title: Effect of low-frequency mechanical vibration on orthodontic tooth movement.
abstract: BACKGROUND
  Our objective was to investigate the effect of low-frequency mechanical vibration (LFMV) on the rate of tooth movement, bone volume fraction, tissue density, and the integrity of the periodontal ligament. Our null hypothesis was that there would be no difference in the amount of tooth movement between different values of LFMV.
  
  
  METHODS
  Sixty-four male CD1 mice, 12 weeks old, were used for orthodontic tooth movement. The mice were randomly divided into 2 groups: control groups (baseline; no spring + 5 Hz; no spring + 10 Hz; and no spring + 20 Hz) and experimental groups (spring + no vibration; spring + 5 Hz; spring + 10 Hz; and spring + 20 Hz). In the experimental groups, the first molars were moved mesially for 2 weeks using nickel-titanium coil springs delivering 10 g of force. In the control and experimental groups, LFMV was applied at 5, 10, or 20 Hz. Microfocus x-ray computed tomography analysis was used for tooth movement measurements, bone volume fraction, and tissue density. Additionally, immunostaining for sclerostin, tartrate-resistant acid phosphatase (TRAP) staining, and picrosirius red staining were used on the histologic sections. Simple descriptive statistics were used to summarize the data. Kruskal-Wallis tests were used to compare the outcomes across treatment groups.
  
  
  RESULTS
  LFMV did not increase the rate of orthodontic tooth movement. Microfocus x-ray computed tomography analysis showed increases in bone volume fractions and tissue densities with applications of LFMV. Sclerostin expression was decreased with 10 and 20 Hz vibrations in both the control and experimental groups. Additionally, the picrosirius staining showed that LFMV helped in maintaining the thickness and integrity of collagen fibers in the periodontal ligament.
  
  
  CONCLUSIONS
  There was no significant increase in tooth movement by applying LFMV when compared with the control groups (spring + no vibration).
authors: Assistant professor, Division of Orthodontics, Health Center, University of Connecticut, Farmington, Conn. Electronic address: yadav_sumit17@yahoo.com.
authors: Sumit
authors: S
authors: Yadav
authors: Visiting assistant professor, Health Center, University of Connecticut, Farmington, Conn.
authors: Thomas
authors: T
authors: Dobie
authors: Resident, Division of Orthodontics, Health Center, University of Connecticut, Farmington, Conn.
authors: Amir
authors: A
authors: Assefnia
authors: Resident, Division of Orthodontics, Health Center, University of Connecticut, Farmington, Conn.
authors: Himank
authors: H
authors: Gupta
authors: Research associate, Health Center, University of Connecticut, Farmington, Conn.
authors: Zana
authors: Z
authors: Kalajzic
authors: Professor and head, Division of Orthodontics, Health Center, University of Connecticut, Farmington, Conn.
authors: Ravindra
authors: R
authors: Nanda
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D048868:Adaptor Proteins, Signal Transducing; D000539:Alveolar Process / Q000166:cytology / Q000502:physiology; D000818:Animals; D001391:Azo Compounds; D001696:Biomechanical Phenomena; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors; D016723:Bone Remodeling / Q000502:physiology; D003094:Collagen / Q000032:analysis; D004396:Coloring Agents; D003722:Dental Alloys / Q000737:chemistry; D006023:Glycoproteins / Q000032:analysis; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D051379:Mice; D008963:Molar / Q000502:physiology*; D009532:Nickel / Q000737:chemistry; D009969:Orthodontic Wires; D010010:Osteoclasts / Q000166:cytology; D010513:Periodontal Ligament / Q000502:physiology; D011897:Random Allocation; D000071681:Tartrate-Resistant Acid Phosphatase; D014025:Titanium / Q000737:chemistry; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D014732:Vibration; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D001391:Azo Compounds; D019485:Bone Morphogenetic Proteins; D004396:Coloring Agents; D003722:Dental Alloys; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; C486030:Sost protein, mouse; C040654:titanium nickelide; C009798:C.I. direct red 80; D009532:Nickel; D003094:Collagen; D014025:Titanium; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase