TEMPORAL AND INFRATEMPORAL REGIONS 183 



teeth. Both the artery and the nerve terminate by dividing 

 into a mental and an incisor branch. 



The mental artery and nerve appear on the face through 

 the mental foramen, and have been examined already ; the 

 incisor artery and nerve pass forwards to the symphysis and 

 send up twigs to the canine and incisor teeth. The vessel 

 anastomoses, in the bone, with the corresponding artery of 

 the opposite side. 



SUBMAXILLARY REGION. 



The superficial area of the submaxillary region has been 

 dissected already, under the name of the submental triangle 

 of the digastric triangle (p. 127). It is now necessary to 

 carry the dissection to a deeper plane, in order to expose a 

 number of parts in connection with the tongue and floor of 

 the mouth. The structures to be displayed are : 



1. Submaxillary gland and its duct. 



2. Sublingual gland. 



3. Side of the tongue, and the mucous membrane of the mouth. 



Mylo-hyoid. 



Digastric. 



Stylo-hyoid. 



Hyoglossus. 



Stylo-glossus. 



Genio-hyoid. 



Genio-glossus. 



Mylo-hyoid. 



4. Muscles. 



Glosso-pharyngeal. 



6. Submaxillary ganglion. 



7. Lingual artery and veins. 



8. Part of the external maxillary artery. 



9. Stylo-hyoid ligament. 



Dissection. To prepare the part for dissection, it is necessary 

 to throw back the head to its full extent, and turn it slightly to 

 the opposite side. If the stuffing in the mouth has not been 

 previously removed, it should be taken out now. When that 

 has been done, divide the external maxillary artery and the 

 anterior facial vein at the point where they cross the lower 

 border of the mandible. Next, detach the anterior belly of the 

 digastric from its attachment to the anterior part of the medial 

 aspect of the lower border of the mandible ; and then, with the 

 saw, cut through the mandible lateral to the median plane. 1 



1 If the part is soft and pliable there may be no necessity to make this 

 division of the bone, 

 m 12 c 



