174 MYOLOGY, OR ANATOMY OF MUSCULAR SYSTEM 



malar process of the superior maxilla, and lower border of the 

 zygomatic arch for its anterior two-thirds by tendinous bundles 

 which project between the muscular fasciculi; it passes down 

 and back to the lower half of the jaw from the angle to the 

 third molar tooth; the deep part is triangular, and passes yearly 

 vertically from the posterior third of the zygoma, lower border, 

 and from all the deep surface of the arch; inserted, after unit- 

 ing with the superficial part, into the upper half of the ramus 

 and coronoid; this is almost wholly covered by the superficial 

 portion. 



There may be a bursa between these two parts. 



The buccal fat pad is between the forepart of the masseter 

 and the buccinator, and is prolonged into the zygomatic fossa; 

 it is well developed in the infant, and inappropriately called 

 the "sucking pad." 



The temporal fascia is a dense aponeurosis covering the 

 temporal muscle above the zygoma; it is attached to the tem- 

 poral crest of the frontal and upper temporal line, and below 

 divides into two layers attached to the inner and outer sur- 

 faces of the zygomatic arch; it is separated from integument 

 by a lateral projection of the galea aponeurotica, and by the 

 superior and anterior auricular muscles. 



2. M. temporalis rises, fan-shaped, from the whole of the 

 temporal fossa (not its anterior malar wall), which is covered 

 with fat, from the deep surface of the temporal fascia, and 

 may blend with some deep fibers of the masseter. The anterior 

 fibers are nearly vertical, the posterior nearly horizontal; 

 all converge to a tendon which is inserted into the posterior 

 and anterior borders of the coronoid process, and deeper fibers 

 have a fleshy insertion into its inner surface as far as the union 

 of the ramus and body of the jaw. 



3. M. ptcryg&ideus externus occupies the zygomatic fossa, 

 and rises by two heads, the upper and smaller from the zygo- 

 matic surface of the great wing of the sphenoid and infra- 

 temporal crest or pteryg'oid ridge; the lower and larger from 

 the outer surface of the external pterygoid plate. The fibers 

 from both pass back, converging to a fossa on the front of the 

 neck of the lower jaw, to the interarticular cartilage and capsule. 

 A venous plexus is between its upper surface and base of the 

 skull. 



