BONES OF THE FACE. 



29 



mella, but. attached to the internal face of the os planum. They are 

 the superior^ and middle turbinated bojies^ placed one above the 

 other, and separated by a fissure. This fissure is the superior 

 meatus^ of the nose. The middle meatus is a space observed in an 

 articulated head between the middle and inferior turbinated bones. 

 The anterior cells of the ethmoid bone empty into the middle mea- 

 tus ; the most anterior of these cells is funnel-shaped {infundidum)^ 

 and receives the fluid i>om the frontal sinus ; from the inferior part 

 of these cells there proceeds a hook-like process. The posterior eth- 

 moidal cells and the sphenoidal sinus empty in the superior meatus. 



In children there is attached to the ethmoid bone, on each side, a 

 hollow triangular process, called the pyramid of Wistar, or cor- 

 nu Bertini. The base is connected with the superior turbinated 

 bone, the posterior edge of the cribriform plate, and the posterior 

 edge of nasal lamella. The apex lies under the body of the sphenoid 

 bone, on each side of the processus azygos. These pyramids are de- 

 tached from the ethmoid in after life, and become the sphenoidal sinuses. 



The ethmoid articulates with the frontal, sphenoid, inferior turbi- 

 nate, upper jaw, nasal, lachrymal, palate bones, and vomer. 



BONES OF THE FACE. 



These are fourteen in number, and exist in pairs with the exception 

 of two, the lower jaw and the vomer. 



SUPERIOR MAXILLARY BONE. 



This with its fellow constitutes the upper jaw. It articulates with 

 all the bones of the face with ' p- j^ 



the exception of the lower jaw. 

 It has an irregular cubical body 

 and four processes. The body 

 is hollow and has four surfaces. 



The anterior or facial sur- 

 face is bounded above by the 

 inferior margin of the orbit, be- 

 neath which is the infra-orbital 

 foramen^ transmitting the infra- 

 orbital nerve, artery, and vein. 

 Contiguous to this foramen is a 

 depression, called the canine 

 fossa, which gives origin to the 

 levator anguli oris muscle. The 

 posterior or temporal surface is 



rounded. The most prominent part is called the tuber ^'^^ which is 

 rough and perforated by several small foramina which transmit the 

 posterior dental nerve, artery, and vein, to the floor of the antrum. 



The superior or orbital surface is triangular, and traversed by the 



3* 



