Method: This multi-center clinical trial was performed on 90 subjects (73 test subjects and 17 controls) and the Little’s Index of Irregularity (LII) was used as a measure of the rate of change of tooth movement. Subjects requiring orthodontic treatment were recruited into the study and the LII was measured at regular time intervals. Test control subjects used a research device, which produced near infrared light with a continuous 850 nm wavelength near infrared radiation. The surface of the cheek was irradiated with a power density of 60 mW/cm2 for 20, 30 minutes per day and 60 minutes per week to achieve total energy densities of 72, 108, and 216 J/cm2respectively for each treatment session.
Result: The mean LII scores at the start of the clinical trial for the test and control groups were 6.35mm and 5.04mm, respectively. Multi-level mixed effect regression analysis was performed on the data and the mean rate of change in LII was 0.49 mm per week and 1.12 mm per week for control and test groups, respectively (p<0.05).
Conclusion: Photobiomodulation produced clinically significant changes to the rates of tooth movement as compared to a control group during the alignment phase of orthodontic treatment.