THE HEAD AND NECK 1205 



inferior dental canal through the mental foramen, and has been 

 already described (see Index). The incisor artery suppUes the pulps 

 of the incisor teeth of one side. 



Branches of the Second Part. — The branches of this part are 

 muscular in their distribution. The masseteric artery passes out- 

 wards, with the corresponding nerve, over the sigmoid notch of the 

 inferior maxilla, and enters the deep surface of the masseter. 

 The internal and external pterygoid branches are distributed to the 

 corresponding muscles. The posterior and anterior deep temporal 

 arteries pass upwards to the posterior and anterior parts of the 

 temporal fossa beneath the temporal muscle. They supply the 

 muscle and the bones forming the fossa, and anastomose with the 

 middle temporal artery, which is a branch of the superficial temporal. 

 The anterior deep temporal artery also anastomoses with the lach- 

 rymal artery by twigs which pass through minute foramina in the 

 outer wall of the orbit. The buccal artery passes downwards and 

 forwards in company with the long buccal nerve, and is distributed 

 to the buccinator muscle and the buccal mucous membrane which 

 lines it internally. 



Branches of the Third Part. — ^The posterior dental artery arises 

 from the internal maxillary as it is about to pass through the pterygo- 

 raaxillary fissure into the spheno-maxillary fossa, and is sometimes 

 associated with the infra-orbital artery at its origin. It descends 

 upon the zygomatic surface of the superior maxilla, posterior to the 

 malar process, and its principal branches traverse the posterior 

 dental canals to supply the pulps of the upper molar teeth of one 

 side. It also furnishes twigs to the mucous lining of the antrum 

 of Highmore, and to the gum. 



The infra-orbital artery arises in the spheno-maxillary fossa, 

 sometimes in common with the posterior dental. It passes 

 through the spheno-maxillary fissure in company with the superior 

 maxillary nerve, and traverses the infra-orbital groove and canal 

 on the floor of the orbit, the accompanying nerve being now called 

 the infra-orbital nerve. From this canal it emerges through the 

 infra-orbital foramen on to the face, where it has been already 

 described (see Index). The artery is accompanied by the infra- 

 orbital vein. As the artery traverses the infra-orbital canal it 

 furnishes (i) orbital branches to the structures on the floor of the 

 orbit ; and (2) the middle and anterior dental arteries, which descend 

 in the middle and anterior dental canals in the superior maxilla, 

 in company with the corresponding nerv^es, to supply the pulps of 

 the upper bicuspid, incisor, and canine teeth of one side, and the 

 mucous lining of the antrum of Highmore. 



The descending palatine artery passes downwards in the posterior 

 palatine canal, in company with the great or anterior descending 

 palatine ner\'e, to the hard palate, where it passes forwards and 

 inwards to the anterior palatine fossa. In this situation it furnishes 

 a branch which ascends through the incisor canal, or canal of 

 Stensen, to anastomose with the naso-palatine artery. As the artery 



