Chap, vni.] THE MOUTH. i) 



and deformity of the mouth. Contracting cicatrices, 

 also, in the vicinity of the mouth are apt to drag upon 

 the lips, everting them, or producing kindred distor- 

 tions. It is fortunate that the laxity of the tissues 

 around the mouth, and the general vascularity of the 

 part, greatly favour the success of the many plastic 

 operations performed to relieve these deformities. 



The lips are very vascular, and are often the seat 

 of nsevi and other vascular tumours. The coronary 

 arteries are of large size, and their pulsations can 

 generally be felt when the lip is pinched up. These 

 vessels run beneath the orbicularis oris muscle, and 

 are consequently nearer to the mucous membrane than 

 they are to the skin. When the inner surface of the 

 lip is cut against the teeth, as the result of a blow, 

 these arteries are very apt to be wounded. As 

 such wounds are concealed from view, the consequent 

 haemorrhage has sometimes given rise to an erroneous 

 diagnosis. Thus, Mr. Erichsen quotes the case of a 

 drunken man, the subject of such a wound, who, 

 having swallowed, and then vomited, the blood escap- 

 ing from a coronary artery, was for awhile supposed 

 to be suffering from an internal injury. As the anas- 

 tomoses between the arteries of the lip ai'e very free, 

 it is usually necessary to tie both ends of the vessel 

 when it lias been cut across. 



The mucous glands in the submucous tissue are large 

 and numerous. From closure of the ducts of these 

 glands, and their subsequent distension, result the 

 " mucous cysts " that are so common about the lips. 

 It has been shown (Holmes' " System of Surgery," 

 voL ii.) that one form of enlarged lip may depend 

 upon a general hypertrophy of these glands in the 

 submucous tissue. " Hare-lip " is noticed below in 

 connection with the subject of cleft palate. 



The buccal cavity. The following points may 

 be noticed in the examination of the interior of the 



