The effectiveness of some modifications of the Caldwell-Luc standard procedure in the prevention of post-operative mid-facial sensitivity disorders was investigated in a prospective comparative study at the ENT Department, Faculty of Medicine, University of Athens, Greece, from 1986-1992. Sixty-nine maxillary sinuses were operated on in 61 patients suffering from benign pathological conditions. The modifications concerned the type of mucoperiosteal incision and the site and size of the created anterior antrostomy. Only 8.7 per cent of the sinuses operated on by the modified technique presented with post-operative disorders whereas among those operated on by the classical technique, the ratio climbed to 33 per cent. In view of the findings of this study, the modifications applied can be valuable in treating non-extensive maxillary sinus disease with minimal post-operative sensitivity disorders.