624 



CRANIAL NERVES. 



ligament and the ramus of the jaw to the dental foramen. It then passes 

 forwards in the dental canal in the inferior maxillary bone, lying beneath the 

 teeth, as far as the mental foramen, where it divides into two terminal branches, 

 incisor and mental. The incisor branch is continued onwards within the bone 

 to the middle line, and supplies the canine and incisor teeth. The mental branch 

 emerges from the bone at the mental foramen, and divides beneath the Depres- 

 sor Anguli Oris into an external branch, which supplies that muscle, the Orbi 

 cularis Oris, and the integument, communicating with the facial nerve ; and an 

 inner branch, which ascends to the lower lip beneath the Quadratus Menti ; it 

 supplies that muscle and the mucous membrane and integument of the lip, 

 communicating with the facial nerve. 



The branches of the inferior dental are, the mylo-hyoid, and dental. 



The mylo-hyoid is derived from the inferior dental just as that nerve is about 

 to enter the dental foramen. It descends in a groove on the inner surface of 

 the ramus of the jaw, in which it is retained by a process of fibrous membrane. 

 It supplies the cutaneous surface of the Mylo-hyoid muscle, and the anterior 

 belly of the Digastric, occasionally sending one or two filaments to the sub- 

 maxillary gland. 



The dental branches supply the molar and bicuspid teeth. They correspond 

 in number to the fangs of those teeth ; each nerve entering the orifice at the 

 point of the fang, and supplying the pulp of the tooth. 



Two small ganglia are connected with the inferior maxillary nerve: the otic, 

 with the trunk of the nerve ; and the submaxillary with its lingual branch, the 

 gustatory. 



OTIC GANGLION. 



The Otic Ganglion (Arnold's) (Fig. 346), is a small, oval-shaped, flattened 

 ganglion, of a reddish-gray color, situated immediately below the foramen 



Fig. 346. The Otic Gnnerlion and its Branches. 



ovale, on the inner surface of the inferior maxillary nerve, and round the origin 

 of the internal pterygoid nerve. It is in relation, externally, with the trunk of 

 the inferior maxillary nerve, at the point where the motor root joins the sensory 

 portion; internally, with the cartilaginous part of the Eustachian tube, and the 

 origin of the Tensor Palati muscle ; behind it, is the middle mcningeal artery. 



