THE SINUS MAXILLARIS AND ITS RELATIONS IN THE 
KHMBRYO, CHILD, AND ADULT MAN, 
Ae 
JACOB PARSONS SCHAEFFER, 
Instructor in Anatomy, Cornell University Medical College, Ithaca, N. Y. 
WiruH 31 Ficurss. 
This paper is based upon a study of the sinus maxillaris in the 
embryo in successive stages up to the fetus at term, as well as in 
the child and adult man. Most of the adult specimens ranged in 
age from 18 to 80 years. 
The lateral nasal wall of the embryo, at different stages of 
growth, was modeled; thus showing the relations of the sinus 
maxillaris and its progress in development. The blotting-paper 
method was used in all the reconstructions. Both solid structures 
and cavities were modeled, thus securing positive and negative 
views. 
The work also covers a general consideration of the sinus in 
the child and the adult; including a study of the sinus relations, 
its ostium or aperture, and the ostium accessorium. Special 
attention was also given to the cause and effect of recesses occur- 
ring on the walls of the adult sinus. Dissections were made to 
cover all phases of the problem. 
In determining the size of the sinus the following measurements 
were taken: (1) dorsosuperior diagonal; (2) ventrosuperior diag- 
onal; (3) superoinferior; (4) ventrodorsal; (5) mediolateral. 
The capacity of the sinus was determined by filling the cavity 
with a portion of a previously measured liquid, or by measuring 
the amount of water the hardened mucous membrane (represent- 
ing the exact shape and size of the sinus) would displace. 
I wish to take this opportunity for expressing grateful acknowl- 
edgment to the heads of the Departments of Anatomy, and 
Embryology and Histology for valuable criticisms and helpful 
THE AMERICAN JOURNAL OF ANATOMY, VOL. 10, NO. 2. 
