An 18-Year Descriptive Retrospective Review of Subperiosteal Implants for Patients with Severely Atrophied Edentulous Mandibles

Dorsey J. Moore, Paul A. Hansen

Full text link: https://pubmed.ncbi.nlm.nih.gov/15295323/

An 18-Year Descriptive Retrospective Review of Subperiosteal Implants for Patients with Severely Atrophied Edentulous Mandibles

1. Scientific Reference

• Study Title: An 18-Year Descriptive Retrospective Review of Subperiosteal Implants for Patients with Severely Atrophied Edentulous Mandibles
• Authors: Dorsey J. Moore, Paul A. Hansen
• Journal: The Journal of Prosthetic Dentistry
• Year of Publication: 2004
• DOI: 10.1016/j.prosdent.2004.05.018

2. Scientific Background

Managing completely edentulous patients with severe mandibular atrophy remains one of the most demanding situations in implant dentistry and prosthetic rehabilitation. Advanced bone resorption often compromises the retention and stability of conventional mandibular dentures, limiting oral function and patient comfort. Before the widespread adoption of contemporary bone augmentation procedures and modern endosseous implant protocols, subperiosteal implants represented an alternative treatment option for patients with insufficient bone volume for conventional implant placement.

This retrospective study revisits the long-term clinical performance of mandibular subperiosteal implants placed over nearly two decades within a university-based prosthodontic program. By documenting their clinical outcomes after extended periods of function, the investigation provides valuable historical insight into an implant design that played an important role in the management of severe mandibular atrophy before current reconstructive techniques became widely available.

3. Study Objective

The primary objective of this retrospective investigation was to evaluate the long-term survival and clinical performance of mandibular subperiosteal implants placed between 1982 and 2000 at the University of Missouri–Kansas City School of Dentistry. The authors also assessed implant stability, the presence of biological complications, patient comfort, and overall satisfaction with implant-supported mandibular overdentures.

4. Methodology

This investigation was designed as a retrospective observational study involving 40 completely edentulous patients with severe mandibular atrophy. One mandibular subperiosteal implant was placed in each patient between 1982 and 2000.

At the 2000 follow-up evaluation, 39 patients were clinically examined, while one patient had died. Clinical assessment included manual testing of framework stability, observation for implant mobility, evaluation of inflammatory signs, and inspection for intraoral exposure of the implant framework. Patients were also questioned regarding pain, discomfort, satisfaction, and whether the implant-supported prosthesis had met their treatment expectations. The reported mean implant service time was 8 years, with some implants functioning for more than 10 years.

5. Main Findings

Among the patients available for follow-up, the overwhelming majority of implants remained clinically functional. Thirty-eight implants demonstrated neither detectable mobility nor clinical signs of inflammation during examination. One patient, who had diabetes, presented localized inflammation surrounding one implant strut.

No intraoral exposure of the implant framework was observed in any patient. Every patient examined continued to wear the implant-supported prosthesis at the time of evaluation. Furthermore, all participants reported a high level of satisfaction with their treatment and denied experiencing pain or prosthesis-related discomfort.

Overall, the findings indicate that the mandibular subperiosteal implants included in this cohort maintained satisfactory clinical function over extended periods of service.

6. Clinical Analysis

This study offers valuable long-term observational data on a treatment approach that has become considerably less common with the evolution of contemporary implant dentistry. The reported findings suggest that mandibular subperiosteal implants were capable of providing durable prosthetic support in a carefully selected group of patients presenting with severe mandibular atrophy.

The absence of implant mobility in nearly all reviewed cases, together with the limited occurrence of inflammatory complications, supports the clinical stability of these restorations within the study population. Equally important is the consistently high level of patient satisfaction reported after several years of functional loading, indicating that the treatment successfully addressed patients’ prosthetic needs over time.

Nevertheless, these observations should be interpreted cautiously. The investigation is a retrospective case series without a control group and does not compare subperiosteal implants with alternative treatment modalities currently available, such as endosseous implants combined with bone augmentation procedures. Moreover, the available abstract does not provide sufficient information to identify factors associated with long-term success or failure. Consequently, the study should be viewed primarily as a historical clinical experience rather than definitive evidence supporting one implant strategy over another.

7. Clinical Applications

The findings are specifically applicable to completely edentulous patients with severe mandibular atrophy who received mandibular subperiosteal implants supporting overdentures.

From a contemporary perspective, this study contributes to the understanding of historical implant rehabilitation strategies for patients with limited mandibular bone volume. It may also assist clinicians involved in the long-term maintenance or evaluation of patients who continue to function with existing subperiosteal implant frameworks. However, the data provided do not support direct comparisons with modern implant rehabilitation techniques or current treatment protocols.

8. Level of Evidence, Limitations, and Transparency

This publication represents a retrospective observational study, corresponding to a moderate-to-low level of clinical evidence compared with prospective controlled clinical trials.

Its retrospective design and the absence of a comparison group limit the strength of the conclusions. In addition, the study reflects the experience of a single academic institution, which may restrict the generalizability of its findings.

The abstract does not report any funding sources or declarations of conflicts of interest. Likewise, no detailed discussion of methodological limitations is provided within the available summary beyond those inherent to the study design.

9. Key Study Highlights

• Study design: Retrospective descriptive observational study.
• Level of evidence: Retrospective observational case series.
• Study population: 40 completely edentulous patients with severe mandibular atrophy.
• Number of implants: 40 mandibular subperiosteal implants.
• Follow-up: Implant placement between 1982 and 2000; mean implant service time of 8 years.
• Primary outcome: Clinical survival and functional performance of mandibular subperiosteal implants.
• Principal finding: Thirty-eight implants remained clinically stable without detectable inflammation or mobility.
• Patient-reported outcome: All reviewed patients reported high satisfaction and no pain or discomfort.
• Scientific conclusion: Most implants remained functional throughout the observation period.
• Main limitations: Retrospective design, single-center cohort, and absence of a control group.

10. Scientific Impact

This study provides one of the longer clinical observations available for mandibular subperiosteal implants in patients with advanced mandibular atrophy. Rather than introducing a new treatment concept, it documents the long-term clinical behavior of an implant design that historically addressed severe anatomical limitations before modern reconstructive procedures became commonplace.

Its contribution lies in preserving clinical evidence regarding the durability and functional outcomes of subperiosteal implant therapy within a defined patient population. Although contemporary implant dentistry has evolved substantially, these data remain relevant for understanding the historical development of implant rehabilitation and for clinicians responsible for monitoring patients who continue to function with legacy subperiosteal implant systems. The study should therefore be considered an informative historical contribution rather than evidence supporting current treatment recommendations.

11. Editorial Conclusion

This retrospective review demonstrates that mandibular subperiosteal implants remained clinically functional in the vast majority of patients evaluated after several years of service, with high reported patient satisfaction and minimal observed complications. While these findings highlight the historical effectiveness of this treatment approach in selected patients with severe mandibular atrophy, the retrospective design and limited level of evidence require cautious interpretation. The study primarily enriches the historical literature on implant rehabilitation rather than defining contemporary standards of care.