Comparison of Two Subperiosteal Implant Designs in Total Maxillectomy: A Three-Dimensional Finite Element Analysis

Ilgın Ari, Gülin Acar

Full text link: https://pubmed.ncbi.nlm.nih.gov/40246199/

Comparison of Two Subperiosteal Implant Designs in Total Maxillectomy: A Three-Dimensional Finite Element Analysis

1. Scientific Reference

• Study Title: Comparison of Two Subperiosteal Implant Designs in Total Maxillectomy: A Three-Dimensional Finite Element Analysis
• Authors: Ilgın Ari, Gülin Acar
• Journal: Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology
• Publication Year: 2025
• DOI: 10.1016/j.jormas.2025.102377

2. Scientific Background

Rehabilitation following total maxillectomy remains one of the greatest challenges in implant dentistry and maxillofacial reconstruction. Extensive maxillary bone loss severely limits the use of conventional endosseous implants, prompting the development of patient-specific subperiosteal implant systems designed to utilize the remaining facial skeletal structures. Advances in digital planning, CAD/CAM manufacturing, and three-dimensional imaging have significantly improved the precision of these customized devices, yet their biomechanical optimization continues to be an active area of research.

An essential aspect of implant design is the ability to distribute functional loads efficiently across the residual bone while minimizing mechanical stress on implant components. Finite element analysis (FEA) has become an established preclinical tool for evaluating these biomechanical behaviors before clinical implementation. Within this context, the present study investigates whether a modified subperiosteal implant incorporating a diagonal zygomatic support offers biomechanical advantages over a conventional design in patients undergoing total maxillectomy reconstruction.

3. Study Objective

The purpose of this study was to compare the biomechanical performance of two different subperiosteal implant designs intended for reconstruction after total maxillectomy. Using three-dimensional finite element analysis, the investigators evaluated how each implant configuration influenced stress distribution within the surrounding bone as well as mechanical loading of the implant components under simulated masticatory forces.

4. Methodology

This investigation was a preclinical computational study based on three-dimensional finite element analysis (FEA).

A digital three-dimensional model representing a completely resected Class II maxilla was generated. Two reconstruction scenarios were analyzed:

• SC-1: a conventional subperiosteal implant design.
• SC-2: a modified design incorporating a diagonal supporting bar in the zygomatic region.

To simulate functional mastication, the models were subjected to two loading conditions:

• a 450 N vertical load, and
• a 93 N oblique load.

The primary biomechanical outcomes included maximum and minimum principal stresses within the bone and von Mises stress values affecting the implant components, particularly the fixation screws.

The abstract does not provide information regarding patient involvement, implant numbers, or clinical follow-up, as the study was entirely simulation-based.

5. Main Findings

The biomechanical simulations demonstrated measurable differences between the two implant configurations depending on the direction of loading.

Under vertical loading conditions, the modified SC-2 design generated higher maximum principal stress values within the zygomaticomaxillary region than the conventional implant design. Similar findings were observed under oblique loading, where SC-2 exhibited greater stress levels in both evaluated anatomical regions compared with SC-1.

Mechanical behavior of the fixation screws varied according to the loading direction. During vertical loading, von Mises stresses were lower in the screws of the conventional design, whereas under oblique loading, lower stress values were recorded in the modified SC-2 configuration.

Overall, the numerical analysis did not demonstrate a meaningful biomechanical advantage for the diagonal-bar implant design over the conventional subperiosteal implant. Based on these observations, the authors suggest that future design improvements should explore additional anatomical support areas rather than relying solely on the diagonal reinforcement.

6. Clinical Analysis

Although this study does not provide clinical outcome data, it offers valuable biomechanical insights into the design of customized subperiosteal implants for complex maxillary reconstruction. The findings illustrate that increasing the structural complexity of an implant does not necessarily translate into more favorable stress distribution throughout the supporting skeletal structures.

From an implantology perspective, these results emphasize the importance of evidence-based implant design rather than assuming that additional framework components will automatically improve biomechanical performance. Customized subperiosteal implants are increasingly manufactured using digital workflows and CAD/CAM technologies, making optimization of their structural geometry particularly relevant for future clinical applications.

However, the conclusions should be interpreted within the limitations inherent to finite element analysis. Computational models reproduce controlled mechanical conditions but cannot fully account for biological variables such as bone remodeling, individual anatomical variability, tissue healing, implant integration, or long-term functional adaptation. Consequently, the observed stress patterns should be regarded as biomechanical indicators rather than direct predictors of clinical success.

The authors therefore appropriately recommend further investigations aimed at refining conventional implant designs through alternative anatomical support strategies instead of adopting the modified diagonal-bar configuration as a superior solution.

7. Clinical Applications

The findings may contribute to the future development of customized implant rehabilitation strategies in situations involving extensive maxillary defects, particularly:

• patient-specific subperiosteal implant design;
• digital treatment planning for maxillofacial reconstruction;
• CAD/CAM-guided implant fabrication;
• biomechanical optimization of implant-supported prosthetic rehabilitation after total maxillectomy.

The available data do not allow conclusions regarding implant survival, biological complications, prosthetic outcomes, or long-term clinical performance.

8. Level of Evidence, Limitations, and Transparency

This publication represents a preclinical finite element analysis, corresponding to a computational biomechanical study rather than a clinical investigation. Consequently, its level of evidence is lower than prospective clinical studies or randomized controlled trials.

The findings provide useful information regarding mechanical stress distribution but should not be interpreted as direct evidence of clinical effectiveness. The principal limitation derives from the inherent nature of numerical simulation, which cannot replicate the full range of biological and functional conditions encountered in patients.

No information regarding funding sources, conflicts of interest, or industry affiliations is provided in the abstract or the materials supplied.

9. Key Takeaways

• Study type: Preclinical three-dimensional finite element analysis
• Level of evidence: Computational biomechanical study
• Population or models analyzed: One digital maxillary model comparing two implant designs
• Number of patients or implants: Not specified in the available information
• Follow-up: Not applicable
• Primary outcome: Bone stress distribution and von Mises stress within implant components
• Main finding: The diagonal-bar design (SC-2) did not demonstrate a significant biomechanical advantage over the conventional subperiosteal implant design.
• Scientific conclusion: Future implant development should investigate alternative anatomical support strategies to improve conventional subperiosteal designs.
• Limitations: Simulation-based investigation without clinical validation.

10. Scientific Impact

This study contributes to the growing body of research dedicated to patient-specific subperiosteal implants for complex maxillofacial rehabilitation. Rather than supporting increasingly complex implant geometries, the findings suggest that biomechanical performance depends on thoughtful structural optimization rather than the addition of individual design features such as a diagonal zygomatic bar.

The work also reinforces the value of finite element analysis as a preclinical design tool capable of identifying potential mechanical limitations before clinical application. Although the study does not establish clinical superiority of either design, it provides useful guidance for engineers, implant designers, and maxillofacial surgeons involved in the development of next-generation customized implant systems. Future clinical investigations will be required to determine whether these biomechanical observations translate into meaningful improvements in patient outcomes.

11. Editorial Conclusion

This finite element study provides a careful biomechanical comparison of two customized subperiosteal implant designs intended for reconstruction following total maxillectomy. Within the limitations of computational modeling, the modified design incorporating a diagonal zygomatic bar did not demonstrate a clear mechanical advantage over the conventional configuration. These findings support continued refinement of customized implant designs while highlighting the need for clinical validation before biomechanical observations can be translated into routine surgical practice.