Does the oral microbiota evolve differently during orthodontic treatment with vestibular multi-attachment fixed appliances versus aligners? A systematic review of the literature

Abstract

Oral microbiota of patients is impacted during orthodontic treatment. The objective of this systematic review was to observe the evolution of oral microbiota (primary objective) and periodontal health (secondary objective) during orthodontic treatment, and to compare these changes during treatment with vestibular fixed appliances and aligners. In accordance with PRISMA guidelines, an electronic search was performed in four databases until January 2022, completed by a manual search, including all prospective controlled studies, randomized or not, on the subject. Two independent authors were involved in the selection of studies, and a third author was consulted in case of disagreement. The Cochrane Collaboration's tool and ROBINS-I tool was used to assess the risk-of-bias in randomized and non-randomized trials, respectively. Finally, the risk of bias graphs were made with the robvis visualization tool. Out of the 994 results obtained from these searches, 11 eligible articles were included (4 randomized clinical trials and 7 non-randomized controlled studies) with varying levels of bias. Results suggested that patients treated with aligner appliances have more favorable microbial flora and less biofilm mass during their treatment compared with those treated with fixed appliances. In addition, inflammatory marker cytokines and periodontal indices were higher in fixed orthodontic treatment compared to aligners treatment. Considering the limitations of this systematic review of the literature, the results suggested that aligners have a more favorable impact on the oral microbiota and periodontium compared to vestibular fixed appliances. PROSPERO registration: CRD42022276486.