Background: The use of the intraoral distractors has been associated with different drawbacks resulting in their untimely removal and treatment relapse.
Objective: This study aimed to estimate the therapeutic effect of diode laser on bone cells in the mandibular distraction osteogenesis (DO).
Materials and Methods: 28 adult rabbits were equally divided into 4 groups. The left and right mandibular corticotomy was performed with distractor fixation. The left side served as the non-laser subgroup whereas the right side served as the laser subgroup. After 3 days of latency and 7 days of the distractor activation (0.5mm/12h) to reach 7mm expansion limit, the distractor was removed after 2 weeks of consolidation. The laser sides were treated with 10 J/cm2 per point every 48 hours during consolidation. The animals of the four groups were sacrificed 1, 2, 3 and 4weeks after the consolidation commencement respectively. The dissected hemimandibles were processed for histological and immunohistochemical (using anti-osteonectin (ONN) and anti-osteopontin (OPN) antibodies) examination.
Results: Histologically, the apparently increased new bone amount was higher in the laser subgroup at all time periods. Immunohistochemically, the ONN and OPN expressions were significantly increased in bone matrix and cells of groupIII>groupII>groupI but with insignificant difference between groups I and II for ONN. GroupIV revealed a decreased ONN and OPN reactivity which was significant compared to the laser side groupIII in particular, but still with increased ONN and OPN positivity compared to most subgroups of groups I and II with variation in the significance levels.
Conclusion: Diode low-level laser application exhibited superior cellular differentiation, ossification and amount of bone regeneration in mandibular DO over the unescorted conventional DO procedure thus reducing the consolidation time. Therefore, LLL can fasten tissue regeneration via the bio-stimulatory impact of laser on cells.