THE NERVES OF THE TEETH. 267 



is spent upon the side of the head and temple ; the malar 

 branch also passes through the malar hone and is dis- 

 tributed to the muscles and integuments upon this hone. 



The inferior maxillary nerve forms the third and largest 

 division of the fifth. It arises from the lower portion of 

 the Gasserian ganglion, passes through the foramen ovale 

 of the sphenoid bone, and as it leaves this foramen unites 

 with the motor root, and then divides into two branches, 

 an external or superior, and internal or inferior. 



The inferior gives off the branch which supplies the teeth 

 of the lower jaw. This is the inferior dental nerve. It 

 separates from the gustatory nerve, and descends between 

 the pterygoid muscles, along the ramus of the lower jaw 

 to the posterior dental foramen into which it enters. It now 

 proceeds along the canal in the inferior maxillary bone, 

 supplying the teeth in its course to the anterior dental fo- 

 ramen through which it emerges, and is distributed to the 

 muscles and integuments of the lower lip and chin ; at this 

 latter foramen a small branch is continued forward, the 

 incisive branch, to supply the incisor teeth. 



The mylo-hyoideus is the only branch generally given off 

 by the inferior dental nerve. It comes off at the posterior 

 dental foramen and passes along a groove on the inferior 

 maxillary bone, to the mylo-hyoid and digastric muscles. 



The gustatory is the next in size of the internal or lower 

 division of the inferior maxillary. It connects with the 

 inferior dental, and is joined by the chorda-tympani soon 

 after this junction. It descends between the ramus of the 

 lower jaw and the internal pterygoid muscle; proceeds ob- 

 liquely forwards above the submaxillary gland and mylo- 

 hyoid muscle, accompanied by the duct of Wharton, and is 

 distributed to the lateral and anterior parts of the tongue. 

 The gustatory gives off, in this course, filaments to the 

 pterygoideus internus, the pharynx, tonsils, muscles of the 

 palate and the gums, as well as communicating branches 

 with the lingual. 



The auricular is the smallest branch of the inferior divis- 

 ion, it passes posterior to the neck of the lower jaw and in 



