Effect of High Frequency Mechanical Vibration on Orthodontic Tooth Movement

Objectives: To investigate the effect of high-frequency mechanical vibration accelerated the tooth movementin rats.
Methods: The sixteen 8 week old male wistar rats were divided into six groups: control (n=3), sham (n=3), 5 gram force (F5), 10 gram force(F10), 5 gram force + vibration (FV5), and 10 gram force + vibration (FV10)group. This study was performed as a split-mouth design, one side was the orthodontic force group (F5 or F10) and the contralateral side was combination with vibration (FV5 & FV10). A sham group received no activation and the contralateral side of sham group was the controlgroup.The maxillary first molars were moved mesially using closed coil spring. Additional vibrational stimulation (125 Hz) was applied to the first molars using an electric toothbrush for 15 minutes a day for 14 days. The animals were sacrificed under anesthesia and each maxilla was dissected. Micro-focus computed tomography was used for tooth movement measurements. The sections were stained with tartrate-resistant acid phosphatase staining (TRAP) and the amount of root resorption was measured in hematoxylin and eosin sections.
Results: The amount of tooth movement of F10 groupwas greater than F5 groupafter 14 days but not significantly while the amount of teeth movement of FV 10 and FV5 group were greater than F10 and F5 significantly, P <.05. The number of osteoclasts in the orthodontic forces group (F5 & F10) was significantly increased more than the combination with high frequency vibrationgroup on day 7(P <.05). Additionally,there was no significant difference in the amount of root resorption between the 6 groups.
Conclusions: Orthodontic force combined with high frequency vibration (125 Hz) accelerated the amount of tooth movement.