The importance of virtual surgical planning in mandibular resective procedures has been clearly elucidated in the literature, both in terms of control of disease-free margins and accuracy. Moreover, coupling computer-guided mandibular resection with a planned reconstruction also optimizes the recipient site for the subsequent flap or prosthesis. 3D printing provided a significant advance in the field of surgical guides for resection, which enables the most correct translation of a digital osteotomy in the real patient. A systematic analysis of surgical guides is mandatory to define the most appropriate virtual workflows and design techniques for different surgical scenarios, and this chapter provides a comprehensive overview of resective procedures for a variety of situations, including cases with previous osteosynthesis and soft tissue disease, which should always be incorporated in the virtual model, when possible, to drive a most effective skeletal resection.