400 INFERIOR DENTAL NERVE. 



Internal pterygoid ; a long and slender branch, which passes inwards 

 to the internal pterygoid muscle, and gives filaments in its course to the 

 tensor palati and tensor tympani. This nerve is remarkable from its con- 

 nexion with the otic ganglion, to which it is attached. 



The Internal trunk divides into three branches 



Gustatory, 

 Inferior dental, 

 Anterior auricular. 



The GUSTATORY NERVE descends between the two pterygoid muscles 

 to the side of the tongue, w r here it becomes flattened, and divides into 

 numerous filaments, which are distributed to the papillae and mucous 

 membrane. 



Relations. It lies at first between the external pterygoid muscle and 

 the pharynx, next between the two pterygoid muscles, then between the 

 internal pterygoid and ramus of the jaw, and between the stylo-glossus 

 muscle and the submaxillary gland ; lastly, it runs along the side of the 

 tongue, resting upon the hyo-glossus muscle, and covered in by the mylo- 

 hyoideus and mucous membrane. 



The gustatory nerve, while between the t\vo pterygoid muscles, receives 

 a branch from the inferior dental ; lower down it is joined at an acute 

 angle by the chorda tympani which passes downwards in the sheath of the 

 gustatory to the submaxillary gland, where it unites with the submaxillary 

 ganglion. On the hyo-glossus muscle some branches of communication 

 are sent to the hypoglossal, and in the course of the nerve several small 

 branches to the mucous membrane of the fauces, to the tonsils, submaxil- 

 lary gland, Wharton's duct, and sublingual gland. 



The INFERIOR DENTAL NERVE passes downwards with the inferior den- 

 tal artery, at first between the two pterygoid muscles, and then between 

 the internal lateral ligament and the ramus of the lower jaw, to the dental 

 foramen. It then runs along the canal in the inferior maxillary bone, 

 distributing branches (inferior maxillary plexus) to the teeth and gums, 

 and divides into two terminal branches, incisive and mental. The incisive 

 branch passes forwards, to supply the incisive teeth : the mental branch 

 escapes through the mental foramen, to be distributed to the muscles and 

 integument of the chin and lower lip, and to the mucous membrane of the 

 latter, communicating with the facial nerve. 



The inferior dental nerve gives off but one branch, the mylo-hyoidean, 

 which leaves the nerve just as it is about to enter the dental foramen. 

 This branch pierces the insertion of the internal lateral ligament, and de 

 scends along a groove in the bone to the inferior surface of the mylo- 

 hyoid muscle, to which, and to the anterior belly of the digastricus, it is 

 distributed. 



The ANTERIOR AURICULAR NERVE, originates by two roots, between 

 which the arteria meningea media takes its course, and passes directly 

 back\vards behind the articulation of the lower jaw, against which it rests. 

 In this situation it divides into two branches, which reunite, and form a 

 kind of plexus. From the plexus two branches are given off ascending 

 and descending. The ascending or temporal branch sends one or twu 

 considerable branches of communication to the facial nerve, and then 

 ascend in front of the ear to the temporal region, upon which it is distri 



