WHAT occurs in the paranasal sinuses after surgical removal of the mucous membrane has been a controversial subject for many years. McGregor,1 of Toronto, found a good deal of regeneration in 26 specimens taken from the antrum, stating that perfectly reformed mucous membrane was present. He went on to say that it grows by inundation and transplantation and that bone itself may produce connective tissue.
Coates and Ersner2 found regenerated mucous membrane in the frontal sinus of a dog two months and seven months after surgical removal of the membrane.
Gorham and Bacher,3 of San Francisco, observed remarkable regeneration in the human maxillary antrum in from three to five months after operation in most cases, and certainly in ten months in others. They noted that ciliated columnar epithelium with loose stroma, serous and mucous glands and a definite basement membrane were present.
Unfortunately, in our experimental work on the frontal