Evaluation of an Optimized Photobiomodulation Protocol for Accelerated Tooth Movement

Introduction Photobiomodulation (PBM) has a stimulatory effect on periodontal ligament cells involved in bone remodelling and acts synergistically with the applied orthodontic force to accelerate tooth movement and reduce treatment time. This study aims to compare the mean monthly rate of en-masse maxillary extraction-space closure over five months between PBM plus standard orthodontic force and standard force alone. Material and methods A randomised, parallel arm, single-blinded pilot study was carried out with control and PBM groups. For all patients after extraction of first bicuspids, a retraction force of 300g per side was applied using a nickel-titanium (NiTi) closed coil spring. Additionally, in the PBM group, PBM irradiation was done at two buccal and two palatal points along the roots for all six maxillary anterior teeth with an 810 nm diode laser (continuous wave (CW), 200 mW, 0.3cm2, 8 sec per spot, four spots per tooth, 6.4J per tooth) on the first, third, seventh, and 14th day from appliance activation day. Thus, appliance activation was done one time per month and four PBMs were done in a month for five consecutive months. The amount of anterior segment retraction and extraction space closure was measured for every patient on the maxillary right and left side at monthly intervals using a digital caliper (Method I) and 3D software (Method II). The collected data were tabulated and statistically analysed using SPSS 25.0 for Windows (IBM Corp., Armonk, NY, USA) and an independent sample t-test was performed (p