Efficacy of low-level laser therapy for accelerating tooth movement during orthodontic treatment: a systematic review and meta-analysis.

This review aimed to evaluate the efficacy of low-level laser therapy (LLLT) for accelerating tooth movement during orthodontic treatment. An extensive electronic search was conducted by two reviewers. Randomized controlled trials (RCTs) and quasi-RCTs concerning the efficacy of LLLT for accelerating tooth movement during orthodontic treatment were searched in CENTRAL, Medline, PubMed, Embase, China Biology Medicine Disc (CBM), China National Knowledge Infrastructure (CNKI), and Google Scholar. Six RCTs and three quasi-RCTs, involving 211 patients from six countries, were selected from 173 relevant studies. All nine articles were feasible for the systematic review and meta-analysis, five of which were assessed as moderate risk of bias, while the rest were assessed as high risk of bias. The mean difference and the 95 % confidence interval (95 % CI) of accumulative moved distance of teeth were observed among all the researches. The results showed that the LLLT could accelerate orthodontic tooth movement (OTM) in 7 days (mean difference 0.19, 95 % CI [0.02, 0.37], p = 0.03) and 2 months (mean difference 1.08, 95 % CI [0.16, 2.01], p = 0.02). Moreover, a relatively lower energy density (5 and 8 J/cm(2)) was seemingly more effective than 20 and 25 J/cm(2) and even higher ones.

Efficacy of low-level laser therapy in the management of orthodontic pain: a systematic review and meta-analysis.

This review aimed to identify the efficacy of low-level laser therapy (LLLT) in the management of orthodontic pain. This systematic review and meta-analysis was carried out in accordance with Cochrane Handbook and the PRISMA statement. An extensive literature search for RCTs, quasi-RCTs, and CCTs was performed through CENTRAL, PubMed, Embase, Medline, CNKI, and CBM up to October 2011. Risk of bias assessment was performed via referring to the Cochrane tool for risk of bias assessment. Meta-analysis was implemented using Review Manager 5.1. As a result, four RCTs, two quasi-RCTs, and two CCTs were selected from 152 relevant studies, including 641 patients from six countries. The meta-analysis demonstrated that 24% risk of incidence of pain was reduced by LLLT (RR = 0.76, 95% CI range 0.63-0.92, P = 0.006). In addition, compared to the control group, LLLT brought forward "the most painful day" (MD = -0.42, 95% CI range -0.74- -0.10, P = 0.009). Furthermore, the LLLT group also implied a trend of earlier end of pain compared with the control group (MD = -1.37, 95% CI range -3.37-0.64, P = 0.18) and the pseudo-laser group (MD = -1.04, 95% CI range -4.22-2.15, P = 0.52). However, because of the methodological shortcomings and risk of bias of included trials, LLLT was proved with limited evidence in delaying pain onset and reducing pain intensity. In the future, larger and better-designed RCTs will be required to provide clearer recommendations.

Callus formation enhanced by BMP-7 ex vivo gene therapy during distraction osteogenesis in rats.

This study was designed to observe the effects of bone morphogenetic protein-7 (BMP-7) ex vivo gene therapy on callus formation during rat mandibular distraction osteogenesis (DO). Fifty-four Sprague-Dawley rats underwent osteodistraction of the right mandible and were then randomly divided into three groups. Immediately after distraction, autologous bone marrow mesenchymal stem cells (MSCs) transfected with BMP-7, MSCs untransfected with BMP-7, and physiological saline were injected into the distraction gaps of the mandibles in groups A, B, and C, respectively. Nine animals from each group were euthanized at 2 and 6 weeks after completion of distraction. The distracted mandibles were removed and processed for radiographic, histological, immunohistochemical, and scanning electron microscopic examinations as well as Ca/P ratio analysis. Group A animals showed greater bone formation and earlier mineralization in the distracted callus when compared with group B. Similarly increased callus formation was found in group B than group C. Positive immunostaining of BMP-7 was observed in the distracted callus in all groups. However, BMP-7 expression was much stronger in group A compared with groups B and C. The results of this study suggest that BMP-7-mediated ex vivo gene transfer based on MSCs may accelerate callus formation in distraction osteogenesis and facilitate consolidation. Local gene therapy may ultimately be an alternative or supplemental approach to DO enhancement, especially for patients whose osteogenic potentials are compromised by diseases such as osteoporosis, severe trauma, and postoncologic irradiation.