“…In 2004, they described a new surgical technique for maxillary sinus augmentation with only sinus membrane elevation and replacement of the bony window 5 . The replacement of the bony window could have been another factor in bone formation by preventing soft-tissue growth into the sinus, which would disturb the maintenance of the secluded space 4,5 . Surgical trauma to the maxillary sinus could also have contributed, as explained in the study on the situation after the Caldwell-Luc operation 9 .…”