154 



TOPOGRAPHICAL ANATOMY OF THE 



The communication between the maxillary sinus and the nasal 

 cavity (aditus nasomaxillaris) is in the form of an elongated opening, 

 about the level of the last cheek-tooth, which leads into the posterior 

 part of the middle meatus of the nose. The aditus is above the level of 



Concho-frontal sinus 



Naso-Iachrymal duct.- 



Nasal septum,- 



Maxillar\' sinus. 



Soft palate. - 



M. masseter. 



Mm. buccinator et' 

 depressor labii 

 inferioris. 



M. genioglossus.. 



M. styloglossus 



M. mvlohvoideus 



Nasal cavity. 



K. infraorbitalis. 



Nasal mucous 

 membrane. 

 A. palatina major. 



V. reflexa. 



^Nn. buccales. 



, Buccal gland. 

 .Tongue. 

 V. buccinatoria. 

 lingualis. 



N. lingualis. 

 _. A. sublinaualis. 



-N. alveolaris inferior. 



/ / 



M. digastricus. ,' 

 M. geniohyoideus. 



^ Parotid duct. 

 ^ 'A. facialis. 



Submaxillary duct. 

 N. hypoglossus. 



Lymph glands. 



Fig. 68. — Transverse section of the face at the level indicated by D in Fig. 1 

 (looking forward). The section strikes the communication between 

 the concho-frontal and maxillary sinuses. 



the infraorbital canal, and is only rendered visible from the nose by the 

 removal of a portion of the upper turbinated bone. 



The concho-frontal (or frontal) sinus (sinus conchofrontalis) is 

 formed by the frontal, nasal, ethmoid, lachrymal and upper turbinated 

 bones. Its posterior limit is slightly behind a transverse plane taken on 

 a level with the posterior border of the zygomatic process of the frontal 

 bone (in the macerated skull, about midway between this plane and the 



