THE PTERYGO-MAX1LLARY REGION. 59 



vision of the fifth, which passes into the region through 

 the foramen ovale of the sphenoid. The nerve consists 

 of two portions a muscular, distributed to all the mus- 

 cles of mastication viz., masseteric, deep temporal, 

 pterygoid, buccal ; and a sensory the inferior dental, 

 auriculo-temporal, and gustatory. The relations of the 

 salivary glands to the body of the inferior maxilla are 

 of considerable importance with regard to operations on 

 it. The parotid envelops the posterior border of its 

 ramus, and passes behind its neck as far as the styloid 

 process of the temporal bone; the submaxillary gland is 

 partially lodged in a fossa, below the attachment of the 

 mylo-hyoid, which during flexion of the head is con- 

 cealed beneath, and in extension is considerably disen- 

 gaged from the bone facts to be considered in opera- 

 tions in the region of the upper part of the neck. 



The temporo-maxiilary articulation is formed between 

 the glenoid cavity of the temporal bone and the condyle 

 of the lower jaw. Interposed between the bones is a 

 biconcave interarticular fibro-cartilage, above and below 

 which is a synovial membrane. The external portion of 

 the circumference of this cartilage is connected with the 

 external lateral ligament, internally with the capsular 

 ligament, whilst a portion of the tendon of the external 

 pterygoid muscle is inserted into it in front control- 

 ling its movements The ligaments are the external 

 lateral, attached to the tubercle on the zygoma and to 

 the external surface of its neck, which is covered over 

 by the parotid gland; and the internal lateral, attached 

 to the spine of the sphenoid and to the inner margin of 

 the dental foramen. The external pterygoid muscle is in 

 relation with this ligament above, the internal maxillary 

 artery lies between it and the neck of the jawbone, and 



