Dose analysis for translating animal based vibrational force study for accelerating orthodontic tooth movement to clinic

Dose analysis for translating animal based vibrational force study for accelerating orthodontic tooth
movement to clinic
ABSTRACT
Controlled Differential Tooth Movement (CDTM) refers to the ability to move teeth to be displaced faster, or
to minimize the movement of teeth to be stationary (i.e., anchorage teeth or teeth during the retention phase).
CDTM is highly desired in common orthodontic treatments such as canine retraction, canine impaction, molar
protraction, and space closure. Successful CDTM drastically shortens treatment time and reduces common side-
effects such as root resorption and anchorage loss. Studies show that an intermittent vibration force (IVF)
superimposed on orthodontic force accelerates tooth movement. Further, in the absence of orthodontic force,
IVF strengthens bone mineral density of the alveolar bone. However, currently there is little evidence to facilitate
optimal selection of stimulation level. Furthermore, lack of control on stimulation level on the target tooth
inevitably results in inconsistent reporting of outcomes. The overarching goal of the proposed work is to enable
CDTM in the clinic by transitioning from successful animal studies to clinical applications. Objectives of the
proposed project include: 1) identifying optimal IVF stimulation level for accelerating orthodontic tooth movement
in rats as well as associated side-effects; 2) verifying effects of IVF on bone strengthening resulting in tooth
stabilization; and 3) determining the threshold that can be used to scale stimulation level up for larger species
like dogs and humans. We hypothesize that: (H1) there is an optimal level of IVF that accelerates movement of
targeted teeth without side-effects; (H2) the same IVF can strengthen the bone surrounding the tooth without
orthodontic force and reduce relapse during retention; and (H3) stress in the periodontal ligament (PDL) can be
used as the threshold to effectively scale up the stimulation level from rats to larger species for achieving
accelerated tooth movement. These hypotheses will be tested through three specific aims. Aim 1: Determine
the optimal level of IVF (OLIVF) stimulation superimposed on an orthodontic load system that accelerates tooth
movement in a rat model (H1) and the associated biological responses. Aim 2: Determine the effects of OLIVF
on the tooth without orthodontic force (H2). Aim 3: Scale up stimulation level for larger species including dogs
and humans, by normalizing to stress in the PDL, and validate the theory on dogs (H3). A PDL stress threshold
will be used as the criterion for scaling up IVF from rats to dogs in this proposed study, with an eye toward scaling
up to humans in future studies. Thus, a novel method to ensure delivery of the specified IVF on each individual
tooth in the clinic will also be tested. This comprehensive study will pave the way for clinical trials using this
technology. Further, associated biomechanics and biological studies will elucidate the mechanism behind IVF
based CDTM, which will further advance the field as well as methods for applying this technology.

Grant Number: 5R01DE030413-06
NIH Institute/Center: NIH
Principal Investigator: JIE CHEN