1238 



HUMAN ANATOMY. 



into the orbital, posterior nasal and palatine branches. While in neither case are the 

 trigeminal fibres interrupted in the ganglion, in both instances they receive sympa- 

 thetic fibres from the ganglion, which accompany the trigeminal ones. 



3. The posterior superior dental nerve (r. alveolaris superior posterior) 

 (Fig. 1060) is h'equently double. It passes downward and forward with the posterior 

 dental artery through the pterygo-maxillary fissure to reach the zygomatic surface of 

 the maxilla. It supplies tiny filaments to the gum and adjacent mucous membrane of 

 the cheek and enters the posterior dental canals to supply the molar teeth. It forms 

 a fine plexus (plexus dentalis superior) (Fig. 1059) with the middle and anterior 

 superior dental nerves. 



Variation. — In the absence of the buccal branch of the fifth, the posterior superior dental 

 has been observed to be of large size and to assume the distribution of the buccal. 



4. The temporo-malar or orbital nerve (n. zygomaticus) (Fig. 1053) after 

 arising from the maxillary passes from the spheno-maxillary fossa into the orbit 



GA5S .GANG. 

 "" -OPTHALMIC 



eMAMLLARY 



Fig. 1059. 



NT PALPCBRAL 



LATtRAL NA»Ai 

 JUP LAOIAk 



Diagram showing plan and connections of second and third divisions of trigeminus and their ganglia. 



through the spheno-maxillary fissure. It courses along the external orbital wall and 

 divides into a temporal and a malar branch. The temporal branch (n. zygomaticotem- 

 poralis) after inosculating with the lachrymal nerve passes through the spheno-malar 

 foramen to enter the temporal fossa. It then runs between the bone and the temporal 

 muscle and pierces the temporal fascia to be distributed to the skin of the anterior 

 temporal region. It communicates with the temporal branch of the facial nerve. 

 The malar branch (n. zygomaticofacialis) traverses the malar foramen to supply the 

 skin of the malar region. It joins with filaments from the malar branch of the 

 seventh. 



Variations. — The nerve may pass through the malar bone before it divides, both branches 

 may pass separately through canals confined to the malar bone, or the temporal branch may pass 



