Influence of a Magnetic Field and Laser Therapy on the Quality of Mandibular Bone During Distraction Osteogenesis in Rabbits

Purpose: This study evaluated the use of low-level laser therapy (LLLT) and exposure to a magnetic field (MF) during distraction osteogenesis. Materials and Methods: The sample consisted of 18 rabbits divided into 3 groups of 6 animals each: control, MF exposure (briefly, magnetized gold-coated washers were placed next to the distractor device), and LLLT exposure (830 nm applied every 48 hours over 4 points [dose, 5 J/cm(2)] during the consolidation period). The same distraction osteogenesis protocol was used in all 3 groups (0.5 mm every 12 hours for 1 week). Results: Quantitative microscopic analysis of sections stained with hematoxylin and eosin showed a statistically significant difference in the amount of newly formed bone in the MF group compared with the LLLT group (P = .006). The number of cells with more than 3 argyrophilic nucleolar organizer regions also was significantly different between the LLLT and control groups (P = .038). Conclusion: Distraction osteogenesis effectively promoted bone lengthening. The LLLT group exhibited a larger amount of newly formed bone and a larger number of osteoblasts in the cell division phase, but the difference was not statistically relevant compared with the control group. (C) 2016 American Association of Oral and Maxillofacial Surgeons