Three-Dimensionally Printed Subperiosteal Implants for Primary Maxillectomy Reconstruction: A Report of Nine Cases

De Riu, M.Y. Mommaerts, D. Soma, A. Biglio, M. Roy, S. Troise, A. Maniaci, J.R. Lechien, L.A. Vaira.

Full text link: https://pubmed.ncbi.nlm.nih.gov/40683801/

Three-Dimensionally Printed Subperiosteal Implants for Primary Maxillectomy Reconstruction: A Report of Nine Cases

1. Scientific Reference

• Study Title: Three-dimensionally printed subperiosteal implants for maxillectomy reconstruction: report of nine cases.
• Authors: G. De Riu, M.Y. Mommaerts, D. Soma, A. Biglio, M. Roy, S. Troise, A. Maniaci, J.R. Lechien, L.A. Vaira.
• Journal: International Journal of Oral and Maxillofacial Surgery
• Publication Year: 2025.
• DOI: 10.1016/j.ijom.2025.07.001.

2. Scientific Background

Maxillary reconstruction following oncologic resection remains one of the most demanding procedures in oral and maxillofacial surgery. Removal of the maxilla frequently results in complex composite defects affecting mastication, swallowing, speech, facial support, and the possibility of implant-supported dental rehabilitation. Although microvascular bone flaps remain the current standard of care for reconstructing these defects, they are technically demanding and may not be suitable for every patient.

Advances in digital surgery—including virtual planning, CAD/CAM workflows, and metal additive manufacturing—have created new opportunities for personalized reconstruction. Patient-specific subperiosteal implants have already demonstrated promising results in secondary maxillary reconstruction and in the rehabilitation of severely atrophic jaws. However, their application during primary oncologic reconstruction has received very limited scientific attention. This study explores whether customized 3D-printed titanium subperiosteal implants can be successfully integrated into the initial reconstructive procedure, combining tumor ablation, skeletal reconstruction, and preparation for implant-supported prosthetic rehabilitation within a single surgical workflow.

3. Study Objective

The primary objective of this retrospective investigation was to assess the feasibility and clinical performance of patient-specific additively manufactured subperiosteal implants used during primary maxillary reconstruction after tumor resection. The authors aimed to evaluate implant stability, surgical and prosthetic outcomes, postoperative complications, and short- to medium-term clinical results following simultaneous tumor resection, flap reconstruction, and implant placement.

4. Methodology

This retrospective observational case series included nine patients who underwent primary maxillary reconstruction between May 2021 and June 2023 following surgical resection of maxillary tumors. Each patient received a customized titanium subperiosteal implant manufactured using direct metal laser sintering of Ti6Al4V alloy. Implant design relied on a fully digital workflow incorporating computed tomography (DICOM data), intraoral digital scans, virtual prosthetic planning, and CAD/CAM engineering.

Tumor resection, placement of the patient-specific implant, and reconstruction using either free or pedicled flaps were performed during the same operation. The implants simultaneously served as osteosynthesis devices and prosthetic implant supports. The complete design and manufacturing process required approximately nine days.

Patients were followed for a minimum of six months, with an overall follow-up ranging from 6 to 20 months (mean: 13.7 months). Clinical assessment included implant stability, peri-implant soft tissue health, surgical complications, radiographic evaluation, and prosthetic outcomes.

5. Main Findings

The study population consisted of seven men and two women, ranging in age from 45 to 90 years (mean age: 70.8 years). The underlying diagnoses included five squamous cell carcinomas, three osteosarcomas (two high-grade and one low-grade), and one high-grade chondrosarcoma. Reconstruction strategies were individualized according to tumor characteristics, defect morphology, and patient-related factors, with the free fibula flap representing the most frequently selected reconstructive option.

All nine customized subperiosteal implants were successfully inserted according to the preoperative digital plan. Throughout the follow-up period, none of the implants exhibited clinical mobility or signs of infection. Radiographic examinations performed at six months and one year demonstrated stable fixation, with no evidence of screw loosening or peri-implant bone resorption. Likewise, no prosthetic complications were reported during follow-up.

Only one major postoperative complication occurred: necrosis of a fibula free flap secondary to venous thrombosis. According to the authors, this event was unrelated to the customized implant itself. Another patient experienced wound dehiscence associated with a small oroantral fistula, which was subsequently managed by incorporating a palatal obturator extension into the implant-supported prosthesis. Among the five patients who received adjuvant radiotherapy, one developed severe mucositis around the transmucosal abutments, requiring temporary interruption before completion of radiation therapy. Regarding peri-implant soft tissue health, eight implants demonstrated complete mucosal coverage, while one exhibited limited exposure of a vertical abutment without associated inflammation (score 1A).

6. Clinical Analysis

This case series provides some of the first clinical evidence supporting the use of patient-specific 3D-printed subperiosteal implants during primary maxillary reconstruction rather than secondary rehabilitation. While previous publications have largely focused on delayed reconstruction after healing or on rehabilitation of severely atrophic maxillae, this investigation evaluates the feasibility of integrating a customized implant directly into the initial oncologic procedure.

One of the most noteworthy aspects of this approach is the integration of multiple surgical objectives into a single digitally planned workflow. Beyond replacing missing bone, the customized implant functions simultaneously as an osteosynthesis plate and as the definitive foundation for future implant-supported prosthetic rehabilitation. This design may reduce the need for additional reconstructive procedures and simplify subsequent restorative treatment, provided adequate soft tissue healing is achieved.

The authors also highlight a potential role for these implants in patients who are poor candidates for conventional vascularized bone reconstruction. Although this observation is based on a limited number of cases, the study illustrates that customized subperiosteal implants may offer an alternative means of supporting prosthetic rehabilitation when extensive bone grafting cannot be performed because of anatomical or systemic limitations. These findings should be interpreted as preliminary rather than definitive clinical recommendations.

Another important contribution concerns surgical planning. Because implant fabrication is completed before tumor resection, surgeons must anticipate possible intraoperative modifications to resection margins. The authors therefore emphasize designing implants with additional fixation points and sufficiently long supporting arms to accommodate larger-than-expected defects without compromising fixation stability. This observation underscores the importance of meticulous virtual surgical planning within a comprehensive CAD/CAM workflow.

Radiotherapy remains an important consideration in this patient population. One case of severe mucositis developed around the transmucosal abutments during adjuvant radiation therapy. Based on this experience, the authors discuss the theoretical advantage of using screw-retained abutments that could remain submerged beneath the mucosa during irradiation and be uncovered only after treatment completion. However, this concept is presented as a technical consideration rather than a validated clinical protocol, since it was not formally investigated within this study.

Overall, the findings suggest that customized additively manufactured subperiosteal implants can achieve encouraging short-term clinical stability in carefully selected patients. Nevertheless, because the study is based on only nine patients with relatively short follow-up, the results should primarily be viewed as evidence of feasibility. Larger prospective studies with long-term evaluation are necessary before the technique can be considered an established reconstructive option.

7. Clinical Applications

The findings suggest that patient-specific 3D-printed subperiosteal implants may become a valuable option for complex maxillary reconstruction requiring simultaneous oncologic surgery and implant-supported rehabilitation. Their integration into a fully digital workflow combining virtual surgical planning, CAD/CAM design, and additive manufacturing enables reconstruction and prosthetic preparation to be performed during a single surgical procedure.

The technique may be particularly relevant for patients presenting with extensive maxillary defects or for individuals in whom conventional bone reconstruction is difficult or contraindicated. The customized implants may also provide stable support for implant-supported prostheses or obturator prostheses in selected cases with persistent oroantral or oronasal communications. However, these potential indications should be interpreted cautiously, as they are based on a limited retrospective case series and require validation through larger prospective clinical studies with extended follow-up.

8. Level of Evidence, Limitations, and Transparency

This publication is a retrospective observational case series, representing a relatively low level of clinical evidence. While this study design cannot establish comparative effectiveness or definitive treatment recommendations, it is appropriate for evaluating the feasibility and early clinical performance of an emerging reconstructive technique. The primary objective was to document initial clinical outcomes rather than to compare customized subperiosteal implants with conventional reconstructive approaches.

The authors explicitly acknowledge several important methodological limitations. First, the study included only nine patients, which substantially limits the statistical strength and generalizability of the findings. Second, the follow-up period ranged from 6 to 20 months, preventing meaningful conclusions regarding long-term implant survival, prosthetic longevity, or biological complications. In addition, the absence of a control group makes it impossible to directly compare this technique with established reconstructive protocols.

The investigators therefore emphasize that their findings should be regarded as preliminary, serving primarily as proof of feasibility. They recommend future prospective studies involving larger patient cohorts and longer follow-up periods to validate these early clinical observations and better define the role of customized subperiosteal implants in maxillary reconstruction.

Regarding research transparency, the authors report no competing interests. The study was funded by the University of Sassari Research Fund (Fondo di Ateneo per la Ricerca 2019–2020). Implant design and manufacturing were performed in collaboration with a biomedical engineering company responsible for producing the customized devices, a methodological aspect described in the study but not identified as a conflict of interest. Ethical approval was obtained from the Institutional Ethics Committee, and informed patient consent was secured before treatment.

9. Key Study Highlights

• Study Design: Retrospective observational case series.
• Level of Evidence: Low to moderate (retrospective case series).
• Study Population: Nine patients undergoing primary maxillary reconstruction following tumor resection.
• Number of Implants: Nine patient-specific 3D-printed titanium subperiosteal implants.
• Follow-up Period: 6–20 months (mean: 13.7 months).
• Primary Outcome: Feasibility, implant stability, peri-implant soft tissue health, surgical complications, and radiographic outcomes.
• Main Finding: All implants remained stable throughout follow-up, with no implant mobility, infection, prosthetic complications, or radiographic evidence of fixation failure.
• Major Complication: One fibula free flap necrosis caused by venous thrombosis, considered unrelated to the implant itself.
• Scientific Conclusion: Patient-specific additively manufactured subperiosteal implants appear to be a feasible option for primary maxillary reconstruction, although larger studies with long-term follow-up are required before definitive conclusions can be drawn.
• Main Limitations: Small sample size, retrospective design, absence of a control group, and relatively short follow-up period.

10. Scientific Impact

This study expands the current body of evidence regarding patient-specific 3D-printed subperiosteal implants by investigating their use during primary maxillary reconstruction rather than delayed rehabilitation. Previous reports cited by the authors primarily addressed secondary reconstruction or treatment of severely atrophic maxillae. Consequently, this publication represents one of the earliest clinical series exploring immediate integration of customized implants into oncologic maxillary reconstruction.

Beyond its clinical findings, the study illustrates the growing role of fully digital workflows in contemporary maxillofacial surgery. The integration of three-dimensional imaging, virtual surgical planning, CAD/CAM engineering, and metal additive manufacturing enables surgeons to combine skeletal fixation and prosthetic support within a single patient-specific device. This evolution reflects an increasingly personalized approach to reconstructive surgery and implant rehabilitation.

Although the present evidence remains preliminary, the study demonstrates that customized subperiosteal implants can be incorporated into complex oncologic reconstruction without compromising short-term implant stability. Rather than validating a new standard of care, these findings provide an important proof of concept that may encourage future prospective clinical trials designed to evaluate long-term outcomes, implant survival, prosthetic performance, and patient-reported quality of life.

11. Editorial Conclusion

This retrospective case series provides encouraging early evidence supporting the feasibility of patient-specific 3D-printed subperiosteal implants for primary maxillary reconstruction following oncologic resection. The reported outcomes demonstrate satisfactory short- to medium-term implant stability, a low rate of implant-related complications, and successful integration into digitally planned reconstructive workflows. Nevertheless, because these observations are based on a small cohort with limited follow-up, they should be interpreted cautiously. Larger prospective studies with long-term evaluation will be essential to determine whether this personalized reconstructive strategy can become a reliable component of implant-based maxillofacial rehabilitation.