Quantitative 99mTc-DTPA scintigraphy for determination of maxillary sinus drainage following Caldwell-Luc surgery

Nine maxillary sinuses of 8 patients who had undergone Caldwell-Luc surgery (CWL) were injected with 100-125 microCi 99mTc-DTPA in 0.2 ml from the gingivo-buccal sulcus, passing through the canine fossa window. Sinus half-emptying times and percent contribution of the natural ostium (NO) and the naso-antral window (NA) to the clearance from the sinus were calculated, using time-activity curves as well as the activity of cotton wool plugs placed into the middle and lower conchae. Mean half-emptying times in patients in whom the mucosa had been removed were shorter than those in patients in whom it had been left in place. In the former group percent drainage through the NO was higher than that through the NA whereas in the latter group the opposite was the case. These findings are consistent with the thesis that if the mucosa is retained, the cilia continue their sweeping action towards the NO but if it is removed the NA gains importance in the drainage. This method is promising for the evaluation of maxillary sinus drainage following CWL.