400 CLINICAL APPLIED ANATOMY. 



This is possibly explained by the fact that islets of embryonic 

 cartilage from the first or mandibular arch may remain enclosed 

 within the gland. These innocent growths of the parotid merely 

 displace the contained structures, and although they may reach 

 a considerable size, seldom interfere with the functions of 

 the vessels or the nerves. Excision of such growths is fairly 

 easy, many being encapsuled. Temporary facial paralysis may 

 follow. 



Malignant tumours of the parotid, particularly sarcoma, quickly 

 infiltrate the tissues and soon implicate the facial nerve, pro- 

 ducing paralysis. Such growths are extremely difficult to remove 

 as may be readily understood when the structures contained 

 within the gland are remembered. 



The anterior auricular lymphatic glands may lie upon or within 

 the sheath of the parotid. When enlarged they may simulate a 

 parotid tumour. If lying superficial to the capsule they are 

 readily excised. If residing within the capsule, it may even be 

 necessary to divide some gland tissue before they are exposed, 

 and care must be taken while dissecting them out, especially when 

 dealing with the deeper parts of the wound. 



Parotid Calculi. The duct of the parotid may be the site of a 

 calculus. This may lead to a fluid swelling occupying the region 

 of the gland, filling up the sulcus between the ramus of the jaw 

 and the internal auditory meatus, and passing forward on to the 

 cheek. Occasionally the concretion may be palpated in the line 

 of the duct on the cheek, but it is much more readily demonstrated 

 by a probe passed into the duct through its buccal aperture. If 

 the cheek is drawn outwards and somewhat everted, a small papilla 

 may be observed opposite the second upper molar tooth, and with 

 a little dexterity a fine eye probe can be guided into the opening 

 on its summit. This, if made to pass along the lumen of the duct, 

 will strike the calculus. Excision of the stone should always be 

 made from the buccal surface to avoid the formation of a salivary 

 fistula. 



Submandibular Gland. This salivary gland is much less often 

 the seat of disease than is the parotid, The duct (Wharton's duct) 



