Long-term evaluation of three-dimensional volumetric changes of augmented severely atrophic maxilla by anterior iliac crest bone grafting

Purpose: The purpose of this study was to evaluate long-term three-dimensional graft resorption following reconstruction of the severely atrophic maxilla with anterior iliac crest bone grafting. Methods: Twenty-two patients (13 males), who underwent autogenous bone grafting and implant placement to their severely atrophic maxillary alveolar ridges were identified and included in the study. Preand postoperative cone-beam computed tomography (CBCT) scans of 40 recipient grafting sites were evaluated to calculate volumetric changes over time. CBCT scans were performed preoperatively (V0) and one week (V1), three months (V2), one year (V3), and three years (V4) following the augmentation operation. Results: The average graft resorption from V1 to V2, V1 to V3, and V1 to V4 was 31.42%, 33.96%, and 37.96%, respectively. Initial graft volume reduction within the first three months was statistically higher compared to other postoperative periods (P 0.013). The rate of resorption reduced slightly from the third month of the surgery (V2) (P 0.013). There was no statistical difference between resorption volume and gender, type of prosthesis, the presence of vestibuloplasty, or patient age (P > 0.05). Conclusion: The overall success rate of the iliac bone block grafts was found to be high. The volumetric resorption rates associated with the graft were favourable for the reconstruction of the maxilla and for permitting the placement of dental implants three months after augmentation. The highest graft resorption was found at the third postoperative month. Placement and loading of the implants reduced the resorption rate slightly over time. (C) 2020 Elsevier Masson SAS. All rights reserved.