492 SECOND BRANCH OF THE FIFTH PAIR. 



orbit by the spheno-maxillary fissure, divides into two ramifica- 

 tions. One of them unites with a twig of the lachrymal branch 

 above mentioned, and passes out of the orbit, through a foramen 

 in the malar bone, to the face where it is distributed. The 

 other passes also through a foramen of the malar bone, into the 

 temporal fossa, and, after uniting with twigs from the Inferior 

 Maxillary Nerve, proceeds backwards and perforates the aponeu- 

 rosis of the temporal muscle, to terminate on the integuments of 

 the temporal region. 



Before the Infra Orbitar branch enters the canal of that 

 name, it sends off two twigs, called Posterior Dental Nerves, 

 which pass downwards on the tuberosity of the upper maxil- 

 lary bone, and enter into small canals in that bone, that are 

 situated behind the antrum maxillare. They subdivide into 

 fine twigs that proceed forward to the alveoli of three or four 

 of the last molar teeth, and penetrate each of the roots by a 

 cavity at its extremity. Twigs also proceed from these nerves 

 to the posterior part of the gums and buccinator muscle. 



After the posterior dental nerves have left it, the Infra Orbi- 

 tar nerve proceeds forwards in the canal of that name ; and 

 near the extremity of it, gives off the anterior dental nerve, 

 which accompanies it for some distance, and then proceeds down- 

 wards in a canal in the bone anterior to the antrum maxillare. 

 In its course this nerve divides into many fibres, which pass to 

 the roots of the incisor, canine, and small molar teeth, each in 

 its proper canal. These dental branches sometimes pass in the 

 antrum maxillare between the lining membrane and the bones. 

 The Infra Orbitar nerve passes out of the foramen upon the 

 cheek, and divides into several branches of considerable size, 

 which are distributed on the face from the side of the nose to 

 the back of the cheek, and also upon the under eyelid and the 

 upper lip. 



The Pterygoid Nerve, or posterior branch, passes backwards, 

 from the ganglion to a canal in the base of the pterygoid process 

 of the os sphenoides, and proceeds through it. After leaving 

 this canal, it passes through a substance almost as firm as carti- 

 lage, which closes the anterior foramen lacerum, at the basis of 

 the cranium, and divides into two branches. The smallest of 



