Background: Over the last few years there has been significant interest in the microbiological changes associated with orthodontic treatment. The oral microbiota is constantly changing and so is plaque composition, whose characteristics differ based on supragingival or subgingival placement. Oral bacterial plaque is a polymicrobial biofilm consisting of various bacterial complexes, characterized by coaggregation, adhesion and metabolic interactions. Oral dysbiosis can lead to the onset of the most common oral pathologies including dental caries and periodontal disease. It is known that orthodontic treatment may lead to an increased periodontal risk. In addition to periodontal problems, plaque retention due to the presence of orthodontic appliances has been associated with a greater susceptibility to tooth decay due to a qualitative and quantitative change in the oral microbiota. An increased knowledge of the oral microbiota allows a better identification of species associated with oral pathologies. Objectives: to highlight the association between orthodontic treatment and the qualitative and quantitative changes in the oral microbiota which can lead to the onset of pathologies that damage the hard and soft tissues of the oral cavity. Results: Orthodontic appliances influence the oral microbiota causing an increase in S. mutans, Lactobacillus spp. and potentially pathogenic gram-negative bacteria counts. An increase in the bacterial count of Selenomonas sputigena, a flagellated anaerobe that remains trapped in streptococcal exoglucans but builds a honeycomb structure that encapsulates S. mutans, enhancing acidogenesis, was also found. For this reason, in addition to S. Mutans, which remains the main pathogen related to dental caries, S. sputigena can cause extensive lesions of the enamel. Conclusions: Orthodontic treatment significantly influences the oral microbiota, increasing the risk of oral diseases. It is advisable to maintain excellent oral hygiene at home to counteract bacterial plaque maturation and the reproduction of periodontopathogenic and cariogenic species. Key words: dental plaque, oral dysbiosis, orthodontics, periodontitis, caries, Selenomonas sputigena, oral health.


Learning Objectives
After this lecture, you will be able to recognize the association between oral dysbiosis and orthodontic treatment
After this lecture, you will be able to identify the species most involved in oral dysbiosis
After this lecture, you will be able to recognize the role of Selenomonas sputigena in oral dysbiosis