Custom subperiosteal implants used to rehabilitate the atrophic edentulous maxilla following multiple failures of both conventional as well as zygomatic implants: a case report

Lara Wirth, Kevin Spencer, Larry Benge, George Dimitroulis.

Full text link: https://pubmed.ncbi.nlm.nih.gov/41079132/ 

Custom subperiosteal implants used to rehabilitate the atrophic edentulous maxilla following multiple failures of both conventional as well as zygomatic implants: a case report

1. Scientific Reference

• Study title: Custom subperiosteal implants used to rehabilitate the atrophic edentulous maxilla following multiple failures of both conventional as well as zygomatic implants: a case report
• Authors: Lara Wirth, Kevin Spencer, Larry Benge, George Dimitroulis.
• Journal: Journal of Surgical Case Reports
• Publication year: 2025.
• DOI: 10.1093/jscr/rjaf319.

2. Scientific Background

Rehabilitating patients with severe maxillary atrophy remains one of the greatest challenges in contemporary implant dentistry. Treatment becomes even more demanding in individuals with cleft lip and palate, who often undergo numerous surgical procedures throughout their lifetime and may ultimately experience extensive tooth loss, compromised bone volume, and soft tissue deficiencies. Conventional endosseous dental implants typically require sufficient alveolar bone or prior bone augmentation, while zygomatic implants have become an established alternative for severely resorbed maxillae.

Recent advances in digital workflows, computer-aided design/computer-aided manufacturing (CAD/CAM), and additive manufacturing have introduced a renewed interest in patient-specific subperiosteal implants. Rather than relying on residual bone height for implant placement, these custom-made titanium frameworks are designed to conform precisely to the patient’s remaining maxillary anatomy. This case report explores the application of this technology in a highly complex clinical scenario where both conventional and zygomatic implant therapies had previously failed, leaving very limited reconstructive options.

3. Study Objective

The primary objective of this case report was to describe the rehabilitation of a 72-year-old patient with a cleft palate, severe maxillary atrophy, and complete edentulism following the failure of both conventional endosseous and zygomatic implants. The authors aimed to demonstrate the clinical feasibility of using CAD/CAM-designed, patient-specific titanium subperiosteal implants to support implant-retained prosthetic rehabilitation when further conventional implant placement was no longer possible because of extensive hard and soft tissue deficiencies.

4. Methodology

This publication is a single-patient case report describing the treatment of a 72-year-old man with an unrepaired unilateral cleft palate and a highly complex surgical history. Over approximately ten years, the patient underwent multiple implant procedures, including placement of conventional dental implants and zygomatic implants. These treatments ultimately failed because of complications such as infection, chronic sinusitis, peri-implant bone loss, and lack of osseointegration.

Given the severe maxillary atrophy and extensive loss of both hard and soft tissues, additional conventional implant therapy was considered impossible. The treatment plan therefore consisted of two patient-specific titanium subperiosteal implants designed from computed tomography data using a CAD/CAM workflow. The implants were manufactured to precisely match the patient’s residual maxillary anatomy and secured with multiple self-tapping screws. Two previously retained tuberosity implants were preserved and incorporated into the prosthetic design. Digital impressions were obtained three months after surgery, and the definitive implant-supported obturator prosthesis was delivered six months postoperatively. The report does not describe predefined quantitative outcome measures beyond the clinical outcome observed.

5. Main Findings

This case demonstrates that successful prosthetic rehabilitation was achieved despite an exceptionally challenging clinical history characterized by repeated failures of both conventional and zygomatic implant therapy. Following placement of the two custom subperiosteal implants in combination with the two remaining tuberosity implants, the surgical procedure and postoperative healing were reported to be uneventful. Three months after surgery, digital impressions were obtained for fabrication of the metal framework, and the definitive prosthesis was delivered six months after implant placement.

At the time of publication, the patient had been successfully rehabilitated with an implant-supported prosthesis stabilized by the combination of custom subperiosteal and existing endosseous implants. The authors reported no postoperative complications during the observation period described in the article. They conclude that patient-specific subperiosteal implants provided a reconstructive solution in a situation where additional conventional implants, zygomatic implants, and further bone reconstruction procedures were no longer considered feasible because of the severe maxillary deformity and limited remaining tissues. However, as this publication reports only a single clinical case, no conclusions can be drawn regarding long-term clinical performance or overall treatment predictability.

6. Clinical Analysis

This report highlights the potential role of patient-specific subperiosteal implants in one of the most demanding scenarios encountered in implant dentistry: rehabilitation after the failure of both conventional and zygomatic implant therapy. In this patient, treatment limitations extended beyond severe bone loss to include substantial soft tissue deficiencies and the cumulative effects of multiple previous surgical interventions. Rather than relying on additional bone augmentation or alternative implant trajectories, the customized implant framework was designed to utilize the patient’s remaining anatomical support, illustrating how digital planning and CAD/CAM manufacturing may expand treatment possibilities in highly selected cases.

The discussion also places these findings within the broader context of emerging evidence on digitally manufactured subperiosteal implants. According to the literature reviewed by the authors, custom-designed frameworks may distribute functional loads over a larger bone surface and can potentially facilitate immediate functional loading while avoiding more extensive reconstructive surgery. These observations, however, originate from previously published studies referenced in the discussion and should not be interpreted as outcomes demonstrated by this individual case.

From a clinical perspective, the principal contribution of this report is the demonstration that customized subperiosteal implants may provide a salvage option for patients who have exhausted conventional reconstructive alternatives. Nevertheless, the evidence remains limited by the inherent nature of a single case report. The authors themselves acknowledge that robust long-term clinical data are still lacking and emphasize the need for larger clinical investigations to establish implant longevity, complication rates, and the appropriate indications for this treatment approach.

7. Clinical Applications

The findings presented in this report relate to a highly specific clinical indication and should not be generalized to all edentulous patients. Nevertheless, they suggest that patient-specific subperiosteal implants may represent a valuable treatment alternative for individuals with severe maxillary atrophy, extensive hard and soft tissue deficiencies, or multiple failures of conventional endosseous and zygomatic implants, where further implant placement is no longer feasible.

This treatment approach relies on a fully digital workflow integrating three-dimensional imaging, CAD/CAM planning, and additive manufacturing to fabricate a titanium implant precisely adapted to the patient’s residual anatomy. In the present case, this customized solution provided sufficient support for an implant-retained obturator prosthesis after conventional reconstructive options had been exhausted. Although the clinical outcome was favorable, these findings originate from a single patient and should therefore be interpreted as evidence of technical feasibility rather than confirmation of broad clinical effectiveness.

8. Level of Evidence, Limitations, and Transparency

This publication is a single case report, representing a low level of clinical evidence. While it provides a detailed description of an innovative treatment strategy for an exceptionally complex clinical situation, it cannot establish treatment efficacy, predictability, or superiority over alternative rehabilitation techniques.

The authors acknowledge that long-term evidence regarding the durability and effectiveness of custom CAD/CAM subperiosteal implants remains limited. They emphasize the need for additional clinical studies with larger patient cohorts and extended follow-up periods before definitive conclusions can be drawn regarding the long-term role of these implants in maxillary rehabilitation.

From a transparency perspective, the authors disclose a relevant conflict of interest. George Dimitroulis is the Founder and Clinical Director of MAXONIQ, the company that developed and manufactured the subperiosteal implants used in this case. The publication also states that informed patient consent was obtained and that no external funding supported the study. These declarations should be considered when interpreting the reported findings.

9. Key Study Highlights

• Study design: Single-patient case report.
• Level of evidence: Low.
• Study population: One patient with an unrepaired cleft palate, severe maxillary atrophy, and complete edentulism following multiple implant failures.
• Number of patients: 1.
• Implants placed: Two custom titanium subperiosteal implants used in combination with two pre-existing tuberosity implants.
• Follow-up reported: Definitive prosthesis delivered six months after surgery; no long-term follow-up data were available.
• Primary outcome evaluated: Feasibility of implant rehabilitation after failure of conventional and zygomatic implant therapy.
• Main finding: Successful prosthetic rehabilitation was achieved without postoperative complications during the observation period described.
• Scientific conclusion: Patient-specific subperiosteal implants may provide an alternative reconstructive option in carefully selected patients when conventional implant approaches are no longer feasible.
• Main limitations: Single clinical case, absence of a control group, limited follow-up, and lack of long-term outcome data.

10. Scientific Impact

This case report contributes to the growing body of literature exploring patient-specific subperiosteal implants for the management of severe maxillary atrophy. Its originality lies in documenting a clinical situation in which both conventional endosseous implants and zygomatic implants had previously failed, leaving virtually no conventional reconstructive options. Within this highly challenging context, the successful use of custom CAD/CAM-manufactured titanium subperiosteal implants demonstrates the potential of digitally planned, anatomy-driven implant designs to restore function in carefully selected patients.

Beyond the individual clinical outcome, the study illustrates how digital planning, three-dimensional imaging, and additive manufacturing continue to expand the possibilities of implant rehabilitation in cases previously considered untreatable. At the same time, the authors appropriately recognize that current evidence remains limited, particularly regarding long-term implant survival, biological complications, and treatment predictability. Consequently, this publication should be viewed as a proof of concept rather than definitive clinical validation. It supports continued research into customized subperiosteal implant systems while highlighting the importance of prospective clinical studies with larger cohorts and extended follow-up.

11. Editorial Conclusion

This case report demonstrates the potential value of custom CAD/CAM subperiosteal implants as a salvage treatment option for exceptionally complex cases of maxillary rehabilitation in which conventional and zygomatic implant therapies have failed. Through a fully personalized digital workflow and patient-specific titanium implant design, functional prosthetic rehabilitation was achieved despite severe anatomical limitations. However, given the inherently low level of evidence associated with a single case report and the absence of long-term clinical data, these findings should be interpreted cautiously. Larger prospective studies will be necessary to determine the long-term safety, durability, and clinical indications of this emerging treatment modality.