458 SURGICAL ANATOMY. 



The masseteric is a small branch which passes outwards above the sigmoid 

 notch of the lower jaw, to the deep surface of the Masseter. It supplies that 

 muscle, and anastomoses with the masseteric branches of the- facial and with 

 the transverse facial artery. 



The buccal is a small branch which runs obliquely forwards between the 

 Internal Pterygoid and the ramus of the jaw, to the outer surface of the Buc- 

 cinator, to which it is distributed, anastomosing with branches of the facial 

 artery. 



3. Branches of the Third, or Spheno-maxillary Portion. 



Alveolar. Vidian. 



Infraorbital. Pterygo-palatine. 



Posterior or Descending Palatine. Nasal or Spheno-palatine. 



The alveolar is given off from the internal maxillary by a common branch 

 with the infraorbital, and just as the trunk of the vessel is passing into the 

 spheno-maxillary fossa. Descending upon the tuberosity of the superior max- 

 illary bone, it divides into numerous branches ; one, the superior dental, larger 

 than the rest, supplies the molar and bicuspid teeth, its branches entering the 

 foramina in the alveolar process; some branches pierce the bone to supply the 

 lining of the antrum, and others are continued forwards on the alveolar process 

 to supply the gums. 



The infraorbital appears, from its direction, to be the continuation of the 

 trunk of the internal maxillary. It arises from that vessel by a common trunk 

 with the preceding branch, and runs along the infraorbital canal with the 

 superior maxillary nerve, emerging upon the face at the infraorbital foramen, 

 beneath the Levator Labii Superioris. Whilst contained in the canal, it gives 

 off branches which ascend into the orbit, and supply the Inferior Rectus and 

 Inferior Oblique muscles, and the lachrymal gland. Other branches descend 

 through canals in the bone, to supply the mucous membrane of the antrum, 

 and the front teeth of the upper jaw. On the face, it supplies the lachrymal 

 sac, and inner angle of the orbit, anastomosing with the facial artery and nasal 

 branch of the ophthalmic ; and other branches descend beneath the elevator of 

 the upper lip, and anastomose with the transverse facial and buccal branches. 



The four remaining branches arise from that portion of the internal maxillary 

 which is contained in the spheno-maxillary fossa. 



The descending palatine passes down along the posterior palatine canal with 

 the posterior palatine branches of Meckel's ganglion, and emerging from the 

 posterior palatine foramen, runs forwards in a groove on the inner side of the 

 alveolar border of the hard palate, to be distributed to the gums, the mucous 

 membrane of the hard palate, and palatine glands. Whilst it is contained in 

 the palatine canal, it gives off' branches, which descend in the accessory pala- 

 tine canals to supply the soft palate, anastomosing with the ascending palatine 

 artery ; and anteriorly it terminates in a small vessel, which ascends in the an- 

 terior palatine canal, and anastomoses with the artery of the septum, a branch 

 of the spheno-palatine. 



The Vidian branch passes backwards along the Vidian canal with the Vidian 

 nerve. It is distributed to the upper part of the pharynx and Eustachian tube, 

 sending a small branch into the tympanum. 



The ptery go -palatine is also a very small branch, which passes backwards 

 through the pterygo-palatine canal with the pharyngeal nerve, and is distri- 

 buted to the upper part of the pharynx and Eustachian tube. 



The nasal or spheno-palatine passes through the spheno-palatine foramen into 

 the cavity of the nose, at the back part of the superior meatus, and divides 

 into two branches; one internal, the artery of the septum, passes obliquely 

 downwards and forwards along the septum nasi, supplies the mucous mem- 



