TREPHINING OF THE FACIAL SINUSES. 17 



Veterinarians trephine the sinuses by two fundamentally 

 different plans ; with, and without excision of the cutaneous 

 disk corresponding to the piece of the bone removed. The 

 first is generally used in Great Britain and North America, 

 while the last is the prevailing method in continental 

 Burope and other parts of the world. The reason assigned 

 for these variations in method are conflicting. To us there 

 seem to be adequate reasons for preferring the excision of 

 the cutaneous disk. We regard as the chief considerations 

 in an operation the following : the avoidance of infection ; 

 the prevention of pain during the operation or the after- 

 treatment ; the reduction of the scar to a minimum ; rapidity 

 and certaintj' 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. If we take as a type the usual 

 European technic and compare it with that given below we 

 would find the wound areas approximately a^ follows : in 

 the European method 2.2 sq. in. whife in the operation as 

 given below we have only about .44 sq. in. or proportion- 

 ately the wound area in the soft tissues in the European 

 operation to that given below would be as 5 : i . 



It is very evident that the technic given below 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 

 chiefly upon the extent of the skin incision which is equal 

 in the two plans so that the only difference would be ih the 

 dissection of the skin from the bone in the European 

 operation. The pain caused in dressing must be greater in 

 the European method because the detached, overhanging 

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