The objective of this article was to conduct a systematic review of the literature to contrast the existing evidence on the effect of mechanical vibrations, either high or low frequency, as an alternative to accelerate orthodontic tooth movement in humans. A literature search from 2010 to June 2021 was conducted in the electronic databases: PubMed, NCBI, Google Scholar, EBSCO, Cochrane, and Ovid, using the eligibility criteria to identify the studies. Only randomized clinical trials (RCT) were included. The certainty of the evidence was assessed using the GRADE tool and the risk of bias (RoB) in individual studies was evaluated according to the Cochrane bias risk tool. Fifteen RTCs were included for final review. Overall, the RoB was classified as low (3), moderate (5), and high (7). Three articles with low RoB, four with moderate RoB, and four with high RoB found no significant effect in the use of vibrations on orthodontic movement. Only four articles, three of them with high RoB and one with moderate RoB, found that mechanical vibrations are effective at accelerating orthodontic tooth movement. The results seemed to indicate that there is no evidence that vibratory stimuli can increase the rate of dental movement or reduce neither the time of dental alignment nor canine retraction during orthodontic treatment. It is important to note that a greater number of high-quality randomized controlled trials are urgently needed.

Mechanical vibrations have a biphasic effect depending on the context in which they are applied; their anabolic action has been used in medicine to increase bone density. In dental specialties such as orthodontics, their catabolic effect during mechanical compression has been widely studied, but the anabolic effect of vibrations is less investigated, so it is important to carry out research to clarify the effect of vibrations on the alveolar bone, explore a new approach to its use in orthodontics, and the increase of post-treatment bone density to prevent relapse. Hence, this work aims to systematically review the literature to evaluate the evidence regarding vibratory stimulation and its anabolic effects on alveolar bone in animal models. Methodology: A systematic review followed the PRISMA guidelines in PubMed, Scopus, and Web of Science databases. With the PICO strategy, we formulate the subsequent research question: Does the application of vibrational force induce an anabolic effect in the alveolar bone of animal models? Due to the lack of human studies, the population of interest was animal models; only articles where mechanical vibrations were the intervention method and the alveolar bone density or osteogenesis were evaluated and included. The selected studies underwent quality and risk of bias assessment through ARRIVE and SYCRLE instruments, respectively. This protocol was registered in INPLASY, under ID number: 202280103. Results: All eight articles included in this work demonstrate that applying low and high frequency vibrations increases the osteogenic effect by increasing the density and volume of bone tissue and increasing the expression of osteogenic markers. The included studies present a medium quality and risk of bias. Conclusion: It is important to highlight that, regardless of the protocol used, low or high frequency vibrations increase bone density, particularly in the alveolar bone, since this is the bone of interest in orthodontics. These promising results set an important precedent for the design of experimental protocols but now in the context of post-orthodontic treatment in humans.