INFERIOR MAXILLARY NERVE. 399 



in the malar bone and enters the temporal fossa ; it then pierces the tem- 

 poral muscle and fascia and is distributed to the integument of the temple 

 and side of the forehead, communicating with the facial and anterior 

 auricular nerve. In the temporal fossa it communicates with the deep 

 temporal nerves. The malar, or inferior branch, takes its course along 

 the lower angle of the outer wall of the orbit, and emerges upon the cheek 

 through an opening in the malar bone, passing between the fibres of the 

 oibicularis palpebrarum muscle. It communicates with branches of the 

 infra-orbital and facial nerves. 



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 running forwards in 

 the base of the alveolus, supply the posterior teeth and gums. 



The Middle and anterior dental branches descend to the corresponding 

 teeth and gums ; the former beneath the lining membrane of the antrum, 

 the latter through distinct canals in the walls of the bone. Previously to 

 their distribution, the dental nerves form a plexus (superior maxillary 

 plexus) in the outer w r all of the superior maxillary bone immediately above 

 the alveolus. From this plexus the filaments are given off which supply 

 the pulps of the teeth, N the gums, the mucous membrane of the floor of the 

 nares, and the palate. Some gangliform masses have been described in 

 connexion with this plexus, one being placed over the canine, and another 

 over the second molar tooth. 



The Muscular and cutaneous branches are the terminating filaments of 

 the nerve ; they supply the muscles, integument, and mucous membrane 

 of the cheek, nose, and lip, 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 internal, which are separated 

 from each other by the external pterygoid muscle. 



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

 motor root, immediately divides into five branches which are distributed 

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



The Masseteric, which crosses the sigmoid notch with the masseteric 

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

 muscle, and a filament to the temporo-maxillary articulation. 



Temporal ; two branches passing between the upper border of the ex- 

 ternal pterygoid muscle and the temporal bone to the temporal muscle. 

 Two or three filaments from these nerves pierce the temporal fascia, and 

 communicate with the lachrymal, subcutaneous malae, auricular and facial 

 nerve. 



Buccal; a large branch which pierces the fibres of the external ptery- 

 goid, to reach the buccinator muscle. This nerve sends filaments to the 

 temporal and external pterygoid muscle, to the mucous membrane and 

 integument of the cheek, and communicates with the facial nerve. 



