title: Microbiologic changes in subgingival plaque before and during the early period of orthodontic treatment.
abstract: OBJECTIVE
  To evaluate changes in subgingival microbiota before and during the leveling and alignment orthodontic stage using the polymerase chain reaction (PCR) method.
  
  
  METHODS
  Thirty orthodontic patients (17 females and 13 males; aged 16.7 ± 6.5 y) were included in this study. Subgingival microbial samples were taken from the disto-buccal gingival crevice of the left upper central incisors, the left lower central incisors, the mesio-buccal gingival crevice of the left upper first molars, and the left lower first molars, at four different times: at baseline, before placement of orthodontic appliances (T1), and 1 week (T2), 3 months (T3), and 6 months after placement of orthodontic appliances (T4). DNA was extracted from the samples, and the 16S rRNA-based PCR detection method was used to determine the prevalence of Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Campylobactor rectus, Eikenella corrodens, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola, which are considered as putative periodontopathogens.
  
  
  RESULTS
  The frequency of T forsythia, C rectus, and P nigrescens significantly increased after placement of orthodontic appliances. For the other species, the frequency tended to increase but no statistically significant difference was noted. The frequency of the change, representing microorganisms not existing at T1 but newly developing at T2, T3, and T4, was higher at the molars than at the incisors.
  
  
  CONCLUSIONS
  The placement of orthodontic appliances affects the subgingival microbial composition even during the early period of orthodontic treatment, increasing the prevalence of periodontopathogens, especially in the molar region.
authors.affiliation: Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, South Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Kim
authors.forename: Dong-Soon
authors.initials: DS
authors.lastname: Choi
authors.forename: Insan
authors.initials: I
authors.lastname: Jang
authors.forename: Bong-Kuen
authors.initials: BK
authors.lastname: Cha
authors.forename: Paul-Georg
authors.initials: PG
authors.lastname: Jost-Brinkmann
authors.forename: Jae-Seok
authors.initials: JS
authors.lastname: Song
mesh_terms: D000293:Adolescent; D016976:Aggregatibacter actinomycetemcomitans / Q000302:isolation & purification; D058491:Bacterial Load; D001439:Bacteroides / Q000302:isolation & purification; D044883:Campylobacter rectus / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D003773:Dental Plaque / Q000382:microbiology*; D016124:Eikenella corrodens / Q000302:isolation & purification; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000145:classification*; D006801:Humans; D007180:Incisor / Q000382:microbiology; D008297:Male; D008963:Molar / Q000382:microbiology; D009967:Orthodontic Appliances / Q000382:microbiology; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D018713:Prevotella intermedia / Q000302:isolation & purification; D045242:Prevotella nigrescens / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D048373:Treponema denticola / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S