This study evaluated the effect of low-level laser therapy (LLLT) on bone regeneration at the midpalatal suture (MPS) after rapid maxillary expansion (RME), using cone beam computed tomography. Fourteen 8-14-year-old patients with transverse maxillary deficiency underwent RME with a Hyrax-type expander activated with one full turn after installation and two half turn daily activations until achieving overcorrection. Patients were randomly assigned to either a control group (RME alone, n = 4) or an experimental group (n = 10) in which RME was followed by 12 LLLT sessions (GaAlAs, p = 70 mW, λ = 780 nm, Ø = 0.04 cm(2)). Two tomographic images of the MPS were obtained-T0, after disjunction and T1, after 4 months. Bone regeneration was evaluated by measuring the optical density (OD) on the tomographic images using InVivo Dental 5.0 software. Data were analyzed by the paired Student's t test (α = 0.05 %). A statistically significant difference between T0 and T1 OD values was observed in the laser-treated group (p = 0.00), but this difference was not significant in the control group (p = 0.20). Intergroup comparison of OD values at T1 revealed higher OD in the laser-treated group (p = 0.05). In conclusion, LLLT had a positive influence on bone regeneration of the midpalatal suture by accelerating the repair process.
Keywords: Bone remodeling; Cone beam computed tomography; Low-level laser therapy; Rapid maxillary expansion.