This 3D animation video represents bone resorption that both in the maxillary sinus, due to its increased pneumatization, and in the alveolar ridge related to tooth loss. The residual bone would be insufficient to provide a secure anchor for a future dental implant. With reconstructive sinus lift surgery, it is possible to access the sinus laterally, detach the Schneiderian membrane without breaking it and finally fill in the space created with particulate artificial bone (heterologous bone of bovine origin). The side will be protected by a collagen membrane of porcine origin. The filling will turn into bone within 6-8 months that allows optimal anchorage for the future dental implant.