The effect of low-level laser therapy after rapid maxillary expansion: Micro-CT analysis

This study aimed to evaluate quantitatively the effects of low-level laser therapy (LLLT) on bone healing performed after rapid maxillary expansion (RME) in rats, using micro-computed tomography (micro-CT). Ninety rats were used, randomly distributed into three groups: control (n = 10) (young and adult rats - intact suture), experimental I (n = 40) (young and adult rats with RME without LLLT), and experimental II (n = 40) (young and adult rats with RME + LLLT). Five rats from the groups were euthanized on days 0, 7, 14, and 21 of the experiment and evaluated by microCT analysis. The laser increased the bone formation volume at 7 and 14 days (young rats) and 14 days (adult rats) were statistically significant (p < 0.05), but at the end of the healing (21 days), no statistically significant difference was observed between the laser and no-laser groups (p > 0.05). These findings suggest that LLLT improves bone mineralization during the early healing phases after RME, accelerating the process of bone mineralization during the initial experimental phase, which may have clinical implications in reducing orthodontic treatment duration and improving bone stability.