Background Orthodontic treatment is widely used to treat malocclusion. However, the influence of treatment on the oral microbiome remains unclear. In this study, we investigated salivary microbial changes in patients undergoing orthodontic treatment. Methods In total, 19 orthodontic patients participated in this study. Saliva samples were collected at the following three timepoints: before (T0) and 3 months (T1) and 6 months (T2) after the placement of orthodontic appliances. High-throughput sequencing was performed based on the 16S rRNA gene V4 region. Results The phyla of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Fusobacteria were predominant. Observed Species, Chao1 and ACE, which represent α diversity, were significantly decreased at T1 and subsequently increased at T2. In addition, the β diversity at T1 based on the Bray-Curtis distances differed from T0 and T2. The relative abundances of Prevotella, Porphyromonas and Peptostreptococcus were decreased with treatment, whereas those of Capnocytophaga and Neisseria exhibited the opposite results. In total, 385 of 410 operational taxonomic units were shared at T0, T1 and T2. The co-occurrence networks with hub nodes at T1 were the most complex. Conclusion Orthodontic treatment temporarily affected the saliva microbial community. This dynamic alteration in species did not induce deterioration in oral health. Oral hygiene instructions were necessary and should be emphasized during each visit. Further studies with longer observation periods and more participants are required.

中文翻译：

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正畸治疗前 6 个月唾液微生物变化

背景正畸治疗被广泛用于治疗咬合不正。然而，治疗对口腔微生物组的影响仍不清楚。在这项研究中，我们调查了接受正畸治疗的患者唾液微生物的变化。方法共有19名正畸患者参加了本研究。在以下三个时间点收集唾液样本：放置正畸矫治器之前（T0）和3个月（T1）和6个月（T2）。基于16S rRNA基因V4区域进行高通量测序。结果变形菌门、拟杆菌门、厚壁菌门、放线菌门和梭杆菌门占优势。观察到的物种，Chao1 和 ACE，代表 α 多样性，在 T1 显着减少，随后在 T2 增加。此外，基于 Bray-Curtis 距离的 T1 的 β 多样性不同于 T0 和 T2。Prevotella、Porphyromonas 和 Peptostreptococcus 的相对丰度随着处理而降低，而 Capnocytophaga 和 Neisseria 的相对丰度显示相反的结果。总共有 410 个操作分类单元中的 385 个在 T0、T1 和 T2 共享。在 T1 具有中心节点的共现网络是最复杂的。结论 正畸治疗会暂时影响唾液微生物群落。物种的这种动态变化不会导致口腔健康恶化。口腔卫生说明是必要的，每次就诊时都应强调。需要更长观察期和更多参与者的进一步研究。处理后卟啉单胞菌和消化链球菌减少，而二氧化碳嗜血杆菌和奈瑟菌的结果相反。总共有 410 个操作分类单元中的 385 个在 T0、T1 和 T2 共享。在 T1 具有中心节点的共现网络是最复杂的。结论 正畸治疗会暂时影响唾液微生物群落。物种的这种动态变化不会导致口腔健康恶化。口腔卫生说明是必要的，每次就诊时都应强调。需要更长观察期和更多参与者的进一步研究。处理后卟啉单胞菌和消化链球菌减少，而二氧化碳嗜血杆菌和奈瑟菌的结果相反。总共有 410 个操作分类单元中的 385 个在 T0、T1 和 T2 共享。在 T1 具有中心节点的共现网络是最复杂的。结论 正畸治疗会暂时影响唾液微生物群落。物种的这种动态变化不会导致口腔健康恶化。口腔卫生说明是必要的，每次就诊时都应强调。需要更长观察期和更多参与者的进一步研究。在 T1 具有中心节点的共现网络是最复杂的。结论 正畸治疗会暂时影响唾液微生物群落。物种的这种动态变化不会导致口腔健康恶化。口腔卫生说明是必要的，每次就诊时都应强调。需要更长观察期和更多参与者的进一步研究。在 T1 具有中心节点的共现网络是最复杂的。结论 正畸治疗会暂时影响唾液微生物群落。物种的这种动态变化不会导致口腔健康恶化。口腔卫生说明是必要的，每次就诊时都应强调。需要更长观察期和更多参与者的进一步研究。