Management of Severe Atrophy with a Customised Subperiosteal Implant in the Posterior Mandible

Luminita Nedelcu, Ioan Sirbu, Valentin Daniel Sirbu, Andreea Mihaela Custura, Adelin Radu, Vladimir Nastasie

Full text link: https://pubmed.ncbi.nlm.nih.gov/39974462/

Management of Severe Atrophy with a Customised Subperiosteal Implant in the Posterior Mandible

1. Scientific Reference

• Study Title: Management of Severe Atrophy with a Customised Subperiosteal Implant in the Posterior Mandible
• Authors: Luminita Nedelcu, Ioan Sirbu, Valentin Daniel Sirbu, Andreea Mihaela Custura, Adelin Radu, Vladimir Nastasie
• Journal: Maedica – A Journal of Clinical Medicine
• Year of Publication: 2024
• DOI: https://doi.org/10.26574/maedica.2024.19.4.861

2. Scientific Background

Severe posterior mandibular atrophy remains one of the most demanding clinical situations in implant dentistry and oral surgery. As alveolar bone resorption progresses, the available bone height above the inferior alveolar nerve may become insufficient for conventional endosseous implant placement, making prosthetic rehabilitation considerably more challenging. Clinicians are often required to balance surgical complexity, anatomical limitations, and long-term treatment predictability when selecting the most appropriate therapeutic approach.

Traditional management options—including guided bone regeneration, onlay bone grafting, inferior alveolar nerve lateralisation or transposition, and short implants—can provide solutions in selected cases but may also introduce additional surgical risks or biological limitations. Against this background, advances in digital workflow, cone beam computed tomography (CBCT), CAD/CAM planning, and metal additive manufacturing have renewed interest in customised subperiosteal implants. This case report explores how these technologies can be integrated to manage an advanced mandibular defect in a patient for whom conventional implant strategies were considered less suitable.

3. Study Objective

The purpose of this case report was to describe the clinical management of severe posterior mandibular atrophy using a patient-specific 3D-printed subperiosteal implant. The authors aimed to present the digital planning process, implant design characteristics, surgical workflow, and clinical rationale supporting the selection of this customised solution in a complex anatomical situation.

4. Methodology

This publication is a single-patient case report involving a 76-year-old patient who presented with discomfort, bleeding, prosthetic mobility, and significant posterior mandibular bone loss following failure of a previously placed implant-supported restoration.

After removal of the compromised implant and a healing period, CBCT imaging was performed to evaluate the remaining bone volume and the location of the inferior alveolar nerve. Digital DICOM data were used for virtual implant planning and the fabrication of a customised titanium subperiosteal implant using direct metal laser sintering. The surgical procedure was performed under local anaesthesia with inhalation sedation, followed by immediate placement of a temporary prosthetic restoration.

No long-term follow-up duration or predefined clinical outcome measures are specified in the article.

5. Main Findings

Radiographic assessment demonstrated severe vertical and horizontal bone loss, with limited residual alveolar bone height, making conventional implant placement unsuitable because of the proximity of the inferior alveolar nerve. After reviewing alternative treatment options, the clinicians selected a customised subperiosteal implant designed to fit the patient’s individual mandibular anatomy.

The digital workflow included CBCT-based planning, CAD design, and additive manufacturing of the implant together with a complete surgical kit containing a polymer model, fixation screws, prosthetic components, and bone substitute material. During surgery, the implant was stabilised with osteosynthesis mini-screws and immediately restored with a temporary prosthesis. Postoperative panoramic radiography confirmed the position of the customised implant and prosthetic restoration.

The authors report successful functional rehabilitation in this clinical case. However, implant survival rates, long-term clinical outcomes, and quantitative success measures were not reported.

6. Clinical Analysis

This case illustrates how patient-specific subperiosteal implants may represent a valuable treatment option for selected cases of advanced mandibular atrophy where conventional implant therapy becomes technically difficult or carries increased surgical risk. Rather than relying on bone augmentation or inferior alveolar nerve repositioning, the customised framework was designed to adapt directly to the patient’s residual mandibular anatomy while avoiding critical anatomical structures.

From a clinical perspective, the report also highlights the growing role of digital implantology. The integration of CBCT imaging, computer-aided design, and metal 3D printing enables highly individualised treatment planning and may simplify surgical execution in carefully selected patients.

Nevertheless, the findings should be interpreted with appropriate caution. As a single case report, the study provides descriptive clinical evidence rather than definitive proof of efficacy. It cannot establish superiority over guided bone regeneration, nerve lateralisation, or short implants. Furthermore, the absence of long-term follow-up prevents conclusions regarding implant longevity, biological stability, or prosthetic maintenance. The authors themselves acknowledge that larger comparative studies will be necessary before broader clinical recommendations can be established.

7. Clinical Applications

The findings may be relevant for clinicians managing complex implant rehabilitation in patients presenting with severe posterior mandibular atrophy and insufficient residual bone for conventional implant placement.

The described protocol may be considered in situations where anatomical limitations reduce the feasibility of bone augmentation procedures or inferior alveolar nerve repositioning. The study also demonstrates the potential integration of digital planning, CAD/CAM technologies, CBCT imaging, and additive manufacturing into contemporary implant rehabilitation workflows. Because the evidence is limited to a single clinical case, these applications should be interpreted as illustrative rather than definitive indications.

8. Level of Evidence, Limitations and Transparency

This publication is a case report, representing a low level of clinical evidence.

Its principal methodological limitations include the inclusion of only one patient, the absence of a control group, and the lack of long-term clinical follow-up. The authors explicitly recognise that additional large-scale clinical investigations are required to better evaluate the long-term performance of customised subperiosteal implants.

Regarding transparency, the authors declare no conflicts of interest and no financial support. They also state that written informed consent was obtained from the patient and that the study complied with the ethical principles of the Declaration of Helsinki.

9. Key Study Highlights

• Study type: Case report
• Level of evidence: Low
• Study population: One patient
• Number of patients: 1
• Follow-up duration: Not specified in the available information
• Primary outcome assessed: Rehabilitation of severe posterior mandibular atrophy using a customised subperiosteal implant
• Main finding: Successful placement of a digitally planned patient-specific subperiosteal implant with immediate temporary prosthetic rehabilitation
• Scientific conclusion: Customised 3D-printed subperiosteal implants may represent a treatment alternative in carefully selected cases of severe mandibular atrophy where conventional implant procedures are not feasible or involve increased risk.
• Main limitations: Single-patient case report, no comparative analysis, and no long-term clinical follow-up.

10. Scientific Impact

This publication contributes to the growing body of literature investigating digitally designed patient-specific subperiosteal implants for the rehabilitation of severely atrophic jaws. Rather than providing comparative clinical evidence, it demonstrates the practical implementation of an entirely digital workflow that combines CBCT imaging, virtual treatment planning, CAD/CAM design, and metal additive manufacturing.

Its principal contribution lies in illustrating how modern digital technologies may expand treatment possibilities for patients with challenging anatomical conditions who are poor candidates for conventional implant approaches. At the same time, the authors appropriately recognise that their observations remain preliminary. Future prospective studies involving larger patient cohorts and extended follow-up periods will be necessary to determine long-term implant survival, biological performance, prosthetic outcomes, and the comparative value of this approach relative to established treatment modalities.

11. Editorial Conclusion

This case report presents a carefully documented example of digital implant rehabilitation using a customised 3D-printed subperiosteal implant in a patient with severe posterior mandibular atrophy. The study highlights the potential role of patient-specific implant design in situations where conventional implant therapy is constrained by anatomical limitations. Although the clinical outcome reported is encouraging, the evidence remains limited to a single case, and broader clinical adoption should await confirmation through larger studies with long-term follow-up.