Application of Fixed Implant Superstructures Following Multistage Maxillary Reconstruction in Osteosarcoma Patients: A Case Report
Extensive resections of the maxillary bone often result in significant defects that affect oral functions, such as speech and chewing. Although dentomaxillary prostheses are common, they frequently lead to instability and reduced chewing ability. Vascularized bone grafts, including the fibula, are increasingly used to address these challenges due to their anatomical suitability and functional restoration benefits. Despite advances, problems remain, including insufficient bone height for stable implantation. A 60-year-old Japanese woman presented with swelling of the right maxilla and nasal obstruction and was diagnosed with osteosarcoma. Following chemotherapy and partial maxillary resection, she experienced discomfort with dentomaxillary prosthetics, prompting subsequent reconstruction with fibula and particulate cancellous bone and marrow (PCBM) grafts. This patient was taking methotrexate regularly for rheumatoid arthritis, so there was concern that she would be immunosuppressed. Therefore, we did not choose a zygomatic implant, which would be difficult to control in the event of infection. In addition, the fibula alone was insufficient for reconstruction; sufficient vertical and horizontal bone augmentation was required, and we chose a combination of titanium mesh and PCBM that met these requirements. Sequential implant procedures culminated in fixed superstructures that significantly improved occlusal function and prosthetic stability over a 6-year follow-up period. This case highlights the challenges of prosthetic instability following maxillary resections and demonstrates the effectiveness of multistage reconstructions using fibula grafts and PCBM for alveolar ridge augmentation. The structured approach to maxillofacial reconstruction provides valuable insights into optimizing functional outcomes following surgical procedures and highlights the importance of tailored treatment strategies in complex maxillofacial cases.

Intraoral view of the right maxilla. A 24 × 16 mm swelling extended from the buccal side to the palatal side. (b) Flipped mirror image.

Panoramic radiographic findings. (a) On the first visit, a slight increase in opacity was observed throughout the right maxilla. (b) After partial maxillary resection, the patient had a missing jaw following right maxillary resection. (c) After reconstruction with the vascularized fibula, the fibula graft provides continuity with the maxilla. (d) After repair of the alveolar ridge with a particulate cancellous bone and marrow graft and a titanium mesh tray, bone augmentation can be confirmed even in 2-dimensional images using a titanium mesh. (e) After the placement of 5 dental implants, 5 implants were correctly placed. (f) After the placement of the fixed implant superstructures.

Imaging and pathological findings at the first visit. (a) Computerized tomography (CT) scan with a contrast medium, (b) gadolinium-enhanced T1-weighted magnetic resonance imaging, (c) positron emission tomography with CT, and (d) pathological image. The tumor consists of spindle-shaped and round-shaped cells with abundant nuclear chromatin, frequently forming lobulated structures during proliferation. The osteoid formation is observed in the central part of these lobulated structures, whereas the hyaline cartilage matrix is observed at the margins of the osteoid; original magnification, ×100; scale bar, 500 μm.

Three-dimensional computerized tomographic findings. (a) After partial maxillary resection, the patient had a missing jaw following right maxillary resection. (b) After reconstruction with a vascularized fibula graft, although the fibula graft provides continuity with the maxilla, the width and height of the fibula graft are insufficient. (c) After repair of the alveolar ridge with a particulate cancellous bone and marrow graft and a titanium mesh tray, bone augmentation could be observed in width and height under the titanium mesh. (d) After the placement of 5 dental implants, sufficient bone formation was confirmed for implant placement.

Intraoral findings. (a) After partial maxillary resection, the oral and nasal cavities communicated. (b) After reconstruction with a vascularized fibula graft, the communication between the oral and nasal cavities was blocked. (c) After repair of the alveolar ridge with a particulate cancellous bone and marrow graft and a titanium mesh tray, the titanium mesh was slightly exposed in the anterior area. (d) After the placement of 5 dental implants and vestibuloplasty, adequate oral cavity preparation was achieved. (e) After placement of fixed implant superstructures, the patient was satisfied with the functional and esthetic results.

Intraoral findings during titanium mesh tray removal and implant placement. (a) Before titanium mesh tray removal, the anterior titanium mesh tray had been removed in advance because it was exposed in the oral cavity. (b) After the titanium mesh tray removal, bone augmentation was observed under the titanium mesh tray. (c) After implant placement, the parallelism of the implant was confirmed using indicators.

Intraoral findings during vestibuloplasty and second stage surgery. (a) First incision line: An incision line was made palatal to the alveolar crest. (b) Second incision line: The palatal gingiva was rotated around the axis of the anterior part and moved to the gingiva directly over the implants. (c) Attachment of the artificial dermis: The raw surface of the palatal side was covered with the artificial dermis. (d) At the end of surgery, a tetracycline-coated gauze and a protective splint were applied (a, b, c, and d: flipped mirror image).
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