Insufficient crown height space, particularly in the interforaminal region of edentulous ridges with knife-edge morphology, may prevent successful prosthetic rehabilitation. Such conditions require osteoplasty, which might complicate computer-guided implant placement. This clinical report illustrates the treatment of a patient with complete edentulism rehabilitated with a mandibular implant-supported fixed dental prosthesis by using a virtually guided approach. Both alveolar ridge reduction and prosthetically driven implant insertions were computer-guided by surgical stents to increase accuracy and predictability. This approach enabled the immediate loading of the implants with an interim prosthesis before the delivery of a definitive screw-retained fixed prosthesis. At the 1-year follow-up visit, clinical and radiographic examination revealed a stable outcome.