The classic surgical approach to the maxillary sinus described originally by Caldwell and Luc, which is still very much in use, calls for an incision in the upper part of the buccal vestibulum. This incision has many disadvantages. A surgical technique that uses the full-thickness gingivomucoperiosteal flap avoids these disadvantages. This method was used in 74 cases during the last three years,and the results have been most satisfactory.