Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 28
People in Orthodontics
Faculty Files
How Fast Can Teeth Move? Factors
That Matter
Dr. Laura R. Iwasaki
Portland, OR
Dr. Iwasaki is a professor in the Oregon Health &
Sciences University (OHSU) Division of Orthodontics
and chair of the Department of Oral and Craniofacial
Sciences. Dr. Nickel is professor-provisional in
the OHSU Division of Orthodontics and Program
Director of Advanced Education in Orthodontics.
Together, they have co-authored several articles
studying the rate of tooth movement. In this Faculty
Files feature, they summarize some of the key findings
of their studies for application in clinical care.
How fast can human teeth move and what factors
affect this are questions basic to orthodontics. However,
there is surprisingly little information about
controllable factors during orthodontic treatment,
such as the optimal amount of force to apply for the
fastest, nonharmful tooth movement.1-3
In addition,
although younger, growing patients are expected to
show faster tooth movement than older, nongrowing
patients, direct comparisons are sparse.4-6
This is
Dr. Jeffrey C. Nickel
Portland, OR
a summary of the outcomes of a study series with a
common protocol using bodily retraction (translation)
of maxillary canines to address these questions.
The series and outcomes are described in more
detail in our previous publications.5,7
To compare
Dr. Kathryn Preston
Phoenix, AZ
PCSO Bulletin Section Editor
the outcomes to other teeth and other conditions,
we measured not only the amount of force applied
but also estimated the area of tooth surface loaded
by the force (aka. stress) and the amount of tooth
movement over time (aka speed) in three dimensions.
Thus, we provide answers to questions about
how the speed of tooth translation is affected by (1)
stress magnitude and (2) growth status and (3) how
the results compare with those from other studies
using methods to accelerate tooth movement.
Study Protocol
The protocols were approved by the Institutional
Review Boards of 2 clinical sites. In brief, patients
with good oral hygiene and accepted orthodontic
treatment plans involving extraction of both maxillary
first premolars and without other medical or
dental problems were invited to participate.5
and the same custom maxillary fixed appliances
(Figure 1A, B). Posterior anchorage was established
first (Nance appliance plus passive right and left
posterior stainless-steel rectangular cross section
[SRC] arch-wire segments with figure-eight
ligation) then subjects had extractions and, at least
two weeks later, maxillary canine retraction was
begun (day 0) via a SRC wire vertical-loop auxiliary
(customized for resultant force delivery at the
canine's center of resistance) ligated to the canine
bracket and activated by a calibrated nitinol coil
spring (Figure 1B). Coil springs were calibrated at
mouth temperature and selected to deliver a target
force magnitude when stretched the distance (d)
between hooks on the auxiliary wire loop and the
first molar band on the same side (Figure 1B). The
target force (F) for a given maxillary canine was determined
by estimating the distal root surface area
(A) and using stress = F/A, where a stress of either 4,
13, 26, 52, or 78 kPa was randomly assigned to one
Those
who consented received oral hygiene instructions,
chlorhexidine gluconate for twice-daily oral rinsing,
instructions to avoid taking any other medications,
Figure 1. (A) Occlusal and (B) vestibular views of
example posterior anchorage and maxillary canine
retraction appliances
28
PCSO Bulletin Spring 2023
Pacific Coast Society of Orthodontists Bulletin Spring 2023
Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Spring 2023
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 1
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 2
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 3
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 4
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 5
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 6
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 7
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 8
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 9
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 10
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 11
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 12
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 13
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 14
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 15
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 16
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 17
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 18
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 19
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 20
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 21
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 22
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 23
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 24
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 25
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 26
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 27
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 28
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 29
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 30
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 31
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 32
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 33
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 34
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 35
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 36
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 37
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 38
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 39
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 40
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 41
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 42
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 43
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 44
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 45
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 46
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 47
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 48
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 49
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 50
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 51
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 52
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 53
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 54
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 55
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 56
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 57
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 58
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 59
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 60
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 61
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 62
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 63
Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 64
https://www.nxtbook.com/allen/pcso/bulletin_summer2023
https://www.nxtbook.com/allen/pcso/95-2
https://www.nxtbook.com/allen/pcso/95-1
https://www.nxtbook.com/allen/pcso/94-4
http://www.brightcopy.net/allen/pcso/94-03
http://www.brightcopy.net/allen/pcso/94-02
http://www.brightcopy.net/allen/pcso/93-3
http://www.brightcopy.net/allen/pcso/93-2
http://www.brightcopy.net/allen/pcso/93-1
http://www.brightcopy.net/allen/pcso/92-3
http://www.brightcopy.net/allen/pcso/92-2
http://www.brightcopy.net/allen/pcso/92-1
http://www.brightcopy.net/allen/pcso/91-4
http://www.brightcopy.net/allen/pcso/91-3
http://www.brightcopy.net/allen/pcso/91-2
http://www.brightcopy.net/allen/pcso/91-1
http://www.brightcopy.net/allen/pcso/90-04
http://www.brightcopy.net/allen/pcso/90-3
http://www.brightcopy.net/allen/pcso/90-2
http://www.brightcopy.net/allen/pcso/90-1
http://www.brightcopy.net/allen/pcso/83-4
http://www.brightcopy.net/allen/pcso/89-3
http://www.brightcopy.net/allen/pcso/89-2
http://www.brightcopy.net/allen/pcso/89-1
http://www.brightcopy.net/allen/pcso/88-4
http://www.brightcopy.net/allen/pcso/88-3
http://www.brightcopy.net/allen/pcso/88-2
http://www.brightcopy.net/allen/pcso/88-1
http://www.brightcopy.net/allen/pcso/87-4
https://www.nxtbook.com/allen/pcso/87-03
https://www.nxtbook.com/allen/pcso/87-2
https://www.nxtbook.com/allen/pcso/87-1
https://www.nxtbook.com/allen/pcso/86-4
https://www.nxtbook.com/allen/pcso/86-3
https://www.nxtbook.com/allen/pcso/86-2
https://www.nxtbook.com/allen/pcso/86-1
https://www.nxtbook.com/allen/pcso/85-4
https://www.nxtbook.com/allen/pcso/85-3
https://www.nxtbook.com/allen/pcso/85-2
https://www.nxtbook.com/allen/pcso/85-1
https://www.nxtbook.com/allen/pcso/preview-program-2013
https://www.nxtbook.com/allen/pcso/84-4
https://www.nxtbook.com/allen/pcso/84-2
https://www.nxtbookmedia.com