TREPHINING OF THE FACIAL SINUSES. 19 



there seem to be adequate reasons for preferring the excision 

 of the cutaneous disk. We regard as the chief considera- 

 tions in an operation the following : the avoidance of infec- 

 tion ; the prevention of pain during the operation or the 

 after-treatment ; the reduction of the scar to a minimum ; 

 rapidity and certainty of recovery ; convenience in operating 

 and dressing. Infection is largely dependent, aside from 

 aseptic operation and protective dressing, upon the area of 

 the wound, the facility for maintaining cleanliness and the 

 degree of disturbance to the tissues while being dressed. 

 The wound area in the bone is alike in all cases but that in 

 the skin varies greatly. Jf we take as a type the usual Ger- 

 man technic and compare it with that given below we would 

 find the wound areas approximately as follows : in the Ger- 

 man method, an incision 2. 7 in. (7 cm. ) long which assuming 

 that the skin is f\ in. thick would yield an area of 2.7" X 2 = 

 5.4" X y\" = J sc l- }u - The subctitem is then separated 

 from the periosteum and the skin drawn apart far enough to 

 admit of the insertion of, say, a -J" trephine giving 2 triangles 

 each having a base of 2.7" in. and a perpendicular of yV'- 

 or an area of 2.7" X T y = 1.2 sq. in. ; thus giving a total 

 wound area of 2.2 sq. in. Assuming the same thickness of 

 skin and the same size of the trephine in the operation as 

 given belovy we have only the wound caused by the circular 

 incision which would measure " X 3.1416 = 2.7" in cir- 

 cumference X y\" = .44sq. in. or proportionately the wound 

 area in the soft tissues in the German operation to that given 

 below would be as 5:1. 



It is very evident that the technic below given affords 

 immeasureably better facility for maintaining cleanliness in 

 the wound and with a minimum amount of insult to the 

 tissues in the process of dressing. 



The amount of pain caused in the operation would depend 

 chifly on the extent of the skin incision which is equal in 

 the two plans so that the only difference would be in the dis- 



