Virtual Surgical Planning and Customized Subperiosteal Titanium Maxillary Implant (CSTMI) for Three Dimensional Reconstruction and Dental Implants of Maxillary Defects after Oncological Resection: Case Series

Virtual Surgical Planning and Customized Subperiosteal Titanium Maxillary Implant (CSTMI) for Three-Dimensional Reconstruction and Dental Implants of Maxillary Defects after Oncological Resection: Case Series

1. Scientific Reference

• Study title: Virtual Surgical Planning and Customized Subperiosteal Titanium Maxillary Implant (CSTMI) for Three-Dimensional Reconstruction and Dental Implants of Maxillary Defects after Oncological Resection: Case Series
• Authors: Jose Luís Cebrián Carretero, José Luis Del Castillo Pardo de Vera, Néstor Montesdeoca García, Pablo Garrido Martínez, Marta María Pampín Martínez, Iñigo Aragón Niño, Ignacio Navarro Cuéllar, Carlos Navarro Cuéllar
• Scientific journal: Journal of Clinical Medicine
• Year of publication: 2022
• DOI: 10.3390/jcm11154594

2. Scientific Background

The reconstruction of maxillary defects following tumor resection remains one of the major challenges in maxillofacial surgery. These bone defects can lead to significant functional consequences, including impairments in mastication, swallowing, speech, as well as alterations in midfacial projection. Conventional reconstructive techniques are mainly based on microvascular free flaps, prosthetic obturators, or certain specific implant solutions.

However, the simultaneous restoration of bone volume, facial aesthetics, and implant-supported function remains complex. The emergence of virtual surgical planning, 3D printing, and CAD/CAM technologies has opened new perspectives in oral surgery and implant rehabilitation. In this context, customized titanium subperiosteal implants appear to be a potential alternative for patients presenting complex maxillary reconstructions or situations in which conventional approaches are difficult to implement.

3. Study Objective

The objective of the authors was to evaluate the outcomes of three-dimensional reconstruction of segmental maxillary defects using Customized Subperiosteal Titanium Maxillary Implants (CSTMI), designed through Virtual Surgical Planning (VSP), STL models, and CAD/CAM manufacturing.

The study also sought to analyze the feasibility of fixed implant-supported rehabilitation associated with this reconstructive strategy in patients who had undergone oncological resection of the maxilla.

4. Methodology

This was a retrospective case series conducted between 2018 and 2021 in a Spanish hospital center specialized in oral and maxillofacial surgery.

Four patients presenting segmental maxillary defects secondary to maxillary squamous cell carcinoma were included. All had previously undergone reconstructive treatments or presented situations making conventional techniques particularly difficult.

Planning was based on high-resolution computed tomography examinations, three-dimensional digital reconstruction of the residual bone structures, integration of data obtained from intraoral scanning, and the customized design of subperiosteal implants manufactured in titanium using CAD/CAM technology.

Clinical follow-up ranged from 9 months to 3 years and 2 months, with a mean follow-up of 1 year and 8 months. Evaluation criteria included soft tissue healing, implant or prosthetic complications, functional outcomes, and aesthetic assessment reported by the patients.

5. Main Results

All four patients underwent customized maxillary reconstruction followed by fixed implant-supported prosthetic rehabilitation. The maxillary defects ranged from 4.1 cm to 9.6 cm in length, with a mean of 7.1 cm. The vertical reconstruction achieved ranged from 9.3 mm to 17.4 mm, with a mean of 13.17 mm.

Two patients had received radiotherapy before implant placement. Despite the complexity of the treated situations, no signs of infection, soft tissue dehiscence, exposure of the titanium structure, or prosthetic failure were reported during the follow-up period.

Postoperative examinations confirmed the correct adaptation of the implants to the initial digital planning. All patients achieved normal alimentation and speech considered intelligible. The reported aesthetic outcomes were considered satisfactory for all cases studied.

6. Clinical Analysis

This publication illustrates the complete integration of the digital workflow in complex maxillofacial reconstruction. Beyond the simple placement of an implant, the proposed approach aims to simultaneously restore lost bone volume, prosthetic support, and projection of the middle third of the face.

The main clinical interest lies in the possibility of offering a customized solution to patients with extensive reconstructive histories or situations in which conventional techniques have failed. In this series, several patients had already undergone microvascular reconstructions that had not enabled satisfactory functional rehabilitation.

The study also suggests that CAD/CAM technology and virtual surgical planning allow precise adaptation of the implant structure to the residual bony anatomy. This precision could contribute to reducing certain operative difficulties associated with complex reconstructions.

Nevertheless, these observations should be interpreted with caution. The small sample size, the absence of a comparison group, and the relatively limited follow-up do not allow conclusions regarding the superiority of this strategy compared with other reconstructive options such as vascularized flaps or zygomatic implants. The authors themselves emphasize the need for prospective studies and long-term follow-up before any clinical generalization.

7. Clinical Applications

The reported results may be of particular interest in the following situations:

• Maxillary reconstruction after oncological resection.
• Complex implant rehabilitation after failure of previous reconstructive techniques.
• Patients for whom microsurgical reconstruction is difficult or contraindicated.
• Cases requiring simultaneous restoration of prosthetic support and facial volume.
• Use of a digital workflow integrating 3D imaging, virtual planning, and customized CAD/CAM manufacturing.
• Fixed implant-supported rehabilitation in extensive maxillary defects.

These applications should nevertheless be considered within the methodological limitations of this case series.

8. Level of Evidence, Limitations and Transparency

This publication corresponds to a retrospective case series, which represents a limited level of evidence compared with controlled trials or large prospective studies.

The main identifiable limitations are:

• Very small sample size (4 patients);
• Absence of a control group;
• Variable follow-up depending on the patient;
• Absence of direct comparison with other reconstructive methods.

The authors indicate that no external funding was received for this study and declare no conflicts of interest.

The results should therefore be considered preliminary and mainly hypothesis-generating for future research.

9. Key Points of the Study

• Study type: Retrospective case series.
• Level of evidence: Low to moderate (case series).
• Population analyzed: 4 patients with maxillary squamous cell carcinoma.
• Number of patients: 4.
• Number of implants: Between 4 and 6 implants depending on the case.
• Follow-up duration: 9 months to 3 years and 2 months (mean: 1 year and 8 months).
• Primary outcome assessed: Three-dimensional maxillary reconstruction and fixed implant rehabilitation.
• Main result: Functional and aesthetic rehabilitation achieved in all patients without major complications reported during follow-up.
• Scientific conclusion: CSTMI may represent an interesting reconstructive alternative in certain complex maxillary defects.
• Potential limitations: Small sample size, absence of control, need for long-term data.

10. Scientific Impact

This study contributes to the emerging literature dedicated to customized subperiosteal implants manufactured using digital technologies. It concretely illustrates the application of virtual planning and additive manufacturing to maxillofacial reconstruction following oncological surgery.

Its principal contribution lies in demonstrating the clinical feasibility of an approach combining virtual bone reconstruction, customized implant support, and fixed prosthetic rehabilitation in particularly complex situations.

Although the sample size is limited, the observed results support the growing interest in individualized implant devices for the management of maxillary defects. This publication also contributes to the discussion regarding alternatives to conventional reconstructions when these are impossible, insufficient, or have failed.

Finally, it opens the way for more robust prospective studies aimed at clarifying the long-term safety and stability of these devices.

11. Editorial Conclusion

This case series highlights an innovative approach to maxillary reconstruction based on digital technologies and customized titanium subperiosteal implants. The reported results demonstrate favorable functional and aesthetic restoration in four patients presenting complex reconstructive situations. However, the level of evidence remains limited and does not allow definitive conclusions to be established. Prospective studies including a larger number of patients and extended follow-up will be necessary to confirm the role of this strategy in post-oncological implant rehabilitation.