A female patient with non-small-cell lung cancer presented with a huge area of exposed bone in the mandible following spontaneous teeth loss. She was receiving multimodal chemotherapy containing bevacizumab. No previous treatment with bisphosphonates or comorbid conditions was reported. Pain medications and infection control were offered to the patient who was closely followed up. Initial imaging and histology of bone and surrounding mucosa (8 weeks after bevacizumab cessation) confirmed the clinical suspicion of avascular osteonecrosis of the mandible. Subsequent imaging and histology of bone and gingiva (12 weeks after bevacizumab cessation) revealed the initial sequestration of the mandible with a marked expansion of the mucosal vascular network. Spontaneous bone sequestration eventually occurred few months later, followed by stable and painless mucosal coverage of the mandibular bone. The patient remained disease-free up to 3 years of follow-up.