Peri-implantitis as a rare local manifestation of actinomycosis: A case report.

Background: Actinomycosis can be caused by periapical endodontic infection, trauma, or surgical dental procedures. Due to its rare occurrence in a healthy adult patient, persistent actinomycotic osteomyelitis around implants presenting as severe peri-implantitis may be challenging to diagnose.

Methods: A 26-year-old male patient with non-contributory medical history presented to the Oral and Maxillofacial Surgery Clinic in 2018 with pain and edema associated with endodontically treated maxillary premolar teeth with poor prognosis. Oral examination revealed fair oral hygiene, heavily restored dentition, multiple carious teeth, failing restorations, endodontic treatments in both maxillary quadrants, and normal periodontal examination.

Results: Two years following extractions and restoration with implants, the patient returned with a bony sequestrum and fistula in the buccal gingiva adjacent to the implants. The patient reported shifting of implants and slight change in his occlusion. Clinical, radiographic, and endodontic examinations did not demonstrate a clear origin of the fistula. A periodontist was consulted regarding the possibility of peri-implantitis and tracing of the fistula suggested intraosseous involvement of the implant surface. Flap surgery, biopsy, culture, implant removal, and surgical debridement were performed. Histologic examination revealed colonies of actinomycotic organisms and confirmed likely diagnosis of actinomycosis. The patient was placed on a long course of penicillin VK.

Conclusions: The occurrence of actinomycosis in a healthy adult patient is rare. This case report describes persistent actinomycosis presenting as osteomyelitis with severe peri-implantitis in a healthy patient, which may have been associated with a previously existing periapical endodontic infection.