818 ■ TEE NERVES. 



roots after a brief forward course, and give some thin filaments to the membrane 

 lining the maxillaiy sinuses. 



The second is only at first a single branch — the anterior dental nei-ve — which 

 rises from the maxillary trunk shortly before it leaves its bony canal. After a 

 somewhat long course in the substance of the maxillary bones, this branch becomes 

 expended in ramuscules for the canine tooth and the incisors ; it is always accom- 

 panied by a very slender aiterial twig. 



6. Infra-orbital or Terminal Branches of the Superior Maxillary 

 Nerve. — These ramuscules spread on the side of the face in a magnificent 

 expansion, which may be looked upon as one of the richest ner\ous apparatuses 



Fig. 453. 



GENERAL VIEW OF THE SUPERIOR AND INFERIOR MAXILLARY NERVES. 



The eye has been excised, after sawing through and removing the orbital and zygomatic processes. 

 The maxillary sinuses have been exposed by means of a gouge or chisel, the masseter muscle 

 removed, and the inferior maxilla opened to show the nerve in its interosseous course. 



1, Facial nerve; 2, origin of the posterior auricular nerve ; 3, filament distributed to the stylo-hyoid 

 muscle; 4, digastric branch; 5, trunk of the anterior auricular nerve; 6, origin of the" cervical 

 filament; 7, plexus formed by the union of the facial and superficial temporal nerve; 7', branch 

 of that plexus united to the infra-orbital nerves, 15'; 11, inferior maxillary nerve; 8, superficial 

 temporal nerve; 9, masseteric nerve; 10. gustatory nerve; 12, 12, dental branches; 13, mylo- 

 hyoidean nerve; 14, buccal nerve; 15, superior maxillary nerve; 16, spheno-palatine ganglion; 

 17, staphyline (or palatine) nerve; 18, common carotid ai^tery ; J 9, trunk of the occipital; 20, 

 trunk of the internal carotid; 21, external carotid; 22, trunk of the posterior auricular artery 

 embraced by a loop of the facial ; 23, trunk of the superficial temporal ; 24, internal maxillary 

 artery ; 25, trunk of the deep anterior temporal artery ; 26, orbital branch of the superior 

 dental; 27, buccal artery; 28, inferior dental artery. 



in the animal econon.y. Covered at its emergence from the infra-orbital foramen 

 by the levator labii superioris proprius muscle, this fasciculus descends beneath 

 the levator labii superioris alaeque nasi and lateral dilator of the nostril towards 

 the nostrils and upper lip, which receive the terminal extremities of its consti- 

 tuent branches in the substance of their muscular and tegumentary tissues ; 

 these branches are slightly divergent and flexuous, and for the most part 

 anastomose with a large motor trunk furnished by the facial nerve (Fig. 453, 15'). 

 C. Infeeior Maxillary Nerve (Figs. 168, 12 ; 453, 11). — At its exit from 

 the cranium, this branch is situated immediately within the temporo-maxillary 

 articulation, and thence is directed forward and downward, passing at first 



