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Association between signs of hyperalgesia and reported frequent pain in jaw-face and head

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Abstract

Objective: To analyze the relationship between different sites of elicited pain to muscle palpation (PtP), and reported frequent pain in jaw-face and head. Materials and methods: The analysis was based on an epidemiological sample of 1200 randomly selected individuals, of which 779 (65%) both completed a questionnaire and participated in a clinical examination. The questionnaire addressed the presence of pain in the jaw-face region and headache, respectively. Part of the clinical examination entailed palpation of the jaw, neck, shoulder, arm, thumb and calf muscles. Logistic regression was applied with pain and headache as dependent variables. A p-value < .05 determined statistical significance. Results: Five percent of participants reported frequent pain in jaw-face, and 17% reported frequent headaches. In the regression analysis, frequent headaches were significantly associated with jaw muscle PtP (OR 2.1, CI 1.4-3.4), regional PtP (OR 4.5, CI 2.6-7.6), and generalized PtP (OR 6.1, CI 2.2-17.0). Jaw-face pain was significantly associated with regional PtP (OR 5.3, CI 2.2-13.0) and generalized PtP (OR 30.1, CI 9.3-97.0). The relationship between pain prevalence and PtP showed a dose-response pattern. Conclusions: The study indicates that frequent jaw-face pain and headache are primarily associated with signs of regional and widespread hyperalgesia, which may be linked to the central sensitization mechanism. Signs of widespread hyperalgesia should be accounted for in the diagnostic algorithms when examining patients with pain in the jaw, face, and head regions.
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Association between signs of hyperalgesia and
reported frequent pain in jaw-face and head
Negin Yekkalam & Anders Wänman
To cite this article: Negin Yekkalam & Anders Wänman (2020): Association between signs of
hyperalgesia and reported frequent pain in jaw-face and head, Acta Odontologica Scandinavica,
DOI: 10.1080/00016357.2020.1814963
To link to this article: https://doi.org/10.1080/00016357.2020.1814963
© 2020 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Group on behalf of Acta Odontologica
Scandinavica Society.
Published online: 12 Sep 2020.
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ARTICLE
Association between signs of hyperalgesia and reported frequent pain in
jaw-face and head
Negin Yekkalam and Anders W
anman
Department of Clinical Oral Physiology, University of Umeå, Umeå, Sweden
ABSTRACT
Objective: To analyze the relationship between different sites of elicited pain to muscle palpation
(PtP), and reported frequent pain in jaw-face and head.
Materials and methods: The analysis was based on an epidemiological sample of 1200 randomly
selected individuals, of which 779 (65%) both completed a questionnaire and participated in a clinical
examination. The questionnaire addressed the presence of pain in the jaw-face region and headache,
respectively. Part of the clinical examination entailed palpation of the jaw, neck, shoulder, arm, thumb
and calf muscles. Logistic regression was applied with pain and headache as dependent variables. A
p-value <.05 determined statistical significance.
Results: Five percent of participants reported frequent pain in jaw-face, and 17% reported frequent
headaches. In the regression analysis, frequent headaches were significantly associated with jaw
muscle PtP (OR 2.1, CI 1.43.4), regional PtP (OR 4.5, CI 2.67.6), and generalized PtP (OR 6.1, CI
2.217.0). Jaw-face pain was significantly associated with regional PtP (OR 5.3, CI 2.213.0) and gener-
alized PtP (OR 30.1, CI 9.397.0). The relationship between pain prevalence and PtP showed a dose-
response pattern.
Conclusions: The study indicates that frequent jaw-face pain and headache are primarily associated
with signs of regional and widespread hyperalgesia, which may be linked to the central sensitization
mechanism. Signs of widespread hyperalgesia should be accounted for in the diagnostic algorithms
when examining patients with pain in the jaw, face, and head regions.
ARTICLE HISTORY
Received 23 April 2020
Revised 15 August 2020
Accepted 20 August 2020
KEYWORDS
Epidemiology; myofascial
pain; temporomandibular
disorders; head-
aches; diagnosis
Introduction
Pain is defined by the International Association for the study
of Pain (IASP) as an unpleasant sensory and emotional
experience associated with actual or potential tissue damage
or described in terms of such damage[1]. Chronic pain is
considered when the duration exceeds 3 months [1], and
hence, exceeds the acute warning function of physiological
nociception [2]. The prevalence of chronic pain has been rec-
ognized at 20% worldwide [3], and it is often associated
with sleep disorders, mood disturbance [4], and low quality
of life [5]. It has been estimated that 52% of patients with
chronic pain have comorbid depressive symptoms [6] that
result in low work function (e.g. sick leave) and high health
care utilization [7].
Pain in the craniofacial region often termed orofacial pain,
is a common condition and for many is a disabling condition
[8]. The prevalence of orofacial pain varies considerably
between studies (1.348%) depending on the questionnaires
wordings; however, approximately 2025% may report
chronic orofacial pain (more than 3 months) in surveys [5]. In
a large population-based survey from the United Kingdom, a
low prevalence of facial pain was observed with approxi-
mately 2% reporting the presence of facial pain within the
last month that also interfered with usual activities [9]. In the
introduction of a recently presented international classifica-
tion of Orofacial pain, the editors point out that there is no
comprehensive, internationally accepted classification of oro-
facial pain, which results in too many cases of misdiagnosis
and misdirected treatment efforts [10].
Temporomandibular disorders (TMDs) is a term that refers
to a number of painful and non-painful disorders that affect
the muscles of mastication, the temporomandibular joint
(TMJ) and contiguous structures [10]. TMDs are considered as
the most prevalent chronic pain condition in the orofacial
region [11]. Similar to many other musculoskeletal pain con-
ditions and headaches [1,12], the prevalence of TMDs is
higher in women than men with a gender ratio of approxi-
mately 2:1 [1315].
Diagnosis and aetiological views of orofacial pain, as well
as TMD pain, are debatable since these are predominantly
classified on anatomical location, signs and symptoms rather
than on the understanding of the underlying pathophysio-
logical mechanisms of the persisting pain [12]. Moreover, the
multifactorial aetiology for TMD [16], as well as the presence
of several comorbid conditions [17,18] renders the decision-
making process in relation to diagnosis even more complex
CONTACT Negin Yekkalam negin.yekkalam@umu.se Department of Clinical Oral Physiology, University of Umeå, Umeå S-901 87, Sweden
ß2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Acta Odontologica Scandinavica Society.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/),
which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.
ACTA ODONTOLOGICA SCANDINAVICA
https://doi.org/10.1080/00016357.2020.1814963
[12]. Although different potential causes that include bio-
logical, chemical, physical, occupational, psychological factors
and genetic predisposition have been suggested by previous
research, no necessary or sufficient cause has been identified
[19,20]. The work by Schwartz, one of the pioneers in this
field, showed that pain in TMD can develop to regions not
innervated by the fifth cranial nerve such as trapezius, pos-
terior cervical, neck, and shoulder regions [21]. In another
study, more than 50% of the patients who were referred to
the facial pain clinic, had widespread pain outside the trige-
minal and cervical regions [22]. Patients with a combination
of TMD and chronic neck pain reported more pain sites and
showed widespread hyperalgesia compared to subjects with
only chronic neck pain [23]. Already in a 35-year old epi-
demiological study, pain in the orofacial region, jaw muscle
tiredness and headaches were all significantly associated
with muscle pain sites to palpation outside the area inner-
vated by the trigeminal nerve [24]. Therefore, TMD may be
viewed as a condition involving the joints, the muscles, and
the peripheral and central nervous systems. Understanding
the pathophysiological and behaviour mechanism underlying
a disorder is important for both a correct diagnosis as well
as for proper treatment options [12].
The aim of this study was to analyze the relationship
between different sites of elicited pain to muscle palpation,
and reported frequent jaw-face pain and frequent headache,
respectively.
Materials and methods
The study population included 35, 50, 65, and 75-year-old
subjects residing in the county of V
asterbotten, Sweden,
which totals 11,324 individuals. The study population was
stratified based on where the subjects lived, that is, inland or
coastal regions. Random selection was applied to include
150 individuals in each age group and for each region (in
total 1200 individuals). The study included both a question-
naire and a clinical examination. The questionnaire was sent,
along with a return envelope, to an individuals home
address. A filled-in questionnaire was returned by 987 indi-
viduals (response rate 82%), and 779 (response rate 65%)
participated in a clinical examination.
Questionnaire
The questionnaire included 65 questions that focussed on
socio-demographic characteristics, self-perceived general
health and oral health, tobacco use, medication, dental care
habits, symptoms in the jaw-face region and headache. The
six questions in the questionnaire related to symptoms in
the jaw-face region inquired about the presence of the fol-
lowing symptoms during the past 3 months: TMJ clicking
sound; jaw-facial pain; jaw tiredness/stiffness; difficulties in
opening wide; locking of the jaw; and headache. The fre-
quency scale was as follows: No; Yes, occasionally; Yes, once
or twice every week; Yes, several times a week; or Yes, daily.
A reported occurrence once a week or more often was
defined as frequent symptoms. The responses in the
analysis were dichotomized into frequent symptoms and
those remaining.
Clinical examination
The clinical examinations were performed by four dentists
and four chair-side assistants at public dental clinics close to
the living address of the participants. Before the study
started, the examiners were trained and their examination
techniques were calibrated for all of the clinical variables.
The calibration was done in relation to a golden standard.
Two calibrations on voluntary subjects were needed before
the accepted level for inter-examiner reliability (Kappa value
0.640.84) was achieved. The examinations included registra-
tion of dental status, occlusal supporting zones (Eichner
index), periodontal pocket depth, soft tissue examination,
the function of temporomandibular joint, maximal jaw open-
ing capacity, presence of pain to palpation, and decision on
treatment need. Details of the clinical examination have
been presented in a previous paper [25].
The pain to palpation of specified muscle sites was regis-
tered when the palpation during two seconds elicited a pal-
pebral reflex in the eyes or a protection/withdrawal reflex.
One of the authors (AW) was the instructor, and in his opin-
ion, the pressure applied was close to that currently advo-
cated of 1 kg; however, no Palpometer was available.
The following muscle or/and tendon attachment sites
were palpated:
Extra oral sites
Temporal muscle; with the index, middle and ring fingers
over the temple to palpate the anterior part, and posterior
part extra orally.
Medial pterygoid muscles; subjects were asked to tilt the
head slightly towards the palpated site, and the inner surface
of the mandible angle was palpated with the index finger.
Deep masseter muscle; with the index finger in the area
located between the backside of the ramus and the back
border of the superficial masseter 2 cm below the tragus.
Intra oral sites
The origin of the masseter muscle was palpated bi-digitally
with the index finger from the inside, and the thumb from
the outside below the zygomatic arch.
The tendon of the temporal muscles; subjects were asked
to open the jaw. The region of the insertion of the temporal
muscle was palpated on the upper part of the inside of the
coronoid process with the index finger.
Lateral pterygoid area; subjects were asked to move the
jaw towards one side to palpate behind the buccal area of
the third molar region with the tip of the little finger in a
medial direction behind the maxillary tuberosity.
2 N. YEKKALAM AND A. WÄNMAN
Body sites
The centre part of the sternocleidomastoid muscles, the tra-
pezius muscles, the underside muscles of the forearm, thumb
muscles, and calf muscles were palpated bi-digitally.
The location of the elicited pain to muscle palpation was
grouped into the following 5 groups: those who had no reg-
istered pain to palpation (reference group); pain at jaw
muscle sites only; pain at neck/shoulder muscle sites only;
pain at both jaw and neck muscle sites (regional pain); and
generalized pain to palpation (pain at neck/shoulders and
arm, and hand, and calf muscles sites).
Statistical method
The data analysis was done with STATA statistical software
version 10. The analysis was based on 779 individuals who
participated in the clinical examination. Due to minor varia-
tions in missing data the included numbers of individuals in
the regression analysis varied. The operational definition of
dependent and independent variables is presented in Table
1. In the regression analysis, jaw-face pain once a week or
more during the past 3-month period and headache once a
week or more during the past 3-months period were used as
dependent variables. The results are presented as odds ratios
(OR) with a 95% confidence interval (CI). A p-value of less
than .05 was considered statistically significant.
Results
For the 779 participants included in the analyses, the preva-
lence of frequent jaw-face pain during the past 3-month
period was 5% (n¼38), and for frequent headache was 17%
(n¼127). The majority did not react to muscle palpation
(52%), still, 29% (n¼224) showed pain to palpation only in
the jaw muscles sites, 5% (n¼35) in only the neck/shoulder
muscles sites, 12% (n¼95) had regional PtP in jaw and neck
muscle sites, and 2% (n¼18) had generalized PtP at all pal-
pated sites (Table 1).
The relationship between symptoms and PtP showed a
dose-response pattern (Table 2). With frequent headache
used as the dependent variable, there was a significant rela-
tionship to local jaw muscle PtP (OR 2.1, CI 1.33.4), regional
PtP (OR 4.5, CI 2.67.6) and generalized PtP (OR 6.1, CI
2.216.9) With frequent jaw-face pain used as the dependent
variable there was a significant relationship to regional PtP
(OR 5.3, CI 2.213.0) and generalized PtP (OR 30.1, CI
9.397.0) but not to local jaw muscle PtP (OR 1.9, CI 0.84.5).
Discussion
The present study indicates that frequent jaw-face pain and
headache are primarily associated with signs of regional and
widespread hyperalgesia which may be linked to the central
sensitization mechanism. The odds of reporting craniofacial
pain increased in a dose-response like pattern with the
spread of pain response to manual palpation. The novelty of
the result is that it seriously questions the presence of pain
to palpation over the jaw-face muscles as a significant sign
of local muscle injury.
The dependent variables in our study had a prevalence in
line with what has previously been reported in epidemio-
logical studies on adults [11,15,26]. The prevalence of sites
eliciting pain to manual palpation was remarkably similar to
that in a previous study among 35-year olds [24]. In both the
previous and present studies, approximately half of the study
population did not report pain at the palpated sites. The
most common elicited pain locations were within the trige-
minal innervation area and in both trigeminal and cervical
innervated areas [27]. Based on previous research, the preva-
lence of fibromyalgia in the population, as a cluster of
Table 1. Description of dependent and independent variables (n¼779).
Definition n(%)
Dependent variables
Frequent headaches Reported headaches once a week or more 127 (17)
Frequent jaw-face pain Reported pain in the jaw-face area once a week or more 38 (5)
Independent variables
No pain to palpation (PtP) (Reference) No registered pain to palpation (PtP) 402 (52)
Local jaw PtP PtP in jaw muscle sites only 224 (29)
Local neck/shoulder PtP PtP in neck muscle sites only 35 (5)
Regional PtP PtP in both jaw and neck muscle sites 95 (12)
Generalized PtP PtP in all palpated regions of neck, arm, hand, and calf muscles 18 (2)
Table 2. Association between prevalence of frequent headache, jaw-face pain,
and headache and/or jaw-face pain, respectively, to different patterns of
muscle pain to palpation (PtP) in an adult population.
OR (CI) p-Value
Frequent headache (17%)
No PtP (control) 1.0
Local neck/shoulder PtP 1.6 (0.64.3) NS
Local jaw PtP 2.1 (1.33.4) .001
Regional PtP 4.5 (2.67.6) <.001
Generalized PtP 6.1 (2.216.9) <.001
Frequent jaws-face pain (5%)
No PtP (control) 1.0
Local neck/shoulder PtP nc
Local jaw PtP 1.9 (0.84.5) NS
Regional PtP 5.3 (2.213.0) <.001
Generalized PtP 30.1 (9.397.0) <.001
Frequent headache and/or jaws-face pain (19%)
No PtP (control) 1.0
Local neck/shoulder PtP 1.4 (0.5.3.7)
Local jaw PtP 2.3 (1.53.5) <.001
Regional PtP 4.9 (2.98.2) <.001
Generalized PtP 9.8 (3.527.5) <.001
Percentage values represent the proportion of subjects out of the 779
included in the clinical examination.
CI: 95% confidence interval; OR: odds ratio; nc: not computable; NS: non-
significant.
ACTA ODONTOLOGICA SCANDINAVICA 3
patients with generalized pain and hyperalgesia, is 1.75%
[28]. In the present study, the individuals who presented
with a widespread pattern of hyperalgesia (2%) may thus
have related conditions, although this was not specific-
ally verified.
Myofascial pain syndrome (MPS) is considered the most
common pain condition involving the muscle and its con-
nective tissues (i.e. fascia) [29]. MPS is characterized by the
presence of trigger points [30] and is associated with other
pain conditions such as craniomandibular dysfunction, ten-
sion-type headache, migraine, joint dysfunction, back, neck
and shoulder pain [31,32]. The concept of myofascial trigger
points is still instrumental in defining diagnosis and treat-
ment targeted for many pain conditions [33], including the
recently launched diagnostic criteria of TMD [34]. Despite the
ambition to distinguish between joint pain and muscle pain,
a substantial overlap between TMJ arthralgia and masticatory
muscle myalgia has been reported [35].
The results of the present study show that tender/trigger
points to palpation are commonly found in trigeminal and
upper cervical innervated areas. These areas are closely inte-
grated in sensorimotor functions that include the conver-
gence of afferent signals to the brainstem and in nociceptive
transmission [36]. One example of convergence between tri-
geminal nerves and cervical nerves in the brainstem is found
in Whiplash injuries [37]. Those with chronic symptoms of
such an injury with trigger points in the cervical area may
experience referred pain in the trigeminal region [38]. In fact,
intermittent pain induces changes at different levels in the
nervous system that in turn lead to abnormal function and
structural changes in the CNS [39,40]. Expansion of the
receptive field of pain, secondary hyperalgesia, co-contrac-
tion or autonomic responses can be manifestations of such
changes [33]. Central sensitization also results in more trigger
points, which in turn might create widespread pain [32].
Therefore, the experience of pain is not only necessarily
related to the state of the body tissue but is also a complex
interplay between sensory, affective and cognitive features
[41,42]. In the case of misinterpreting the source of pain,
there is a risk that local pain conditions develop to more
complex muscle pain disorders.
In the present study, different types of headache were
considered as a single group of headache due to the ques-
tionnaire design. Frequent headache was significantly associ-
ated with all types of pain to palpation patterns except for
local pain at neck/shoulder sites. Previous studies have
reported a higher prevalence of TMD in headache patients
and vice-versa due to a high degree of comorbidities among
these disorders [43,44]. For example, in a patient-based
study, 40% of the patients with tension-type headaches
(TTH) also had myofascial TMD diagnosis [45]. In another
study, patients with TTH experienced pain mostly at the mas-
seter muscle, pericranial and neck regions [46]. A study
among healthy controls and cases with chronic TTH showed
larger referred pain areas from trigger points in the upper
trapezius muscle among cases [47]. Based on an updated
pain model, referred pain from active trigger points in the
posterior cervical, head and shoulder muscles can be partly
assumed for TTH due to central sensitization [48]. Headache
disorders were ranked as the sixth cause of years lived with
disability among other causes worldwide based on the
Global burden of disease study [26]. Reflecting on the over-
lap and probably shared pathophysiological mechanism
between myofascial TMD and tension-type headache, differ-
ential diagnoses between TMD and headache disorders and
consequently accurate treatment strategies should be consid-
ered [49].
Another condition associated with central sensitization is
fibromyalgia which may mislead clinicians in the diagnosis of
the primary source of the pain. Fibromyalgia is a chronic and
widespread musculoskeletal pain that has been present
3 months or longer in the four quadrants of the body [50]. In
the present study, elicited palpebral reflex to palpation of
each of the four different functional and anatomic parts of
the body (shoulder, arm, hand, and leg) was used to esti-
mate of the generalized tenderness. The study was not
intended to identify cases with fibromyalgia. Previous
research has reported an overlap of similar types of com-
plaints among patients with fibromyalgia and those with
TMD [51,52]. The work by Plesh et al. revealed that 75% of
patients with fibromyalgia had TMD, while 18% of cases with
TMD met the diagnostic criteria for fibromyalgia syndrome
[53]. In a study by John et al., widespread pain was highly
associated with the risk of developing TMD pain among
women [54]. In the present study, 18% of the study popula-
tion with frequent orofacial pain showed a pattern of wide-
spread pain to palpation. Although we found significant
associations between jaw-face pain, headache, and the
spread of pain to muscle palpation, the wide confidence
interval of odds ratios should be considered, and thus the
results should be interpreted with caution.
Strengths and limitations
A random sample was drawn from the general population to
ensure the representativeness of the population under study.
The response rate to the questionnaire was good (82%) and
the number of participants attending the clinical examination
was acceptable (65%).
Different types of headaches were considered as one sin-
gle group, without any attempt to distinguish between a pri-
mary and secondary form of headache, nor was there any
diagnostic aim for reported pain conditions. The prevalence
of headache occurring once a week or more often was
defined as frequent headache which is similar to that which
has been reported in another population-based study [55].
The response to palpation was measured when it elicited a
palpebral or protection reflex since reliability was improved
[56]. Psychological features and environmental factors (atten-
tion, anxiety) that may influence the pain expression were
not included in the study due to the design of the question-
naire and the clinical examination protocol. The palpation of
the region of the lateral pterygoid muscle was included in
the examination protocol even though there was a risk for
false positiveresponses. However, the palpated muscles and
tendon sites were those commonly used at the time of the
4 N. YEKKALAM AND A. WÄNMAN
study. In 2014, a Delphi based consensus document advo-
cated to palpate primarily extra oral muscle sites and added
the criterion of familiar painelicited during the palpation,
with a pressure of 1.0 kg, in order to increase both sensitivity
and specificity for the diagnostic decision-making process
[34]. The aim of the present study was not to arrive in or
test the predictive values for a specific diagnosis, but was to
analyze if pain elicited at local palpation in the craniofacial
region may be confounded by more generalized hyperalge-
sia; and if so, this should be taken into consideration in the
diagnostic decision process along with other components of
the diagnostic puzzle.
Conclusions
The study indicates that both headache and jaw-face pain
are associated with signs of regional and widespread hyper-
algesia that may be linked to central sensitization. Palpation
of muscles outside regions of the masticatory system should
thus be accounted for in the diagnostic algorithms when
examining patients with orofacial pain. The results of the
present study may imply that there is a need for modifica-
tion of current clinical diagnostic criteria for local myalgia in
the temporomandibular region.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Funding
This study was funded by V
asterbotten County Council.
ORCID
Negin Yekkalam http://orcid.org/0000-0002-2183-7497
Anders W
anman http://orcid.org/0000-0002-8346-5289
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6 N. YEKKALAM AND A. WÄNMAN
Article
Objective: Chronic craniomandibular/cervical pain and temporomandibular disorders have not been studied in patients who had a craniotomy several years previously. The aim of the current clinical work was to address these issues. Methods: A total group of 150 ambulant patients who had a previous craniotomy was subclassified according to whether or not the temporalis muscle was manipulated. Results: The average incidence of multiple subsite regional head and neck pain was 69.3% a number of years after a craniotomy. Evidence of internal derangement of the temporomandibular joint was significantly higher in the group that required manipulation of the temporalis muscle during the procedure. Conclusion: The pattern of chronic craniomandibular/cervical pain experienced years after a craniotomy supports the brain neuromatrix theory of pain.
Article
Objective To analyse the effectiveness of exercise therapy in improving pain and active or passive maximum mouth opening in patients with temporomandibular disorders. Data sources PubMed Medline, Web of Science, Scopus, CINAHL Complete and Physiotherapy Evidence Database, until April 2022, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Review methods We included randomized controlled trials evaluating the effect of exercise therapy on pain and on active and passive maximum mouth opening in patients with temporomandibular disorders. Effect size was calculated using Cohen's standardized mean difference (SMD) and their 95% confidence interval (95% CI) in a random-effects model. Results A total of 16 studies with 812 participants were included. Exercise therapy is effective in reducing pain (SMD: −0.58; 95% CI: −1.01 to −0.12) and increasing the pain pressure threshold (SMD: 0.45; 95% CI: 0.14–0.76), active and passive maximum mouth opening (SMD: 0.43; 95% CI: 0.14–0.71 and SMD: 0.4; 95% CI: 0.06–0.75, respectively). Subgroup analyses showed more effect of exercise therapy more splints versus splints on pain (SMD: −0.5; 95% CI: −0.73 to −0.26), active and passive maximum mouth opening (SMD: 1.14; 95% CI: 0.22–2.07 and SMD: 0.56; 95% CI: 0.06–1.06, respectively). On pain pressure threshold, exercise therapy was better than physiotherapy approach (manual therapy and electrotherapy) (SMD: 0.48; 95% CI: 0.09–0.87). Conclusions Therapeutic exercise is an effective therapy to reduce pain and increase pain pressure threshold and active and passive maximum mouth opening in patients with temporomandibular disorders.
Article
Objectives: To evaluate the linkage underpinning different clinical conditions as painful TMD and neck pain in patients affected by primary headaches. Materials and methods: In this machine learning study, data from medical records of patients with headaches as migraine, tension-type headache (TTH) and other primary ones, referring to a University Hospital over a 10-year period were analysed. VAS was used to evaluate the intensity of the TMD and neck pain. Moreover, the magnetic resonance imaging was used to supplement the clinical data. Results: A total of 300 patients (72 male, 228 female), mean aged 37.78 ± 5.11 years, were included. Higher TMD and neck pain VAS in migraine patients were reported. The machine learning analysis focussed on type of primary headache demonstrated that a higher TMD VAS was correlated to migraine, whereas a higher neck pain VAS was correlated to TTH or migraine. Concerning the TMD type, arthrogenous and mixed TMD were correlated to mild-moderate TMD pain (depending on neck pain intensity), whereas myogenic TMD was correlated to moderate-severe TMD pain. Conclusions: Machine-learning approach highlighted the complexity of diagnosis process and demonstrated that neck pain might be an influential variable on the belonging to different group of headaches in TMD patients.
Article
Introduction: Migraine involves neurovascular, functional, and anatomical alterations. Migraine sufferers experience an intense unilateral and pulsatile headache frequently accompanied with vomiting, nausea, photophobia, etc. Although there is no ideal preventive medication, frequency in migraine days may be partially decreased by some prophylactics, including antihypertensives, antidepressants, antiepileptics and CGRPergic inhibitors. However, the mechanisms of action involved in antimigraine prophylaxis remain elusive. Areas covered: This review recaps some of the main neurovascular phenomena related to migraine and currently available preventive medications. Moreover, it discusses the major mechanisms of action of the recommended prophylactic medications. Expert opinion: In the last three years, migraine prophylaxis has evolved from purely non-specific to specific antimigraine treatments. Overall, non-specific treatments involve neural actions, whereas specific pharmacotherapy (represented by CGRP receptor antagonists and CGRPergic monoclonal antibodies) is predominantly mediated by neurovascular mechanisms that may include, to a greater or lesser extent: (i) reduction in the frequency of cortical spreading depression (CSD) events; (ii) inhibition of pain sensitization; (iii) blockade of neurogenic inflammation; and/or (iv) increase in cranial vascular tone. Accordingly, the novel antimigraine prophylaxis promises to be more effective, devoid of significant adverse effects (unlike non-specific treatments), and more beneficial to the quality of life of migraine patients.
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The upcoming 11th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD) of the World Health Organization (WHO) offers a unique opportunity to improve the representation of painful disorders. For this purpose, the International Association for the Study of Pain (IASP) has convened an interdisciplinary task force of pain specialists. Here, we present the case for a reclassification of nervous system lesions or diseases associated with persistent or recurrent pain for ≥3 months. The new classification lists the most common conditions of peripheral neuropathic pain: trigeminal neuralgia, peripheral nerve injury, painful polyneuropathy, postherpetic neuralgia, and painful radiculopathy. Conditions of central neuropathic pain include pain caused by spinal cord or brain injury, poststroke pain, and pain associated with multiple sclerosis. Diseases not explicitly mentioned in the classification are captured in residual categories of ICD-11. Conditions of chronic neuropathic pain are either insufficiently defined or missing in the current version of the ICD, despite their prevalence and clinical importance. We provide the short definitions of diagnostic entities for which we submitted more detailed content models to the WHO. Definitions and content models were established in collaboration with the Classification Committee of the IASP's Neuropathic Pain Special Interest Group (NeuPSIG). Up to 10% of the general population experience neuropathic pain. The majority of these patients do not receive satisfactory relief with existing treatments. A precise classification of chronic neuropathic pain in ICD-11 is necessary to document this public health need and the therapeutic challenges related to chronic neuropathic pain.
Article
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Background Chronic pain is a major public health problem and 30% to 45% of sufferers experience severe depression. Acupuncture is often used to treat both depression and a range of pain disorders. We aim to conduct a systematic review of randomized controlled trials (RCTs) to evaluate the efficacy of acupuncture for patients experiencing chronic pain with depression. Methods To identify relevant RCTs, the following databases will be searched electronically from their inception to July 1, 2017: PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, the Allied and Complementary Medicine Database, the Cumulative Index to Nursing and Allied Health Literature, Chinese medical databases, and others. Manual retrieval will also be conducted. RCTs that evaluated acupuncture as the sole or adjunct treatment for patients with chronic pain and depression will be included. The primary outcomes will be based on a visual analog pain measurement scale and the Hamilton Depression Scale. The secondary outcomes will include scores on a numerical rating scale, verbal rating scale, and the Hospital Anxiety and Depression Scale. The study selection, data extraction, and study quality evaluation will be performed independently by 2 researchers. If the data permit, meta-analysis will be performed using RevMan V5.3 statistical software. If the data are not appropriate for meta-analysis, descriptive analysis or subgroup analysis will be conducted. The methodological quality of the included trials will be assessed using the Cochrane risk-of-bias criteria and the Standards for Reporting Interventions in Controlled Trials of Acupuncture checklist. Results This study will provide a high-quality synthesis of current evidence of acupuncture for chronic pain with depression from several scales including visual analog pain measurement scale, the Hamilton Depression Scale, a numerical rating scale, verbal rating scale and the Hospital Anxiety and Depression Scale. Conclusion The conclusion of our study will provide updated evidence to judge whether acupuncture is an effective intervention for patients suffered from chronic pain with depression.
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In 2006, the OPPERA project (Orofacial Pain: Prospective Evaluation and Risk Assessment) set out to identify risk factors for development of painful temporomandibular disorder (TMD). A decade later, this review summarizes its key findings. At 4 US study sites, OPPERA recruited and examined 3,258 community-based TMD-free adults assessing genetic and phenotypic measures of biological, psychosocial, clinical, and health status characteristics. During follow-up, 4% of participants per annum developed clinically verified TMD, although that was a "symptom iceberg" when compared with the 19% annual rate of facial pain symptoms. The most influential predictors of clinical TMD were simple checklists of comorbid health conditions and nonpainful orofacial symptoms. Self-reports of jaw parafunction were markedly stronger predictors than corresponding examiner assessments. The strongest psychosocial predictor was frequency of somatic symptoms, although not somatic reactivity. Pressure pain thresholds measured at cranial sites only weakly predicted incident TMD yet were strongly associated with chronic TMD, cross-sectionally, in OPPERA's separate case-control study. The puzzle was resolved in OPPERA's nested case-control study where repeated measures of pressure pain thresholds revealed fluctuation that coincided with TMD's onset, persistence, and recovery but did not predict its incidence. The nested case-control study likewise furnished novel evidence that deteriorating sleep quality predicted TMD incidence. Three hundred genes were investigated, implicating 6 single-nucleotide polymorphisms (SNPs) as risk factors for chronic TMD, while another 6 SNPs were associated with intermediate phenotypes for TMD. One study identified a serotonergic pathway in which multiple SNPs influenced risk of chronic TMD. Two other studies investigating gene-environment interactions found that effects of stress on pain were modified by variation in the gene encoding catechol O-methyltransferase. Lessons learned from OPPERA have verified some implicated risk factors for TMD and refuted others, redirecting our thinking. Now it is time to apply those lessons to studies investigating treatment and prevention of TMD.
Article
Neurology has not typically been associated with international relief work; however, with the growth of chronic cardiovascular disease and stroke associated with unhealthy eating and sedentary ways, the appearance of “new” neurologic diseases, such as the Zika and West Nile viruses, and the high numbers of seizure disorders resulting from neuroinfectious diseases, more opportunities are arising for international and globally oriented neurologists. Multiple opportunities exist for developing a global clinician–educator career pathway, including private institutions, nongovernmental organizations, government-funded opportunities such as Medical Education Partnership Initiative, Fogarty and Fulbright Scholarships, and the American Academy of Neurology's Global Health Section. Furthermore, increasing research capacity in developing countries and increased funding opportunities for global health research have led to new opportunities for neurologists to establish global health research careers. These opportunities could not have come at a better time, as many faculty members have noted a particularly strong interest in global neurology from medical students and residents. Career categories and opportunities for neurologists desiring to work globally are discussed along with the emerging “global neurologist” academic pathway.
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At the turn of the century, most of the world's population lived in regions where the prevalence of headache was unknown and its impact poorly understood. Lifting The Burden (LTB), a nonprofit organization in official relations with the World Health Organization, established the Global Campaign against Headache, with the ultimate purpose of reducing the burden of headache worldwide. First, the scope and scale of this burden had to be known. LTB embarked upon a program of population-based studies in countries in all world regions in order to achieve its aim. Its studies have demonstrated a high prevalence of headache disorders, including migraine, tension-type headache, and medication-overuse headache, and their associations with impaired quality of life, substantial lost productivity, and high economic costs in every country surveyed. Informed by these, the Global Burden of Disease study ranks headache disorders as the second leading cause of years lived with disability worldwide; migraine alone is third among people aged 15 to 49 years. With interventions urgently needed to reduce these burdens throughout the world, we review the epidemiological studies conducted by LTB, examine proposed interventions to improve provision of headache care including a three-tier system of structured headache services, and consider the challenges still remaining in providing effective, efficient, and equitable headache care especially in low-income countries.
Article
Objective. Insufficient evidence exists to compare widespread pain (WP), pain sensibility, and psychological factors that occur in patients presenting with chronic neck pain (CNP) or a combination of temporomandibular disorder (TMD) and other complaints. The present study compared the pain sensibility and psychological factors of subjects with CNP with those with TMD + CNP. Design. Cross-sectional study. Setting. Local community. Subjects. A nonprobabilistic convenience sample of 86 persons with CNP or TMD was recruited into three groups: CNP, TMD with myofascial pain in masticatory muscles with cocomitant CNP (TMD + CNP), and asymptomatic control groups consisted of 27, 29, and 30 participants, respectively. Methods. Participants underwent a clinical examination to evaluate WP with computerized assessment based on the pain drawing, pressure pain thresholds (PPT), and psychological factors, which were evaluated using the pain catastrophizing scale (PCS) and the state-trait anxiety inventory (STAI). Results. Statistically significant differences were observed between participants with CNP and TMD + CNP for WP (t = -2.80, P < 0.01, d = -1.06). Post hoc analyses only revealed significant differences between TMD + CNP participants and asymptomatic controls for PPT at extratrigeminal areas. Pearson correlation analyses showed a moderate positive association between symptomatic groups within the WP and STAI (P < 0.05) and a moderate negative association between PCS and PPT (P < 0.05) at the right tibialis muscle. Conclusion. TMD + CNP participants had more areas of pain and also showed widespread pain hyperalgesia. Both groups of participants had psychological factors positively associated with STAI and WP; further, PCS and the PPT at the extratrigeminal region were negatively associated with each other in both groups, except for the left tibialis in the TMD + CNP group.
Article
Temporomandibular disorders (TMD) are common but seem to be largely undetected within general dental care. To improve dentists' awareness of these symptoms, three screening questions (3Q/TMD) have been introduced. Our aim was to validate 3Q/TMD in relation to the diagnostic criteria for TMD (DC/TMD), while taking into account the severity level of the symptoms. The study population consisted of 7831 individuals 20-69 years old, who had their routine dental check-up at the Public Dental Health Service in Västerbotten, Sweden. All patients answered a health declaration, including the 3Q/TMD regarding frequent temporomandibular pain, pain on movement and catching/locking of the jaw. All 3Q-positives (at least one affirmative) were invited for examination in randomised order. For each 3Q-positive, a matched 3Q-negative was invited. In total, 152 3Q-positives and 148 3Q-negatives participated. At examination, participants answered 3Q/TMD a second time, before they were examined and diagnosed according to DC/TMD. To determine symptom's severity, the Graded Chronic Pain Scale and Jaw Functional Limitation Scale-20 (JFLS-20) were used. In total, 74% of 3Q-positives and 16% of 3Q-negatives met the criteria for DC/TMD pain or dysfunction (disc displacements with reduction and degenerative joint disorder were excluded). Fifty-five per cent of 3Q-positives had a TMD diagnosis and CPI score ≥3 or a JFLS-20 score ≥5, compared to 4% of 3Q-negatives. The results show that the 3Q/TMD is an applicable, cost-effective and valid tool for screening a general adult population to recognise patients in need of further TMD examination and management.
Article
This review explores the principles and process associated with the diagnosis of temporomandibular disorders (TMDs). TMD diagnosis has evolved substantially over the past 25 y. Previously, diagnosis focused solely on aberrations in oral structures, largely without empirical evidence. The Research Diagnostic Criteria for TMD (RDC/TMD) were developed on core principles of 1) a dual-axis system reflecting the biopsychosocial model, 2) a clear operationalization for reliability, and 3) the allowance of multiple diagnoses. These principles were retained in the subsequent validation research of the RDC/TMD, and the current diagnostic system—the Diagnostic Criteria for TMD (DC/TMD)—has improved on those principles as well as on diagnostic validity and protocols for assessing the psychosocial domain. Further investigations into etiology and its potential contribution to taxonomy revision are described, particularly within the context of complex disease. The review concludes with an outline of major research areas already underway that will support future revisions of the DC/TMD.
Article
The muscle tissue primarily does not pertain to a particular nerve fiber which produces pain referred to mechanical stimuli. But polymyositis is known to produce pain in the muscle at rest. A high serum level of creatine phosphokinase and positive C-reactive protein and rheumatic factor are characteristic in this pathological condition. Muscle spasm, in most cases, derives from spinal nerve root involvement, so that a radiographic survey of the spinal column should be taken into consideration. In the process of rehabilitation, muscle pain has to be experienced by patients. This sort of pain should be overcome for the sake of restoration of the function of the locomotor system.