Accepted Manuscript

Does alveolar corticotomy accelerate orthodontic tooth movement when retractingupper canines? A split-mouth-design randomized controlled trial

Fadi Al-Naoum , Mohammad Y. Hajeer , Azzam Al-Jundi

PII: S0278-2391(14)00503-5

DOI: 10.1016/j.joms.2014.05.003

Reference: YJOMS 56319

To appear in: Journal of Oral and Maxillofacial Surgery

Received Date: 20 December 2013

Revised Date: 1 May 2014

Accepted Date: 5 May 2014

Please cite this article as: Al-Naoum F, Hajeer MY, Al-Jundi A, Does alveolar corticotomy accelerateorthodontic tooth movement when retracting upper canines? A split-mouth-design randomized controlledtrial, Journal of Oral and Maxillofacial Surgery (2014), doi: 10.1016/j.joms.2014.05.003.

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Does alveolar corticotomy accelerate orthodontic tooth movement when retracting upper canines? A split-

mouth-design randomized controlled trial

Fadi Al-Naouma; Mohammad Y Hajeerb; Azzam Al-Jundic

a Specialist in Orthodontics (MSc), PhD student, University of Al-Baath Dental School,

Hamah, Syria

b Associate Professor of Orthodontics, University of Damascus Dental School, Damascus, Syria.

c Professor of Orthodontics, King Saud Bin Abdulaziz University for Health Sciences,

Riyadh, Kingdom of Saudi Arabia.

Corresponding Author

Dr Mohammad Y Hajeer

Associate Professor of Orthodontics at University of Damascus Dental School,

Damascus, Syria.

E-mail: myhajeer@gmail.com

Mobile: 00963940404840

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Does alveolar corticotomy accelerate orthodontic tooth movement when

retracting upper canines? A split-mouth-design randomized controlled trial

Short running title: Acceleration of tooth movement by alveolar corticotomy

ABSTRACT

Purpose: To evaluate the efficacy of alveolar corticotomy on orthodontic tooth movement when

retracting upper canines compared to the conventional technique; and to evaluate patients’ pain

and discomfort levels following corticotomy.

Methods: A split-mouth-design randomized controlled trial at the Orthodontic Department of

University Al-Baath Dental School. Thirty patients whose orthodontic treatment required canine

retraction were included. The predictor variable was the use of corticotomy to facilitate tooth

movement. Velocity of space closure was evaluated as a primary outcome variable by measuring

the distance between the canine and first molar on each side of the mouth immediately following

corticotomy; then at one week, 2 weeks, 4 weeks, 8 weeks and 12 weeks following corticotomy.

Levels of pain and discomfort were evaluated as secondary outcome variables using a

questionnaire administered four times during the first week following corticotomy. Paired t tests or

Wilcoxon matched-pairs signed-rank tests were used to detect significant differences.

Results: Thirty patients (15 males and 15 females) were recruited with a mean age of 20.04 ± 3.63

years (range: 15-24 years). Space closure velocities following corticotomies were significantly

faster on the experimental side than on the control side ( x =0.74 mm/weak vs. 0.20 mm/week

between T1-T0, respectively; P<0.001).The pain encountered during eating was high with 50 and

30% of patients reporting 'severe' pain at one day and three days postoperatively, respectively. No

significant differences could be detected between males and females regarding tooth movement

velocity on the experimental side.

Conclusions: Alveolar corticotomy procedure increased orthodontic tooth movement and this

was accompanied with moderate degrees of pain and discomfort.

Funding University of Al-Baath Postgraduate Research Budget (58801200927DEN)

Key words: Tooth movement velocity, corticotomy, canine retraction, pain, discomfort

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INTRODUCTION

The duration of orthodontic treatment is one of the issues patients complain about most,

especially in adult patients; this may be the reason behind many refusals of undergoing

orthodontic treatment. 1 To shorten orthodontic tooth movement times, various attempts have

been made: local or systemic administration of medicines, 2-5 mechanical or physical stimulation,

6,7 and surgery, including gingival fiberotomy, 8 alveolar surgery, 9 and distraction osteogenesis.1

In 1959, Köle described a surgical procedure involved a radicular corticotomy and supra-apical

osteotomy. This was accomplished by creating blocks of bone with vertical buccal and lingual

corticotomies and a supra-apical horizontal osteotomy connecting cut to enable rapid movement

of the dentoalveolar process. 10,11 Suya believed that a corticotomy was able to make tooth

movement faster because of the simultaneous movement of the tooth and the surrounding bone

block.12

Wilcko et al in a series of case reports 10,13 mentioned that rapid orthodontics with corticotomies

could increase tooth movement by increasing bone turnover, decreasing bone density14,15 and

decreasing hyalinization of the periodontal ligament.1 Frost found a direct correlation between the

severity of bone corticotomy and/or osteotomy and the magnitude of the healing response,

leading to accelerated bone turnover at the surgical site. This was called “regional acceleratory

phenomenon” (RAP). RAP was explained as a temporary stage of localized soft and hard-tissue

remodeling that resulted in rebuilding of the injured sites to a normal state through recruitment of

osteoclasts and osteoblasts via local intercellular mediator mechanisms involving precursors.16

Bogoch found a five-fold increase in bone turnover in a long bone adjacent to a corticotomy

surgery site. In alveolar bone adjacent to corticotomy, there is a marked increase in regional bone

turnover due to activation of new remodeling. Calcium is released from alveolar bone creating a

reversible demineralized condition (alveolar osteopenia) resulting in a decrease in bone mass

(mineral content or density), but no change in bone volume.17

According to Hajji, the active orthodontic treatment times in patients with corticotomies were 3 to 4

times shorter compared to those of patients without corticotomies.18 Cho et al in a study

conducted on the lower and upper jaws of two beagle dogs, applied cortical activation to the

buccal and lingual side of the alveolar bone in the right jaw where 12 holes were made on each

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cortical plate. This experiment showed that rapid initial tooth movement was apparent following

the application of orthodontic force after cortical activation.19 In another experiment by Lino et al

on 12 adult beagles, premolars were moved for 2 weeks after alveolar corticotomy.20 Lino et al

found an increase in tooth movement and postulated that post-corticotomy dental movement was

a combination of the classical orthodontic tooth movement and the movement of bone blocks

containing the tooth.20

However, corticotomy-facilitated (CF) anterior teeth retraction has not been evaluated in humans

employing randomized controlled trials (RCTs) except for one recent study in which the CF canine

retraction was supported with posterior mini-implants. 21 However, this study was conducted on a

relatively small sample size (n=13) with no assessment of the associated pain and distress

despite the apparently increased exposure to surgical intervention. Furthermore, assessment of

sex differences in tooth movement velocity for space closure is lacking in the available literature.

The purpose of the current study was to evaluate the efficacy of alveolar corticotomy in

accelerating orthodontic tooth movement. The researchers postulated that CF canine retraction

would be accomplished in a shorter period of time compared to the conventional canine retraction

method with no significant degrees of pain and discomfort. Therefore, the specific aims of the

current study were threefold: (1) to compare the velocity of canine retraction between the

surgically assisted side and the conventional side, (2) to evaluate patients’ responses towards

corticotomies and (3) to evaluate sex differences in tooth movement velocity on the experimental

side of the mouth.

MATERIAL AND METHODS

Study design and study sample

A split-mouth design randomized controlled trial was conducted at the Orthodontic Department of

University of Al-Baath Dental School and was approved by the University of Al-Baath Dental

School Research Ethics Committee (UBDS_16014_20081PG). Funding was provided by the

University of Al-Baath Postgraduate Research Budget (58801200927DEN).

An evaluation of patients referred to the Orthodontic Department for treatment was performed and

those who were planned for premolar extraction to facilitate canine retraction were included

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according to the following inclusion criteria: (1) Class II division 1 and division 2 malocclusions; (2)

permanent dentition with an age range between 15 and 24; (3) good general health with no

diseases that would contraindicate local anesthesia; (4) absence of craniofacial syndromes, cleft

lip/palate or previous dentofacial traumas; (5) good oral hygiene with no periodontal disease in the

upper jaw; (6) no previous orthodontic treatment; (7) absence of canine restorative or endodontic

treatment; and (8) absence of structural or morphological canine abnormalities. The research

project was explained to 73 candidates who met the inclusion criteria and information sheets

about the proposed trial were given. Fifty-five patients accepted participation and their informed

consents were obtained. A priori pilot study was conducted on 7 patients, and the variance of the

primary outcome measure (i.e. the canine retraction velocity) was calculated (SD= 0.4 mm/week).

Using paired-samples t tests with an alpha level of 0.05 and a power of 80% assuming that the

smallest difference requiring detection in canine retraction velocity was 0.25 mm/week between

the two related groups, a sample of 29 subjects was required. A disproportionate stratified random

sampling was employed to obtain a sample of 30 patients with equal numbers of females and

males. Using Minitab®15 (Minitab Inc, State College, Pa). A flow diagram of patients’ recruitment,

allocation and follow-up is given in Figure 1.

Randomization of the intervention side (split-mouth design)

Each patient was asked to pick an opaque sealed envelope from a container to allocate the

surgical intervention side. The containers included 15 envelopes with the letter ‘R’ indicating the

right-hand side and 15 envelopes with the letter ‘L’. All patients were treated with preadjusted

fixed appliances, with a 0.022” X 0.028” slot brackets (MBT prescription, American Orthodontics®,

Sheboygan, WI, USA). A conventional anchorage protocol was employed (i.e. transpalatal arches

soldered to the first upper molars bands). The orthodontic treatment as well as the surgical

intervention was performed by the same principal researcher (F. A-N) who was an orthodontic

MSc student and had undergone a previous training in oral and maxillofacial surgery.

Predictor and outcome variables

The predictor variable was the canine retraction technique (i.e. corticotomy-facilitated canine

retraction versus conventional sliding canine retraction). The primary outcome measure was the

velocity of space closure during canine retraction, whereas the secondary outcome measures

were levels of pain and discomfort during the first week following the surgical procedure.

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(1) Velocity of space closure. The distance between canine bracket hook and the first molar hook

was recorded using a digital caliper (Figure 2). Measurements were performed at immediately

following corticotomy (T0), one week (T1), 2 weeks (T2), 4 weeks (T3), 8 weeks (T4), and at 12

weeks following corticotomy (T5). These measurements were considered as an indicator of

canine retraction speed taking into account that transpalatal arches were used for anchorage

which should have resisted partially two possible molar movements, i.e. orthodontically-induced

and physiological mesial drift.

(2) Assessment of patients’ perception of pain, discomfort and satisfaction towards corticotomy. A

questionnaire (Appendix 1) was administered at the following assessment times: one day (T1), 3

days (T2), 5 days (T3), and at one week following corticotomy (T4). It contained five questions

with four-point Likert-scales and one question with three-point scale. Patients were asked to

provide their subjective opinion about any possible complaints such as pain during eating, pain

during daytimes, pain awaking them during night times, and their feeling of swelling on the

surgical side.

Data collection methods

Intervention Group:

A fixed appliance was used on the upper jaw. Leveling and alignment was performed using a

sequence of arch wires. Following the insertion of a 0.019 X 0.025 stainless steel wire, the

extraction of the upper first premolars was performed. Four weeks following extraction, the

alveolar bone on the experimental side was corticotomized as follows: the gingival mucoperiosteal

flaps were raised to expose cortical bone on both the buccal and the palatal sides of the canine

(Figures 3 and 4). The horizontal cut line of the corticotomy was made above the apices of the

canine 2-3 mm on the buccal side and at the level of palatal groove on the palatal side. The

vertical cut lines were made 1-2 mm apical to the alveolar crests of the canine to the horizontal cut

lines on the buccal and palatal sides. Small corticotomy perforations were drilled in the buccal and

palatal cortical bone (about 20 perforations on each side; Figures 5 and 6). The corticotomy cuts

were performed with a depth of 2 mm by a fissure bur (width 2 mm), whereas perforations were

made with a round bur (diameter 2 mm) under saline-solution irrigation. The mucoperiosteal flaps

were sutured with absorbable surgical sutures. Immediately after corticotomies, the canines of the

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experimental and control sides were moved distally along the orthodontic wire with a continuous

force of 120g22 by using Sentalloy® Nickel-Titanium closed coil springs (American Orthodontics®,

Sheboygan, WI, USA) on 0.019 × 0.025” stainless steel archwires. One end of the spring was

fixed to the hook of the canine bracket with a ligature wire, and the other side was fixed to the

hook of the band of the upper first molar. The length of each spring, which corresponded to a

contractile force of 120g, was measured intraorally with a caliper and strain gauge, and the

activation of the spring was set at that length. Non-steroid anti-inflammatory drugs were not

allowed to be taken following surgery. Patients were allowed to take analgesics (Tramadol® 50-mg

tablets) only when they felt that the pain was severe but after filling their questionnaires.

Application of a lower fixed appliance was postponed until the completion of the canine retraction

procedure on the upper jaw.

Data Analyses

Statistical analysis was conducted using Minitab® 15. Paired-sample t tests or Wilcoxon matched-

pairs signed-rank tests were employed to evaluate intra- and inter-group differences (with α set at

0.05). A Bonferroni correction of the significance level was used to adjust for multiple comparisons

(i.e. results with P values less than 0.01 were considered significant for each of the five

comparisons made between the two groups). The error of the measurement method was

calculated based on double measurements on 20 randomly selected tooth movement

measurements using Dahlberg’s formula.23 The measurement was repeated after an interval of 30

minutes for the selected patients. The error of the method was 0.08 mm and was considered low.

No systematic error was detected when paired t test was applied. Intraclass correlation coefficient

(ICC) confirmed the high reliability of the measuring procedure (r=0.992).

RESULTS

This split-mouth-design RCT was conducted on 30 patients (15 males and 15 females) with a

mean age of 20.04 (SD=3.63) years. Baseline sample characteristics are given in Table 1. Sixty

upper canines were retracted using two methods: accelerated retraction with alveolar corticotomy

(the experimental side) and conventional retraction without any surgical intervention (the control

side).

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The movement velocity on the experimental side was faster than that on the control side

throughout the experiment (Table 2). There was a significant difference (P<0.001) between the

experimental and control sides at the T0-T1 and T1-T2 intervals and the tooth movement velocity

was approximately 4 times faster on the experimental side. There was a significant difference (P<

0.001) between the experimental and control sides at the T2-T3 and T4-T5 intervals in which

movement was approximately 3 times faster on the experimental side. No significant differences

could be detected between males and females regarding tooth movement velocity on the

experimental side (Table 3).

Regarding the subjective assessment of pain (Table 4), 50 % of patients reported extreme pain

during eating at T1. There was a significant reduction in the mean score of pain during eating at

all assessment times (P=0.039 at T2, P=0.008 at T3, P<0.001 at T4) with no patients reporting

extreme pain at the last assessment time (i.e. one week following corticotomy). When daytime

pain was evaluated, more than half of the sample had mild to moderate feeling of pain during

daytimes. There was also a reduction in the mean score of daytime pain, but this reduction was

not significant in the T2-T1 and T3-T1 comparisons, whereas it was significant at the T4-T1

comparison (P=0.003). The proportion of patients that had no or mild pain was 66.66% at T4. The

levels of the night-time pain were low and acceptable at almost all assessment times.

When perception of swelling was explored (Question 4; Table 5), the ratio of patients who suffered

from medium or severe swelling at T1 was 80%. The level of swelling was relatively higher on the

third day (T2) of corticotomy compared to that at T1, but without being statistically significant

(p=0.476). A significant reduction in the amount of swelling was observed at T4 compared to the

baseline data (p<0.001) with no patients suffering from severe swelling at seven days following

corticotomy. More than half of the sample had moderate to severe feeling of discomfort on the

surgical side (Question 5; Table 5) at T1. Significant changes were observed in the T3-T1 and T4-

T1 comparisons in this scale.

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When patients were asked to choose the more annoying experience between the two surgical

procedures (premolar extraction versus corticotomy; Table 6), most patients indicated that

premolar extraction was more traumatic to them.

DISCUSSION

This randomized controlled trial was undertaken to primarily investigate the influence of corticotomy

on tooth movement in comparison with the standard orthodontic technique and to secondarily

assess the levels of patients’ pain, discomfort and satisfaction following corticotomy. The current

findings show that the corticotomy-facilitated (CF) technique accelerated tooth movement

significantly. The rate of tooth movement in the CF group was 2-4 times greater than that of the

standard group. The pain encountered during eating was high at the first two days. The levels of

the pain began to decrease at the third day and continued decreasing until the end of the first

weak. A high proportion of patients had moderate to severe swelling immediately following

corticotomy which subsided substantially at one week postoperatively.

These results of increased speed of canine retraction agree with those of Lino et al20 in their animal

study. The current findings also corroborate the clinical observations of Wilcko et al10,13 and Hajji18

who reported similar significant reductions in treatment times. Space closure velocity on the

experimental side was significantly faster than on the control side at T0-T1 and T1-T2 compared to

the readings obtained at T2-T3, T3-T4 and T4-T5. Therefore, it seems that acceleration of tooth

movements occurs more prominently in the immediate post-corticotomy stage. This trend was also

documented by Wilko et al,10 Aboul-Ela et al 21 and Lino et al. 20

It may be argued that the current surgical intervention is somewhat aggressive in comparison with

the so-called ‘corticision’ procedure which has been shown to highly accelerate tooth movement in

animal studies with minimal surgical intervention. 24 In corticision, a reinforced scalpel is used as a

thin chisel to separate the interproximal cortices transmucosally without reflecting a flap in

premolar-canine region. While significantly reducing the surgical operation’s duration, this

technique does not give the operator the wide and clear access which is usually obtained after

reflecting flaps in the corticotomy procedures. In addition, the excessive use of the hammer and

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chisels in the maxilla adds a risk of having benign paroxysmal positional vertigos which have been

documented in many cases. 24

In orthodontics, anchorage reinforcement is of prime importance when the extraction of premolars

is involved. In an apparently invasive investigation, Aboul-Ela et al found no significant molar

anchorage loss during canine retraction on either the corticotomy or the control side, but mini-

implants were used for anchorage on both sides. 21 In the current study, anchorage loss was not

evaluated and the performed measurements represented space closure velocity and gave an

indication of the canine retraction speed. However, the use of transpalatal arches in the current

study aimed to minimize molar mesial drift taking into account that only moderate amount of force

was applied for canine retraction and only one tooth was subjected to this force. The effect of

increased speed of canine retraction on the anchor teeth should be critically evaluated in future

clinical trials and the incorporation of absolute anchorage devices should also be considered.

During the surgical intervention, bone blocks surrounding the retracted canines were not created.

Therefore, the rapid rate of tooth movement seemed to depend mostly on the regional

acceleration phenomenon (RAP); i.e. the increased alveolar bone reaction rather than bony block

movement. The current findings support the clinical observations of Wilko et al10 and disagree with

the proposed mechanism by Suya et al who depended on the ‘bone block movement’

hypothesis.12 Further histological studies with longer follow-up periods are required to investigate

the underlying biologic picture of the suggested mechanism.

Non-steroid anti-inflammatory drugs were not allowed to be taken following surgery. This

precaution was undertaken to avoid their possible interferences with the RAP. However,

analgesics (such as Tramadol) were allowed only when the pain was unbearable. The pain

encountered during eating was high at the first two days and decreased substantially at the

following assessment times. This finding is generally in agreement with clinical observations of

Wilcko et al10 who suggested that "total recovery from the procedure takes seven to 10 days."

The proportion of patients who suffered from medium to severe swelling immediately following

corticotomy was 80%. The level of swelling was relatively higher on the third day of corticotomy

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(T2) compared to that at T1. A significant reduction in the amount of swelling was observed at T4

(one week following corticotomy) compared to the baseline data (p<0.001) with no patients

suffering from severe swelling at seven days following corticotomy. These findings do not support

the clinical observations of Wilcko et al,10 who mentioned that ‘some swelling and very little

bleeding’ might be encountered, whereas the current results showed high levels of swelling in the

first five days. When a question was posed about the more annoying experience between the two

surgical procedures (premolar extraction versus corticotomy), most patients indicated that

premolar extraction was more traumatic to them. This finding may be attributed to the fact that

corticotomy was conducted in one side, whereas upper first premolars were extracted bilaterally in

one session. Thus, the alveolar corticotomy procedure appeared to be well tolerated by our

patients with moderate degrees of pain and discomfort in general.

The strengths of the current research work can be summarized as being apparently the first RCT

assessing tooth movement speed of the CF canine retraction compared to the ordinary canine

retraction method in a split mouth design as well as being probably the first to systematically

assess the associated levels of pain and discomfort in a sample of orthodontic patients. However,

several shortcomings should be avoided in future clinical trials such as: (1) the need for a rigid

back reference plane to assess the accurate amounts of tooth movements without being affected

by the untoward movement of the posterior anchoring teeth; (2) the need for a radiographic

assessment of tooth positions and angulation following CF retraction to verify whether the

increased velocity has affected the required ideal tooth positions at the end of treatment; (3) the

need for longer follow-up periods to verify whether the surgically assisted tooth movements could

really shorten the overall orthodontic treatment times.

CONCLUSIONS

Alveolar corticotomy procedure increased orthodontic tooth movement and was associated with

moderate degrees of pain and discomfort. Tooth movement velocities following corticotomies were

2-4 times faster on the experimental side than on the control side particularly during the early stage

after corticotomy. No significant differences could be detected between males and females

regarding tooth movement velocity on the experimental side.

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13. Wilcko WM, Ferguson DJ, Bouquot JE, Wilcko MT: Rapid orthodontic decrowding with

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Legends

Figure 1: A flow chart showing patients’ recruitment, assignment and follow-up.

Figure 2: Measuring the distance between canine bracket hook and the first molar band hook.

Figure 3: Schematic drawing of the incision performed on the palatal side.

Figure 4: Schematic drawing of the incision performed on the buccal side.

Figure 5: Vertical and horizontal corticotomy cuts and perforations on the buccal side.

Figure 6: Vertical and horizontal corticotomy cuts and perforations on the palatal side.

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Table 1: Baseline sample characteristics

30 patients (60 canines) Number of patients

15 males & 15 females Gender distribution

20.04 (3.63) years Mean age (SD)

19 Class II division 1

11 Class II division 2

12 Mild anterior crowding

9

3

10/3/17

Anterior deep bite

Posterior cross bite

Facial height

(normal/increased/decreased)

SD: standard deviation

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Table 2 Comparison of space closure velocity between the experimental and the control sides (mm/week)

group time

Experimental Mean (SD)

control Mean (SD)

Difference Mean

P-Value

T0-T1 0.739 (0.365)

0.201 (0.149) 0.538 <0.001

T1-T2 0.455 (0.402)

0.105 (0.115) 0.350 <0.001*

T2-T3 0.308 (0.248)

0.095 (0.161) 0.213 <0.001*

T3-T4 0.282 (0.113)

0.124 (0.061) 0.158 <0.001

T4-T5 0.243 (0.073)

0.080 (0.060) 0.163 <0.001*

Paired-samples t tests or Wilcoxon matched-pairs signed-rank tests (the non-parametric equivalent) were employed to evaluate within- and intra-group differences. * employing Wilcoxon matched-pairs signed-rank tests instead of paired t tests.

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Table 3 Comparison of space closure velocity (mm/week) between males and females in the experimental side

Group

Time

Males Mean (SD)

Females Mean (SD)

Difference Mean

P-Value

T0-T1 0.723 (0.262)

0.747 (0.414) - 0.024 0.851

T1-T2 0.355 (0.122)

0.485 (0.464) - 0.130 0.045*

T2-T3 0.318 (0.248)

0.308 (0.161) 0.01 0.792*

T3-T4 0.271 (0.093)

0.287 (0.124) - 0.016 0.689

T4-T5 0.252 (0.083)

0.263 (0.077) - 0.011 0.729

T0-T5 0.333 (0.081)

0.366 (0.080) - 0.033 0.302

* employing Mann-Whitney U test instead of two-sample t test.

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Assessment of Pain following alveolar corticotomy using a four-point Likert scales at four different times during the first week following corticotomy.

Table 4

Patients’ Responses % P-value* (vs T1)

4 (Severe)

3 (Moderate)

2 (Mild)

1 (NO)

Questions

Pain during eating Q1 50 30 10 10 T1

0.039 30 36.67 23.33 10 T2 0.008 20 43.33 26.67 10 T3

<0.001 0 46.67 33.33 20 T4 Pain during daytimes Q2 23.33 33.33 33.33 10 T1

0.326 20 33.33 36.67 10 T2 0.057 16.67 30 43.33 10 T3 0.003 0 33.33 53.33 13.33 T4

Pain interrupting sleeping at night times Q3 10 10 36.67 43.33 T1

1.000 10 10 36.67 43.33 T2 1.000 10 10 36.67 43.33 T3 0.211 0 16.67 40 43.33 T4

Q1: "Do you feel pain during eating?", Q2: "Do you feel pain during

daytimes?", Q3: "Do you feel pain which may awaken you during night

times?".

* Comparisons with the baseline data (recorded at T1) were performed

using Wilcoxon matched pairs signed rank tests. Bonferroni correction was

employed for multiple comparisons.

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Assessment of Swelling and Discomfort following alveolar corticotomy using a four-point Likert scales during the first week following corticotomy.

Table 5

Patients’ Responses % P-value* (vs T1)

4 (Severe)

3 (Moderate)

2 (Mild)

1 (NO)

Questions

Swelling on the surgical side Q4 40 40 10 10 T1

0.476 43.33 33.33 23.33 0 T2 0.823 43.33 26.67 30 0 T3

<0.001 0 20 46.67 33.33 T4 Discomfort on the surgical side Q5 10 43.33 26.67 20 T1

0.573 10 40 30 20 T2 0.005 0 30 50 20 T3 0.005 0 30 50 20 T4

Q4: "Do you feel swollen on the surgical side?"

Q5: "Do you feel discomfort on the surgical side?"

* Comparisons with the baseline data (recorded at T1) were performed

using Wilcoxon matched pairs signed rank tests. Bonferroni correction was

employed for multiple comparisons.

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Overall patients' perception of discomfort regarding the surgical intervention compared to the premolar extraction. Table 6

Which one caused more discomfort? Patients' Response (%) Q6

P-values (vs. T1) Both Surgery Premolar

Extraction

20 20 60 T1 0.573 16.67 20 63.33 T2 0.573 16.67 20 63.33 T3 0.573 16.67 20 63.33 T4

Comparisons with the baseline data (recorded at T1) were performed using

Wilcoxon matched pairs signed rank tests. A Bonferroni correction was employed for multiple comparisons.

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Appendix 1

Please answer the following questions using the possible answers given:

Question 1: Do you feel pain during eating?

1 No □ 2 mild □ 3 moderate □ 4 severe □

Question 2: Do you feel pain during daytimes?

1 No □ 2 mild □ 3 moderate □ 4 severe □

Question 3: Do you feel pain which may awaken you during night times?

1 No □ 2 mild □ 3 moderate □ 4 severe □

Question 4: Do you feel swollen on the surgical side?

1 No □ 2 mild □ 3 moderate □ 4 severe □

Question 5: Do you feel discomfort on the surgical side?

1 No □ 2 mild □ 3 moderate □ 4 severe □

Question 6: Which one of the following has caused more discomfort to you?

1 extraction of premolars □ 2 surgical procedure □ 3 both of them have caused discomfort □

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