TREPHINING SUPERIOR MAXILLARY SINCSES. 



33 



the trephine opening be aimed at the probable focus of the 

 malady and, should this fail to reach the desired locality, 

 the proper location for the opening may now be determined 

 by digital or other examination through the first opening. 

 A second operation should then be made to directly reach 

 the seat of the affection and if need be, yet a third to secure 

 proper drainage. 



Shave and disinfect as much of the area as may be re- 

 quired bounded above by the inferior border of the orbital 

 cavity, laterally by the zygomatic ridge, inferiorly by the 

 lower end of the zygoma and medianwards by the middle 

 line of the face. Determine the proper point for operation 

 by percussion or otherwise. If it be desired to enter the 

 superior maxillary sinus only, SM, Plates III-X, locate the 

 opening beneath tlie orbital cavity and in front of the zygo- 

 matic ridge, SM, Plate III, or at any point directly beneath 

 this to midway between SM and IM, Plate III, at about 

 the level of the dotted line IM'. 



The trephining is carried out as described for the frontal 

 sinuses on page 19. ilfter the trephining has been com- 

 pleted remove any purulent collection or tumors or carry 

 out any other necessary operation in the affected sinuses 

 and after cleansing, if the trephine opening does not insure 

 perfect drainage of the lateral sac, either lower it by cutting 

 away its Inferior border with the bone forceps or make a 

 second trephine opening at the necessary point. 



Since empyema of the superior maxillary sinuses is due in 

 the vast majority of ca.ses to infection derived from diseased 

 teeth or dental alveoli it is es.sential after the sinus has been 

 opened that the operator search carefully and minutely over 

 the alveoli of the molars for naked, eroded tooth fangs or 

 for fastulae leading down into the dental alveoli. If dental 

 disease is recognized the trephining of the sinus is to be 

 supplemented by repulsion of the offending tooth as 

 described on page 8. 

 3 



