UCSF

Full fixed appliance orthodontic treatment commonly called braces increases plaque accumulation and risk of periodontal disease. Previously, microbial analysis was limited to cultivable bacteria using Sanger sequencing often assaying for candidate species. Considering the enormity of the oral microbiome and the restrictions of prior studies, we have utilized 16S rRNA next-generation sequencing (NGS) to catalog global changes in subgingival microbiomes at distinct mandibular tooth sites in subjects before and after orthodontic treatment over 12 weeks. Subjects with braces showed significant increases and maintenance in microbial richness 6 and 12 weeks after treatment. The increase in richness was accompanied by a decrease in Streptococcus, the most abundant genera found across all samples. An increase in shared OTUs was also observed at 6-12 weeks demonstrating the tendency of subgingival microbiomes to become more uniform with orthodontic treatment. We confirmed the presence of candidate bacteria associated with periodontal diseases, and also identified numerous novel species in subgingival microbiomes that showed significant changes with orthodontic intervention. We have generated for the first time, global profiles of subgingival microbiomes during orthodontic treatment and demonstrate that traditional orthodontic treatment may predispose subjects to periodontal diseases such as gingivitis regardless of oral hygiene.