458 Anatomy Applied to Medicine and Smgery. 



organ be removed through a curved incision below the 

 jaw, with its convexity touching the hyoid bone, and 

 extending from the angle of the jaw to the symphysis. 

 The object of this external incision is that the submaxil- 

 lary and the deep cervical glands, which are oftentimes 

 early affected in malignant disease, may be removed at 

 the same time as the tongue. 



In profound anesthesia, the relaxation of the tissues 

 permits the tongue to fall backwards and thus depress the 

 epiglottis, thereby obstructing respiration. To relieve 

 this condition the anaesthetist carries the lower jaw for- 

 wards by his ringers placed behind the angles of that bone. 

 This procedure puts tension on the genio-hyo-glossus, the 

 genio-hyoid, and the mylo-hyoid, the hypo-glossal mem- 

 brane, the glosso-epiglottidean folds and the hyo-epiglot- 

 tidean ligament, thereby drawing forwards the tongue, 

 the epiglottis and the hyoid bone, and opening the su- 

 perior aperture of the larynx. 



Gums. The gums are formed of dense areolar tissue, 

 covered by mucous membrane. This compact tissue is 

 closely attached to the periosteum of the alveolar pro- 

 cesses, and, since the periosteum of the jaw is prolonged 

 into the tooth socket, it follows that inflammatory pro- 

 cesses at the root of the tooth may burrow beneath the 

 periosteum of the jaw and form what is known as a gum- 

 boil. 



Floor of the Mouth. Between the tongue and the 

 jaw is a fossa presenting a ridge or elevation on either 

 side of the frsenum. This elevation is due to the presence 

 of the underlying sublingual glands, which, touching each 

 other in front near the fnenum, extend backwards for 

 about an inch. Opening on the surface of the mucous 

 membrane over these glands are their ducts the ducts of 

 Rivini while, on either side of the frsenum, is the orifice 



