Background and Objectives: This research describes the management of mandibular fractures in edentulous patients with atrophic mandibles and implant-retained overdentures, exploring etiologies and treatment options. Materials and Methods: A retrospective study (January 2010–December 2023) was conducted on six patients from two hospitals (Hospital Gregorio Marañón y Hospital La Paz, Madrid). The data collected included fracture etiology, treatment type, and complications. Results: All six patients were women, with a mean age of 76.33 years. The most common cause of fracture was peri-implantitis (50%). Surgical treatment (open reduction and internal fixation) was performed in five patients, with different surgical approaches and fixation methods. One patient, due to multiple comorbidities, received conservative treatment. Complications occurred in 50% of cases, including delayed healing and hypoesthesia. The average hospital stay was four days, with a mean follow-up of 34 months. Conclusions: Mandibular fractures in these patients are rare. Surgical treatment using rigid fixation plates is recommended. The rational use of bone grafting should be taken into account. Treatment depends on fracture type, patient condition, and surgeon experience.