Elimination of contrast medium from the maxillary sinus.

Drainage of contrast medium from the maxillary sinus during blowing and sniffing was studied by cine-roentgenography in 11 healthy subjects. The functional size of the maxillary ostium was measured by a manometric method. Sniffing facilitated drainage more than blowing but the effect was minimal for both procedures except when sniffing was performed with the head tilted to the side opposite the filled sinus. The latter procedures may trap air in the sinus above the level of the ostium and thus facilitate drainage during sniffing. Another facilitating factor which is discussed is that blowing the nose may catch tenacious mucus which has partly passed through the ostium by the ciliary activity in the sinus. The influence of the fluid viscosity is discussed. The time required for complete emptying of the sinus from contrast medium, studied over a period of several days, was found to be inversely correlated to the functional diameter of the maxillary ostium.