Journal of Back and Musculoskeletal Rehabilitation 26 (2013) 9–15 9
Work related neck pain in Iranian dentists:
An epidemiological study
, Mohsen Amiri
, Mohammad Ali Mohseni-Bandpei
, Holakoo Mohsenifar
Mohammad Reza Pourahmadi
Student Research Committee, The University of Social Welfare and Rehabilitation Sciences, Evin, Tehran, Iran
Department of Physiotherapy, The University of Social Welfare and Rehabilitation Sciences, E vin, Te hran, Iran
Pediatric Neurorehabilitation Research Center, The University of Social Welfare and Rehabilitation Sciences,
Evin, Tehran, Iran
Department of Physiotherapy, Faculty of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran
OBJECTIVE: The purpose of this study was to determine the prevalence of and risk factors for neck pain in dentists of Tehran
province and to analyze the association of neck pain with individual and occupational characteristics.
DESIGN: Following ethical approval, a cross sectional study was conducted on 300 randomly selected dentists at Tehran city.
Different questionnaires were used to collect personal and occupational characteristics as well as the prevalence and risk factors
of neck pain. The Iranian validated version of visual analogue scale and neck disability questionnaires were also used to assess
the pain intensity and functional disability of neck, respectively.
RESULTS: Point, last month, last year and lifetime prevalence of neck pain were 19.3%, 27.3%, 29.9% and 34.7%, respectively.
The prevalence of neck pain was signiﬁcantly correlated with regular exercise, general health condition and having an assistant
(P<0.05 in all instances) and was not signiﬁcantly correlated with body mass index, age and gender. Prolonged sitting, awkward
postures and repeated movements were the most signiﬁcant aggravating factors.
CONCLUSIONS: Results indicated that the pre valence of neck pain in dentists appears to be high. Therefore, further studies
on different prev entive strategies in dentists’ population seem necessary.
Keywords: Dentists, neck pain, prevalence, risk factors
Musculoskeletal disorders (MSDs) are relatively
common conditio n and determined as injuries to the
human support system such as muscles, tendons, liga-
ments, joints, peripheral nerves, and supporting blood
vessels. Individuals with musculoskeletal pain often
report multiple pain sites including pain in the neck,
shoulders, arms, wrists, hands, upper and lower back,
hips, knees and feet [1–4]. MSDs are known to be the
most important occupational health issues in healthcare
workers with substantial costs and impact on quality of
Corresponding author: Dr. Mohsen Amiri, Department of Phys-
iotherapy, The University of Social Welfare and Rehabilitation Sci-
ences, Evin, Tehran, P.O. Box, 1985713834, Iran. Tel.: +98 21
22180039; Fax: +98 19 85713834; E-mail: firstname.lastname@example.org.
Different research demonstrated that neck pain is a
common musculoskeletal problem in both the devel-
oped and developing countries [10–16]. Studies suggest
that the annual p revalence of neck pain varied across
occupations, ranged from 10.2% in France to 27.1%
in Norway to 33.7% in the UK and to 47.8% in Que-
bec, Canada [17–20]. The one week prevalence of neck
pain was variably reported from 7.3% in ofﬁce workers
to 53% in female plant workers exposed to repetitive
work [2,21, 22]. Among healthcare workers, dentists
and nurses seem to be more affected by neck disorders
with high annual prevalence rates ranging from 17%
to 66% . The socioeconomic cost of neck pain is
considerable, resulting in substantial consumption of
healthcare resources, absenteeism from work, disabil-
ity and compensation payments. In The Netherlands,
a 1 -year cost of MSDs reported to be US$ 686 mil-
ISSN 1053-8127/13/$27.50 2013 – IOS Press and the authors. All rights reserved
10 N. Rahmani et al. / Work related neck pain in Iranian dentists: An epidemiological study
lion, representing 1% of total healthcare expenditure
and 0.1% of Gross Domestic Product .
Dentists are at high risk fo r developing many work-
related disorders particularly neck and back pain. Neck
pain was reported as the most prevalent musculoskeletal
complaint at 57.5% in Queensland, Australia . In a
cross-sectional study carried out on 227 randomly se-
lected dental students to evaluate the presence of work-
related MSDs in Brazil, 76.2% reported pain during or
after clinical work . T hey have also reported sig-
niﬁcant difference between gender and the occurrence
of pain. In a recent study conducted on 220 dentists in
Poland, over 92% of dentists experienced MSDs, espe-
cially in the neck (47%) and lower back (35%). Statis-
tically signiﬁcant association was also found between
the years of pr actice and the prevalence of MSDs .
A number of work-related factors have been es-
tablished as predisposing factors for MSDs [26, 27].
Among different identiﬁed predisposing factors, years
of practice, overstrained and awkward back pos-
tures, repetitiveness, health behaviors and psychosocial
stresses were commonly reported [23,26, 27]. Female
dentists were reported to have more musculoskeletal
complaints than their male colleagues [10,28]. Previ-
ous research also demonstrated that the incidence of
neck pain increases with age. It appeared that older
worker were more likely to develop neck pain com-
pared with younger workers [23,26].
Most of the differences in prevalence rate of neck
pain may be due mainly to different methodologies
used, variations in deﬁnition of neck pain, pr evalence
periods (such as point versus lifetime), less restrictive
deﬁnition of neck p a in (any pain in the neck versus neck
pain accompanied with shoulder pain), heterogeneity
of study populations, follow up periods and different
sample size. Every effort was made in the present study
to address the gaps in prev ious research by providing a
clear deﬁnition f or neck pain speciﬁcally, a deﬁned in-
clusion and exclusion criteria, and a deﬁned prevalence
period. A cross sectional study was designed, target-
ing dentists currently workin g in Tehran city of Iran to
investigate the prevalence of and risk factors for neck
pain in dentists, and to assess how individual and occu-
pational characteristics contribute to the risk of injuries
2. Materials and methods
2.1. Study design and data collection
This cross-sectional study was given ethical approval
from the Medical Ethics Board at the University of So-
cial Welfare and Rehabilitation Sciences. Three hun-
dred and ﬁfty dentists were randomly selected from
Tehran city and were sent the questionnaires. Dentists
were included if they were qualiﬁed to work as a den-
tist, had at least 1 year of work experience in the current
position and were willing to participate in the present
study. The exclusion criteria were: spinal deformi-
ties (e.g. scoliosis), malignancy, osteoporosis, multiple
sclerosis, any fracture, trauma or disorders in the head
or the neck, and any inﬂammatory conditions.
Dentists were identiﬁed and invited to par ticipate by
an invitation letter. All dentists were given oral and
written information about the aims of the study by a
research coordinator allocated in each region. Partic-
ipants were asked to sign a consent form if they were
willing to take p art. All participants who gave their
consent were informed that they were free to withdraw
from the study at any time. In order to maximize like-
ly response returns, a decision was made to allocate
a research coordinator to each region. The study was
carried out from July to October 2011.
Different questionnaires were used to collect person-
al and occupational characteristics as well as the preva-
lence of and risk factors for neck pain and d isability.
The questionnaires involved information on individu-
al and occupational characteristics and physical load
at work, general health status , and prevalence of
neck pain. Individual characteristics and work history
included certain questions such as age, anthropome-
try, gender, marital status, level of education, years of
experience, and working hours per day. Questions on
physical work load and clinical data concerned repeti-
tive movements, various types of treatments provided
each day (surgery, root canal, and ﬁlling or tooth ex-
traction), awkward working postures, prolonged sitting
or standing, and use of vibrating tools, medical history,
location and nature of symptoms. Dentists were also
asked to report if they had any pain at the time of com-
pleting questionnaire, within last month, last year and
any pain during lifetime.
For this study mechanical neck pain was deﬁned as
generalized neck symptoms provoked by maintain neck
posture, neck movements or manual muscle palpation.
Pain intensity was measured on Visual Analogue Scale
(VAS). The scale used was the typical 100 mm horizon-
tal line, with 0 mm indicating “No pain” and 100 mm in-
dicating “Unbearable pain”. VAS is a common, quick,
reliable and valid means to measure pain intensity in
a variety of clinical contexts . Neck disability in-
ex (NDI) was also used to assess functional disability
of neck . All questionnaires used in this study had
N. Rahmani et al. / Work related neck pain in Iranian dentists: An epidemiological study 11
Variables Mean (SD) Range
Age (years) 41.30 (8.43) 28–70
Height (cm) 175.83 (8.77) 156–196
Weight (kg) 73.56 (12.68) 49–102
BMI 27.85 (3.67) 18.90–39.01
Years of practice 12.83 (7.46) 1–42
Working hours per day 7.25 (2.43) 2–16
BMI, Body mass index.
Neck pain prev alence for dentists
Period of prevalence Total pre valence rate
Point prevalence 19.3%
Last month prevalence 27.3%
Annual prevalence 29.9%
Lifetime prevalence 34.7%
previously been translated into Persian and the relia-
bility and validity of Iranian versions had been test-
ed and approved [29,32]. The participants were also
asked if they received any treatments. Their responses
were categorized into different groups, those being rest,
medication, physiotherapy and exercise, and surgery
2.2. Statistical analysis
Categorical and numerical variables were analyzed
using cross-tabulation, and Chi-Square analysis was
used to examine the relationship between two or more
variables. Pearson Correlation Coefﬁcient was applied
to assess the existence of linear relationships between
variables. Data were analyzed with calculation of odds
ratio (ORs) and their 95% conﬁdence intervals (CIs)
by univariate and multivariate logistic regression for
neck pain in relation to different variables. The level
of statistical signiﬁcance was set up at 0.05. Statistical
analysis was performed using SPSS (Version 16).
A response rate of 86% (n = 300) was obtained from
the original eligible sample (n = 350). Two hundred
and ﬁfteen (71.7%) of the dentists were male and 85
(28.3%) were female. The sample characteristics and
the epidemiological data collected from dentists are
summarized in Tables 1 and 2, respectively. Table 3
demonstrates the management of neck pain received by
dentists. Table 4 presents frequencies and adjusted ORs
and CIs for predictive factors of point prevalence of
Management of neck pain for those dentists who received treatment
Procedure/Treatment No (Percent)
Rest 10 (9.2%)
Medication 38 (36.2%)
Physiotherapy and Exercise 53 (51.3%)
Surgery 3 (3.3%)
neck pain using a logistic regression model. Point, last
month, last year and lifetime prevalence of neck pain
were 19.3%, 27.3%, 29.9% and 34.7%, respectively.
The mean and standard deviation of pain intensity on
VAS was 44.48 ± 20.13 mm (range 5 mm to 92 mm)
for those who suffered from neck pain. The mean and
standard deviation of function disability on NDI for
those with neck pain was 40.14% ± 20.11% (range
4% to 86%) which was signiﬁcantly correlated with
pain intensity as assessed using Pearson Correlation
Coefﬁcient analysis (r = 0.56, P = 0.019).
As demonstrated in Table 3, 104 (34.7%) of partic-
ipants had sought treatment and had received different
management for their pain. Of these, 38 (36.2%) den-
tists had medication only, including analgesics, mus-
cle relaxants and non steroid anti inﬂammatory drugs
(NSAIDs); 53 (51.3%) dentists received physiotherapy
and exercise; 10 (9.2%) dentists had rest; and 3 (3.3%)
dentists received surgical treatment in addition to med-
ication, physiotherapy and exercise (Table 3). Approx-
imately, 27% had taken off work due to neck pain rang-
ing from 2 days to 3 months with an average duration
of 21.5 days.
Female dentists appeared to be more affected than
men but this did not reach statistical signiﬁcance (P =
0.359). The results also indicated that the o lder dentists
(> 50 years old) seemed to be more at risk of devel-
oping neck pain (Table 4) compared with younger den-
tists although this did not reach statistical signiﬁcance
(P = 0.719). Similarly the results of body mass index
(BMI) indicated no statistically signiﬁcant correlation
between BMI and prevalence of neck pain (P = 0.083).
The prevalence of neck pain was also associated with
working history in dentists. Whilst dentists who had a
work experience longer than 20 years were more likely
to report neck pain, this did not reach statistical sig-
niﬁcance (P = 0.078). There was also a signiﬁcant
correlation between perceived g eneral health and the
prevalence of neck pain using Pearson Correlation Co-
efﬁcient analysis (r = 0.79, P = 0.003). Participants
who had not considered themselves healthy on gener-
al health questionnaire were more likely to experience
neck pain compared with those who reported healthy
12 N. Rahmani et al. / Work related neck pain in Iranian dentists: An epidemiological study
Adjusted odds ratio and 95% conﬁdence interva ls for predictive factors of point prevalence of neck pain using logistic regression model
Variables Frequency Frequency Chi-square Odds ratio 95% P-value
(%) of (%) affected conﬁdence
total sample by neck pain intervals
Male 215 (71.7) 71 (33) 0.71 1.03 0.89–1.38 0.359
Female 85 (28.3) 33 (38.8)
< 40 125 (41.7) 42 (33.6) 0.23 0.91 0.83–1.42 0.719
41–50 83 (27.6) 31 (37.3)
51–60 57 (19) 23 (40.3)
> 60 35 (11.7) 8 (22.8)
< 20 17 (6) 6 (35.2) 2.67 1.19 0.87–2.01 0.083
20–25 97 (32) 27 (27)
25–30 156 (52) 62 (40.3)
> 30 30 (10) 8 (26.6)
Reported healthy 211 (70.3) 48 (22.7) 37.13 8.03 4.11–19.76 0.000
Reported unhealthy 89 (29.7) 56 (62.9)
Years of practice
< 10 103 (34.3) 32 (31.1) 2.83 0.98 0.67–1.21 0.078
10–20 129 (43) 43 (33.3)
> 20 68 (22.7) 29 (42.6)
Not exercising 204 (68) 91 (44.6) 1.39 0.73 0.41–1.09 0.114
Exercising 96 (32) 37 (38.5)
Preventive strategies (PS)
Without PS 108 (36) 55 (50.9) 6.14 2.93 1.57–4.08 0.013
With PS 192 (64) 75 (39.5)
Without assistant 183 (61) 89 (48.6) 4.18 2.03 1.07–3.96 0.036
With assistant 117 (39) 37 (31.6)
J ob satisfaction
No 11 (3.6) 2 (18.2) 3.06 1.13 0.49–1.28 0.071
Low 63 (21) 26 (41.2)
Moderate 191 (63.7) 71 (37.1)
High 35 (11.7) 5 (14.2)
Ninety six dentists (32%) in this study reported that
they were doing exercise on regular basis. Although
those dentists who were not exercising were more likely
to report neck pain compared with those who were
exercising on regular basis, this did not reach statistical
signiﬁcance (P = 0.114). According to the data on
a structured questionnaire, prolonged sitting, repeated
movements and bad postures were reported to be the
most signiﬁcant aggravating factors, respectively.
The results of this cross-sectional study demonstrate
that neck pain is a common complaint in studied den-
tists. A correlation was found between the prevalence
of neck pain and certain factors, those being general
health condition, years of practice, using preventive
strategies, having an assistant at work and job satis-
faction. It seems that the physical load amongst d en-
tists put them at risk for the occurrence of neck pain.
Available epidemiological studies on occupational in-
juries demonstrate that the prevalence of neck pain in
different profession s in healthcare setting is relatively
high . The point and life time prevalence of neck
pain in the present study was 19.3% and 34.7% which
are consistent with most previously reported prevalence
rates fo r neck pain in healthcare setting [23,26].
A number of studies have investigated the effects of
certain personal and professional factors such as gen-
der, age, BMI, general health condition, years of prac-
tice, job satisfaction, etc. on prevalence of MSDs. Al-
though there is conﬂicting results on gender differences
in MSDs, being a female is frequently reported to be
N. Rahmani et al. / Work related neck pain in Iranian dentists: An epidemiological study 13
a risk factor for MSDs [10,24,33]. Cote et al.  in
a systematic review reported that women experience
more neck pain than men. It was also suggested that
female gender is positively correlated with severity of
musculoskeletal pain. The results of the study conduct-
ed on Australian dentists indicated that those dentists
who rate their pain severity at the highest rank were
more likely to be female . Although no signiﬁcant
correlation was found between gender and the preva-
lence o f neck pain in the current study, further large
scale studies are n ecessary to investigate the association
between gender and prevalence of neck pain.
Despite the extensive research, there is still no gener-
al consensus on the effect of age and the prevalence of
neck pain. Some studies reported a positive association
between age and the prevalence of n eck pain (e.g. [17,
34]), some suggested negative association (e.g. [33,
35]) and some found no correlation (e.g. ). It was
reported that the incidence of neck pain increases with
age and older workers were more likely to develop neck
pain than younger workers [17,34]. Although no sig-
niﬁcant relationship was found between age and preva-
lence of neck pain in the current study, but the results
is in agreemen t with those studies in wh ich the peak
effect of age was reported to be in the fourth and ﬁfth
decade of life.
Data from the present study suggest that the longer
the year of practice, the greater the risk of suffering
neck pain. Some studies reported positive correlation
between years of practice and the preva lence of MSDs
in dentists [25,37]. These results were consistent with
the ﬁndings of Szymanska  and Kierlo et al. .
They reported that symptoms of MSDs increased with
the number of years of practice . It was also report-
ed that dentists who did not report symptoms had less
than ﬁve years of practice . Conversely some stud-
ies reported that musculo skeletal pain is negatively as-
sociated with years of practice [10,16,38]. Chowanadi-
sai et al.  found Thai dentists to have a lesser chance
of experiencing MSDs in the previous 12 months if
they had more years of clinical experience. It appears
that long term exposure to different physical and psy-
chological demands in dentistry makes dentists more
vulnerable to MSDs. However, the results of the cur-
rent study give support to the notion that the longer
the years of practice, the higher the prevalence rate of
Dentists who had not considered themselves healthy
on general health questionnaire were more likely to ex-
perience neck pain compared with those who reported
healthy condition and this was strongly associated with
prevalence of neck pain. It seems that regular practice
of exercise is an effective strategy to prevent MSDs,
as those people who took part in any kind of athletic
activity or physical conditioning demonstrated lower
levels of severe symptoms than those who did not. It
was reported that the risk of neck pain increased by
15% to 22% among workers with low to moderate static
endurance of neck muscles . In contrast, reported
that general health status was not associated with neck
pain recurrence . However, the result of the cur-
rent stu dy is in agreement with those studies in which
physical capacity was found to be associated with neck
The results of previous studies on the association be-
tween job satisfaction and prevalence of neck pain are
conﬂicting. Korhonen et al.  demonstrated no rela-
tionship between job satisfaction and local or radiating
neck pain. Some studies suggested that workers with
low level of satisfaction had higher rates of neck pain
compared with those who were more satisﬁed (e.g. [36,
42]). Whilst dentists with low level of satisfaction were
more likely to report neck pain compared with those
who reported m oderate and high level of satisfaction,
job satisfaction was not found to be associated with the
prevalence of neck pain in the present study.
Work related MSDs particu larly low back pain and
neck pain are common and costly among other health-
care workers who are in direct contact with patients [5–
9,43]. It was reported that a large number of physiother-
apists, nurses, surgeons, etc. are suffering from work
related MSDs. Previous studies demonstrated that some
work related activities such as lifting patients and heavy
equipments, transferring patients,maintaining the same
posture for a long period of time, manual therapy prac-
tices, repeated movements and awkward posture, and
prolonged sitting and standing were the most common
mechanisms lead to injury in healthcare professionals.
These wide ranges of injuries have major impact on
society, workers, employers, and the insurance com-
panies due to work absenteeism, long term disability
and delay in returning to work, decreased productivi-
ty, and psychological effects on employees. Therefore,
developing preventive strategies to minimize work re-
lated injuries and to improve working conditions have
signiﬁcant potential social and economic beneﬁts.
The ﬁndings of the present study revealed that the
prevalence of neck pain amongst d entists appears to be
14 N. Rahmani et al. / Work related neck pain in Iranian dentists: An epidemiological study
high and highlights a major health concern. The as-
sociations of certain risk factors such as BMI, general
health condition, years of practice, having an assistant
at work, preventive strategies used, and job satisfaction
were addressed in the current study. The results also
highlight the need to allocate more resources in order
to control the identiﬁed predisposing factors and to re-
duce the incidence of neck pain in dentists’ population.
Further research should focus on evaluating the effect
of different preventive strategies to reduce the impact
of such a major health issue.
This paper is taken from a research project funded
by the Student Research Committee at the University
of Social Welfare and Rehabilitation Sciences. The
authors acknowledge the University of Social Welfare
and Rehabilitation Sciences for ﬁnancial support of this
study. The authors would like to thank all dentists for
their contribution to the present study and all research
coordinators for their kind cooperation and support.
 Allison TR, Symmons DP, Brammah T, Haynes P, Rogers A,
Roxby M, Urwin M. Musculoskeletal pain is more generalised
among people from ethnic minorities than among white people
in Greater Manchester. Ann Rheum Dis 2002; 61: 151-156.
 Picavet HS, Schouten JS. Musculoskeletal pain in the Nether-
lands: prevalences, consequences and risk groups, the DMC
(3)-study. Pain 2003; 102: 167-178.
 Haukka E, Leino-Arjas P, Solovie va S, Ranta R, Viikari-
Juntura E, Riihimaki H. Co-occurrence of musculoskeletal
pain among female kitchen workers. Int Arch Occup Environ
Health 2006; 80: 141-148.
 Rustoen T, Wahl AK, Hanestad BR, Lerdal A, Paul S, Mi-
asko wski C. Prevalence and characteristics of chronic pain in
the general Norwegian population. Eur J Pain 2004; 8: 555-
 Mohseni-Bandpei MA, Fakhri M, Bagheri-Nesami M,
Ahmad-Shirvani M, Khalilian AR, Shayesteh-Azar M. Occu-
pational back pain in Iranian nurses: an epidemiological study.
Br J Nursing 2006; 15: 914-917.
 Mohseni-Bandpei MA, Ahmad-Shirvani M, Golbabaei N, Be-
htash H, Shahinfar Z, Fernandez-de-las-Penas. Prevalence and
risk factors associated with low back pain in Iranian surgeons.
J Manipulativ e Physiol Ther 2011; 34: 362-370.
 Smith DR, Mihashi M, Adachi Y, Koga H, Ishitake T. A de-
tailed analysis of musculoskeletal disorder risk factors among
Japanese nurses. J Safety Res 2006; 37: 195-200.
 Dolan LM, Martin DH. Backache in gynaecologists. Occup
Med 200; 5: 1433-8.
 Babar-Craig H, Banﬁeld G, Knight J. Prev alence of back and
neck pain amongst ENT consultants: national survey. J Laryn-
gol Otol 2003; 117: 979-982.
 Marshall ED, Duncombe LM, Robinson RQ, Kilbreath SL.
Musculoskeletal symptoms in New South Wales dentists. Aust
Dent J 1997; 42: 240-246.
 Rundcrantz BL, Johnsson B, Moritz U. Pain and discomfort
in the musculoskeletal system among dentists. Swed Dent J
1991; 15: 219-228.
 Borghouts JAJ, Koes BW, Vonderling H, Boulter LM. Cost-of
illness of neck pain in The Netherlands in 1996. Pain 1999;
 Guez M, Hildingsson C, Nilsson M, Toolanen G. The preva-
lence of neck pain. A population-based study from northern
Sweden. Acta Orthop Scand 2002; 73: 455-459.
 Lau EM, Sham A, Wong KC. The prevalence of and risk
factors for neck pain in Hong Kong Chinese. J Public Health
Med 1996; 18: 396-399.
a M, Heliov aara M, Sievers K, Impiv aara O, Knekt
P, Aromaa A. Prevalence, determinants and consequences of
chronic neck pain in Finland. Am J Epidemiol 1991; 134:
 Leggat PA, Smith DR. Musculoskeleta l disorders self-reported
by dentists in Queensland, Australia. Aust Dent J 2006; 51:
 Cassou B, Derriennic F, Monfort C, Norton J, Touranchet A.
Chronic neck and shoulder pain, age, working conditions:
longitudinal results from a large random sample in France.
Occup Environ Med 200; 59: 537-544.
 Palmer KT, Walker-Bone K, Grifﬁn MJ, Syddall H, Pannett
B, Coggon D, Cooper C. Prevalence and occupational asso-
ciations of neck pain in the British population. Scand J Work
En viron Health 200; 27: 49-56.
 Eriksen W, Natvig B, Knardahl S, Bruusgaard D. Job charac-
teristics as predictors of neck pain. A 4-year prospecti ve study.
J Occup Environ Med 1999; 41: 893-902.
 Leroux I, Dionne CE, Bourbonnais R, Brisson Cl. Prev alence
of musculoskeletal pain and associated factors in the Quebec
working population. Int Arch Occup Environ Health 2005; 78:
 Hansson GA, Balogh I, Ohlsson K, Pålsson B, Rylander L ,
Skerfving S. Impact of physical exposure on neck and upper
limb disorders in female workers. Appl Ergon 2000; 31: 301-
 Bergqvist U, Wolgast E, Nilsson B, Voss M. Musculoskeletal
disorders among visual display terminal workers: Individual,
ergonomic, work organizational factors. Ergonomics 199; 38:
 Cote P, van der velde G, Cassidy D, Carrol LJ, Hogg-Johnson
S, Holm LW. The burden and determinants of neck pain in
workers. Results of the Bone and Joint Decade 2000–2010
Task Force on Neck Pain and Its Associated Disorders. J Ma-
nipulati ve Physiol Ther 2009; 32: S70-S86.
 de Carvalho MV, Soriano EP, Caldas AF, Campello RC, de Mi-
randa HF, Cavalcanti FD. Work-related musculoskeletal dis-
orders among Brazilian dental students. J Dent Educ 2009; 73:
 Kieklo A, Kobus A, Jaworska M, Botulinski B. Work-related
musculoskeletal disorders among dentists-a questionnaire sur-
vey. Ann Agric Environ Med 2011; 18: 79-84.
 Hayes M, Cockrell D, Smith DR. A systematic revie w of
musculoskeletal disorders among dental professionals. Int J
Dent Hyg 2009; 7: 159-165.
 Carroll LJ, Hogg-Johnson S, Cote P, van der Velde G, Holm
LW, Carragee EJ. Course and prognostic factors for neck pain
in workers. Results of the Bone and Joint Decade 2000–2010
N. Rahmani et al. / Work related neck pain in Iranian dentists: An epidemiological study 15
Task Force on Neck Pain and Its Associated Disorders. J Ma-
nipulati ve Physiol Ther 2009; 32: S108-116.
 Chowanadisai S, Kukiattrakoon B, Yapong B, Kedjarune U,
Leggat PA. Occupational health problems of dentists in south-
ern Thailand. Int Dent J 200; 50: 3-40.
 Montazeri A, Harirchi AM, Shariati M, Garmaroudi G Ebadi
M Fateh A. The 12-item General Health Questionnaire (GHQ-
12): translation and validation study of the Iranian version.
Health Qual Life Outcomes 2003; 1: 166-169.
 Waterﬁeld J, Sim J. Clinical assessment of pain by visual
analogue scale. Br J Ther Rehabil 199; 3: 94-7.
 Vernon H, Mior S. The Neck Disability Index: a study of
reliability and validity. J Manipulative Physiol Ther 1991; 14:
 Mousavi SJ, Parnianpour M, Montazeri A, Mehdian H, Karimi
A, Abedi M. Translation and validation study of the Iranian
versions of the Neck Disability Index and the Neck Pain and
Disability Scale. Spine 2007; 32: 825-831.
 Harutunian K, Gargallo-Albiol J, Figueiredo R, Gay-Escoda
C. Ergonomics and musculoskeletal pain among postgraduate
students and faculty members of the School of Dentistry of
the University of Barcelona (Spain). A cross-sectional study.
Med Oral Patol Oral Cir Bucal 2011; 16: 425-429.
 Luime JJ, Koes BW, Miedem HS, Verhaar JA, Burdorf A. High
incidence and recurrence of shoulder and neck pain in nursing
home employees was demonstrated during a 2-year follow-up.
J Clin Epidemol 200; 58: 407-413.
Ostergren PO, Hanson BS, Balogh I, Ektor-Andersen J, Isacs-
son A, Orbaek P, Winkel J, Isacsson SO. Incidence of shoulder
and neck pain in a working population: effect modiﬁcation
between mechanical and psychosocial exposures at work? Re-
sults from a one year follo w up of the Malmo shoulder and
neck study cohort. J Epidemiol Community Health 200; 59:
 Brandt LP, Andersen JH, Lassen CF, Kryger A, Overgaard
E, Vilstrup I, Mikkelsen S. Neck and shoulder symptoms and
disorders among Danish computer workers. Scand J Work
En viron Health 200; 30: 399-409.
 Szymanska J. Disorders of the musculoskeletal system among
dentists from the aspect of ergonomics and prophylaxis. Ann
Agric Environ Med 200; 9: 16-173.
 Finsen L, Christensen H, Bakke M. Musculoskeletal disorders
among dentists and variation in dental work. Appl Ergon 1998;
 Hamberg-van Reenen HH, Ariens GA, Blatter BM, Twisk JW,
van Mechelen W, Bongers PM. Physical capacity in relation
to low back, neck, or shoulder pain in a working population.
Occup Environ Med 200; 63: 371-377.
 Luime JJ, Kuiper JI, Koes BW, et al. Work-related risk factors
for the incidence and recurrence of shoulder and neck com-
plaints among nursing-home and elderly-care workers. Scand
J Work Environ Health 2004; 30: 279-86.
 Korhonen T, Ketola R, Toivonen R, Luukkonen R, H
M, Viikari-Juntura E. Work related and individual predictors
for incident neck pain among ofﬁce employees working with
video display units. Occup Environ Med 2003; 60: 475-782.
 Smedley J, Inskip H, Trevelyan F, Buckle P, Cooper C, Coggon
D. Risk factors for incident neck and shoulder pain in hospital
nurses. Occup Environ Med 200; 60: 864-869.
 Salik Y, Ozcan A. Work-related musculoskeletal disorders: a
survey of physical therapists in Izmir-Turkey. BMC Muscu-
loskelet Disord 2004; 5: 27-34.