When the gums are heavily atrophied and the teeth are loose, supragingival scaling and subgingival scaling can be performed first to remove calculus, diseased bone and granulation tissue, remove bad restorations, adjust occlusion, remove local irritation and control inflammation, and then ligature fixation can be performed on teeth with 1-2 degrees of looseness to restore normal chewing function. When the alveolar bone destruction reaches the middle 1/3 of the root, periodontal flap surgery can be performed to implant bone powder and periosteum around the tooth to increase the strength of hard tissue support, so that the tooth looseness can be reduced. When the tooth loosening is more than 3 degrees, there is no retention value, so it can be directly extracted and restored at a later date.