124 



HEAD AND NECK 



in concentric ellipsoidal rings, and a series of superficial fibres 

 into which all the other muscles of the lips and cheeks con- 

 verge. The details of its formation cannot be understood 

 until the attachments of the other muscles have been studied. 



Frontalis 



Orbicularis oculi 



M. quadratus labii superioris 

 angular head 



M. nasalis pars trans versa 



M. quadratus labii superioris 

 infra-orbital head 



Procerus 



M. zygomaticus 

 M. caninus 

 Risorius 



Orbicularis oris 



rbicularis oris 



M. quadratus labii inferioris 

 M. triangularis 



Piatysma 

 FIG. 57. The Facial Muscles. 



Musculus Quadratus Labii Superioris. The quadratus 

 labii superioris possesses three heads a zygomatic, an infra- 

 orbital, and an angular. As the muscle is cleaned the 

 dissector should secure the upper part of the anterior facial 

 vein, which crosses its superficial surface. 



