Chap, vii.] THE FACE. 115 



interarticular cartilage remaining behind. On reaching 

 its new position it is immediately drawn up by the 

 temporal, internal pterygoid, and masseter muscles, and 

 is thereby more or less fixed. A specimen in the 

 Musee Dupuytren shows that the fixity of the luxated 

 jaw may sometimes depend upon the catching of the 

 apex of the coronoid process against the malar bone. 



Subliixation of the jaw is a name given to a 

 slight and quite incomplete dislocation of the jaw, not 

 infrequently met with in delicate women. It is due 

 to a displacement of the interarticular cartilage, and 

 can be cured by exposing the cartilage and attaching 

 it by suture to the fibrous structures around the joint 

 (Annandale). 



Excision of the inferior maxilla. Con- 

 siderable portions of the lower jaw can be excised 

 through the mouth without external wound. In 

 excising one entire half of the maxilla a cut is made 

 vertically through the lower lip down to the point of 

 the chin, and is then continued back along the inferior 

 border of the jaw, so as to end near the lobule of 

 the ear, after having been carried vertically upwards 

 in the line of the posterior border of the ramus. The 

 soft parts divided may be considered under three 

 heads : (1) Those concerned in the first incision ; (2) 

 in clearing the outer surface of the bone ; (3) in 

 clearing the inner surface of the bone. 



1. (a) In the anterior vertical cut: Skin, etc., 

 orbicularis oris, inferior coronary and inferior labial 

 vessels, branches of submental artery, levator menti. 

 mental vessels and nerve, some radicles of anterior 

 jugular vein, (b) In the horizontal cut : Skin, etc., pla- 

 tysma, branches of superficial cervical nerve, branches 

 of supramaxillary part of facial nerve, facial artery and 

 vein at edge of masseter, and inframaxillary branch 

 of facial nerve (not necessarily divided), (c) The pos- 

 terior vertical incision would not go down to the bone, 



