Date of Award

Spring 2010

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Dentistry

First Advisor

Dawei Liu

Second Advisor

T. Gerard Bradley

Third Advisor

Jose Bosio, Jeff Toth

Abstract

Purpose: The purpose of this study was to use micro CT to evaluate the effect of mechanical vibration on orthodontic tooth movement (OTM) in mice. Materials and Methods: Thirty-six mice (C57BL/6, 20 weeks old, male) were randomly divided into four groups: spring/vibration (SV), spring only (S), vibration only (V), control (C). A nickel-titanium (NiTi) spring was fabricated and inserted bilaterally between the maxillary 1st molars, delivering an initial force of 20 grams. From day 0, mechanical vibration (4Hz frequency, 20micron displacement, 5 min per session duration) was applied to the left maxillary 1st molar every three days for 3 weeks (21 days). Following the completion of the experiment, animals were euthanized and the harvested maxillae were evaluated by micro CT analysis. Various variables (5 on coronal view and 6 on axial view) were defined and measured on the micro CT images. One way ANOVA with Dunnett's post hoc was employed to determine the statistical significance of differences between the vibrated and non-vibrated sides, and among the treatment groups (p value set at 0.05). Results: Significant orthodontic tooth movement was observed in the spring and spring/vibration groups versus the control and vibration alone groups (p<0.05). Differences between spring and spring/vibration groups as targeted were not identified statistically however an overall tendency was observed demonstrating that the vibrated side had increased OTM when compared to its contra-lateral non-vibrated side in the spring/vibration group. Conclusion: Micro CT can be used to evaluate orthodontic tooth movement in mice, which however requires improvement to further study the effect of mechanical vibration on orthodontic tooth movement.