In this article, we describe the first case in the literature in which 3D computer-assisted treatment planning and guided surgery enabled a patient affected by extreme paraphysiologic mandibular bone atrophy to be treated with a free vascularized fibula flap and, after a period of healing, the flapless installation of 4 immediately loaded dental implants. The computer-fabricated surgical guide allowed placement of the implants according to the "All-on-Four" concept in a proper spatial preplanned position and by tilting 1 implant, avoiding an area of bone discontinuity. Additionally, this technique allowed the production of a prefabricated temporary prosthesis, delivered after implant insertion, which could be immediately loaded. The use of a fibula flap makes it possible to create greater bone thickness while computer-assisted treatment planning and guided surgery provide several advantages over the traditional technique.