# Unveiling Periapical Actinomycosis: A Rare Extraradicular Infection

## TL;DR

This paper presents a rare case of periapical actinomycosis, a persistent infection following root canal treatment, successfully treated with apicoectomy.

## Contribution

The paper contributes a clinical case highlighting the diagnosis and treatment of a rare form of actinomycosis in endodontics.

## Key findings

- Periapical actinomycosis can persist despite repeated endodontic treatments.
- Apicoectomy led to successful healing in a case of refractory periapical infection.
- The infection was linked to microbial infiltration through disrupted epithelial continuity.

## Abstract

Actinomycosis is an insidious infection caused by the facultative anaerobic Gram-positive bacterium Actinomyces, commonly found in the oral microbiome. Among its manifestations, periapical actinomycosis stands out as a rare subtype within cervicofacial actinomycosis, speculated to play a role in the persistence of periapical radiolucencies following root canal therapy. Instances of this occurrence often arise from disruptions in epithelial continuity, stemming from surgical procedures, trauma, or prior infections, paving the way for deep microbial infiltration. A 35-year-old woman presented with persistent pain and swelling in the premolar region of her mandible. Examination unveiled a radiolucent lesion in an endodontically treated premolar. The tooth remained symptomatic, and the draining sinus tract persisted despite multiple attempts at disinfecting and re-medicating the canal. A subsequent apicoectomy was performed, yielding promising outcomes, with satisfactory periapical healing observed at both the 6- and 12-month follow-up evaluations.