Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 31

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benefits1
or show potentially undesirable side
effects, such as more distopalatal rotation.
For question 2 (how is the speed of tooth translation
affected by growth status?), the results showed
that speed was, on average, 1.5-fold and significantly
faster in G compared with NG subjects. When
only G subjects were considered, stress magnitude
explained 50% of the variability in speed (partial
η2
= 0.495). Thus, growth status is an important
factor clinically as well as for future studies of tooth
movement.
For question 3 (how do the current results compare
with those from other studies using methods to
accelerate tooth movement?), our literature search
revealed split-mouth studies of bilateral maxillary
canine retraction using sliding mechanics in which
corticotomies,10,11
perforations12
piezocision,10
and tissue microon
one side were compared with the
control side in samples of ≤20 subjects (Table 2).
Two of these studies showed that after one month,
speeds of tooth movement for corticotomies and
microperforations versus controls were 1.89 versus
0.75 mm/month11 and 1.1 versus 0.5 mm/month,12
respectively. The former study further showed that
speeds were enhanced by surgical intervention
for the first two months, but by the fourth month,
experimental and control speeds were similar
(i.e., 0.89 and 0.85 mm/month, respectively).11
The
current results demonstrated tooth translation
via stresses of 26 to 52 kPa with average speeds
of ≥2.13 mm/month in G subjects and ≥1.20 mm/
month in NG subjects over three months. These
results argue for attention to appliance design and
amount of applied stresses (and thus, forces and
sizes of teeth) for both effective and efficient tooth
translation at comparable or better speeds than
have been demonstrated to date using relatively
invasive techniques for temporarily acceleration.
Limitations of the methods used in the current
study series have been previously described9
and
include unbalanced G versus NG sample sizes and
assumptions about free sliding of the distal end
of the auxiliary wire, the applicability of static mechanical
principles, and stress as a main biological
stimulus for orthodontic tooth movement. Future
Table 2. Results from Maxillary Canine Retraction Studies With and Without Stimuli Intended to Accelerate Tooth Movement*
Study
n
Aboul-Ela et al.,
201111
Alikhani et al., 201312
Abbas et al., 201610
Iwasaki et al., 20175
Age (Years)
13 Mean: 19
20
20-33
20 Mean: 21
Mean: 20
20 Mean: 14
20 Mean: 15
16 Mean: 16
20 Mean: 14
16 Mean: 14
F (cN)
150
100
150
18
60
120
240
360
Speed (mm/month)
Stimulus
1.89
0.89
1.10 ± 0.15
1.56
1.34
Not applicable
No
Stimulus
0.75
0.85
0.84
Stimulus
Corticotomy
Corticotomy
0.50 ± 0.15 Microperforation
Corticotomy
1.03 ± 0.44
1.41 ± 0.58
1.99 ± 0.74
2.03 ± 0.49
2.36 ± 0.90
*n = number of maxillary canines; F = applied force; speed = rate of maxillary canine movement.
Spring 2023 PCSO Bulletin
31
Piezocision
None
First
Fourth
First
Third
Third
Third
Timepoint
(month)
Pacific Coast Society of Orthodontists Bulletin Spring 2023

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Spring 2023
