THE SUPERIOR MAXILLARY REGION. 47 



forating its socket before interfering with any doubtful 

 tumor connected with the cavity. 



Besides the growths which are developed in the an- 

 trum, the bone is surgically interesting as being subject 

 to an arrest in its development, known as fissured or deft, 

 palate, frequently associated with a similar one in its 

 appendage, the upper lip, termed hare-lip. During its 

 development that portion which carries the incisor teeth 

 is a separate segment, and if this segment be ununited 

 the result is a deep fissure, extending backwards into the 

 palate; occasionally these segments in both bones are 

 thus disconnected, in which case they both hang from 

 the end of the vomer, leaving a chasm in the roof of the 

 mouth, a condition usually associated with a double 

 hare-lip. 



Structures divided in Excision of the Upper Jawbone. 

 Supposing the incision through the upper lip, along the 

 ala of the nose, towards the inner angle of the orbit and 

 along its lower margin to be adopted ; first are the tis- 

 sues composing the upper lip viz., the integument, the 

 orbicularis oris muscle, the cellular tissue containing the 

 labial glands, the coronary vessels, facial, and branches 

 of the second division of fifth nerves, and the mucous 

 membrane. Next carrying the incision along the ala 

 and side of the nose, the integument, fascia, levator labii 

 superioris alseque nasi, with its aponeurosis, the angular 

 vessels and branches of the infra-orbital and facial nerves. 

 The incision along the lower border of the orbit divides 

 the integument, aponeurosis, orbicularis palpebrarum 

 muscle, the vessels of the lower eyelid, and the orbital 

 fascia ; and if a portion of the floor of the orbit be re- 

 moved, the tendon of the inferior oblique, and by turn- 

 ing back the flap inclosed by these incisions, the attach- 



