OF THE DIFFERENT MUSCLES. 145 



Use. — To extend this angle, by drawing it upwards and 

 backwards. 



LEVATOR ANGULI ORIS. 



Upon the fore part of the cheek. 



Use. — To retract the angle of the mouth, assist in the 

 elevation of the upper lip, and dilate the nostril. 



RETRACTOR LABII SUPERIORIS. 



Insertion. — Into the side of the upper lip, and lower part 

 of the nostril. 



Use. — To retract those parts, and thus assist in raising the 

 upper lip, and dilating the nostril. 



LEVATOR LABII SUPERIORIS. 



Use. — To raise the upper lip and dilate the false nostrils. 

 If one contracts, the lip will be distorted. 



BUCCINATOR. 



Origin. — From the lower jaw. 



Insertion. — Into the buccal membrane, and into the angle 

 of the mouth. 



Use. — To contract the jaws, and retain the food for mas- 

 tication. 



ORBICULARIS ORIS. 



The use of this muscle is to close the lips. 



DEPRESSOR LABII SUPERIORIS. 



Use. — To depress the lip, and project it forwards, and to 

 assist in dilating the nostril. 



LEVATOR LABII INFERIORIS. 



Use. — - To raise the lip, and project it forwards. 



HYOIDEAL REGION 



Comprehends the digastricus, mylo-hyoideus, genio-hyoi- 

 deus, and hyoideus muscles. 

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