Use of a Lateral Sinus Bony Window as an Intraoral Donor Site for Guided Bone Regeneration in Wide Post-Extraction Defects

Abstract

Maxillary sinus augmentation (MSA) and guided bone regeneration (GBR) have shown successful clinical, radiological, and histological outcomes for implant-related bone reconstruction and have been used to augment bony defects of various shapes and sizes. This study demonstrated that the lateral sinus bony window obtained during MSA can be used as an autogenous block bone graft for the augmentation of wide post-extraction defects. During the uncovering procedure performed 6 months after surgery, the grafted lateral bony window was well integrated with the adjacent native bone, and complete bone filling was observed in all bony defects around the implants. All of the implants survived. Within the limitations of this study, autogenous block bone obtained from lateral window sites can be used as novel donors for the resolution of wide bony defects around implants.

Keywords: autografts; bone transplantation; dental implant; intraoral donor; lateral sinus window; sinus floor augmentation.

Figure 1

Case 1: (a) preoperative panoramic radiograph; (b) sagittal image of the preoperative CBCT scan showing a severely resorbed bone defect; (c) preoperative clinical view two months after tooth extraction; (d) after the flap reflection, a lateral window was prepared, and the buccal bony window was obtained during the maxillary sinus augmentation; (e) the obtained lateral bony window was passively placed on the distal intraosseous defect of the #17 implant without fixation; (f) the surgical site was covered with a resorbable collagen membrane; (g) the flaps were closed with minimal tension; (h) the uncovering procedure was performed six months after the operation, and the lateral window bone was well incorporated with the adjacent native bone; (i) clinical view at two years after prosthesis delivery; (j) panoramic radiograph immediately after surgery; (k) sagittal image of the CBCT scans after prosthesis delivery; (l) sagittal image of the CBCT two years after prosthesis delivery, where the lateral bony window was well incorporated with the surrounding native bone, and the bone density was increased.

Figure 2

Case 2: (a) preoperative panoramic radiograph; (b) preoperative panoramic image of the CBCT scan showing a severely resorbed bone defect and a pneumatized maxillary sinus on the left side; (c) preoperative clinical view at two months after extraction of the left maxillary second premolar and first molar; (d) after reflection of the mucoperiosteal flap, the lateral bony window was obtained; (e) thorough debridement was performed to remove inflammatory granulation tissue; (f) after maxillary sinus augmentation, an appropriately trimmed lateral bony window was placed on the defect, and the gap was filled with particulate bone graft; (g) the grafted site was covered with a collagen membrane; (h) the mucoperiosteal flaps were closed with minimal tension; (i) implants were placed six months after the surgery, and additional bone grafting was performed at the lateral window site where bone loss had occurred due to the sinus graft infection; (j) the uncovering procedure was performed six months after implant placement; (k) a prosthesis was delivered two months after the uncovering procedure; (l) preoperative sagittal image of the CBCT scan; (m) sagittal images of the CBCT taken immediately after surgery; (n) sagittal image of the CBCT one year after prosthesis delivery.

Figure 3

Case 3: (a) preoperative panoramic radiograph; (b) preoperative panoramic image of the CBCT scan; (c) posterior superior alveolar arteries (PSAAs) are shown on the coronal images of the preoperative CBCT scans on both sides; (d) coronal image of the preoperative CBCT scan showing a severely resorbed bone defect around the extraction site of the left maxillary second molar; (e) preoperative clinical view after extraction of the right maxillary second premolar; (f) after flap reflection, a lateral bony window was prepared for maxillary sinus augmentation; (g) a bony defect was observed after implant placement and sinus augmentation; (h) the buccal bony defect was filled with particulate bone graft; (i) the obtained lateral bony window was placed on the bony defect without fixation; (j) the surgical site was covered with a resorbable collagen membrane; (k) clinical view six months after surgery; (l) the lateral bony window was well incorporated with the surrounding native bone at six months after surgery; (m) clinical view after final prosthesis delivery; (n) after flap reflection, the #24 implant was explanted and a lateral bony window was prepared for maxillary sinus augmentation; (o) after sinus augmentation and implant placement, the buccal bony defects are shown; (p) after filling the buccal bony defect with particulate bone graft, the obtained lateral bony window was positioned on the bony defect; (q) the surgical site was covered with a resorbable collagen membrane; (r) the flaps were closed with minimal tension; (s) the uncovering procedure was performed six months after surgery, and the grafted lateral bony window was well integrated with the surrounding native bone; (t) the bone above the cover screw was removed with a round surgical bur, and after the healing abutments were inserted, the flaps were closed; (u) clinical view after final prosthesis delivery; (v) coronal CBCT image at six months after prosthesis delivery; (w) coronal CBCT scan showing the filling of the defect around the implant placed at the extraction site of the left maxillary second molar.

Figure 4

Case 4: (a) preoperative panoramic radiograph; (b) panoramic image of the preoperative CBCT scan; (c) after flap reflection, the lateral bony window was prepared; (d) obtained lateral bony window; (e) implants were placed after the maxillary sinus augmentation; (f) the lateral bony window was cautiously trimmed and placed on the mesial bony defect; (g) additionally, particulate bone graft was used to fill the gap; (h) a resorbable collagen membrane was placed on the grafted site; (i) a clinical view at six months after surgery; (j) the grafted lateral bony window was well integrated with the surrounding native bone; (k) clinical view after prosthesis delivery; (l) panoramic radiograph at six months after prosthesis delivery; (m) panoramic image of the CBCT at six months after prosthesis delivery; (n) coronal image of the CBCT scan showing posterior superior alveolar arteries on both sides; (o) coronal image of the CBCT scan showing reduced mucosal thickening on the right maxillary sinus.