116 A MANUAL OF ANATOMY. 



Expose the external lateral ligament of the lower jaw, then divide it, and 

 continue the disarticulation of the lower jaw. 



Sever the attachment of the internal pterygoid muscle and the stylomaxil- 

 lary ligament close to the jaw. Work carefully forward until the dental 

 foramen is reached, then sever the internal lateral ligament. This releases 

 the lower jaw sufficiently to permit its being drawn forward and downward. 



Expose the inferior dental nerve and artery and cut them close to the dental 

 foramen. Save the mylohyoid nerve. 



Trace the auriculo-temporal nerve, from where it was found posterior to the 

 temporal artery, around the temporomaxillary articulation to its origin by two 

 branches from the inferior maxillary nerve. 



Clean the branches of the first portion of the internal maxillary artery, viz. : 

 deep auricular, tympanic, middle meningeal, small meningeal, inferior dental ; 

 and of the second portion, viz. : masseteric, deep temporal, buccal, and the 

 buccal. 



All of these will be found with care, excepting, perhaps, the first two. 



Clean the pterygoid muscles as far as possible at this stage. 



Divide the external pterygoid close to its insertion into the front of the neck 

 of the jaw, cut away the buccinator from the lower jaw, and draw the jaw 

 still farther downward and forward. 



Trace the inferior maxillary nerve up to the foramen ovale, and its inferior 

 dental (has been divided), mylohyoid, lingual, and buccal branches. 



Cut away the external pterygoid, follow the internal maxillary artery to the 

 sphenomaxillary fossa. Draw the jaw upward, complete the stylopharyngeus 

 muscle, facial nerve, the occipital artery, to where it passes between the rectus 

 lateralis and the origin of the posterior belly of the digastric, the spinal 

 accessory, glossopharyngeal, pneumogastric, sympathetic, and hypoglossal 

 nerves. Find the branch from the loop between the first and second cervical 

 nerves to the last nerve. 



Divide the stylopharyngeus, styloglossal muscles, the hypoglossal nerve. 



Trace upward the ascending pharyngeal and internal carotid arteries to the 

 carotid canal. 



Cut the mylohyoid muscle, anterior belly of the diagastric, and the genial 

 muscles close to the lower jaw, and remove it entirely. Fasten the tongue 

 forward with a chain hook. 



The second plan is intended to give more room for the dissection, and thus 

 render it somewhat easier. 



It contemplates the division of the zygomatic arch at both ends and its 

 removal, the division of the lower jaw at the symphysis with a saw, and the 

 separation of its halves. 



The jaw can be divided in the first plan if the student so desires. 



The dissection of the parts then takes place as outlined above. 



The student should remember that the dissection of small spaces where im- 



