Abstract
Rehabilitation of the posterior maxilla with dental implants can be challenging because of reduced bone height, poor bone quality, and sinus pneumatization. This report describes the treatment of a severely atrophic posterior maxilla with a residual ridge height of 2.43 mm using a lateral window (direct) sinus lift. A bovine-derived xenograft was used in conjunction with a resorbable collagen membrane, followed by delayed placement of two implants and prosthetic restoration. A 43-year-old female patient underwent sinus augmentation with deproteinized bovine bone mineral and collagen membrane. After nine months of healing, two Bioline implants (4.2×13 mm) were inserted and later restored with a screw-retained prosthesis. One-year follow-up demonstrated stable marginal bone, healthy peri-implant tissues, and excellent esthetic and functional outcomes. This case highlights the reliability of direct sinus augmentation using xenograft and membrane in sites with extremely limited bone height and also discusses potential risks and limitations of the procedure.