IADR Abstract Archives
Application of Mechanical Vibration to Enhance Orthodontic Tooth Movement – The Science Behind It
Objectives: To review and present the current evidence on the application of mechanical vibration to enhance orthodontic tooth movement.
Methods: Using mechanical vibration to enhance orthodontic tooth movement seems to become one of the promising new technologies in orthodontics. Although several papers have been published, the scientific evidence behind it is largely unknown. Through searching engines such as PubMed, the current literature on this topic was reviewed. With the funding support of NIDCR, the author’s group has been conducting a series of experiments on this topic, using study models of animal (in vivo), tissue and organ culture (ex vivo) and cell culture (in vitro). In addition to the biologic effect, the role of vibration in reducing the friction in the fixed orthodontic appliance system was also investigated. These new findings were presented.
Results: Among the very limited amount of publications on this topic, current findings are of controversy and no conclusion can be made.
Using a mouse model, we applied mechanical vibration to the orthodontically moved upper 1st molars for 4 weeks. As results, the vibrated molar moved 35% faster than the control molar, with more bone resorption found on the compression side and more newly formed bone presented on the tension side. To minimize variation of the animals, we further developed a tissue (organ) culture model in which the rat mandibular slices were preloaded with an orthodontic force then subjected to vibration for 7 days. The histologic findings in this tissue model supported our findings in the animal experiment. To investigate the cellular and molecular mechanism, we subjected human PDL cells to fluid shear stress with and without vibration. Interestingly, vibration enhanced the shear stress induced decrease of OPG/RANKL (mRNA) ratio. As practically vibration imposes on orthodontic fixed appliance system, we investigated the impact of vibration on the friction in the fixed appliance system and found that vibration significantly reduces 23% of friction between the orthodontic bracket and arch wire.
Conclusions: In summary, mechanical vibration potentially impacts both biologic and mechanic aspects of orthodontic tooth movement. However, the science behind it is still not absolutely solid, which asks for more future endeavors on this topic.
Methods: Using mechanical vibration to enhance orthodontic tooth movement seems to become one of the promising new technologies in orthodontics. Although several papers have been published, the scientific evidence behind it is largely unknown. Through searching engines such as PubMed, the current literature on this topic was reviewed. With the funding support of NIDCR, the author’s group has been conducting a series of experiments on this topic, using study models of animal (in vivo), tissue and organ culture (ex vivo) and cell culture (in vitro). In addition to the biologic effect, the role of vibration in reducing the friction in the fixed orthodontic appliance system was also investigated. These new findings were presented.
Results: Among the very limited amount of publications on this topic, current findings are of controversy and no conclusion can be made.
Using a mouse model, we applied mechanical vibration to the orthodontically moved upper 1st molars for 4 weeks. As results, the vibrated molar moved 35% faster than the control molar, with more bone resorption found on the compression side and more newly formed bone presented on the tension side. To minimize variation of the animals, we further developed a tissue (organ) culture model in which the rat mandibular slices were preloaded with an orthodontic force then subjected to vibration for 7 days. The histologic findings in this tissue model supported our findings in the animal experiment. To investigate the cellular and molecular mechanism, we subjected human PDL cells to fluid shear stress with and without vibration. Interestingly, vibration enhanced the shear stress induced decrease of OPG/RANKL (mRNA) ratio. As practically vibration imposes on orthodontic fixed appliance system, we investigated the impact of vibration on the friction in the fixed appliance system and found that vibration significantly reduces 23% of friction between the orthodontic bracket and arch wire.
Conclusions: In summary, mechanical vibration potentially impacts both biologic and mechanic aspects of orthodontic tooth movement. However, the science behind it is still not absolutely solid, which asks for more future endeavors on this topic.