Orthodontic tooth movement under extracorporeal shock wave therapy: the characteristics of the inflammatory reaction--a preliminary study

Extracorporeal generated shock waves were introduced in medical therapy approximately 20 years ago in order to disintegrate kidney stones. Over the last 10 years, extracorporeal generated shock waves have been used to stimulate healing processes. No report to date has examined its influence on different inflammation mediators and growth factors in the periodontium. Orthodontic tooth movement is a model including the induction of an aseptic inflammation and its resolution. We conducted a preliminary study to investigate the periodontium cytokine concentration fluctuations after induction of orthodontic force with and without extracorporeal shock wave therapy (ESWT) in a rat model. An orthodontic appliance was fabricated and applied between the molars and the incisors of rats. The rats were treated by a single episode of 1000 shock waves and gingival crevicular fluid was collected for 3 days. The concentration of typical acute phase cytokines was evaluated by ELISA assay. Of the three tested cytokines, IL-1beta was the only detected cytokine along the study timeframe. IL-1beta concentration rose in both the treated and non treated shockwave groups on the first day, however it was statistically significantly higher in the treated group on day 2. On day 3, IL-1beta concentrations in both groups decreased and reached a lower level in the treated group, revealing a statistically significant difference than its level on the previous day. The application of ESWT during orthodontic force induction enhances IL-1beta production as part of mechanical forces transduction triggering a biologic response, which may contribute to accelerated periodontal remodeling and therefore foreshortening the orthodontic tooth movement period.