Abstract: Objective： Operation in the maxillary sinus tends to injure the debouchement of the nasolacrimal canal in the inferior nasal meatus and the walls of the fossa orbitalis. We tried to find a program with the least injury, duration and that was the most convenience. Methods： From March 2002 to the present, we designed an upright cut of 1 to 1.5 cm in the side labiogingival groove of the ill side above the canine tooth, separated to the bone in canine fossa, drilled a hole of 1 cm with an osteotome or electrodrill, removed the local mucosa, inserted an endoscope, and inspected the lesions inside. If submucous cysts were found, the capsule wall was removed and proper hemostasis was performed; if the mucosa was normal, there was no need to enlarge the aperture, an absorbable hemostatic gauze was laid in the wound surface and the hole, and sutured with 2 stitches; or adhered with biological glue. In patients with an antral polyp, the management was the same as the cases with sumucosa cyst. In patients with aspergillosis, we enlarged the apertures to 1-1.5cm, did not pack the nasal cavity, if we enlarged the apertures, we may pack expansive sponge. The face was oppressed with a four head belt, the plug was taken out after 48 or 72 hours according to the pathogenetic condition, and stitches were taken out after 4 or 5 days. Results： Primary healing was found in all 36 cases, with an unobstructed nasal cavity and disappearance of the symptom. No relapse was found in the period of four months to four years of followup; only 2 cases complained about transient numbness in the upper lips. All patients recovered after 7-8 days. Granulations were found in the enlarged aperture in 2 cases, and they disappeared after treatment. Conclusion： The feature of the operation is the small upright cut in the labiogingival grooves, small windowing in canine fossa, and delicate operation in the sinus cavity with a clear visual field. Lesions may be treated conveniently, which lead to less complications and less severe reactions. The maxillary sinus drains naturally, accords to the normal physiological functions and also problems are avoided that happen in other approaches.

Key words: Surgical procedures, Sinus, operative, Canine tooth fossa