Perception of pain during orthodontic treatment

Abstract

The aims of this study were to investigate the initial time at which pain occurs after insertion of two initial wires of different sizes, the duration of the pain, the areas affected within the mouth, the level of self-medication, the effect of this pain on daily life, and whether gender is important in the perception of pain. The study group consisted of 109 patients (52 boys, 57 girls) with a mean chronological age of 13.6 years for boys and 14.7 years for girls. Insertion of either a 0.014 or 0.016 inch wire was by random selection. Following insertion of the archwires, a questionnaire comprising a total of 49 questions was given to the patients. They described the time of initial pain in the first question, answered the next 24 questions as 'yes' or 'no', and used a visual analogue scale for the final 24 questions. No significant differences were found in terms of gender, in the perception period of initial pain as regards the areas affected within the mouth or the effect of pain on daily living when the 0.014 and 0.016 inch wire groups were compared at 6 hours, 1, 2, 3, 4, 5, 6 and 7 days. At 24 hours, which was found to be statistically significant, more pain relief was used in the 0.014 inch archwire group. The results show that in both groups, initial pain was perceived at 2 hours, peaked at 24 hours and had decreased by day 3.

Full text

European Journal of Orthodontics 26 (2004) 79–85 European Journal of Orthodontics vol. 26 no. 1
 European Orthodontic Society 2004; all rights reserved.
Introduction
Pain is one of the most important reasons why patients are
discouraged from seeking orthodontic treatment (Oliver
and Knapman, 1985). Although the reason for the pain
encountered during orthodontic tooth movement is not
fully understood, various concepts have been discussed.
Furstman and Bernick (1972) suggested that
periodontal pain is caused by a process of pressure,
ischaemia, inflammation, and oedema. Burstone (1964)
identified an immediate and delayed pain response; the
former being related to the initial compression of the
periodontal ligament (PDL) immediately after placement
of the archwire. The latter response, which started a
few hours later, was termed hyperalgesia of the PDL.
Prostaglandins have been shown to cause hyperalgesia,
which is an increased sensitivity to noxious agents such
as histamine, bradykinin, serotonin, acetylcholine and
substance P. There are indications that perceptions of
pain are due to changes in blood flow in the PDL
(Burstone, 1964; White, 1984; Kvam et al., 1987) and are
correlated with the presence of substances such as
prostaglandins and substance P (Burstone, 1964; White,
1984; Kvam et al., 1987; Ngan et al., 1989).
The subjective perception of pain is difficult to measure.
Burstone (1964) noted a wide range of individual
responses when similar forces were applied to the teeth.
Several investigations have described patient responses
to fixed orthodontic appliances. These reported that
pain begins a few hours after application of an
orthodontic force and lasts approximately 5 days (Jones,
1984; Jones and Richmond, 1985; Sinclair et al., 1986;
Kvam et al., 1987; Ngan et al., 1989; Wilson et al., 1989;
Jones and Chan, 1992). Jones (1984), in a study
examining the discomfort experienced by patients after
placement of initial archwires, found statistically higher
discomfort experienced by adults compared with
adolescents.
Ngan et al. (1989) suggested the use of non-steroid
anti-inflammatory agents such as aspirin and ibuprofen
to provide a level of relief.
The aims of this study were to determine following
application of two wires of different sizes: (1) the time at
which pain starts, (2) the duration of the pain, (3) the
areas it affects within the mouth, (4) the level of self-
medication, (5) the effect of this pain on daily living and
(6) whether gender is important in the perception of
pain. Comparisons were made between each wire group
and also by comparing the two wire groups with each
other.
Subjects and method
The study group comprised 109 patients (52 boys,
57 girls) treated at the Department of Orthodontics,
Faculty of Dentistry, University of Ege, I
˙
zmir, Turkey.
The chronological mean age was 13.6 years for the boys
[standard deviation (SD) = 1.38)] and 14.7 years for the
girls (SD = 1.47). Dental crowding was not evaluated.
Pre-angulated and pre-torqued 0.018 inch Edgewise
appliances ‘Roth System’ (Forestadent, Pforzeim,
Germany) were used in all patients. After bracket
bonding, 0.014 or 0.016 inch NiTi (Ormco, CA, USA)
wires were used initially. The patients were randomly
Perception of pain during orthodontic treatment
with fixed appliances
Aslıhan M. Ertan Erdinç and Banu Dinçer
Department of Orthodontics, Faculty of Dentistry, University of Ege, I
·
zmir, Turkey
SUMMARY The aims of this study were to investigate the initial time at which pain occurs after insertion
of two initial wires of different sizes, the duration of the pain, the areas affected within the mouth,
the level of self-medication, the effect of this pain on daily life, and whether gender is important in the
perception of pain. The study group consisted of 109 patients (52 boys, 57 girls) with a mean chronological
age of 13.6 years for boys and 14.7 years for girls. Insertion of either a 0.014 or 0.016 inch wire was by
random selection. Following insertion of the archwires, a questionnaire comprising a total of 49 questions
was given to the patients. They described the time of initial pain in the first question, answered the next
24 questions as ‘yes’ or ‘no’, and used a visual analogue scale for the final 24 questions.
No significant differences were found in terms of gender, in the perception period of initial pain as
regards the areas affected within the mouth or the effect of pain on daily living when the 0.014 and
0.016 inch wire groups were compared at 6 hours, 1, 2, 3, 4, 5, 6 and 7 days. At 24 hours, which was found
to be statistically significant, more pain relief was used in the 0.014 inch archwire group. The results show
that in both groups, initial pain was perceived at 2 hours, peaked at 24 hours and had decreased by day 3.
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selected for insertion of the 0.014 or 0.016 inch wires.
Following placement of the archwires they were ligated
to all teeth. The 0.014 inch group consisted of 56 sub-
jects (29 boys, 27 girls). The wire was inserted in both
arches in 42 patients and in the maxilla in 14 patients in
this group. The 0.016 inch group consisted of 53 subjects
(23 boys, 30 girls). In this group, the wire was inserted
in both arches in 41 patients and in the maxilla in
12 patients. No extra-oral appliances, palatal arches or
quad-helix appliances were used during the experimental
period.
Following archwire insertion the patients were given
previously prepared questionnaires and instructed
on how they should be completed. The questionnaires
were completed by all 109 patients and returned at the
following appointment. Question 1 asked the time at
which pain was first perceived after archwire insertion.
In the following questions, the patients were asked
separately for each day, from 6 hours to day 7, whether
they had pain, in which areas they perceived the pain,
whether they took pain relief and whether the pain
affected their daily living (Figure 1). The patients were
allowed to take medication when they felt it necessary.
The questions relating to daily living asked whether
any of the activities carried out in their free time, such
as sports and/or social activities, were affected. The
questionnaire comprised 49 questions in total. The
patients described the initial pain in the first question,
they answered 24 questions as ‘yes’ or ‘no’, and in the
other 24 questions the patients with ‘yes’ answers were
provided with a visual analogue scale (VAS) divided
into tens, in which 0 indicated no pain and 100 the
greatest pain. This method is widely used for measuring
pain and has been described by other investigators as
being sensitive and reliable and having certain advantages
over verbal scales (Huskisson, 1974; Seymour et al.,
1985).
Statistical analysis
For statistical analysis the Statistical Package for Social
Sciences 10.0 (SPSS Inc., Chicago, IL, USA) was used.
Gender was taken into consideration and chi-squared
and Fisher’s exact tests were applied. The Kolmogorov–
Smirnov test of normality was used for the VAS scores.
A Mann–Whitney U-test was applied because of non-
normal distribution. For assessment of the relationship
between VAS scores and consumption of pain relief, the
Spearman rank correlation analysis was utilized.
The level of statistical significance was set at P < 0.05.
Results
Because gender differences were not found to be
statistically significant in the perception of pain, the
findings were evaluated without sex discrimination.
Initial pain (Table 1 and Figure 2)
Initiation of pain was perceived 2 hours after wire inser-
tion in both groups. There were no statistically significant
differences between the groups. In the 0.014 inch group,
80 A. M. ERTAN ERDINÇ AND B. DINÇER
Figure 1 The questionnaire used in the present study.
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32.1 per cent (18 patients) perceived pain. In the
0.016 inch group, 35.7 per cent (20 patients) perceived
pain. No pain was reported by 10.7 per cent (six patients)
in the 0.014 inch group and 11.4 per cent (six patients)
in the 0.016 inch group.
Periods of pain (Table 2 and Figures 3 and 4)
Six hours after appliance insertion, pain was reported by
83.9 per cent (47 patients) in the 0.014 inch group and
by 88.1 per cent (47 patients) in the 0.016 inch group.
At the end of day 1, 91 per cent (51 patients) in the
0.014 inch group and 90.5 per cent (48 patients) in the
0.016 inch group perceived pain. From day 2 to day 7
there was a daily decrease in pain. On day 7, pain was
reported by 41 per cent (23 patients) in the 0.014 inch
group and by 26.4 per cent (14 patients) in the 0.016 inch
group. These findings were not statistically significant.
Some subjects reported the pain as being unbearably
strong (score 100), but the mean score of 50 was
relatively moderate. The peak for pain intensity was
recorded on day 1 in both archwire groups and started
to decline after day 3.
Pain regions (Tables 3 and 4 and Figure 5)
Although not statistically significant, in both archwire
groups pain was perceived at the anterior and posterior
teeth during the first few hours, but this decreased
over the following hours. Again, while not statistically
significant, the pain perceived at the anterior teeth was
greater than at the posterior teeth.
Consumption of pain relief (Table 5)
The highest consumption of pain relief for both groups,
although not statistically significant, was recorded at
the end of the first 6 hours. On the following days, the
consumption of pain relief decreased day by day. At
the end of day 1 there was a statistically significant
difference (P < 0.05) in the consumption of pain relief
between the two groups. Fifty-five per cent (31 patients)
in the 0.014 inch group and 32 per cent (17 patients) in
the 0.016 inch group consumed pain relief. There was no
consumption of pain relief in the 0.014 inch group on
day 7 and in the 0.016 inch group on days 5, 6 and 7.
VAS scores and consumption of pain relief (Table 6)
There was a statistically significant correlation on days
1, 2, 3 and 4 (P < 0.01) and at 6 hours and on days 5 and
PERCEPTION OF PAIN 81
Table 1 Distribution of initial pain versus wire size and time.
Time after insertion (hours) 0.014 inch wire 0.016 inch wire
% n % n
1 7.1 4 3.7 2
2 32.1 18 35.7 20
3 16 9 7.1 4
4 10.7 6 22.6 12
5 3.5 2 – –
6 19.6 11 16.9 9
%, percentage of total reporting pain; n, number of respondents.
Figure 2 Time of initial pain perception.
Table 2 Distribution of pain periods and mean visual analogue scale scores versus wire size and time.
Time after insertion 0.014 inch wire 0.016 inch wire
% n Mean pain intensity score SD Range % n Mean pain intensity score SD Range
6 hours 83.9 47 38 26.9 0–100 88.1 47 45 30.1 0–100
1 day 91 51 49 28.3 0–100 90.5 48 48 28.1 0–100
2 days 87.5 49 39 21.8 0–100 86.7 46 40 20.9 0–100
3 days 82.1 46 31 20.3 0–60 71.6 38 29 15.1 0–60
4 days 66 37 28 12.5 0–50 50.9 27 23 13.1 0–55
5 days 60.7 34 23 10.2 0–50 45.2 24 20 11.8 0–55
6 days 48.2 27 18 8.6 0–45 35.8 19 11 2.6 0–40
7 days 41 23 13 6.3 0–45 26.4 14 9 5.3 0–45
%, percentage of total reporting pain; n, number of respondents answering ‘yes’; SD, standard deviation.
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6 (P < 0.05) between VAS scores and the consumption
of pain relief in the 0.014 inch group. A statistically
significant correlation (P < 0.01) was also observed in
the 0.016 inch group at 6 hours and on days 1, 2, 3 and 4.
Effect of pain on daily life (Table 7)
Although not statistically significant, the most highly
affected daily living activity (sports and/or social) was
observed at 6 hours, with a rate of 57 per cent (33 patients)
in the 0.014 inch group and 50.5 per cent (27 patients) in
the 0.016 inch group. In the following days there was a
decrease in the number of patients reporting such an effect.
Discussion
This study was performed on 109 patients, who were asked
to complete a questionnaire concerning pain perceived
82 A. M. ERTAN ERDINÇ AND B. DINÇER
Figure 3 Percentage of patients perceiving pain within a reporting
period.
Figure 4 Mean pain intensity scores on the visual analogue scale
index of pain periods.
Table 3 Perception of pain at the anterior teeth and mean pain intensity scores versus wire size and time.
Time after insertion 0.014 inch wire 0.016 inch wire
% n Mean pain intensity score SD % n Mean pain intensity score SD
6 hours 44.6 25 50 30.6 52 28 51 28.3
1 day 39.2 22 44 32.4 49 26 46 25.2
2 days 44.6 25 41 25.3 43 23 43 29.7
3 days 37.5 21 38 15 30 16 39 16
4 days 39.2 22 28 12.3 37 20 24 13.7
5 days 33.9 19 23 12.3 24 13 21 15.2
6 days 28.5 16 20 11 28 15 18 10.7
7 days 33.9 19 11 8.1 25 14 7 6.7
%, percentage of total reporting pain; n, number of respondents answering ‘yes’; SD, standard deviation.
Table 4 Perception of pain at the posterior teeth and mean pain intensity scores versus wire size and time.
Time after insertion 0.014 inch wire 0.016 inch wire
% n Mean pain intensity score SD % n Mean pain intensity score SD
6 hours 26.7 15 40 24.5 20 11 38 16.1
1 day 17.8 10 38 15.7 18 10 35 12.7
2 days 21.4 12 35 11.4 26 14 33 11.2
3 days 14.2 8 24 11.4 24 13 21 11.5
4 days 10.7 6 18 11.2 11 6 19 9.7
5 days 8.9 5 15 8.8 13 7 18 7.3
6 days 10.7 6 13 8.3 16 9 9 5.2
7 days 7.4 4 10 6 13 7 7 4.3
%, percentage of total reporting pain; n, number of respondents answering ‘yes’; SD, standard deviation.
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after insertion of fixed orthodontic appliances. The form
was given to the patients at the first appointment after
insertion of the archwires and returned at the next
appointment. The system of measuring discomfort by
VAS was found to be appropriate, with even young
children able to understand the concept and respond
to the questions.
Space analysis was not included in the assessment
as no correlation has been found between pain and
severity of crowding (Jones and Richmond, 1985).
Feinmann et al. (1987) reported that pain is related
to gender and social class. In this study, no significant
difference was found between pain and gender, which is
in agreement with the findings of Jones and Chan
(1992). Gender discrimination was therefore excluded
and boys and girls were evaluated together.
Following ligation of the archwires, the patients
started to feel uncomfortable and perceived pain.
Clinically and statistically, it was expected that there
would be a difference between the pain perceived by
those in whom different sized wires were inserted.
However, no statistically significant difference was
found between the initial pain reported by the 0.014
and 0.016 inch groups. Jones (1984), in a study of pain
perceived following insertion of initial archwires,
reported that some patients had great discomfort for the
first few days, with adults affected more than adolescents.
In this study, although not statistically significant, pain
peaked at 24 hours in both groups following archwire
ligation. This finding is in agreement with Scheurer et al.
(1996) and Wilson et al. (1989).
Again, while not statistically significant, pain started
to decrease after day 3 and the mean pain intensity
score was between 0 and 60, indicating that the pain
perceived was moderate (Table 2).
As can be seen from Tables 3 and 4, although not
statistically significant, the data show higher pain scores
for the anterior than for the posterior teeth, in agreement
with the results of other investigators (Ngan et al., 1989;
Scheurer et al., 1996). This may be explained by the fact
that during the levelling phase the anterior teeth are
often more involved and incisors have smaller root
surfaces than molars. In addition to this, biting while
eating might be the reason for the higher pain perceived
in the anterior teeth.
At 24 hours, the consumption of pain relief was
higher in the 0.014 than in the 0.016 inch group; this was
PERCEPTION OF PAIN 83
Figure 5 Mean pain intensity scores on the visual analogue scale
index of perception of pain at the anterior and posterior teeth.
Table 5 Consumption of pain relief versus wire size and time.
Time after insertion 0.014 inch wire 0.016 inch wire
% n % n
6 hours 58.9 33 49 26
1 day 55 31 32 17
2 days 33 19 16 9
3 days 19 11 7.5 4
4 days 10 6 9.4 5
5 days 3.5 2 – –
6 days 5.3 3 – –
7 days – – – –
%, percentage of total reporting consumption of pain relief;
n, number of respondents.
Table 6 Evaluation of the relationship between mean
pain intensity scores and consumption of pain relief using
Spearman rank correlation analysis.
Time after insertion 0.014 inch wire 0.016 inch wire
6 hours 0.551** 0.766**
1 day 0.709** 0.817**
2 days 0.612** 0.724**
3 days 0.698** 0.513**
4 days 0.632** 0.686**
5 days 0.370* –
6 days 0.493** –
7 days – –
*P < 0.05; **P < 0.01.
Table 7 Effect of pain on daily life versus wire size and time.
Time after insertion 0.014 inch wire 0.016 inch wire
% n % n
6 hours 57 33 50.5 27
1 day 48 27 47 25
2 days 44 25 37 20
3 days 35 20 45 24
4 days 30 17 37 20
5 days 25 14 26 14
6 days 32 18 24 13
7 days 28.5 16 30 16
%, percentage of total reporting an effect on daily life;
n, number of respondents.
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statistically significant (Table 5). However, no statistically
significant difference was observed as regards perception
of pain between the 0.014 and 0.016 inch groups. Self-
medication was statistically significantly higher in the
0.014 inch group compared with the 0.016 inch group. A
possible explanation is that the patients in the 0.014 inch
group consumed more pain relief on a preventive basis
with the anxiety of probable pain.
In contrast to Feinmann et al. (1987), who found
no correlation between pain experience and analgesic
consumption, a correlation between pain intensity
scores and the consumption of pain relief was observed
in the present study, which is in agreement with the
findings of Scheurer et al. (1996). The results are also in
agreement with Jones (1984), who reported a correlation
between perceived discomfort and analgesic consumption.
Scheurer et al. (1996) claimed that perceived pain and
the consumption of pain relief would decrease if the
patient was efficiently informed about the discomfort
that would be experienced.
Brown and Moerenhout (1991) reported that pain
from appliances and its influence on daily life are seen
as major causes of discontinuance of treatment. In the
present study, although not statistically significant, it
was observed that the daily lives of 50 per cent of the
patients were influenced by the orthodontic wire at
6 hours and on days 1 and 2. However, there was a
significant decrease in the number of patients whose
daily lives were affected starting from day 3 until day 7
(Table 7).
Sergl et al. (1998) reported that patients who are
aware of the severity of their orthodontic irregularities
and can control their emotions perceive a less intense
feeling of discomfort. Before commencing orthodontic
treatment, patients should be motivated by informing
them of the nature and extent of the malocclusion.
Because psychological factors during orthodontic treat-
ment influence patient adaptation to discomfort and
pain (Brown and Moerenhout, 1991; Jones and Chan,
1992), the possibility of physiological adaptation by
patient distraction techniques is also feasible.
Conclusions
No gender discrimination was found for perception of
pain in the two different archwire groups. No significant
correlation was found for the time at which initial pain
was perceived after insertion of the two initial archwires
of different sizes. In both groups, initial pain was
perceived at 2 hours. Although not statistically sig-
nificant, pain reached a peak in both groups on day 1,
started to decrease on day 3 and was perceived as being
greater at the anterior than the posterior teeth. The
consumption of pain relief was highest at 6 hours after
archwire insertion and gradually decreased on the
following days. The consumption of pain relief was
greater in the 0.014 than the 0.016 inch group on day 1,
which was statistically significant.
The results of this study show that pain was perceived
after insertion of the two wires of different sizes used for
initial alignment. Either of these can therefore be chosen
as the initial archwire depending on the mechanics used
by the orthodontist.
Address for correspondence
Aslıhan M. Ertan Erdinç
Department of Orthodontics
Faculty of Dentistry
University of Ege
Bornova
35100 I
˙
zmir
Turkey
Acknowledgement
We wish to thank Dr Sonia Amado for help with the
statistical analysis.
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