Sinus membrane perforation is the most frequent intraoperative complication of lateral window sinus floor elevation, with reported incidences ranging from 7 % to 56 %. Pre-existing oroantral communications (OACs) represent a frequently associated clinical situation encountered during implant rehabilitation of the posterior edentulous maxilla. Despite an extensive literature, no clear consensus guides the clinician in selecting a management technique. The aim of this work is to propose an educational clinical decision tree, based on a narrative review of the literature, to guide the management of intraoperative sinus membrane perforations and OACs in the context of posterior maxillary implant rehabilitation.

A narrative review of the literature was conducted. MEDLINE (via PubMed), Embase, Cochrane Library, Scopus and Web of Science were searched from 1999 to March 2026. Included studies addressed the surgical management of sinus membrane perforations during lateral or transcrestal sinus floor elevation, as well as the management of OACs in the context of implant rehabilitation.

Four main major determinants of the therapeutic decision were identified: perforation size, perforation location, residual bone height (RBH) and clinical context (associated OAC, smoking, sinus pathology). For small perforations (<5 mm), spontaneous self-folding, suturing or fibrin sealants may be considered. For perforations of 5–10 mm, collagen membranes are the most commonly described approach, whereas Loma Linda-type pouch techniques represent one option for larger defects. Implant survival rates reported under repaired membranes (97.6–97.9 %) are comparable to those observed under intact membranes (98.4–98.9 %).

The proposed decision tree integrates the main clinical and anatomical parameters guiding decision-making. It is intended as an educational tool for early-career clinicians, without substituting for clinical experience or for up-to-date evidence.