404 THE MUSCLES AND FASCIA. 



the sphenoid below. It is also attached to the inner surface of the temporal fascia. 

 Its fibres converge as they descend, and terminate in an aponeurosis, the fibres of 



FIG. 273. The Temporal muscle, the zygoma and Masseter having been removed. 



which, radiated at its commencement, converge into a thick and flat tendon, which 

 is inserted into the inner surface, apex, and anterior border of the coronoid process 

 of the jaw, nearly as far forward as the last molar tooth. 



Relations. By its superficial surface, with the integument, the Attrahens and 

 Attollens aurem muscles, the temporal vessels and nerves, the aponeurosis of the 

 Occipito-frontalis, the temporal fascia, the zygoma, and Masseter ; by its deep 

 surface, with the temporal fossa, the External pterygoid and part of the Buccinator 

 muscles, the internal maxillary artery, its deep temporal branches, and the deep 

 temporal nerves. Behind the tendon are the masseteric vessels and nerve, and in 

 front of it the buccal vessels and nerve. Its anterior border is separated from the 

 malar bone by a mass of fat. 



Nerves. Both muscles are supplied by the inferior maxillary nerve. 



10. Pterygo-maxillary Region (Fig. 274). 

 4 External Pterygoid. ) Internal Pterygoid. 



Dissection. The Temporal muscle having been examined, saw through the base of the 

 coronoid process, and draw it upward, together with the Temporal muscle, which should be 

 detached from the surface of the temporal fossa. Divide the ramus of the jaw just below the 

 condyle. and also, by a transverse incision extending across the middle, just above the dental 

 foramen ; remove the fragment, and the Pterygoid muscles will be exposed. 



The External Pterygoid is a short, thick muscle, somewhat conical in form, 

 which extends almost horizontally between the zygomatic fossa and the condyle of 

 the jaw. It arises from the pterygoid ridge on the great wing of the sphenoid and 

 the portion of bone included between it and the base of the pterygoid process, 

 and from the outer surface of the external pterygoid plate. Its fibres pass 

 horizontally backward and outward, to be inserted into a depression in front of 

 the neck of the condyle of the lower jaw and into the corresponding part of the 

 interarticular fibro-cartilage. This muscle, at its origin, appears to consist of two 

 portions separated by a slight interval ; hence the terms upper and lower head 

 sometimes used in the description of the muscle. 



Relations. By its external surface, with the ramus of the lower jaw, the 



