Histological evaluation of the effect of low-level laser on distraction osteogenesis in rabbit mandibles.

OBJECTIVES This study evaluated the action of low level laser therapy (LLLT) on the percentage of newly formed bone in rabbit mandibles that underwent distraction osteogenesis (DO). STUDY DESIGN Ten rabbits underwent bone lengthening according to the following protocol: Latency - 3 days; Activation - 7 days 0.7 mm/d; and Consolidation - 10 days. The control group was composed of 4 rabbits. The experimental group, composed of 6 rabbits, received infrared GaAlAs LLLT (wavelength=830 nm, P=40 mW) according to the following protocol: point dose of 10 J/cm(2) applied directly on the bone site that underwent DO during bone consolidation at 48-hour intervals. RESULTS The percentage of newly formed bone was greater in the LLLT group (57.89%) than in the control group (46.75%) (p=0.006). CONCLUSION The results suggest that LLLT had a positive effect on the percentage of newly formed bone. Better-quality bone sites may allow early removal of the osteogenic distractors, thus shortening total treatment time.