Microbial Diversity in Odontogenic Sinusitis: Next-Generation Sequencing Versus Culture

Background Odontogenic sinusitis (ODS) is a common cause of unilateral infectious maxillary sinusitis but is frequently underdiagnosed due to nonspecific symptoms, subtle dental findings on imaging, and limitations of traditional bacterial cultures—particularly for anaerobic organisms. Next-generation DNA sequencing (NGS) may enhance detection of odontogenic bacteria. Objective This study compared bacterial detection between standard cultures versus NGS in patients with confirmed ODS. Methods Twenty consecutive adults with confirmed ODS were enrolled. Maxillary sinus purulence was collected endoscopically and submitted for routine aerobic and anaerobic bacterial cultures and for NGS-based microbial profiling using 16S rRNA gene sequencing. Detected organisms were categorized by aerotolerance and ODS relationship, and likely nasal colonizers were excluded from analyses. Alpha diversity, beta diversity, and compositional differences between methods were analyzed statistically. Results NGS detected significantly more bacterial species per specimen than culture (mean 4.9 vs 2.7; P = .0015). Compared to cultures, NGS identified more anaerobic bacteria (4.2 vs 0.9; P = .00004) and more ODS-related species (4.4 vs 1.0; P = .0001), while detection of aerobic species was similar between methods. Cultures also often yielded nonspeciated results, whereas NGS consistently revealed polymicrobial communities dominated by oral anaerobes. Microbial composition differed significantly between detection methods. Conclusion In confirmed ODS, NGS detected significantly more anaerobic and ODS-related species than culture from the same specimens. These findings suggest that culture alone may underestimate odontogenic contributions to purulent sinusitis. Future studies should explore he utility of NGS as an adjunctive tool to facilitate diagnosis and treatment in the setting of possible ODS.