Minimally Invasive Transcrestal Sinus Floor Elevation in Compromised Maxillary Extraction Sockets: A Case Series

This report presents a novel clinical approach to transcrestal sinus floor elevation in erratically healed maxillary posterior extraction sockets with severely limited residual bone height (< 1 mm). Three patients underwent delayed implant placement following simultaneous sinus membrane elevation and guided bone regeneration (GBR) within compromised extraction sites. Despite the absence of sufficient bone, crestal access to the sinus was achieved without lateral window opening or excessive malleting. Membrane elevation was facilitated through gentle osteotome probing and hydraulic pressure, followed by passive insertion of a xenograft material. Simultaneous GBR was performed at the extraction sites using a particulate xenograft material and resorbable collagen membrane. Postoperative cone-beam computed tomography (CBCT) revealed an hourglass-shaped configuration of the regenerated bone, indicating successful reconstruction of both the sinus and alveolar bone. Implant fixtures were placed in all patients with satisfactory initial stability and maintained long-term function without adverse events during follow-up periods of 13–63 months. This approach reduces procedural invasiveness, minimizes unnecessary sinus exposure, and promotes bone regeneration by leveraging the healing potential of limited spaces. In the presence of favorable anatomical and healing conditions, vertical bone reconstruction can be accomplished despite the absence of residual crestal bone.