To evaluate physiological bone regeneration in the case of a postoperative maxillary cyst (POMC) treated using the deflation and dredging method to augment bone for implant placement. In the case of bone resorption, bone augmentation is required to place a stable implant. Before bone augmentation, the reason for bone resorption must be taken into consideration and should be treated first. The deflation and dredging method, which was originally developed for treating ameloblastoma, can be applied to treat POMC because of the similar treatment objectives of complete epithelium removal and enhancement of bone regeneration. In the first surgery, the cyst wall and overlying alveolar bone were removed under local anesthesia for deflation and histopathological examination. Three months after the deflation, new bone formation was observed along the inner surface of the cavity, the cavity itself became smaller, and the cyst could be easily enucleated. Thereafter, dredging was performed twice at intervals of 3 months. No epithelial cells were found on histopathological examination of the bone excised during dredging, and the bony cavity was filled with regenerated bone. Six months later, the implant body was placed, and the final prostheses were set after another 6 months. There has been no recurrence of POMC for >3 years after the last dredging. Treatment of the POMC and bone augmentation can be performed as a serial treatment without any invasive maneuvers, such as, bone harvesting and grafting. Bone regeneration is expected to occur under proper conditions of preparation.