Changes in oral microbiota at different stages of active orthodontic treatment

INTRODUCTION: There are no sufficient numbers of studies in the modern literature devoted to investigation of the relationship between the use of fixed orthodontic appliances and changes in the qualitative and quantitative bacterial composition at certain periods of orthodontic treatment. AIM: To identify changes in the qualitative and quantitative composition of the microbiocenosis in the area of installed fixed appliances at different periods of orthodontic treatment. MATERIALS AND METHODS: The study included 40 participants aged 18–44 years. All patients had a history of occlusion pathologies, dento-alveolar anomalies, and needed orthodontic treatment with use of fixed metal bracket systems. Before installing a fixed ligature vestibular metal bracket system (OC Orthodontics, USA), all patients underwent sanitation by a dental therapist, professional oral hygiene (removal of hard and soft dental deposits, tooth polishing), and, if necessary, extraction of wisdom teeth/wisdom tooth germs. The microbiocenosis was assessed in the area of intended placement of braces before orthodontic treatment, in the area of installation of braces in the period of adaptation to the fixed appliance (at 1 month after fixing the appliance) and in the period of active treatment (at 6 months after fixing the appliance). RESULTS: On the initial examination, the frequency of detection of stabilizing microflora was 81.25%, periodontopathogenic microflora — 18.75%. In the period of adaptation, the frequency of detection of stabilizing microflora was 56.25%, the frequency of detection of periodontopathogens increased to 43.75% (p = 0.052). In the phase of active orthodontic treatment, a decrease in the frequency of detection of periodontopathogenic bacteria to 40.96% was observed, and the frequency of detection of stabilizing microflora was 59.04% (p = 0.007). The microbial number before the installation of fixed orthodontic appliances was 105 ± 102 CFU/cm2, in the adaptation phase — 107 ± 102 CFU/cm2, in the period of active treatment — 105 ± 102 CFU/cm2 (p = 0.008). CONCLUSION: In the course of clinical and laboratory study, species and quantitative composition of the oral microbiocenosis was found to have characteristic features at different stages of the orthodontic treatment: before installation of fixed orthodontic appliances, the so-called ‘stabilizing’ microorganisms prevail over representatives of the group of periodontopathogens, in the period of adaptation, the proportion of periodontopathogens increases significantly with a decrease in the proportion of stabilizing microflora, in the phase of active orthodontic treatment their ratio normalizes.