Located in the lower 1/3 of the face, the mandible is the only bone in the face that can move its through joints, allowing not only maintenance of the maxillofacial shape but also participating in important functions. However, conditions such as trauma, maxillofacial tumors, and osteoradionecrosis of the jaw (ORNJ) often cause segmental defects of the mandible, not only affecting the appearance but also resulting in dysfunctions such as slurred speech, limited mouth opening, and difficulty in chewing, which greatly reduce the quality of life (QoL) of the patient and even affect their mental health. Vascularized free fibula flap is the current option for reconstructing segmental mandibular defects, providing a sufficient bone length and mass to restore the continuity of the mandible and the maxillofacial shape, achieving satisfactory mandibular reconstruction (Shah and Gil, 2009). After a certain period of follow-up, when the probability of tumor recurrence has been significantly reduced, patients require restoration of intraoral dentition defects to improve their QoL, typically via implant-based restoration. However, sometimes the height of the grafted fibula is far lower than the normal height of the mandible and is unable to meet implantation requirements. Therefore, improving the bone height of the grafted fibula to meet the implant requirements of implantation has emerged as an important research topic.

Sandwich osteotomy was proposed by Schettler (Schettler D, 1977) in the 1970s. Through U-shaped osteotomy of the bone defect area, artificial bone material is filled between the coronal free bone segment and the base bone, producing a result resembling a “sandwich”, while the complete lingual periosteum is reserved to ensure good blood supply for the bone segment and the implant to promote osteogenesis (Santagata et al., 2017), thus eventually resulting in bone augmentation. Currently, the clinical application of sandwich osteotomy is increasing, and satisfactory results continue to be achieved. However, sandwich osteotomy has mostly been applied to alveolar atrophy, while reports on its application for the grafted fibula are rare. Therefore, this study retrospectively analyzed data on the use of sandwich osteotomy for grafted fibula in our hospital and evaluated whether it could achieve similarly substantial bone augmentation as in alveolar atrophy.