First of all, we should pay attention to good health and no organic diseases of important organs. Secondly, there should be no oral infections such as dental caries, periodontitis and oral ulcers. Third, female surgery should avoid menstrual period; Fourth, blood routine, urine routine, chest X-ray and electrocardiogram should be done before operation. Fifth, the frontal and lateral photos of the skull are routinely taken for postoperative comparison and curative effect evaluation, and three-dimensional skull ct can be done if conditions permit. X-ray film of maxilla was taken to understand the development degree of maxillary sinus; Sixth, aspirin, birth control pills and some anti-inflammatory drugs should be stopped before operation, which will cause increased bleeding, so these drugs should be stopped for a period of time before operation.