In the diagnosis of chronic maxillary sinus disease the most reliable means of investigation are lavage and roentgenographic examination. It happens not infrequently that lavage is negative, and that the roentgenogram shows bilateral moderate clouding of such nature that it is interpreted by the roentgenologist as negative for sinus disease. To subject these patients to exploratory operation through the canine fossa or to allow them to go without further study constitutes failure to take advantage of recent researches in the study of the sinuses. If it is feasible to make injections of a contrast medium into a sinus and thus outline the contents of the sinus which are not revealed by irrigation, it must be conceded that this procedure approaches, in information obtained, actual exploration of that cavity.
The use of radiopaque substances in the study of the sinuses is becoming more prevalent, fortunately, as is evidenced by the increase