Efficacy of surgical and non-surgical interventions on accelerating orthodontic tooth movement: a systematic review

To conduct a systematic review of randomised controlled trials (RCTs) evaluating the effect of surgical and non-surgical procedures on the acceleration of orthodontic tooth movement (OTM) as an adjunct to orthodontic therapy (OT) in order to estimate the efficacy of these procedures and the benefit of their use in everyday orthodontic practice.

Literature search was performed on PubMed, Scopus, Web of Science and Cochrane databases up to July 2014. Inclusion criteria were: (1) RCTs; (2) orthodontic therapy on permanent dentition; (3) application of adjunctive surgical or non-surgical procedures for accelerating OTM; (4) measurement of tooth movement. The primary outcome measure was tooth movement expressed as cumulative tooth movement (CTM), rate of tooth movement (RTM) or time of tooth movement (TTM). Pain and discomfort, periodontal health, anchorage loss, bone and root changes, and undesired tooth movement were evaluated as secondary outcomes.

Literature research identified 184 studies. After screening of titles, abstracts and full-text studies, fifteen fulfilled the inclusion criteria and were included in this review. Six of the included studies investigated the effect of corticotomies, one of interseptal bone reduction, four of lowlevel laser therapy (LLLT), three of intraoral/extraoral devices releasing extracorporeal shock waves (ESWT), pulsed electromagnetic field (PEMF) and electrical current, respectively, and one of injected substances (relaxin) as an adjunct to OT. Three studies resulted of high methodological quality, six of medium, and six of low quality. Interseptal bone reduction was reported to increase RTM during the first 2 months (P = 0.002) and CTM at 3 months (P = 0.003). Studies investigating corticotomy reported significantly increased RTM (up to 2.3 times) during the first months after intervention, whereas results on TTM and CTM were quite controversial ranging from non-significant to highly significant (up to three times of TTM increase). The heterogeneity between studies investigating corticotomy could not allow for quantitative synthesis of the findings. Out of four studies investigating LLLT three reported positive effect on OT. Due to inadequate statistical analysis of data from original articles, results could not be summarised in meta-analyses. Effects of both electrical current devices and PEMF devices on CTM were reported to be larger on the experimental sides than on the control sides (P < 0.001). The other interventions were reported to be of no statistical or clinical relevance.

In the short term, corticotomy can accelerate OTM whereas long-term effects are questionable, thus no firm conclusions can be made on its efficacy and benefit of clinical use. There is some evidence that LLLT can slightly accelerate OTM but this result is not significant and the effect estimated is not clinically relevant. The very limited research-based evidence suggesting beneficial effects of interseptal bone reduction, electrical current and PEMF on OTM does not allow for solid conclusions. More high quality clinical research is required in order to estimate the efficacy of adjunctive interventions on accelerating OTM and their potential clinical use.