Currently, there is growing attention toward understanding the biological and microbiological alterations associated with orthodontic therapy. Advances in knowledge of the oral microbiome increasingly enable the identification and characterization of microbial profiles linked to both oral and systemic conditions. This study aims to explore the associations between orthodontic appliances and changes in the composition and quantity of oral microbiota, particularly regarding factors that may predispose patients to caries, periodontal disease, and other infections affecting overall oral and systemic health. Compared with individuals without orthodontic devices, patients undergoing orthodontic treatment exhibited notable qualitative and quantitative differences in both supra- and subgingival plaque throughout the treatment period. Specific elements of fixed appliances, including bonded molar brackets, ceramic brackets, and elastomeric ligatures, were associated with elevated risks of dental caries and periodontal issues. The prevalence of Candida species remains unclear, and research on viral and protozoal components of the oral microbiome in orthodontic patients is limited, warranting further investigation. The findings of this work may assist clinicians in optimizing follow-up schedules and motivating patients to control plaque accumulation, ultimately reducing the incidence of plaque-related oral diseases.
