TREPHINING THE NASAE FOSSAE. 



45 



openings should always be made. The first opening should 

 be made close against the median side of the zygoma near 

 its lower or nasal extremity, Plate III, IM, and the inferior 

 border lowered sufficiently with the bone forceps to provide 

 thorough drainage for the lateral compartment of the sinus. 

 The second opening is to be made on the median side of 

 the nerve conduit, NC, Plates IV-V as indicated at IM' in 

 Plate III. The location may be accurately determined by 

 palpating with the index finger through the first opening 

 at IM, Plate III. This compartment can not be well drained 

 upon the face through either of the trephine openings and 

 a third opening, penetrating the inferior turbinated bone at 

 IT, Plates IV-V, is essential to ideal results by affording 

 free drainage into the nasal chamber. The opening through 

 the inferior turbine is made in the same manner as described 

 for the opening through the superior turbine from the 

 frontal. Thorough search should be made throughout the 

 sinus for the causes of disease, teeth, etc., these removed and 

 followed by after treatment the same as advised for the two 

 preceding operations. 



6. TREPHINING THE NASAL FOSSAE. 

 Plates VII-X. 



Uses. Operations upon the septum nasi, or the tur- 

 binated bones, or the removal of tumors or foreign bodies 

 from the nasal passages. 



Instruments. Same as for the frontal sinuses (page 

 19). 



Technic. The trephining, N, Plate III, is carried out 

 by the method described above, in the nasal bone, close by 

 the median line of the face and according to indications at 

 any point from a level of the dotted line, SM, Plate III, to 

 the juncture between the na.sal and pre-maxillary bones 

 near the upper extremity of the false nostril. 



