96 DISSECTION OF THE PTERYGOID REGION. 



stance ; and after it has passed through the fibres it furnishes a branch to 

 the temporal muscle. The nerve is directed towards the angle of the 

 mouth, supplying the integument, the buccinator muscle, and the lining 

 mucous membrane. It is united freely with the facial nerve, the two 

 forming a plexus. 



The LARGER PART of the inferior maxillary nerve divides into three 

 trunks auriculo-temporal, dental, and gustatory. A few of the fibrils of 

 the small (motor) root are applied to it, and are conveyed to certain mus- 

 cles, viz., tensor tympani, circumflexus palati, pterygoideus, internus, my- 

 lohyoideus, and digastricus. 



The AURICULO-TEMPORAL NERVE (*) separates from the others near 

 the base of the skull, and has commonly two roots. Its course to the sur- 

 face of the head is directed first backwards beneath the external pterygoid 

 muscle, as far as the inner part of the articulation of the jaw; and, then, 

 upwards with the temporal artery in front of the ear. The nerve furnishes 

 branches to the surrounding parts, viz., the joint, the ear, and the parotid 

 gland ; and it communicates with the facial nerve. Its ramifications on 

 the head are described at page 23. In the part now dissected its branches 

 are the following: 



a. Branches of the meatus auditorius. Two offsets are given to the 

 meatus from the point of union of the branches of the facial with the 

 auriculo-temporal nerve, and enter that tube between the cartilage and 

 bone. 



b. Articular branch. The branch to the joint of the jaw arises near 

 the same spot as the preceding, or from the branches to the meatus. 



c. The inferior auricular branch supplies the external ear below the 

 meatus auditorius: it sends offsets along the internal maxillary artery, 

 which communicates with the sympathetic nerve. 



d. Parotid branches. These small filaments ramify in the gland. 



e. Communicating branches. Two or more branches around the ex- 

 ternal carotid artery communicate with the facial and sympathetic 

 nerves. 



The INFERIOR DENTAL ( 7 ) is the largest of the three trunks into which 

 the inferior maxillary nerve divides. In its course to the canal in the 

 lower jaw, the nerve is external to the gustatory, and lies at first beneath 

 the external pterygoid muscle ; it is afterwards placed on the internal 

 pterygoid, and on the internal lateral ligament near the dental foramen. 

 After the nerve enters the bone, it is continued forwards beneath the teeth 

 to the foramen in the side of the jaw, and ends at that spot by dividing 

 into an incisor and a labial branch. Only one muscular offset (mylo-hyoid) 

 is supplied by the dental nerve before it enters the bone. Its branches 

 are: 



a. The mylo-hyoid branch arises from the trunk of the nerve near the 

 dental foramen, and is continued along a groove on the inner aspect of the 

 ramus of the jaw to the cutaneous surface of the mylo-hyoideus, and to the 

 anterior belly of the digastric muscle. 



b. The dental branches arise in the bone, and supply the molar and 

 bicuspid teeth. If the bone is soft, the canal containing the nerve and 

 artery may be laid open so as to expose these branches, 



c. The incisor branch continues the trunk of the nerve onwards to the 

 middle line, and furnishes offsets to the canine and incisor teeth, beneath 

 which it lies. 



d. The labial branch (mental?) (fig. 9. 1S ) issues on the face beneath 



