THE FIFTH NERVE 343 



root from the Gasserian ganglion and the motor root of the 

 fifth. This nerve divides into two trunks, anterior and posterior. 

 The anterior gives off the masseteric, the buccal, the deep 

 temporal, and the two pterygoid nerves. 



The masseteric runs above the external pterygoid, crosses 

 the sigmoid notch to the masseter, supplying also filaments to 

 the jaw. 



The deep temporal are three, the posterior, middle, and 

 anterior. 



The buccal is a sensory nerve, and runs along the inner sur- 

 face of the coronoid process to divide, on the buccinator, into 

 branches to the muscles and skin joining the facial, and extend- 

 ing as far as the angle of the mouth. 



The pterygoid, internal and external, supply those muscles 

 respectively. 



The posterior trunk of the inferior maxillary is mostly sensory. 

 It divides into the auriculotemporal, gustatory, and inferior 

 dental. 



The auriculotemporal runs beneath the external pterygoid, 

 the middle meningeal artery passing up between its two roots 

 of origin to the inner side of the neck on the lower jaw. It 

 then passes up under the parotid gland, and along with the 

 temporal artery over the zygoma, and divides into temporal 

 branches to the skin of the temporal region, joining the facial. 

 This nerve communicates at its origin with the otic ganglion, 

 and gives off the following branches : 



Auricular, the inferior to the external meatus, the superior 

 to the tragus and pinna. 



Articular, one or two to the articulation of the jaw; several 

 to the parotid, and the branches to the external auditory meatus 

 send a filament to the membrana tympani. 



The inferior dental nerve runs along with the artery, enters 

 that canal, supplies the teeth, and at the -mental foramen 

 divides into an incisor and a mental branch. The former supplies 

 the canines and incisors, the latter the skin of the chin and 

 lower lip. The nerve is at first under the external pterygoid; 

 later, between the ramus of the jaw and the internal lateral 

 ligament. Its branches are the mylohyoid and dentals. The 

 mylohyoid runs in the groove to supply the mylohyoid and 

 anterior belly of the digastric muscles. The dentals supply 

 the molars and bicuspids, interlacing to form a fine plexus, 

 the inferior dental. 



