THE NECK 



153 



tracted from one another. In the normal condition this pro- 

 cedure would expose the genio-hyoids lying side by side at the 

 median plane, but when a dermoid cyst is present it separates 

 the two muscles. At a deeper level the cyst separates the two 

 genio-glossi, and its upper surface may be in contact with the 

 mucous membrane of the anterior part of the floor of the mouth. 

 The cyst wall is separated from these structures by blunt dis- 

 section, but it may have to be evacuated prior to removal. 

 The surgical approach for removal of advanced malignant 



Side of tongue 

 Upper lip 



Cut edges of mucous membrane 



Mandible, cut 



Sublingual gland 



^\'~ Lingual nerve 

 Submaxillary 

 " duct 



Submaxillary 

 , deep 



Mylo-hyoid 



Hypoglossal nerve 



Mylo-hyoid 



Genio-hyoid / 

 Genio-glossus 



FIG. 47. Surgical approach for the Removal of Advanced Malignant Disease 

 of the Tongue. The mandible has been divided, lateral to the mental 

 spine, and the mylo-hyoid has been cut. The operation is described 

 below. 



disease of the back of the tongue, epiglottis, floor of the mouth, 

 and fauces may be obtained through the supra-hyoid region. A 

 median vertical incision is made through the lower lip and skin 

 of the chin and neck down to the hyoid bone. Before the man- 

 dible is divided, holes are drilled through it on each side of the 

 symphysis, so that the two halves may subsequently be retained 

 in position by wiring. The bone is then divided, and the median 

 raphe of the mylo-hyoids is split. The two halves of the jaw 

 can now be separated widely, and the mucous membrane of the 

 floor of the mouth is cut through with scissors, near its reflection 



