THE NECK, ANTERIOR. 123 



The Stylohyoid Ligament. 



This is the fibrous band or cord which connects the tip of 

 the styloid process with the lesser cornu of the hyoid bone. 

 It serves to hold the latter in position. 



The Pterygomaxillary Ligament. 



This consists of the fibrous interval between the buccina- 

 tor muscle in front and the superior constrictor muscle 

 behind, and extends from the tip of the hamular process of 

 the internal pterygoid plate to the posterior extremity of 

 the mylohyoid ridge. 



The Stylomaxillary Ligament. 



This is that portion of the deep cervical fascia which ex- 

 tends from the front of the styloid process to the posterior 

 border of the ramus and angle of the inferior maxillary bone. 

 It separates the masseter muscle and parotid gland exter- 

 nally from the internal pterygoid muscle and submaxillary 

 gland internally. 



Pterygoideus Bxternus. 



Origin. Upper head, from the under surface of the great 

 wing of the sphenoid bone between the foramen ovale and 

 spinosum and the pterygoid ridge. 



The lower head, from the outer surface of the external 

 pterygoid plate. 



Insertion. Into the front of the neck of the condyle of 

 the lower jaw, and the interarticular fibrocartilage of the 

 temporomaxillary articulation. 



Nerve Supply. The inferior maxillary nerve. 



Action. To draw the interarticular cartilage and the con- 

 dyle of the jaw forward (and inward). If both muscles act, 

 the jaw is projected directly forward ; when one acts, the 

 jaw is turned to the opposite side ; if they act alternately, the 

 jaw is moved from side to side, as in the grinding movement. 



