Orthodontic force and extracorporeal shock wave therapy: Assessment of orthodontic tooth movement and bone morphometry in a rat model

Objective: The objective was to investigate the effect of extracorporeal shock wave therapy (ESWT) on the magnitude of orthodontic tooth movement, in a rat model, based on a previously established treatment protocol. Design: In conjunction with orthodontic force commencement, rats underwent ESWT. The amount of tooth movement along with different microarchitectural parameters were measured after three weeks by means of microcomputed tomography. In addition, the percentage of cells expressing vascular endothelial growth factor, the number of tartrate-resistant acid phosphatase (TRAP) positive cells/area and blood vessel density were evaluated both for the pressure and tension sides. Results: The addition of ESWT to the orthodontic force after three weeks more than doubled the average tooth movement. The addition of ESWT on the pressure side induced a significant decrease in volumetric bone mineral density. Blood vessel density and the number of TRAP positive cells were higher after the application of ESWT. Conclusion: The induction of ESWT during orthodontic tooth movement in a rat model increases the rate of tooth movement by accelerating bone resorption on the pressure side and possibly enhances bone formation on the tension side.