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2026 Vol.30, Issue 3 Preview Page

Clinical or Case Report

Severe Implant-Related Maxillofacial Infection Associated with Citrobacter Species: A Case Report
Hyunmi Jo1
,
Mikyung Gong2
,
Jun-Young Kim34*
1Clinical Assistant Professor, Department of Oral & Maxillofacial Surgery, Yonsei University Wonju College of Medicine, Wonju, Korea
2Clinical Instructor, Department of Oral & Maxillofacial Surgery, Yonsei University College of Dentistry, Seoul, Korea
3Associate Professor, Department of Oral & Maxillofacial Surgery, Yonsei University College of Dentistry, Seoul, Korea
4Research Scientist, Institute for Innovation in Digital Healthcare, Yonsei University, Seoul, Korea
*Corresponding Author
†These authors contributed equally to this work.
30 September 2026. pp. 205-212
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Abstract

This is a rare case of severe dental implant-related maxillofacial infection associated with Citrobacter spp. in the right submandibular space. An 85-year-old woman presented with facial swelling, extensive skin necrosis, and purulent discharge from a cutaneous fistula in the right mandibular region. Contrast-enhanced computed tomography revealed fenestration of the right mandibular lingual plate by a dental implant, with diffuse swelling and abscess formation in the submandibular space. The patient was immediately admitted, and empirical intravenous antibiotic therapy with cefoxitin (1 g t.i.d.) and metronidazole (500 mg t.i.d.) was initiated. Pus cultures identified Streptococcus constellatus, Citrobacter braakii, and C. freundii. Based on antimicrobial susceptibility testing, the antibiotic therapy was adjusted to ampicillin/sulbactam (3 g q.i.d.) and ciprofloxacin (400 mg b.i.d.). The patient improved significantly and was discharged on hospital day 7. The dental implant was removed under local anesthesia 3 d later and the infection continued to improve. This case highlights the rare involvement of Citrobacter spp. in implant-related maxillofacial infections and importance of microbial identification and susceptibility-guided antibiotic therapy in managing severe polymicrobial infections.

Keywords
Antimicrobial susceptibility
Citrobacter
Dental implant
Peri-implant infection
Submandibular space abscess
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Information
  • Publisher :The Korean Academy of Oral & Maxillofacial Implantology
  • Publisher(Ko) :대한구강악안면임플란트학회
  • Journal Title :Journal of implantology and applied sciences
  • Journal Title(Ko) :대한구강악안면임플란트학회지
  • Volume : 30
  • No :3
  • Pages :205-212
  • Received Date : 2026-07-26
  • Revised Date : 2026-09-15
  • Accepted Date : 2026-09-16
  • DOI :https://doi.org/10.32542/implantology.2026017
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