INFERIOR MAXILLARY NERVE. 549 



upon the face through a foramen in the malar bone, and, perforating the Orbi- 

 cularis palpebrarum muscle on the prominence of the cheek, joins with the 

 facial. 



The Spheno-palatine branches, two in number, descend to the spheno-palatine 

 ganglion. 



The Posterior dental brandies arise from the trunk of the nerve just as it is 

 about to enter the infra-orbital canal; they are two in number, posterior and 

 anterior. 



The posterior branch passes from behind forwards in the substance of the supe- 

 rior maxillary bone> and joins opposite the canine fossa with the anterior dental. 

 Numerous filaments are given off from the lower border of this nerve, which form 

 a minute plexus in the outer wall of the superior maxillary bone, immediately 

 above the alveolus. From this plexus, filaments are distributed to the pulps of 

 the molar and bicuspid teeth, the lining membrane of the antrum, and correspond- 

 ing portion of the gums. 



The anterior branch is distributed to the gums and Buccinator muscle. 



The Anterior dental, of large size, is given off from the superior maxillary nerve 

 just before its exit from the infra-orbital foramen ; it enters a special canal in the 

 anterior wall of the antrum, and anastomoses with the posterior dental. From 

 this nerve some filaments are distributed to the incisor, canine, and first bicuspid 

 teeth ; others are lost upon the lining membrane covering the fore part of the 

 inferior meatus. 



The Palpebral branches pass upwards beneath the Orbicularis palpebrarum. 

 They supply this muscle, the integument, and conjunctiva of the lower eyelid, 

 joining at the outer angle of the orbit with the facial nerve and malar branch of 

 the orbital. 



The Nasal branches pass inwards ; they supply the muscles and integument of 

 the side of the nose, and join with the nasal branch of the ophthalmic. 



The Labial branches, the largest and most numerous, descend beneath the Leva- 

 tor labii superioris, and are distributed to the integument and muscles of the upper 

 lip, the mucous membrane of the mouth, and labial glands. 



All these branches are joined, immediately beneath the orbit, by filaments from 

 the facial nerve, forming an intricate plexus, the infra-orbital. 



(3.) INFERIOR MAXILLARY NERVE. 



The INFERIOR MAXILLARY NERVE distributes branches to the teeth and gums 

 of the lower jaw, the integument of the temple and external ear, the lower part 

 of the face and lower lip, and the muscles of mastication : it also supplies the 

 tongue with one of its special nerves of the sense of taste. It is the largest of 

 the three divisions of the fifth, and consists of two portions, the larger or sensory 

 root, proceeding from the inferior angle of the Casserian ganglion; and the smaller 

 or motor root, which passes beneath the ganglion, and unites with the inferior 

 maxillary nerve, just after its exit through the foramen ovale. Immediately 

 beneath the base of the skull, this nerve divides into two trunks, anterior and 

 posterior. 



The Anterior and smaller division, which receives nearly the whole of the motor 

 root, divides into five branches, which supply the muscles of mastication. They 

 are the masseteric, deep temporal, buccal, and pterygoid. 



The masseteric branch passes outwards, above the External pterygoid muscle, in 

 front of the temporo-maxillary articulation, and crosses the sigmoid notch, with 

 the masseteric artery, to the Masseter muscle, in which it ramifies nearly as far as 

 its anterior border. It occasionally gives a branch to the Temporal muscle, and 

 a filament to the articulation of the jaw. 



The deep temporal branches, two in number, anterior and posterior, supply the 

 deep surface of the temporal muscle. The posterior branch, of small size, is 



,ced at the back of the temporal fossa. It is sometimes joined with the 



