INTERNAL MAXILLARY 495 



with, and a little In-liind and external to, the niandihular nerve It tlien passes 

 along the canal in the interior of the hone, giving oil:" l)ranelies to the molar, l)ieus])id, 

 and canine teeth. On reaching the mental foramen it divides into two hranclies, 

 the incisive and the mental. Tlie incisive continues its course in the l)one, and 

 sui)plies l)ranclies to the incisor teeth, and anastomoses Avith the artery of the 

 opposite side. The mental i)asses through the mental foramen in comi)any with 

 the mental hranch of the mandibular (inferior dental) nerve, and emerges on the 

 chin under cover of the depressor labii inferioris. It anastomoses above with 

 tlie inferior coronary, and below with the submental, and also with the inferior 

 labial. Near its origin the artery gives off (a) a lingual or gustatory branch, 

 whicli accompanies and supjdies the lingual nerve, and ends in the mucous 

 membrane of the mouth; and, just before it enters the dental foramen in the lower 

 jaw, (//) a mylo-hyoidean branch, Avhich accomi^anies the nerve of that name 

 along the groove in tlie lower jaw, and, after supplying the mylo-hyoid muscle, 

 anastomoses with the sublingual and submental arteries. 



(5) The small meningeal arises either from the internal maxillary a little in 

 front of the large middle meningeal, or as a branch of that vessel. It passes 

 upwards along the course of the mandibular division of the fifth nerve, and, enter- 

 ing the skull through the foramen ovale, is distributed to the Gasserian ganglion, 

 and to the walls of the cavernous sinus and the dura mater in the neighbourhood. 



Branches oft/ie tSecond Part of the Internal Maxillary Artery. — The branches of the 

 second portion of the internal maxillary all supply muscles. They are: — (1) The 

 masseteric; (2) the posterior deep temi)oral; (3) the internal pterygoid ; (4) the 

 external pterygoid; (5) the buccal; and (6) the anterior deep temporal. 



(1) The masseteric branch comes oft" from the internal maxillary as the latter 

 is passing from Ijetween the neck of the jaw and the spheno-mandilralar ligament. 

 It is directed outwards along with the masseteric nerve, and, passing through the 

 sigmoid notch in the lower jaw, supplies the masseter muscle. Some filaments 

 perforate the muscle and anastomose Avith the transverse facial and Avith the mas- 

 seteric branches of the facial itself. 



(2) The posterior deep temporal arises, as a rule, from the internal maxillary 

 in common Avith the masseteric or a little beyond that branch. It passes u})wards 

 ])eneath the temporal muscle in a slight groove on the anterior margin of the 

 squamous portion of the temporal bone, supplying the temporal muscle, the peri- 

 cranium, and the external layer of the bone. It anastomoses Avith the anterior 

 deep temporal and the other temporal arteries. 



(3) The internal pterygoid branches are short trunks Avhich pass into and 

 supply the internal ])terygoid muscle. 



(4) The external pterygoid branches supply the external pterygoid muscle, 

 and, like the internal pterygoid Ijranches, are short trunks, and very irregular in 

 their number, origin, and distribution. 



(5) The buccal branch (fig. 330) courses forAvards and doAvinvards Avith the 

 buccal nerve to the Iniccinator muscle, lying in close contact with the inner side 

 and anterior margin of the tendon of the temporal muscle and coronoid i)rocess of 

 the loAver jaAV. It supplies the ])Uccinator muscle and mucous membrane of the 

 mouth, and anastomoses Avith the facial, transverse facial, and infraorbital arteries. 



(6) The anterior deep temporal branch ascends Ixnieath the temporal mu-scle 

 in a slight groove on the greater Aving of the sphenoid l)one. It sup])lies the 

 nuiscle, pericranium, and subjacent l)one, and gives off small branches Avhich pass 

 through minute foramina in the malar bone. Some of these last l^ranches enter 

 the orl)it and anastomose Avith the lachrymal artery; others emerge on the face and 

 anastomose Avith tlie transverse facial artery. 



Branches of the Third I^art of the Litermd Maxillary Artery. — The branches of the 

 third part of the internal maxillary artery, like those of the first ])art, all ]»ass through 

 bony canals. They are the folloAving: — (1) The jjosterior dental, or alveolar ; (2) 

 the infraorbital; (3) the posterior, or descending palatine; (4) the Vidian; (5) the 

 ptery go-palatine; and (6) the naso-palatine, or spheno-]>alatine. 



(1 ) The posterior dental or alveolar branch arises from the internal maxillary 

 as the latter is passing into the splicno-niaxillary fossa, and descends in a tortuous 

 manner in a groove on the back of the l)odv of the maxilla. It gives oft" the fol- 



