Gingival cysts in adults arise from odontogenic epithelial remnants and are most commonly seen in the canine-premolar region of the mandible. The condition is rare. In Japan, an extensive review of the literature revealed only one reported case to date. We have encountered such a case, and report it here. A 22-year-old man was referred to our department on March 27, 1998 because of gingival swelling in the canine region of the right side of the mandible. He had previously consulted a dental clinic because of tenderness in the same region. The gingival swelling had a diameter of about 3 millimeters. It was hemispheric, the border was clear, and the color was similar to that of the normal gingiva. The patient had no spontaneous pain, only tenderness. The surrounding teeth were all vital, and had no pain on percussion or mobility. A radiographic examination showed no abnormalities. We clinically suspected the swelling to be a gingival tumor. We extirpated the lesion on April 28, 1998 under local anesthesia. A 1-mm margin of normal gingiva was resected concurrently. It was pathologically diagnosed as a gingival cyst in an adult. The postoperative course has been good.
