Dynamic Changes in the Oral Microbiome in Adolescents Undergoing Fixed Orthodontic Treatment: A Six-Month Prospective Cohort Study

Objectives This study aimed to comprehensively investigate the dynamic changes of the microbiome in supragingival plaque and saliva among the children and adolescents during the first 6 months of fixed orthodontic treatment.Materials and methods A longitudinal cohort study was conducted among adolescent orthodontic patients who underwent clinical examinations and saliva and plaque sampling at time points: before fixed appliance bonding (T0) and at 1 (T1), 3 (T2), and 6 (T3) months thereafter. Clinical indices included plaque index (PI) and ICDAS-II. Microbial DNA was analyzed by 16S rRNA meta-sequencing based on the abundance of amplicon sequence variants (ASVs). Diversity analysis were employed to explore the dynamic changes in the structure of oral microbiome composition differences and relative abundance at the phylum and genus levels was compared.