Phototherapy is unable to exert beneficial effects on orthodontic tooth movement in rat molars

Abstract

Objectives: To investigate the effects of irradiation lasers and light-emitting diode (LED) light on root resorption in rat molars during orthodontic tooth movement (OTM). Materials and Methods: Twenty-one 12-week-old Wistar male rats were divided into three groups: OTM only (control [CG]), OTM and LED irradiation (DG), and OTM and low laser irradiation therapy (LG). The distance between the first and second molars was used to evaluate the amount of tooth movement. The mesial surfaces of the distopalatal roots were analyzed by scanning electron microscopy, and the area of the resorption was calculated. Results: Statistical analysis showed a decreased amount of tooth movement in the exposed DG or LG compared with CG, which was statistically significant (P = .031 and P = .004, respectively). However, when the DG and LG groups were compared, no statistically significant differences were found (P = .504). The root resorption areas were similar between CG and DG. However, statistically significant differences were found between LG and CG (P = .014) and LG and DG (P = .038). Conclusions: Phototherapy did not enhance tooth movement, while infrared laser irradiation did increase root resorption.

Research progress of animal models on orthodontic tooth movement

“…The OTM animal models are the most common type of orthodontic-related animal models, which can study OTM phenomena 5 , promotion or intervention mechanisms [8][9][10][11][12][13] , mechanisms of orthodontic adverse reactions [14][15][16] , and the impact mechanism of orthodontic treatment and other diseases. 17,18 The OTM animal models also provide important in vivo experimental evidence functional evaluation after periodontal defect reconstruction 19 .…”