Internal Sinus Lift With Allograft For Severe Alveolar Deficiency

This case report presents the successful management of severe alveolar ridge height deficiency in the maxillary posterior region using partially demineralized allogeneic cancellous bone combined with concentrated growth factors (CGF). The patient exhibited inadequate keratinized gingiva width and an extremely limited residual bone height (approximately 2 mm). A staged transalveolar sinus floor elevation approach was implemented: the initial procedure utilized partially demineralized allogeneic cancellous bone blocks saturated with CGF to establish sufficient bone volume for future implant placement, followed by a secondary sinus lift with simultaneous implant placement and bone core retrieval for histologic evaluation. Both radiographic and histologic assessments demonstrated favorable osteogenic outcomes. During stage-two surgery, a palatally positioned flap was elevated and augmented with a medical collagen sponge to enhance keratinized tissue width. This case illustrates that transalveolar sinus elevation with delayed implantation represents a viable alternative to the conventional lateral window technique in cases with critically low residual bone height when cortical bone integrity is maintained. The described protocol offers distinct advantages including simplified operative procedures, reduced surgical trauma, and the provision of structural support through moldable allogeneic bone blocks enhanced with CGF. The findings suggest that allogeneic bone-mediated internal sinus elevation can achieve predictable bone augmentation, while subsequent soft tissue augmentation ensures adequate keratinized mucosa dimensions, ultimately facilitating optimal implant rehabilitation.