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The effect of low-level laser therapy during orthodontic movement: A preliminary study

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It has been emphasized that one of the most valuable treatment objectives in dental practice is to afford the patient a pain-free treatment. By the evolution of the laser applications, the dental committee aimed to achieve this goal without analgesic drugs and painful methods. Orthodontic treatment is one of these concerns, that one of the major components of patient to reject this treatment is the pain accompanied during the different treatment phases. Another great concern of the patient is not to get through prolonged periods of treatment. The aim of this study is to evaluate the effect of the low-level (GaAlAs) diode laser (809 nm, 100 mW) on the canine retraction during an orthodontic movement and to assess pain level during this treatment. A group of 15 adult patients with age ranging from 14 to 23 years attended the orthodontic department at Dental School, Damascus University. The treatment plan for these patients included extraction of the upper and lower first premolars because there was not enough space for a complete alignment or presence of biprotrusion. For each patient, this diagnosis was based on a standard orthodontic documentation with photographs, model casts, cephalometric, panorama, and superior premolar periapical radiographies. The orthodontic treatment was initiated 14 days after the premolar extraction with a standard 18 slot edgewise brackets [Rocky Mountain Company (RMO)]. The canine retraction was accomplished by using prefabricated Ricketts springs (RMO), in both upper and lower jaws. The right side of the upper and lower jaw was chosen to be irradiated with the laser, whereas the left side was considered the control without laser irradiation. The laser was applied with 0-, 3-, 7-, and 14-day intervals. The retraction spring was reactivated on day 21 for all sides. The amount of canine retraction was measured at this stage with a digital electronic caliper (Myoto, Japan) and compared each side of the relative jaw (i.e., upper left canine with upper right canine and lower left canine with lower right canine). The pain level was prompted by a patient questionnaire. The velocity of canine movement was significantly greater in the lased group than in the control group. The pain intensity was also at lower level in the lased group than in the control group throughout the retraction period. Our findings suggest that low-level laser therapy can highly accelerate tooth movement during orthodontic treatment and can also effectively reduce pain level.
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ORIGINAL ARTICLE
The effect of low-level laser therapy during orthodontic
movement: a preliminary study
Mohamed Youssef & Sharif Ashkar & Eyad Hamade &
Norbert Gutknecht & Friedrich Lampert & Maziar Mir
Received: 21 September 2006 / Accepted: 22 January 2007 / Published online: 15 March 2007
#
Springer-Verlag London Limited 2007
Abstract It has been emphasized that one of the most
valuable treatment objectives in dental practice is to afford
the patient a pain-free treatment. By the evolution of the
laser applications, the dental committee aimed to achieve
this goal without analgesic drugs and painful methods.
Orthodontic treatment is one of these concerns, that one of
the major components of patient to reject this treatment is
the pain accompanied during the different treatment phases.
Another great concern of the patient is not to get through
prolonged periods of treatment. The a im of this study is to
evaluate the effect of the low-level (GaAlAs) diode laser
(809 nm, 100 mW) on the canine retraction during an
orthodontic movement and to assess pain level during this
treatment. A group of 15 adult patients with age ranging
from 14 to 23 years attended the orthodontic department at
Dental School, Damascus University. The treatment plan
for these patients included extraction of the upper and lower
first premolars because there was not enough space for a
complete alignment or presence of biprotrusion. For each
patient, this diagnosis was based on a standard orthodontic
documentation with photographs, model casts, cephalomet-
ric, panorama, and superior premolar periapical radiogra-
phies. The orthodontic treatment was initiated 14 days after
the premolar extraction with a standard 18 slot edgewise
brackets [Rocky Mountain Company (RMO)]. The canine
retraction was accomplished by using prefabricated Ricketts
springs (RMO), in both upper and lower jaws. The right
side of the upper and lower jaw was chosen to be irradiated
with the laser, whereas the left side was considered the
control without laser irradiation. The laser was applied with
0-, 3-, 7-, and 14-day intervals. The retraction spring was
reactivated on day 21 for all sides. The amount of canine
retraction was measured at this stage with a digital
electronic caliper (Myoto, Japan) and compared each side
of the relative jaw (i.e., upper left canine with upper right
canine and lower left canine with lower right canine). The
pain level was prompted by a patient questionnaire. The
velocity of canine movement was significantly greater in
the lased group than in the control group. The pain intensity
was also at lower level in the lased group than in the control
group throughout the retraction period. Our findings
suggest that low-level laser therapy can highly accelerate
tooth movement during orthodontic treatment and can also
effectively reduce pain level.
Keywords LLLT
.
Low-level laser
.
Orthodontics
.
Tooth movement
.
Pain
Introduction
Discomfort pain is a burdensome side effect accompanying
orthodontic treatment due to force application for tooth
movement. Clinical observatio n indicates that these sensa-
tions usually appear a few hours after force application [2,
27] or during the first day or first couple of days of
treatment and that pain intensity falls to normal levels after
7 days [8, 16, 29, 34].
It has been emphasized that pain reduction without
analgesic drugs is necessary in orthodontic treatment [3, 6,
8, 15, 21, 28]. Several studies showed an effective pain
Lasers Med Sci (2008) 23:2733
DOI 10.1007/s10103-007-0449-7
M. Youssef
:
S. Ashkar
:
E. Hamade
:
M. Mir
Dental School, Damascus University,
Damascus, Syria
N. Gutknecht
:
F. Lampert
:
M. Mir (*)
Department of Dentistry, RWTH Hospital,
Pauwelsstr. 30,
52074 Aachen, Germany
e-mail: mmir@ukaachen.de
reduction after different dental treatments by using low-
level laser therapy (LLLT) [ 11, 22].
The long treatment period is another concern that makes
patients neglect to go through orthodontic treatment. Accord-
ing to the previous studies [1, 5, 7, 9, 10, 12, 13, 17, 19, 24,
26, 30, 31, 33, 35, 3739, 41, 42], the amount of tooth
movement in response to the applied force is influenced by
several factors such as gender, status of periodontal ligament
(PDL) and, especially, the type of tooth movement, and the
magnitude of the applied force. With a healthy canine and
moderate applied force (150 g), Ricketts reported the
movement to be 1 mm at the end of activation. In general,
the mechanics applied produced canine retraction with
velocities averaging 1.27 and 0.87 mm per month for 13
and 4 kPa of stress, respectively, with minimal linear or
angular tooth movements [13, 14]. However, those studies
used different magnitudes and durations of force, and thus,
direct comparisons of their results are difficult to draw.
To avoid any confusion, we have used the same
magnitude of force (150 g) with same reactivation duration
for all our patie nts involved in the experiment.
The purpose of the present study was to determine the
differences in the velocity of movement of the canines
retraction while applying LLLT. The other aim is to assess a
visual scale of pain level during the experiment.
Materials and methods
Patients selection
A group of 15 patients of both genders, with age ranging
from 14 to 23 years, attended the orthodontic department at
Dental School, Damascus University.
The treatment plan for these patients included extraction
of the upper and lower first premolars to achieve treatment
plan demands. For each patient, the diagnosis was based on
a standard orthodontic documentation with photographs,
model casts, cephalometric, and panoramic radiographics.
An additional superior and inferior premolar periapical rays
were obtained to ensure the absence of any problem that
would impede the extraction procedures.
We considered the following standards for patients
selection:
(a) They should appear healthy.
(b) They should be free of any systemic disease.
(c) They should not be under medical treatment that
could interfere with bone metabolism (the orthodon-
tic movement mechanism) like non-steroidal anti-
inflammatory.
After clearly explaining all the risks and benefits of the
supposed treatment, the patients and each legal responsible
approved to participate in this study. This approval was
documented by a signed paper from each patient and
authorized by the dean of our dental school.
Orthodontic treatment
The orthodontic treatment was initiated 14 days after the
premolar extraction with a standard 0.018-in. slot edgewise
brackets [Rocky Mountain Company (RMO)]. The canine
retraction method chosen was Ricketts prescription by using
the prefabricated 16×16 Blue Elgiloy Ricketts Spring
(RMO). The spring was activated to deliver (150 g) force,
which was measured by Forestadent force gauge. Spring
reactivation was made every 21 days with the same force value
(150 g) and repeated till the closing of the extraction space.
The amount of tooth movement in millimeters was
prompted by measuring the distance between the following
reference points on the model casts:
1. The tip of the mesial cusp of the first molar
2. The tip of the canine cusp
The measurement was done by using a digital caliper
(Mitutoyo, Japan) before initiating the orthodontic treat-
ment and recorded.
At each reactivation interval, new impressions for each
patient of both upper and lower jaws were taken. Then a
new measurement of the previous distance was recorded.
This was maintai ned till the end of the retraction phase. All
of these measurements were organized in schedule accord-
ing to the measuring date.
On every reactivation date, the patient was asked about
the pain expe rienced during the bygone period. These
responses were ranked according to a visual pain scale and
were also organized in a schedule.
Laser irra diation
The right side of the upper and lower jaws was chosen to be
irradiated with the laser beam, whereas the left side was
considered the control without irradiation. The laser type
used was a semiconductor (GaAlAs) laser with 809-nm
Table 1 Tooth movement measurements
Lased group Control group
Days Step 1 Step 2 Step 3 Step 1 Step 2
0 DM SA Laser DM SA
3 DM Laser DM
7 DM Laser DM
14 DM Laser DM
21 DM DM
DM Distance measurement, SA spring activation
28 Lasers Med Sci (2008) 23:2733
wavelength operated at 100-mW output according to the
manufacturers recommendation (Quanta, Italy).
The laser beam was delivered to the tissue by a special
handpiece. The tip of the handpiece was held in contact
with the tissue during application.
The areas chosen to be irradiated were the lingual and
buccal PDL of the canines. These areas were divided into
three:
1. Cervical
2. Middle
3. Apical
The cervical area was lased for 10 s. The middle area
was lased for 20 s. The apical area was lased for 10 s.
The total energy density (dose) at each application was
8 J (2×40 s×100 mW).
To omit patients self-behavior about the pain, we have
put the tip of the handpiece not only on the right side
but also on the left side, without pressing the feet
paddle that ena bles the laser beam. In this manner, just
the red guiding light will be emitted.
The laser regimen was applied on 0-, 3-, 7-, and 14-day
intervals after every activation.
Data collection
Tooth movement
The sequence of steps carried out during each clinical
attendance is shown in Table 1. At every 21-day interval,
the distance measurement was compared between the lased
and control group. The data were compared by two sample
t tests at P<0.05. After 6 months, the lased and control
groups canines areas were examined by periapical radio-
graphs to see if any damage developed in the adjacent
PDLs and dental tissues.
Pain questionnaire
The pain level was assessed as the shown rank values in
Table 2. Every patient was asked about the pain experi-
enced after spring activation. All these data were recorded
in a schedule.
Results
Velocity study
The velocity of the movement was obtained from the
following formulation:
V ¼ d
=
t
where V is the velocity of the canine movement, d is the
amount of canine movement in millimeters at the end of
treatment, and t is the time passed to accomplish the
movement.
Table 3 shows the mean velocity of those movements in
both lased and controlled groups. Figure 1 shows that the
velocity of tooth movement was bigger in the experiment
(lased) side than in the control side (non-lased). Figure 2
shows that the velocity of tooth movement was bigger in
the lased group in both jaws. Figure 3 shows that there
was not any significant statistical difference between the
mean velocity values of the upper and lower canines and
the jaw position did not have an effect on the velocity of
tooth movement.
Table 3 Velocity of movement of the tooth
Group Number of studied
teeth
Mean tooth movement
velocity
SD
Lased 30 2.027 0.114
Control 30 1.019 0.110
Fig. 1 The effect of laser on the amount of velocity of tooth
movement is reported by median of two experimental and control
groups (n=60)
0.092
0.025
0.095
0.024
0.00
0.05
0.10
Median
Upper Jaw Lower Jaw
Position of Jaw
Eperimental
Control
c
Fig. 2 The effect of laser on the velocity of tooth movement
regarding the jaw position is shown (n=60)
Table 2 Pain levels
Degree of pain Rank value
No pain 0
Mild pain 1
Moderate pain 2
Severe pain 3
Intolerable pain 4
Lasers Med Sci (2008) 23:2733 29
Pain study
Figure 4 displays the pain level during different treatment
stages of lased and control groups.
To study the differences in pain levels between the lased
and control groups during combined treatment stages,
ManWhitney U test was done. Table 4 shows mean rank
values for the degree of pain during combined treatment
stages. Table 5 shows MannWhitney U test results.
In Tables 4 and 5, we can observe the following:
P 0.05 at every combined treatment stage.
There is a significant difference in the degree of pain
between the control and the experimental sides.
Mean U values of the control side are higher than the
experimental side.
The degree of pain is higher in the control side during
the first, second, and third stages.
Discussion
Orthodontic tooth movement involves both modeling and
remodeling activities that are modulated by systemic factors
such as nutrition, metabolic bone diseases, age, and drug
usage history [5, 7, 13, 17, 19, 26, 38, 39].
Biologically active substances, such as cytokines,
interleukins (IL-1ß, IL-1RA), and enzymes, are expres sed
by cells within the periodontium in response to mechan-
ical stress from orthodontic appliances [1, 5, 7, 9, 10, 12,
13, 17, 19, 26, 31 , 33, 35, 3739, 41].
IL-1ß is more potent for bone resorption and the
inhibition of bone formation, and its role in orthodontic
tooth movement has been the focus of previous studies
[31, 37].
Inflammatory cytokines have been administered to
enhance orthodontically induced bone modeling. Similar
effects have bee n demonstrated wi th prostaglandin E2
(PGE2) osteocalcin administration to primates [20, 43],
and the results have been confirmed clinically [36].
However, in the clinical practice, this needs to be injected
within the mucosa, which is associated with pain and
discomforts the patients.
Strain-induced catabolic modeling at the bone PDL
interface limits the rate of tooth movement [13, 17, 26, 38].
According to several studies, LLLT is an effective tool
used to prompt bone repair and modeling post-surgery.
This has referred to the biostimulation effect of the LLLT.
This effect had been well studied in the medical field and
proven to have an enhanc ement effect o n fibroblast
growth enhancement, wound healing, and bone repair.
This enhancement can be the r esult of osteoblasts
proliferation and differentiation and intracellular changes
in these cells [ 4 , 6, 15, 18, 23 , 25, 28, 32, 40]. Shimizu et
al. studied the effects of low-power laser irradiation on
bone regeneration in midpalatal suture during expansion
in the rat and conclu ded that one-time or late irradiation
(days 46) had no effect. However, irradiation during
days 02 was most effective. Another research by
Skinner et al. showed that fibroblast procol lagen produc-
0.092
0.095
0.025
0.024
0.00
0.02
0.04
0.06
0.08
0.10
Median
Experimental Control
Upper Jaw
Lower Jaw
c
Fig. 3 The effect of jaw position on the velocity of tooth movement is
not statistically significant (P>0.05)
33.3
50.0
16.7
50.0
46.7
3.3
56.7
40.0
3.3
3.3
36.7
53.3
6.7
66.7
30.0
3.3
6.7
50.0
43.3
13.3
50.0
36.7
63.3
33.3
3.3
76.9
23.1
0
50
100
Percentage
1st 2nd 3rd 1st 2nd 3rd 4th 5th 6th
The Percentage of Pain Levels according to the studied groups and different treatment
stages
No Pain Mild Pain Moderate Pain Severe Pain Intolerable Pain
Experimental Control
Fig. 4 The pain levels during
different treatment stages are
reported (n=60)
30 Lasers Med Sci (2008) 23:2733
tion was increased by using GaAs doses between 0.099
and 0.522 J/cm
2
.
Biostimulation effects on the bone repair are directly
dependent on the dose applied [4, 25, 40]. Different
parameters have proven to be effective for severa l different
lasers, inducing changes within cell cultures and leading to
an increased healing effect. Nevertheless, the optimal
parameters have yet to be determined [4, 40].
Luger et al. used doses of about 64 J/cm
2
during 14 days,
and although this dose could be excessive within the focused
area, the authors believe that the scattering reduces the
energy level of the laser beams to between 3 and 6% of its
original intensity. In our study, the dose of 8 J/cm
2
(the
irradiated area was about 1 cm
2
) at each of the different
points around the tooth is lower than the dose used by Luger
et al. (64 J/cm
2
), but the distribution of energy into six points
surrounding the canine teeth could be more adequate due to
a more homogeneous distribution of the energy.
Infrared radiation has a low absorption coefficient in
hemoglobin and water, and consequently, a high penetra-
tion depth in the irradiated tissue. It is well known that
infrared radiation at 750 nm can penetrate more than visible
radiation at 650 nm into soft tissues. As the objective of our
study was to stimulate bone cells, which are placed deeply
under the soft tissue (e.g., gingiva) in the PDL space, the
infrared laser was selected for our study.
Some authors have analyzed the effects of LLLT during
orthodontic treatment in animals. Saito and Shimizu [32]
studied the effects of LLLT on the expansion of midpalatal
sutures in rats, comparing the bone regeneration obtained
with and without laser treatment. Their results showed that
the therapeutic effects of laser are dependent on the total
dosage, the frequency, and the duration of the treatment.
Their laser-irradiated group showed 2040% better results
when compared to the CG. In another study, Kawasaki and
Shimizu [18] showed that the orthodontic movement of
laser-irradiated rats teeth was 30% quicker than the non-
irradiated rats due to acceleration of bone formation as a
result from the cellular stimulation promoted by LLLT. Our
findings are similar to these reports. However, the ratio
lased group/control group (LG/CG) obtained in our study
was 1.98 (Table of Velocity). This ratio could be the
biostimulation factor prom oted by LLLT.
In Fig. 1, we can observe that the velocity of tooth
movement was bigger in the experi ment (lased) side than in
the contr ol side (non-lased). Also, we can see in Fig. 2 that
the velocity of tooth movement was bigger in the lased
group in both jaws. Analysis of the laser effect on the upper
and lower jaw reveals that there was not any significant
statistical difference between the mean velocity values of
the upper and lower canines and the jaw position did not
have an effect on the velocity of tooth movement (Fig. 3).
Tooth move ment is dependent on a painful, inflammatory
adaptation of the alveolar process. To relieve such pain, several
methods have been used in the literature. One of those is to use
drugs (non-steroidal anti-inflammatory drugs). Although these
drugs could be effective in relieving pain, they may also reduce
the rate of tooth movement [3, 6, 15, 21, 28]. The application
of low-energy lasers in the field of dentistry and oral surgery
has been described since the 1970s. Low-energy laser light is
supposed to reduce pain, to accelerate wound healing, and to
have a positive effect on inflammatory processes. Harazaki et
al. [11]andLimetal.[22] showed that the low-level laser
therapy is an effective tool to manage the post-adjustment
orthodontic pain. Our findings in this research confirmed the
previous findings. Figure 4 displays that, during different
treatment stages, the pain level of the lased group was less in
amount than the control group.
Table 4 Degree of pain reported in different groups (n=60)
Studied variable Combined stages Number of canines Mean rank values
Experimental Control Total Experimental Control
Degree of pain First stage 30 30 60 16.83 44.17
Second stage 30 30 60 15.83 45.17
Third stage 30 30 60 16.22 44.78
Table 5 MannWhitney U test results are presented
Studied variable Combined treatment stages MannWhitney U test value P value Significance
Pain degree First stage 40.0 0.000 Significant differences
Second stage 10.0 0.000 Significant differences
Third stage 21.5 0.000 Significant differences
Lasers Med Sci (2008) 23:2733 31
In this study, radiographies showed no evidence of
damage in the dental and periodontal tissue promoted by
the LLLT. Further studies are required to explain the
mechanisms of laser biostimulation and clinical trials to
optimize treatment parameters and discover other effects
promoted by LLLT.
Conclusion
The (GaAlAs) low-level laser used i n this study is
considered to be an effective too l during orthodontic
treatment, as: the rate of tooth movement raised signifi-
cantly, and the pain level reduced significantly.
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Lasers Med Sci (2008) 23:2733 33
... On the other hand, PBM has an analgesic effect and the ability to reduce pain and discomfort, via two pathways: stimulating the production of beta-endorphin, a natural mediator inhibiting the release of arachidonic acid, preventing the release of metabolites that interact with the pain receptors. The other pathway for reducing pain is repressing the conduction of nervous impulses, at the peripheral nerve endings to impair the transmission of local painful impulses [2]. ...
... The effect of PBM on the rate of OTM was investigated in several performed animal studies and stated that PBM can improve the rate of OTM through high expression of RANKL release stimulating alveolar bone remodeling [3,4]. Clinical studies on patients stated that PBM had a significant effect on accelerating the rate of OTM [2,5]. ...
... The studies used the Visual Analogue Scale to quantify the pain after applying the orthodontic force; most of the studies used a placebo laser control group. From the results, it was concluded that the PBM-treated group had lower levels of pain, when compared to the placebo group, showing the positive effects of PBM in reducing pain during orthodontic treatment [2,6]. Yet a lot of challenges face researchers investigating PBM; the most important is establishing appropriate laser parameters to allow for photoreactions to occur. ...
Article
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Reducing the orthodontic treatment time and pain are real challenges facing orthodontists. Photobiomodulation (PBM) as an intervention treatment modality showed significant outcomes tackling these two challenges. Yet a lot of challenges face researchers investigating PBM as the studies conducted to date have used multiple diverse variables. Unveiling these paradoxes requires standardizing evidence-based guidelines for future investigations.
... A total dose of 2J (2 × 50 sec × 20 mw) was applied to each tooth of the lower four incisors teeth. as described in several studies [45][46][47][48] The laser beam was applied immediately after clear aligner delivery then at days 7, 14. This protocol was repeated every 2 weeks after clear aligner replacement. ...
Article
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Objectives the objective of this study is to compare the root resorption accompanied orthodontic treatment using fixed orthodontic appliance versus removable clear aligner. Material and methods This prospective randomized clinical study was conducted on a sample of 30 patients with mild to moderate crowding. The patient ages ranged from (12-18) years. Patients were randomly divided into three groups; Group Ⅰ: ten patients treated with fixed orthodontic appliance using Roth brackets 0.022-inch slot. Group Ⅱ: ten patients treated with removable clear aligner. Group Ⅲ: ten patients treated with removable clear aligner with application of low-level LASER. Each patient in the study had a pre and post treatment CBCT. Results root resorption was measured by importing pre and post treatment CBCT on Mimics software (version 18, Materialise, Leuven, Belgium) to reconstruct the roots in 3D. conclusion Root resorption accompanied with aligners is considered less than fixed appliances however the difference is not significant. The use of laser has no effect on reducing or minimizing the incidence of root resorption.
... Chiari [19] used an 830 nm gallium-aluminumarsenide diode laser to accelerate the rate of tooth movement. Further, Yamaguchi et al. [20], Fujita et al. [21], Youssef et al. [22], Yoshida et al. [23], and Doshi-Mehta et al. [12] showed that LILT accelerates tooth movement. However, LLLT had no additional benefits on orthodontic tooth movement, according to Limpanichkul et al. [24] and Heravi et al. [11]. ...
... The mean value of pain post-surgical in laser group had significantly decreased by time. This could be attributed to the mechanism of laser cell interaction by stimulation of photoreceptors in the mitochondria respiratory chain, change in cellular ATP levels and cell membrane stabilization in addition to increasing the level of Receptor activator of nuclear factor-κB ligand (RANKL) during orthodontic tooth movement, which subsequently reduced pain in a very short period of time (21,22) . ...
... 15 Garg's study found that canine movement was faster in the laser group than in the control group, 16 because the LLLT irradiation parameter in Limpanichkul's study (25 J/cm2), 3 was too high for the bio stimulating effect to increase tooth movement speed when compared to a lower irradiation dose such as 5 J/cm 2 in Doshi-Mehta and Sousa's study or 8 J/cm 2 in Youssef's study. 15,19,22 According to Amdt-law Schulz's irradiation dose for bio stimulating effect, a low dose generates an effect, a medium dose improves the impact, and a large dose might prevent the effect. 21 Our findings are similar to those of Garg, who discovered in his 84-day study that there was a significant increase in canine movement speed in the laser group compared to the control group in the 3 rd interval (from the 43 rd to the 63 rd day) in the upper jaw, and in the 3 rd (from the 43 rd to the 63 rd day) and 4 th intervals (from the 64 th to the 84 th day) in the lower jaw. ...
Article
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The amount of time necessary for therapy is one of the most worrisome concerns for patients. Orthodontic treatment normally lasts 2 to 3 years, which increases the risk of gingivitis, dental cavities, and root resorption in extraction cases. As a result, minimizing treatment time is critical, and one key feature is speeding tooth movement. Several studies have shown that low-level laser therapy (LLLT) can boost the activity of osteoclasts, osteoblasts, and fibroblasts both in vitro and in vivo; these reactions result in bone remodeling and improve the pace of tooth movement. To assess the effects of LLLT on tooth movement in orthodontic treatment by comparing canine retraction distance and time in two groups at T1 (4 weeks), T2 (8 weeks), and T3 (12 weeks), as well as three-time periods: T1-T0, T2-T1, and T3-T2. This randomized double-blind split-mouth controlled clinical trial comprised 16 orthodontic patients who needed two maxillary first premolars extracted and canines retracted. The time required for canine retraction with LLLT (Group 1) vs the control quadrant of the same patients (Group 2) was measured, as was the distance of canine movement (on models), at three points: 4, 8, and 12 weeks after triggering canine retraction. Group 1 had a greater total distance of canine movement (T1: 0.84 ± 0.08 mm, T2: 1.71 ± 0.11 mm, T3: 2.56 ± 0.11 mm) than Group 2 (T1: 0.80 ± 0.07 mm, T2: 1.66 ± 0.11 mm, T3: 2.38 ± 0.12 mm). Every four weeks, the change was substantial (p 0.001). The distance of canine movement every 4 weeks was bigger in Group 1 (T1: 0.84 ± 0.07 mm, T2: 0.87 ± 0.1 mm, T3: 0.85 ± 0.07 mm) than in Group 2 (T1: 0.80 ± 0.06 mm, T2: 0.86 ± 0.09 mm, T3: 0.72 ± 0.09 mm). Data were unequal in the first and last sessions (p < 0.05). Group 1's movement (0.853 mm/month) was much quicker than Group 2's (0.793 mm/month) (p < 0.001). LLLT is an effective approach for accelerating tooth mobility in orthodontic treatments.
... [5] e pain commonly begins a few hours after fulfillment of an orthodontic force, then progressively decreases and gets back to the norm within 7 days. [6] Lew presented that 30% of patients left orthodontic treatment due to experiencing pain during the early stages of orthodontic treatment. [7] e source of pain during orthodontic tooth movement is not completely understood. ...
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Objectives This study aimed to determine the efficacy of platelet-rich fibrin (PRF) injection on orthodontic pain perception during the 1 st week of the alignment and leveling process. Material and Methods The study sample included 18 patients (11 females and 7 males). The patients were randomly divided into two groups, the PRF group (9 patients) and the control group (9 patients). The mean age of the sample members was 21.9 ± 2.5 and 20.8 ± 2.4 in the control and the PRF group, respectively. Conventional brackets were applied for both groups. PRF was injected into the six upper front teeth at a rate of 0.6 mm for each point before starting the primary wire insertion process. The pain parameters of each patient were evaluated for both groups during the 1 st week of the alignment and leveling process by application of the Visual Analog Scale (VAS) at the durations of (2 h, 6 h, 1 day, 2 days, and 7 days) and all patients were followed up until the end of the alignment and leveling process. Results PRF injection can reduce pain perception in orthodontic patients, overall ( P < 0.05), with an effect size of approx. 53 ± 0.13%. The biggest effect was observed 2 h after exposure ( P < 0.1) which showed a 50% reduction in pain in the PRF group. No significant effects were observed at later times ( P > 0.1). Conclusion The present study concludes that PRF injection can be an effective alternative for decreasing pain perception levels; however, its efficacy needs to be leveraged immediately after the injection of PRF.
... The analgesic effect is believed to be attributed to its antiinflammatory and neuronal effect [26]. Low-level lasers [27][28][29][30]: GaAlAs, GaAlAs diode (twin laser). ...
Article
Laser technique now is widely applied in orthodontic treatment and proved to have many benefits. Soft tissue lasers can be used to perform gingivectomy, frenectomy and surgical exposure of tooth with less bleeding and swelling, improved precision, reduced painand less wound contraction. Other laser applications include enamel etching and bonding andbracket debonding. Lower level lasers have the potential effects of pain control and accelerating tooth movement. Clinicians must be aware of the safety issues and risks associated with laser and receive proper training before the laser treatment is started.
... Comparable results have been reported in some studies 11,30,48,49 , while to the contrary, slightly lower acceleration values with LLLT application were registered in others 7,18,32,40 . On the other hand, much higher acceleration values than those reported in the current trial also have been reported, ranging from a 1.65-fold increase 17 , up to an almost twofold increase in OTM rate 15,34,39,50 , which could be attributed to the use of frictionless self-ligating brackets in some of them 15 . This divergence in the results reported in the literature is probably attributed to the different laser application protocols, wavelength, output power, irradiation time, energy density, treatment interval, and so on, making direct comparisons between different studies rather difficult. ...
Article
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The objective of this study was to evaluate the canine retraction rate with two low-level laser therapy (LLLT) irradiation protocols, involving both a high and a low application frequency. Twenty patients were randomly divided into two equal groups. In Group A, one side of the maxillary arch randomly received LLLT on days 0, 3, 7, 14, and every 2 weeks thereafter, whereas in Group B, one side received LLLT every 3 weeks. Tooth movement was checked every three weeks since the onset of canine retraction, over the 12-week study period. Moreover, Interleukin-1β (IL-1β) levels in the gingival crevicular fluid were assessed. Results revealed a significant increase in the canine retraction rate on the laser sides of groups A and B, in comparison with the control sides (p < 0.05), with no significant differences reported between the laser sides in both groups (p = 0.08–0.55). Also, IL-1β levels were significantly higher on the laser sides of both groups, in comparison with the control sides (p < 0.05). Therefore, LLLT can effectively accelerate tooth movement, with both frequent and less frequent applications, which is attributed to an enhanced biological response as reflected by the elevated IL-1β levels on the compression sides.
Article
PurposeThe aim of this study was to evaluate the effect of light-emitting photobiomodulation therapy (LPT) on the rate of canine distalization.Methods This study was performed on 60 extraction spaces formed by extraction of the upper first premolars of 30 patients (15 in the LPT group and 15 in the control group). Paul Gjessing (PG)-segmented canine retraction springs were used for canine distalization. In the LPT group, the Biolux OrthoPulse™ (Biolux Research Ltd, Vancouver, Canada) intraoral device (wavelength 850 nm LED light and an energy density of 63 mW/cm2 [±13 mW/cm2]) was used for 5 min per day over a period of 84 days. For each patient, the diagnosis was based on standard orthodontic documentation with photographs, digital model casts, and cephalometric and panoramic radiographs. The anchorage loss, canine rotations, canine inclinations, and molar inclinations were also evaluated on plaster models obtained on days 0, 21, 42, 63, and 84. The models were measured by using 3Shape OrthoAnalyzer software (3Shape, Copenhagen, Denmark). Measurements were made by a researcher and a blinded clinician. For statistical comparison, a paired-samples t‑test and one-way analysis of variance (ANOVA) were used at the p < 0.05 level.ResultsThe mean canine distalization rates were 1.36 mm/21 days and 1.02 mm/21 days in the LPT and control groups, respectively, and were statistically greater in the LPT group (p < 0.001). The amount of anchorage loss, canine rotations, canine inclinations and molar inclinations were not significantly different between the LPT and control groups at any of the timepoints.ConclusionLPT has the potential to accelerate orthodontic tooth movement by 33%.
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Aim: To compare the effectiveness of the intra-ligament injection of platelet-rich fibrin (i-PRF) and platelet-rich plasma (PRP) on canine movement rate during its orthodontic retraction. Materials and Methods: A randomized controlled trial with a split-mouth design included 40 patients (21.3±1.8 years) whose all first premolars were indicated for extraction. Twenty patients were randomly allocated to each group (PRP vs. i-PRF). The Canine retraction was performed using Ricketts spring. PRP and i-PRF were injected twice in the intervention side with a 21-day interval. Saline was used likewise in the control side. Canine movement, rotation, and molar anchorage loss were measured on dental casts, whereas canine inclination was studied on cephalograms. Shapiro–Wilk normality test was performed, and a paired t-test was subsequently used for comparison within the same group. In addition, a two-sample t-test was used to compare the two groups. Results: A significantly higher rate of canine movement was observed in the PRP intervention group during the first month, unlike the i-PRF group in comparison with the control side. Besides, canine retracting rate was higher in the PRP group during the third month than in the i-PRF group. No statistical differences in canine inclination, rotation, and molar anchorage loss were found except for mandibular canine rotation in the PRP group and maxillary canine rotation between the two groups. Conclusion: PRP injection was probably better than the i-PRF in accelerating canine movement without avoiding the unwanted effects. Keywords: Accelerated Orthodontics, Canine Inclination, Canine Retraction, Canine Rotation, Injectable Platelet-Rich Fibrin, Platelet-Rich Plasma
Article
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The aims of this study were to investigate the intensity, location and duration of patients' discomfort following insertion of orthodontic appliances, and to examine for interactions between patient age, gender, appliance type and the perception of pain. After insertion of orthodontic appliances, 170 patients received eight questionnaires, one they completed and returned after 4 h, then one daily for 7 days. The respondents' ages ranged from 8–53 years (median age 13 years 7 months); 45 per cent were male and 55 per cent female. Of the patients, 65 per cent reported pain after 4 h and 95 per cent after 24 h. After 7 days, 25 per cent of the patients still reported discomfort. Patients' pain intensity scores were significantly higher for the anterior than for the posterior teeth. On day 1, 16 per cent took analgesics and 18 per cent reported being awakened the first night. Comparing a 2 � 4 appliance, a full appliance in one arch and in both arches, no statistical differences were found for reported pain frequency, general intensity of pain, pain at the teeth, discomfort when biting and chewing and analgesic consumption, The perception of general pain intensity, analgesic consumption, pain when eating and the influence of discomfort on daily life were all significantly greater in girls than in boys. Patients younger than 13 years reported pain significantly less frequently than the older patients. The highest frequency of pain was found in the group of 13–16 year olds. The pain intensity did not differ among the age groups.
Article
Background and Objective Low‐power laser irradiation (LPLI) has been found to have a positive effect on bone fracture healing in animal models, based on morphogenic, biochemical, roentgenographic, and electron microscopic measurements. We investigated the effect of LPLI on bone fracture healing in rats using biomechanical methods. Study Design/Materials and Methods: Two groups of male Wistar rats, divided in a randomized block design in a blinded fashion, each consisting of 25 animals, were subjected to anesthesia and tibial bone fracture with internal fixation. The first group was treated with LPLI (HeNe laser 632.8 nm, 35 mW), applied transcutaneously over 30 minutes to the area of the fracture daily for 14 days. The second group served as a control. After 4 weeks, the tibia was removed and tested at tension up to failure (by a Lloyd LR 50K testing apparatus, U.K.) in 16 rats from group I and 15 from group II. The maximal load at failure, the structural stiffness of the tibia (callus stiffness), and the extension maximal load were measured. Results The maximal load at failure and the structural stiffness of the tibia were found to be elevated significantly in the irradiated group (P = .014 and P = .0023, respectively), whereas the extension maximal load was reduced (P = .015). In addition, gross non‐union was found in four fractures in the control group, compared to none in the irradiated group. Conclusion These results suggest that LPLI treatment may play a role in enhancing bone healing. Lasers Surg. Med. 22:97–102, 1998. © 1998 Wiley‐Liss, Inc.
Article
Background and Objective Low‐energy laser irradiation has many anabolic effects such as the acceleration of bone formation. However, its effects on tooth movement, performed by bone resorption and formation, have not been well characterized. Study Design/Materials and Methods A total of 10 g of orthodontic force was applied to rat molars to cause experimental tooth movement. A Ga‐Al‐As diode laser was used to irradiate the area around the moved tooth, and after 12 days, the amount of tooth movement was measured. Calcein was injected subcutaneously to label the newly formed alveolar bone for quantitative analysis. Immunohistochemical staining of proliferating cell nuclear antigen was performed to evaluate cellular proliferation. TRAPase staining was also performed to facilitate the identification of osteoclasts. Results In the laser irradiation group, the amount of tooth movement was significantly greater (1.3‐fold) than that of the nonirradiation group in the end of the experiment. The amount of bone formation and rate of cellular proliferation in the tension side and the number of osteoclasts in the pressure side were all significantly increased in the irradiation group when compared with the nonirradiation group (P < 0.01). Conclusion These findings suggest that low‐energy laser irradiation can accelerate tooth movement accompanied with alveolar bone remodeling. Lasers Surg. Med. 26:282–291, 2000 © 2000 Wiley‐Liss, Inc.
Article
Macrophages are a source of many important mediators of wound repair. Cells of an established macrophage-cell line (U-937) were exposed in vitro to an 820 nm light source which was both coherent and polarized. the power densities used being either 400 mW/cm2 or 800 mW/cm2. The irradiation times were such that the energy densities to which the cells were exposed were 2.4 and 7.2J/cm2 for both probes. Twelve hours after exposure the macrophage-conditioned medium was removed and placed on 3T3 fibroblast monolayers. Fibroblast proliferation was assessed over a four-day period. By four days after the addition of medium conditioned by macrophages exposed to an energy density of 2.4 J/cm2, there was a statistically significant difference in fibroblast number between the 400 mW/cm2- and 800 mW/cm2 treatments, 800mW/cm2 producing greater cell proliferation. However. there was no significant difference between the effects of sham irradiation and 400 mW/cm2. In contrast, after the addition of medium conditioned by macrophage exposed to an energy density of 7.2 J/cm2, 400 mW/cm2 treatment produced a significantly greater increase in fibroblast number than sham irradiation. There was no significant difference in cell number between the sham irradiated and 800 mW/cm2 irradiated samples, although there was a significant difference between the 400 mW/cm2 and the 800 mW/cm2. 400 mW/cm2 producing greater cell proliferation.
Article
During orthodontic treatment, the early response of periodontal tissues to mechanical stress involves several metabolic changes that allow tooth movement. Many studies have evaluated such modifications by analysis of various host metabolites released into the gingival crevicular fluid (GCF). This study used a cross-sectional design to examine the lactate dehydrogenase (LDH) activity in GCF to assess whether GCF LDH can be proposed as a sensitive marker for periodontal tissue modifications during orthodontic tooth movement. Thirty-seven subjects, 16 males and 21 females (mean age 18.7 years, range 14.0 to 26.7 years), participated in this study. Each subject underwent a session of professional oral hygiene and received oral hygiene instructions; 2 weeks later, a fixed orthodontic appliance was placed on the maxillary arch. A randomly selected maxillary canine was considered as the test tooth, and its antagonist, which had no appliance, was used as the control tooth. From 2 to 12 weeks after orthodontic appliance placement, GCF was harvested from both experimental teeth at the mesiobuccal angle, for GCF volume and LDH activity determinations. Clinical monitoring consisted of recording supragingival plaque presence, bleeding on probing, and probing depth at the same collection sites. The results showed that no differences in clinical conditions and GCF volume occurred between the experimental teeth. On the contrary, GCF LDH activity in the test teeth was significantly greater than that of the control teeth (P .01). Moreover, no differences were found in the enzymatic activity between the sexes by experimental tooth, and no significant correlation was present between GCF LDH activity and patients' ages within experimental teeth. Our enzymatic results initially indicated a possible role of GCF LDH during the early phases of orthodontic treatment and therefore warrant further study as a possible diagnostic tool for tissue response during orthodontic treatment. (Am J Orthod Dentofacial Orthop 2003;124:206-11) O ver the past 35 years, several studies have tried to explain the biomechanical 1 and the biolog-ical 2-4 phenomena that allow tooth movement caused by an orthodontic appliance. Studies have eval-uated the hard and soft tissue responses during ortho-dontic treatment in animal 3,5,6 and human 7,8 models. Most have focused on bone metabolism 3,5 or periodon-tal ligament changes 6,9-11 during tooth movement. Bone metabolism changes seem to be characterized by a combination of tissue resorption and deposition in both the compression and tension periodontal sites. 3,12 Moreover, it has been shown that hyalinization can occur in the most compressed areas of the periodontal ligament after application of orthodontic force on teeth. 9-11 This hyaline zone has also been described as an area of focal aseptic necrosis. 9-11 To better describe the biological responses to ortho-dontic force in humans, noninvasive analyses of vari-ous cell mediators or enzymes in the gingival crevicular fluid (GCF) have also been performed. 4,13-16 In the GCF, Uematsu et al 13 found several cell mediators, such as interleukin1 (IL1-), interleukin 6, tumor necrosis factor-(TNF-), epidermal growth factor, and 2 microglobulin, significantly elevated in teeth undergoing orthodontic forces, compared with un-treated controls. Through such GCF analyses of ortho-dontically treated teeth, similar results were found by Grieve et al 14 for prostaglandin E and IL1-and Lowney et al 4 for TNF-. Finally, Perinetti et al have reported significant elevations in alkaline phospha-tase 15 and aspartate aminotransferase 16 activities in the GCF during the first month of orthodontic treatment. All these studies demonstrate that several processes, eg inflammation, can occur in the periodontal tissues
Article
The purpose of this study was to examine gingival crevicular fluid (GCF) levels of two potent bone resorbing mediators, prostaglandin E (PGE) and interleukin-1β (IL-1β), during human orthodontic tooth movement. The study included 10 patients, each having one treatment tooth undergoing orthodontic movement and a contralateral control tooth. The GCF was sampled at control sites and treatment (compression) sites before activation and at 1, 24, 48, and 168 hours. Prevention of plaque-induced inflammation allowed this study to focus on the dynamics of mechanically stimulated PGE and IL-1β GCF levels. The PGE and IL-1β levels were determined with radioimmunoassay. At 1 and 24 hours, mean GCF IL-1β levels were significantly elevated at treatment teeth (8.9±2.0 and 19.2±6.0 pg, respectively) compared with control teeth (2.0±1.1 pg, p=0.0049, and 2.9±1.0 pg, p=0.0209, respectively). The GCF levels of PGE for the treatment teeth were significantly higher at 24 and 48 hours (108.9±11.9 and 97.9±7.3 pg) than the control teeth (61.8±7.2 pg, p=0.0071, and 70.8±7.4 pg, p=0.0021, respectively). The GCF levels of PGE and IL-1β remained at baseline levels throughout the study for the control teeth, whereas significant elevations from baseline in GCF IL-1β (24 hours) and PGE levels (24 and 48 hours) were observed over time in the treatment teeth (p≤0.05). These results demonstrate that bone-reorbing PGE and IL-1β produced within the periodontium are detectable in GCF during the early phases of tooth movement and return to baseline within 7 days.
Article
Two nickel-titanium archwire types commonly used for initial tooth alignment were compared with regard to the pain/discomfort patients experience during the initial phase of tooth movement. The two archwires used were a superelastic nickel-titanium alloy, 0.014 inch Sentalloy, Light (GAC International Inc. Central Islip, NY, USA) and a 0.014 inch Nitinol (unitek, Monrovia, CA, USA), a conventional nickel-titanium aligning archwire. One hundred and twenty-eight consecutive patients attending an orthodontic university clinic and 2 private practices for routine placement of a fixed appliance were randomly assigned one of these 2 initial archwires. Assessments of pain/discomfort were made daily by means of a 100 mm visual analog scale (VAS) over the first 7-day period after bonding. On the first day, recordings were made every hour for the first 11 hours. The results showed that the level of discomfort increased continuously every hour after the insertion of either a Sentalloy or a Nitinol as first archwires, with a peak in the first night, remaining high on the second day and decreasing thereafter to baseline level after 7 days. During the first 10 hours it was apparent that the pain/discomfort experienced after placement of a Sentalloy was less than that found with the Nitinol archwire, although a significant difference could be found at 4 hours only. No significant gender-specific differences were found in either archwire group. A significant difference between the upper and lower dental arches was observed during the first 11 hours after placement of either a Sentalloy or a Nitinol archwire, with the lower arch having the higher pain experience.
Article
This literature review focuses on previous studies of pain and pain perception in dentistry with special emphasis on orthodontic treatment. The prevalence of pain and background factors such as age, gender and culture/society, in addition to pain physiology and the influence of concomitant emotional and cognitive factors, is examined. Pain during orthodontic tooth movement is reported from the point of view of its physiology and character and different assessment methods. These aspects are described both generally and specifically in relation to the type of orthodontic forces and to the experience of discomfort other than pain. Since the orthodontic treatment may cause some degree of suffering for the patients, it is important for orthodontists to handle this situation in the best possible way. Some ideas about the possibilities of avoiding, reducing or alleviating pain in orthodontics are discussed.Dieser Literaturberblick beruht auf vorangegangenen Untersuchungen des Schmerzes und der Schmerzempfindung mit besonderer Bercksichtigung der kieferorthopdischen Behandlung. Dabei werden die Hufigkeit des Schmerzes und die Hintergrundfaktoren, wie zum Beispiel Alter, Geschlecht und kulturelle/gesellschaftliche Verhltnisse, sowie die Physiologie des Schmerzes und dessen Einflu auf begleitende emotionale und kognitive Faktoren dargestellt. Es wird ber den Schmerz und dessen Charakter whrend der orthodontischen Zahnbewegung aus physiologischer Sicht und ber verschiedene Bewertungsmethoden berichtet. Diese Gesichtspunkte werden sowohl allgemein als auch speziell abhngig von der Art der angewandten orthodontischen Krfte und der Erfahrung des Unbehagens wie des Schmerzes beschrieben. Da die kieferorthopdische Behandlung dem Patienten bis zu einem gewissen Grad Leiden verursacht, sollte der Kieferorthopde mit dieser Situation bestmglich umgehen. Einige Anstze zur mglichen Schmerzvermeidung, Schmerzverminderung und Schmerzlinderung in der Kieferorthopdie werden diskutiert.