Diagnostic imaging has a primary role in presurgical planning. Computerized tomography has become a standard for assessing the feasibility of implant surgery. Three- dimensional diagnostic assessments have a decisive value in presurgical treatment planning, especially in situations in which the alveolar process has pronounced resorption, and therefore insufficient bone volume for placing endosseous implants. These situations, which once limited the placement of implants in the posterior maxilla, can now be overcome via maxillary sinus augmentation procedures. In these cases, diagnostic imaging, in particular using CT scans, plays a vital role in providing reliable and necessary information. MR imaging reveals to be ideal imaging in diagnosing maxillary sinus augmentation.