title: Photobiomodulation accelerates orthodontic alignment in the early phase of treatment.
abstract: BACKGROUND
  Numerous strategies have been proposed to decrease the treatment time a patient requires in orthodontic treatment. Recently, a number of device-accelerated therapies have emerged in orthodontics. Photobiomodulation is an emerging area of science that has clinical applications in a number of human biological processes. The aim of this study was to determine if photobiomodulation reduces the treatment time in the alignment phase of orthodontic treatment.
  
  
  METHODS
  This multicenter clinical trial was performed on 90 subjects (73 test subjects and 17 controls), and Little's Index of Irregularity (LII) was used as a measure of the rate of change of tooth movement. Subjects requiring orthodontic treatment were recruited into the study, and the LII was measured at regular time intervals. Test subjects used a device which produced near-infrared light with a continuous 850-nm wavelength. The surface of the cheek was irradiated with a power density of 60 mW/cm2 for 20 or 30 min/day or 60 min/week to achieve total energy densities of 72, 108, or 216 J/cm2, respectively. All subjects were fitted with traditional orthodontic brackets and wires. The wire sequences for each site were standardized to an initial round alignment wire (014 NiTi or 016 NiTi) and then advanced through a progression of stiffer arch wires unit alignment occurred (LII<1 mm).
  
  
  RESULTS
  The mean LII scores at the start of the clinical trial for the test and control groups were 6.35 and 5.04 mm, respectively. Multi-level mixed effect regression analysis was performed on the data, and the mean rate of change in LII was 0.49 and 1.12 mm/week for the control and test groups, respectively.
  
  
  CONCLUSIONS
  Photobiomodulation produced clinically significant changes in the rates of tooth movement as compared to the control group during the alignment phase of orthodontic treatment.
authors: Department of Orthodontics, School of Dentistry, University of Alabama, Birmingham, AL 35233, USA. ckau@uab.edu.
authors: Chung How
authors: CH
authors: Kau
authors: Alpdogan
authors: A
authors: Kantarci
authors: Tim
authors: T
authors: Shaughnessy
authors: Amornpong
authors: A
authors: Vachiramon
authors: Peerapong
authors: P
authors: Santiwong
authors: Alvaro
authors: A
authors: de la Fuente
authors: Darya
authors: D
authors: Skrenes
authors: Dennis
authors: D
authors: Ma
authors: Peter
authors: P
authors: Brawn
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007259:Infrared Rays / Q000627:therapeutic use; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D010789:Phototherapy / Q000379:methods*; D011829:Radiation Dosage; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult