is bulging 
towards the cavum nasi; 
h. The extension of the recessus zygomaticus of the sinus 
maxillaris into the maxillary border of the zygomatic bone. | 
Zuckerkandl! has found that the sinus may be made smaller, 
on the other hand, by: 
a. Deficient absorption of the cancellated bone on the floor of 
the sinus; 
b. Encroachment of the ventral wall of the cavity; 
c. A deep fossa canina; 
d. Thick sinus walls; 
e. Excessive lateral bulging of the nasal wall; 
