1 8 TREPHINING OF THE FACIAL SINUSES. 



TREPHINING OF THE FACIAL SINUSES. 

 PIRATES IV, V, VI, VII. 



Prefatory Note. The facial sinuses of the horse consti- 

 tute an exceedingly intricate and extensive group of cavities, 

 communicating more or less freely with each other and with 

 the exterior through the medium of the upper air passages, 

 of which they are to be regarded as a part. 



Their arrangement and relations permit them to frequently 

 become the seat of, or central figure in many forms of disease 

 which require for their differential diagnosis, amelioration or 

 cure, the operation known as trephining. Their extent and 

 relations to each other and to surrounding parts varies 

 greatly with age and may be profoundly changed as a result 

 of disease, amounting not infrequently in the frontal, 

 superior and inferior maxillary sinuses ceasing to exist as 

 separate cavities arid becoming merged into one vast diverti- 

 culum. Similar changes ma} 7 occur in the nasal and lur- 

 binated cavities. The general position, extent and relations 

 of these are indicated by Plates IV, V, VI and VII. 



The uses of trephining are in a measure common to all 

 the cavities involved and are chiefly for the relief of 

 empyema of the cavities involved, necrosis of the bony or 

 cartilaginous walls, tumors of various kinds, especially dental 

 tumors in the young and malignant growths in the old, 

 foreign bodies in the sinuses, differential diagnosis of diseases 

 of this region, etc. 



Veterinarians trephine the sinuses by two fundamentally 

 different plans; with, and without excision of the cutaneous 

 disk corresponding to the piece of bone removed. The first 

 is generally used in Great Britain and North America while 

 the last is the prevailing method in continental Europe and 

 other parts of the world. The reasons for these variations in 

 method have not been given so far as we know. To us 



