336 Jacob Parsons Schaeffer. 
Frias. 12 to17. Photographs of dissections showing variations in the teeth 
relations of the sinus maxillaris. 
Fias. 12, 13 (x .48). Note the short ventrosuperior diagonal of the sinus 
maxillaris, due to the simultaneous approximation of the ventral wall and the 
base of the sinus. As a result, the only teeth in direct relation to the cavity are 
the second and third molars. Maes 
Fia. 14 (x .456). Note that the premolar teeth are not in direct relation, and 
that the canine tooth, as in the preceding figures, would certainly be a bad tooth 
to use in attempting to drain the cavity through the canine socket. 
Fic. 15 (x .48). This figure shows to what extreme the body of the maxilla 
may be hollowed out by the sinus maxillaris. Note the very delicate walls of the 
cavity, especially the shell-like alveolar process. Due to the extensive recessus 
alveolaris the ‘“‘remaining tooth’’ projects into the lumen of the cavity and is 
merely covered with the mucuous membrane of the sinus. 
Fig. 16 (Xx .552). Although the processus alveolaris is comparatively thick, 
the second-molar tooth fangs just reach the mucous membrane of the cavity. 
Note the large ostium maxillare accessorium. 
Fia. 17 (X 1.28). Showing the relations of the developing teeth to the sinus 
maxillaris, of a child aged from 18 to 20 months. Note the position of the Anlagen 
of the permanent teeth. 
S. Max., = sinus maxillaris; C. P., = crescentic projection; D. p. r., = dentes 
permanentes rudimentii; Sep. Nasi., = septum nasi; F. Info., = foramen infra- 
orbitale; D. d., = dentes decidui. 
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