Draining Orocutaneous Fistula Associated with a Failing Subperiosteal Implant: A Case Report

Michael R. Markiewicz, Kazuhide Nishiyama, Kaori Yago, Meiko Okada, Soichiro Asanami, Masao Yoshinari, Muneki Hirayama, Joseph E. Margarone III, Sung-Kiang Chuang

Full text link: https://pubmed.ncbi.nlm.nih.gov/18240795/

Draining Orocutaneous Fistula Associated with a Failing Subperiosteal Implant: A Case Report

1. Scientific Reference

• Study Title: Draining Orocutaneous Fistula Associated with a Failing Subperiosteal Implant: A Case Report
• Authors: Michael R. Markiewicz, Kazuhide Nishiyama, Kaori Yago, Meiko Okada, Soichiro Asanami, Masao Yoshinari, Muneki Hirayama, Joseph E. Margarone III, Sung-Kiang Chuang
• Journal: Journal of Oral Implantology
• Year of Publication: 2007
• DOI: 10.1563/1548-1336(2007)33[347]2.0.CO;2

2. Scientific Background

Subperiosteal implants represented one of the earliest treatment options for patients with severe mandibular alveolar ridge atrophy who were not suitable candidates for conventional endosseous dental implants. Before the widespread adoption of bone augmentation techniques and modern implant systems, these custom-made frameworks provided an alternative means of supporting oral rehabilitation in anatomically compromised patients.

Although their use has become uncommon in contemporary implant dentistry, many patients continue to present with legacy subperiosteal implants placed decades ago. Consequently, clinicians may still encounter delayed biological complications associated with these devices. This case report focuses on a chronic infectious complication that resulted in an orocutaneous fistula, highlighting the importance of recognizing historical implant designs during the diagnostic assessment of persistent mandibular infections. The report also raises considerations regarding the long-term behavior of older implant materials and the surgical challenges associated with their removal.

3. Study Objective

The purpose of this study was to document the clinical management of an orocutaneous fistula caused by chronic infection associated with a failing mandibular subperiosteal implant. In addition, the authors sought to characterize the metallic composition of the implant framework to better understand potential material-related factors involved in the implant failure.

4. Methodology

This publication is a single-patient case report, representing a descriptive form of clinical evidence.

The authors describe the diagnosis and treatment of a patient presenting with a chronic orocutaneous fistula linked to a failing mandibular subperiosteal implant. Following implant removal, elemental analysis was performed to determine the composition of the metallic framework. The abstract does not provide detailed information regarding the patient’s demographics, duration of implant function, follow-up period, diagnostic protocol, or additional clinical parameters beyond those summarized in the available text.

5. Main Findings

Clinical evaluation identified a chronic infection originating from a failing subperiosteal implant, which resulted in the development of an orocutaneous fistula.

Elemental analysis demonstrated that the implant framework consisted predominantly of a cobalt-chromium alloy. According to the authors, cobalt-containing alloys were commonly used during the early development of subperiosteal implants but exhibit a higher susceptibility to corrosion than alternative materials. The authors also note that cobalt is no longer used in the fabrication of contemporary subperiosteal implant frameworks.

Management consisted of complete removal of the implant followed by primary closure of both the intraoral wound and the extraoral fistulous tract. Based on the information provided, this treatment resulted in resolution of the patient’s symptoms without reported long-term complications.

6. Clinical Analysis

Rather than proposing a new therapeutic strategy, this case illustrates an uncommon but clinically relevant late complication of historical subperiosteal implant therapy. It emphasizes that chronic mandibular infections and persistent draining fistulas should prompt clinicians to consider the presence of legacy implant systems as a possible underlying cause.

The report also highlights an inherent limitation of subperiosteal implants. While these devices were originally designed to rehabilitate patients with severely resorbed mandibular ridges, the same anatomical circumstances that justified their placement may complicate surgical reconstruction after implant removal. Consequently, management of implant failure extends beyond infection control and may involve complex reconstructive considerations.

The metallurgical findings add an additional dimension to the case by identifying a cobalt-chromium framework. However, the study does not establish a direct causal relationship between alloy composition and implant failure. Because the publication describes only a single patient, its observations should not be generalized to all subperiosteal implants or implant materials.

From a contemporary implantology perspective, the report reinforces the importance of comprehensive clinical assessment in patients carrying older implant systems and demonstrates the value of individualized surgical management when biological complications develop.

7. Clinical Applications

The findings may assist oral surgeons and implant clinicians involved in the management of patients with long-standing subperiosteal implants.

This report supports including historical implant systems in the differential diagnosis of chronic orocutaneous fistulas and persistent mandibular infections. It also illustrates that removal of a failing subperiosteal implant may successfully eliminate the infectious source when clinically indicated.

Although no reconstructive protocol is proposed, the report reminds clinicians that implant removal in severely atrophic mandibles can present significant surgical challenges and should be planned accordingly.

8. Level of Evidence, Limitations, and Transparency

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

Its conclusions are based on a single clinical observation and therefore cannot be considered broadly applicable. No control group, statistical analysis, or comparison with alternative treatment approaches is provided in the available information.

Methodological limitations include the inherent constraints of a single-case design, together with the absence of detailed follow-up data, patient characteristics, and comprehensive clinical documentation within the abstract.

No conflicts of interest or industry affiliations are reported in the information provided.

9. Key Study Highlights

• Study design: 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: Management of an orocutaneous fistula associated with a failing mandibular subperiosteal implant.
• Main finding: Implant removal and primary closure were associated with resolution of the reported clinical symptoms.
• Scientific conclusion: This case demonstrates that chronic infection related to a failing subperiosteal implant may lead to an orocutaneous fistula and that surgical removal of the implant successfully resolved the reported condition.
• Limitations: Single-case design with limited methodological and follow-up information.

10. Scientific Impact

This report contributes to the limited body of literature describing late biological complications associated with historical subperiosteal implants. Although these devices are rarely placed today, clinicians continue to encounter patients who received them decades ago, making knowledge of their potential long-term complications clinically relevant.

The study also provides descriptive information regarding the metallic composition of an explanted subperiosteal implant, offering additional insight into materials historically used in implant manufacturing. While the findings cannot establish cause-and-effect relationships, they add valuable clinical documentation to the literature on implant failure.

Overall, this publication serves as a useful reference for oral surgeons, implantologists, and clinicians managing complications involving legacy implant systems and underscores the importance of individualized diagnosis and treatment planning.

11. Editorial Conclusion

This case report documents a rare but significant complication associated with a failing mandibular subperiosteal implant. Although its scientific strength is limited by its single-patient design, it provides meaningful clinical insight into the diagnosis and management of chronic implant-related infection. The report highlights the importance of recognizing older implant systems in contemporary practice and illustrates that appropriate surgical removal may successfully resolve selected biological complications while acknowledging the technical challenges associated with these historical devices.