— SM 



FIG. 10 

 Trephining of Facial Sinuses 



Cross section of the left side of the head anterior to the last molar, 

 and through the widest part of the inferior maxillary sinus. M^, last 

 superior molar ; SM, superior maxillary sinus at its antero-inferior 

 extremity ; IM, inferior maxillary sinus, lateral portion ; IM', do. 

 median portion ; N, nasal fossa ; S, sound lodged in lachrymal duct ; 

 NF, trifacial nerve ; F, frontal sinus. 



