MUSCLES OF THE FACE AND HEAD 



309 



Name. 



Origin. 



Insertion. 



Action. 



Buccinator and Caninus. 



Orbicularis Oris. 



Dilator Naris Superioris. 



Dilator Naris Inferioris. 



Depressor Labii Superi- 

 oris. 



Levator Menti. 



Attached to the tuberosity 

 of the superior maxilla, 

 to the anterior border of 

 the inferior maxilla be- 

 hind the last molar tooth, 

 and to the outer surface 

 of the sockets of the 

 molar teeth of the upper 

 and lower jaw. Below 

 it blends with the angle 

 of the mouth. 



Has no bony attachment. 



From the side of the nasal 

 peak. 



From the anterior and 

 superior maxillary bones. 



From the anterior maxillary 

 bone above the upper in- 

 cisor teeth. 



From the lower jaw beneath 

 the incisor teeth. 



Encircles the lips. 



Into the false 

 nostril and the 

 anterior turbin- 

 ated bone. 



Into the cartilage 

 at the anterior 

 extremity of the 

 posterior tur- 

 binated bone. 



Into the upper 

 lip. 



Into the sub- 

 stance of the 

 chin. 



To keep the food 

 between the 

 upper and lower 

 molar teeth 

 during mastica- 

 tion. 



Closes the lipsand 

 assists in gather- 

 ing the food, in 

 drinking, and in 

 mastication. 



To dilate the false 

 nostril. 



To dilate the false 

 nostril. 



To depress the 

 upper lip. 



To raise the lower 

 lip. 



Masseter. A broad, thick, square muscle situated on the outer face 

 of the lower jaw. It is largely intersected by tendinous layers and covered 

 by a strong fibrous membrane. 



Origin. From the zygomatic ridge of the upper jaw-bone by a strong 

 broad tendon. 



Insertion. Into the external surface of the upper broad portion of the 

 inferior maxilla or lower jaw. 



Action. It brings the teeth of the lower jaw forcibly into contact with 

 those of the upper in grinding the food. It is the most powerful of the 

 muscles engaged in mastication. 



PterygoideilS Interims. A broad, thick, flat muscle situated on the 

 internal aspect of the superior broad portion of the lower jaw. 



