The mock-up is a diagnostic technique that allows for the intraoral try-in of a prosthetic rehabilitation. Mock-ups facilitate significant improvement in communication with patients by showing them the potential final outcome of the treatment. They also allow for a quick and easy comparison of the pre- and postoperative situations, and permit the clinician to check the functional aspects of the therapy. The purpose of this article is to describe the use of the full-mouth mock-up technique for testing all the functional and esthetic parameters of extensive rehabilitations associated with a VDO increase with completely additive wax-ups. The proposed clinical procedures describe an easy and reversible technique to manage complex prosthetic cases with a more conservative and operator-friendly approach compared with conventional prosthetic therapies, reducing time and costs. All the clinical and technical phases of this approach are described step by step.