l6 TREPHINING OF THE FACIAL SINUSES. 



TREPHINING OF THE FACIAL SINUSES. 

 Pl,ATES III, IV, V, VI, VII AND VIII. 



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 vs^ith 

 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 and becoming merged into one vast diverti- 

 culum. Similar changes may occur in the nasal and tur- 

 binated cavities. The general position, extent and relations 

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



It is to be noted that in cross sections the superior and 

 inferior maxillary sinuses appear to be reversed in relation 

 to their nomenclature. It is difficult to make a cross sec- - 

 tion of these sinuses in such a manner that the superior 

 sinus does not show between the infen©i:-one and the oral 

 cavity. The inferior maxillary sinus is inferior in the 

 sense that it is nearer to the nasal opening so that with the 

 head in a vertical position or in a longitudinal section the 

 inferior sinus is below the superior, while if the head be 

 placed horizontally or a cross section made the superior 

 sinus is below the inferior. 



The uses of trephining are in a measure common to all 

 the sinuses and are chiefly for the relief of empyema of the 

 cavities involved, necrosis of the bony pr cartilaginous walls, 

 tumors of various kinds, especially dental in the young and 

 malignant growths in the old, foreign bodies in the sinuses, 

 differential diagnosis of diseases of this region, etc. 



