Benefit of the replaceable bony window in lateral maxillary sinus augmentation: clinical and histologic study

This retrospective study demonstrates, by clinical and histologic evaluation, the benefit of the replaceable bony window as a homologous bony barrier in lateral sinus augmentation. A total of 103 maxillary sinus augmentations were performed using a piezoelectric device and a Er,Cr:YSGG laser apparatus. The detached bony windows were repositioned over various bone grafts. Sixteen bone biopsy specimens were harvested at the time of uncovering or implant placement. Three sinuses developed postoperative infections (2.91%). After 6 to 8 months of healing, uncovering procedures were carried out. Radiographically, reconstruction of the lateral sinus wall was observed in all cone-beam computed tomogram. Clinically, complete bone healing between the replaceable bony window and the lateral sinus wall was observed in all cases, except for the 3 infected sinuses (100 sinuses, 97.09%). Histologically, favorable new bone formation was observed in all specimens without any fibrous connective tissue invagination. More mature bone was observed along the floor of the replaceable bony window than at the center of the graft site. This study demonstrates that the replaceable bony window acts as an osteoinductive homologous barrier membrane over various bone graft materials and accelerates new bone formation in lateral sinus augmentation.