Complications of postoperative swelling of the maxillary sinus membrane after sinus floor augmentation

Maxillary sinus floor augmentations were performed by the lateral window technique in 132 sites using betatricalcium phosphate (β-TCP) granules. Cone beam computed tomography (CBCT) scans were taken before surgery, the day of surgery, and one week, three months and one year after surgery. The proportion of the area of the postoperative swelling of the sinus membrane in relation to the remaining sinus cavity was determined and classified into three types: Type 1, less than one-third; Type 2, one-third to two-thirds; and Type 3, more than two-thirds of the remaining sinus cavity. The sites were divided into two groups based on the extent of lateral window coverage: Group 1, not completely covered; and Group 2, completely covered. The degree of migration of the β-TCP granules was evaluated and classified into three types: Type A, limited to the lateral window; Type B, limited to the adjacent tooth; and Type C, extending beyond the adjacent tooth.