Effect of low-level laser therapy after rapid maxillary expansion on proliferation and differentiation of osteoblastic cells

Abstract

The aim of this study was to investigate the osteoblastic activity of cells derived from the midpalatal suture upon treatment with low-level laser therapy (LLLT) after rapid maxillary expansion (RME). A total of 30 rats were divided into two groups: experimental I (15 rats with RME without LLLT) and experimental II (15 rats with RME + LLLT). The rats were euthanized at 24 h, 48 h, and 7 days after RME, when the osteoblastic cells derived from the rats' midpalatal suture were explanted. These cells were cultured for periods up to 17 days, and then in vitro osteogenesis parameters and gene expression markers were evaluated. The cellular doubling time in the proliferative stage (3-7 days) was decreased in cultured cells harvested from the midpalatal suture at 24 and 48 h after RME + LLLT, as indicated by the increased growth of the cells in a culture. Alkaline phosphatase activity at days 7 and 14 of the culture was increased by LLLT in cells explanted from the midpalatal suture at 24 and 48 h and 7 days after RME. The mineralization at day 17 was increased by LLLT after RME in all periods. Results from the real-time PCR demonstrated that cells harvested from the LLLT after RME group showed higher levels of ALP, Runx2, osteocalcin, type I collagen, and bone sialoprotein mRNA than control cells. More pronounced effects on ALP activity, mineralization, and gene expression of bone markers were observed at 48 h after RME and LLLT. These results indicate that the LLLT applied after RME is able to increase the proliferation and the expression of an osteoblastic phenotype in cells derived from the midpalatal suture.

The effect of laser therapy on the expression of osteocalcin and osteopontin after tooth extraction in rats treated with zoledronate and dexamethasone

“…Other in vitro [26][27][28] and in vivo [29][30][31] studies showed similar effects of laser irradiation on osteocalcin production.…”

Effects of low-level laser therapy on the expression of osteogenic genes during the initial stages of bone healing in rats: a microarray analysis

“…A recent study demonstrated that LLLT increased the osteoblastic proliferation and gene expression of osteoblastic markers, such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx-2), osteocalcin (OC), type I collagen (COL I), and bone sialoprotein (BSP) in osteoblasts cells derived from the midpalatal suture [19]. In addition, Wu et al, [14] used the microarray analysis to evaluate the gene expression of laser irradiated mesenquimal stem cells (MSCs) and demonstrated that various genes involved in cell proliferation, apoptosis, and the cell cycle were upregulated.…”

RANK/RANKL/OPG Expression in Rapid Maxillary Expansion

“…The immediate expansion of midpalatal suture was performed by inserting a stainless steel circular ring (1.5 mm thick and 0.5 mm diameter; Dental Morelli Ltda®, Sorocaba, SP, Brazil), between the maxillary incisors ( Fig. 1), as previously described (11). This appliance was kept in position with a light cured adhesive (3M® Unitek, Monrovia, CA, USA).…”