## 1 Introduction  
Vibrations are oscillations that take place around an equilibrium point and travel through a certain medium (such as air, water, or soil) [1]. Vibrations have three crucial features: (1) frequency (how many times it entirely goes up and down in a cycle of one second, measured in Hertz (Hz); (2) amplitude (refers to the distance an oscillatory motion travels, measured in millimeters (mm); and (3) direction (refers to the direction in which an oscillatory motion is directed) [2].  
These vibrations have been successfully used in general medicine; their biphasic behavior explains that, in the absence of mechanical compression or a healing process, they promote an increase in theabolism of bone tissue, which improves its formation and density, this effect is known as the anabolic effect [2]. In conditions with compression or injury (use of brackets), their effect will be manifested as increased bone remodeling, known as a catabolism effect [3].  
Vibration stimuli in general medicine are a non-invasive therapy whose main application has been the increase of anabolism, which allows for counteracting the effects of osteoporosis and reducing the risk of fracture [4; 5].  
However, for use in dentistry, vibrations have, in the first instance, been classified into low frequency vibrations (LFV), which are \(\leq\)45 Hz, and high frequency vibrations (HFV) which represent frequencies \(\geq\)90 Hz [6] but, independently, the frequency used and its use in orthodontics has focused on taking advantage of catabolism to accelerate tooth movement [3; 7; 8]. Although they have also been used to reduce post-treatment pain, in this work, we have concentrated on analyzing the possible use of their anabolic effect to prevent post-treatment relapse [9; 10]. To this end, it is important to mention that the literature describes its anabolic effect because of the presence of Ruffini type I receptors that convert the bone tissue into a mechanosensitive medium, easily adaptable to this type of stimuli [11; 12]. In addition, it has been determined that the magnitude of the effect is dependent on the frequency of the vibrations and the state of health of the tissue at the time of applying the stimulus [13]. Finally, it should be noted that the osteogenic effect is a consequence of the activation of the canonical Wnt pathway, overexpression of alkaline phosphatase (ALP), and osteoblast differentiation and proliferation, as well as regulation of the RANK/RANKL/OPG axis [14; 15; 16].  
There is ample evidence of the anabolic effect of vibrations on long bones or the skeletal system in general [4; 5; 16; 17]. Nevertheless, there is a lack of sufficient evidence to assess this anabolic effect on human alveolar bone. A recent study conducted by [PERSON] et al. demonstrated that 120 Hz vibrations improved alveolar bone density, but this is the only clinical study in humans that demonstrated such an effect [11]. However, there are multiple investigations in animal models where the main objective has been to evaluate the effect of vibrations on the alveolar bone and in the context ofomatology. This would allow us to indirectly establish the implications of using vibrations during orthodontic retention.  
Furthermore, in the past ten years, much research has been done about the effects of vibrational stimuli to help move teeth during orthodontic treatment. Still, the anabolic effects of vibrational force on the alveolar bone have been researched less than the catabolic effects. Therefore, there is a real scientific need to elucidate the anabolic effects of vibration on the alveolar bone.  
The systematic review aim is to evaluate the existing evidence regarding mechanical vibrations and their effect on alveolar bone density and/or osteogenic activity in animal models.