SUPERIOR AND INFERIOR MAXILLARY NERVES. 401 



T f , ., 7 ( Middle dental, 



Infra-orbital canal, . j Anterior ^^ 



On the face, j Muscular, 



( Cutaneous. 



The Orbital branch* enters the orbit through the spheno-maxillary 

 fissure, and divides into two branches : lachrymal,^ which ascends 

 along the outer wall of the orbit to the lachrymal gland, and com- 

 municates with the lachrymal nerve : temporo-malar^ which passes 

 forwards and divides into two branches : one piercing the malar 

 bone, is distributed to the integument of the cheek, communicating 

 with the facial nerve; the other escaping through the outer wall of 

 the orbit supplies the temporal muscle and integument in the tempo- 

 ral region, and communicates with the temporal, anterior auricular, 

 and facial nerve. 



The Two branches from Meckel's ganglion ascend from that body 

 to join the nerve, as it crosses the spheno-maxillary fossa. 



The Posterior dental branches pass through small foramina, in the 

 posterior surface of the superior maxillary bone, and supply the pos- 

 terior teeth. 



The Middle and anterior dental branches descend to the teeth ; 

 the former beneath the lining membrane of the antrum, the latter 

 through distinct canals in the walls of the bone. 



The Muscular and cutaneous branches are the terminating fila- 

 ments of the nerve ; they supply the muscles and integument of the 

 cheek, and form an intricate plexus with branches of the facial 

 nerve. 



The INFERIOR MAXILLARY NERVE proceeds from the inferior angle 

 of the Casserian ganglion ; it is the largest of the three divisions of 

 the fifth nerve, and is augmented in size by the anterior or motor 

 root, which passes behind the ganglion, and unites with the inferior 

 maxillary as it escapes through the foramen ovale. Emerging at 

 the foramen ovale the nerve divides into two trunks, external and in- 

 ternal, which are separated from each other by the external ptery- 

 goid muscle. 



The External trunk, into which may be traced the whole of the 

 motor root, immediately divides into five branches which are dis- 

 tributed to the muscles of the temporo-maxillary region; they 

 are 



The Masseteric, which crosses the sigmoid notch with the mas- 

 seteric artery to the masseter muscle. It sends a small branch to 

 the temporal muscle, and a filament to the temporo-maxillary arti- 

 culation. 



Temporal ; two branches passing between the upper border of 

 the external pterygoid muscle and the temporal bone to the tem- 

 poral muscle. Two or three filaments from these nerves pierce the 



* Nervus subcutaneus mala of other anatomists. G. 



t The malar branch. G. t The temporal branch. G. 



51 



