Post-Radiation Microbiological Changes in Osteoradionecrosis: Investigating the Microbial Landscape

Area of Science:

• Oral and Maxillofacial Surgery
• Infectious Diseases
• Oncology

Background:

• Osteoradionecrosis of the jaw (ORNJ) is a serious complication following radiation therapy for head and neck cancers.
• Understanding the microbial landscape and resistance patterns is crucial for effective management.

Purpose of the Study:

• To characterize the microbiologic features of ORNJ.
• To determine antibiotic resistance patterns.
• To identify clinical predictors for reconstructive surgery in ORNJ patients.

Main Methods:

• Retrospective cohort study of 84 adult patients with ORNJ at a single tertiary care center.
• Analysis of clinical and microbiologic data, including culture results and antibiotic susceptibility.
• Logistic regression to identify predictors of autologous reconstruction and specific infections.

Main Results:

• Actinomyces and Streptococcus anginosus were the most common isolates; 22.6% of infections were Gram-negative.
• Gram-negative infections independently predicted autologous reconstruction (OR=14.81) and were associated with fistula presence (OR=6.57).
• High resistance was noted for ampicillin and cefazolin; gentamicin showed high susceptibility. Posterior mandibular involvement and pathologic fracture reduced reconstruction odds.

Conclusions:

• ORNJ presents a polymicrobial, antibiotic-resistant profile.
• Gram-negative infections are key indicators for autologous reconstruction and may signify more severe ORNJ.
• Integrating microbiologic data with anatomic factors is vital for optimal ORNJ treatment strategies.