Purpose: To report the feasibility of oral rehabilitation in patients who had undergone marginal mandibulectomy and to describe the factors that impact the selection of a mandibular resection prosthesis. Materials and Methods: A retrospective review of patients who had undergone marginal mandibulectomy over a 14-year period at a tertiary care cancer center was undertaken. Measurements of the vertical height and width of the mandible and the distance between the alveolar crest and mandibular canal were measured after marginal mandibulectomy. The feasibility and success of tooth-borne or implant-supported resection prostheses were measured. Results: Following marginal mandibulectomy, the median heights between the alveolar crest and lower border of the mandible were 21.8 mm, 17.7 mm, and 14.3 mm in the anterior, premolar, and molar regions, respectively. However, the median distances between the alveolar crest and the mandibular canal in the premolar and molar regions were only 3.98 and 3.4 mm, respectively. These residual bone measurements are not satisfactory for implant-supported mandibular resection prostheses, which can be considered only in the anterior region of the mandible. Patients with marginal mandibulectomy in the premolar and molar regions can only be rehabilitated with removable dentures, provided they have remaining stable teeth to clasp and anchor the removable denture. Conclusion: Implant-supported resection prostheses after marginal mandibulectomy are feasible only in the anterior segment of the mandible and are not possible in the premolar and molar regions.