Effect of low-frequency mechanical vibration on orthodontic tooth movement
Volume 148, Issue 3, September 2015, Pages 440–449
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).
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