Cone-beam computed tomography assessment of bone quality and quantity following laser-assisted orthodontic tooth movement: A randomized controlled trial

Abstract

Low-level laser therapy (LLLT) has been widely implemented in the acceleration of orthodontic tooth movement (OTM). However, the impact of LLLT on the alveolar bone changes accompanying OTM has not been comprehensively addressed in a clinical trial. Hence, the objective of this investigation was to perform a three-dimensional (3D) assessment of the impact of LLLT on the changes in bone quality (bone density), and quantity (bone thickness and volume) during the canine retraction stage of orthodontic treatment. Twenty patients requiring maxillary first premolars’ extraction followed by canine retraction were recruited for this split-mouth study. Before the commencement of canine retraction, the maxillary arch in each of the enrolled subjects was randomly split into an “experimental” side, and a “control” side. In the experimental group, LLLT was performed on days 0, 3, 7, 14, and then every two weeks until the completion of the research duration (12 weeks). The employed diode laser was of 980 nanometers (nm) wavelength and a dosage of 8 joules per square centimeter (J/cm2), in a continuous mode. Canine distalization was accomplished using nickel-titanium closed-coil springs, with a force of 150 grams (g). Pre-retraction and post-retraction cone-beam computed tomography was performed to assess bone quality and quantity, in terms of alveolar bone density, thickness, and volume. A statistically significant reduction in bone density and volume was found following canine retraction (P < 0.05) with and without LLLT application. For the total bone thickness, a statistically significant decrease was observed at both the coronal and mid-root levels of the maxillary canine (P < 0.05), whereas an insignificant change was reported at the apical level (P > 0.05) in both the studied groups. Furthermore, insignificant differences were documented in all the measured outcomes between the experimental and the control groups (P > 0.05). With the employed parameters in the present study, LLLT does not positively influence the changes in neither bone quality (bone density) , nor bone quantity (bone thickness and volume) accompanying OTM. Moreover, a significant reduction in bone density, in bone thickness (coronal and mid-root levels), as well as in bone volume accompanies canine distalization in both groups.