Drs Friedland and Metson present a pragmatic and thorough approach to diagnosing and understanding ramifications of underlying sinus pathology in regards to maxillary sinus augmentation surgery. Surgical placement of implants today often requires sinus grafting procedures. It is imperative to understand diagnostic criteria and which pathologic findings may require treatment or have relevance for planned sinus grafting procedures. This article presents an algorithm for decision making. Examples of various pathologic findings are presented.