Content uploaded by Michel Steenks
Author content
All content in this area was uploaded by Michel Steenks on May 03, 2021
Content may be subject to copyright.
Journal of Oral & Facial Pain and Headache 7
Focus Article
Reliability and Validity of the Diagnostic Criteria for
Temporomandibular Disorders Axis I in Clinical and
Research Settings: A Critical Appraisal
The recently published Diagnostic Criteria for Temporomandibular Disorders
(DC/TMD) Axis I, which is recommended for use in clinical and research settings,
has provided an update of the Research Diagnostic Criteria for Temporomandibular
Disorders (RDC/ TMD). The authors of the DC/ TMD based their publication o n the
results of a Validation Project (2001–2008) and consecutive workgroup sessions
held between 2008 and 2013. The DC/TMD represents a major change in both
content and procedures; nonetheless, earlier concerns and new insights have
only partly been followed up when drafting the new recommendations. Moreover,
the emphasis on immediate implementation in clinical and research settings is
not in line with the provided external evidence on which the DC/TMD is based.
This Focus Article describes these concerns with regard to several aspects of
the DC/TMD: the additional classification categories; the high dependency on
pressure-pain results from use of the recommended palpation technique; the
TMD pain screening instrument; the test population characteristics; the utility of
additional subgroups; the use of a reference standard; the dichotomy between
pain and dysfunction; and the DC/TMD algorithms. Thus, although the DC/TMD
represents an improvement over the RDC/TMD, its immediate implementation in
research and clinical care does not yet appear to be adequately substantiated.
J Oral Facial Pain Headache 2018;32:7–18. doi: 10.11607/ofph.1704
Keywords: classification, diagnosis, facial pain, reference standards,
temporomandibular disorders
Temporomandibular disorders (TMD) are musculoskeletal conditions
that involve the masticatory musculature, the temporomandibular
joints (TMJs), and associated structures. TMD is an umbrella term,
not a diagnostic entity. Loading the affected muscular or articular struc-
tures during activities such as yawning, biting, or chewing hard/tough food
will typically provoke the clinical signs and symptoms that the patients men-
tion at consultation. The international TMD literature is unanimous in differ-
entiating between muscular and articular subtypes of TMD. The Research
Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) has
played a major role in allowing worldwide comparisons of research.1 Axis I
of the RDC/TMD deals with the physical characteristics of TMD, while Axis
II is designed for evaluation of TMD-associated psychosocial aspects.
The RDC/TMD was conceptualized before 1992. New insights
have suggested a need for changes to the original version; indeed,
as early as in their original 1992 publication, the authors of the RDC/
TMD had pointed out the need for its occasional revision. Various in-
vestigations, including study results on the reliability of clinical TMD
diagnoses,2 have indicated that the characteristics of the RDC/TMD
have not met original expectations despite profound calibration of the
researchers testing for Axis I reliability of symptoms and subgroup clas-
sifications.2–4 In fact, for most of the non–pain-related subgroups—and
thereby for this classification system as a whole—both the reliability and
the criterion validity have been found to be barely acceptable for use in
investigations of the general population or in patients asking for therapy
in clinics specialized in TMD diagnosis and management.4,5
Michel H . Steenks, DDS, PhD
Associate Professor
Department of Oral and Maxillofacial
Surgery
Prosthodontics and Special Dental Care
University Medical Center Utrecht
Utrecht, The Netherlands
Jens Christoph Türp, DDS, Dr Med
Dent Habil, MSc , MA
Professor
Department of Oral Health & Medicine
Division of Temporomandibular
Disorders/Orofacial Pain
University Center for Dental Medicine
Basel
University of Basel
Basel, Switzerland
Anton de Wijer, RPT, RMT, OFT, PhD
Senior Lecturer
University of Applied Sciences Utrecht
Department of Physical Therapy
Utrecht, The Netherlands;
Radboud University Medical Center
Department of Oral Function &
Prosthetic Dentistry
Nijmegen, The Netherlands
Correspondence to:
Dr M.H. Steenks
Department of Oral and Maxillofacial
Surgery
Prosthodontics and Special Dental Care
University Medical Center Utrecht
Heidelberglaan 100, PO Box 85500,
3508 GA Utrecht, The Netherlands
Fax: +31302541922
Email: M.H.Steenks@umcutrecht.nl
This Focus Article is based on a
lecture presented during the meeting of
the Dutch Society for Gnathology,
section Temporomandibular Disorders
and Orofacial Pain, in Bunnik,
The Netherlands, October 6, 2015.
©2018 by Quintessence Publishing Co Inc.
8 Volume 32, Number 1, 2018
Steenks et al
In a Validation Project funded by the United
States National Institutes of Health (NIH) and exe-
cuted by several experienced TMD researchers from
the International RDC/TMD Consortium Network
and the Special Interest Group of the International
Association for the Study of Pain (IASP), the RDC/
TMD Axes I and II were evaluated between 2001 and
2008. The results were discussed in working groups
around the world between 2008 and 2014, resulting
in the revised RDC/TMD classifying algorithms in
20106 and in a major revision termed the Diagnostic
Criteria for Temporomandibular Disorders (DC/TMD)
in 2014, with yet again readapted algorithms.7 The
DC/TMD encompasses existing, new, and extended
subgroups of TMD to support the claim for immediate
implementation in clinical and research settings. The
DC/TMD partly incorporates the American Academy
of Orofacial Pain (AAOP) classification,8 and one
DC/TMD muscular subgroup (headache attributed
to TMD) originates from the International Headache
Society (IHS) classification.9 The criterion validi-
ty of most of the TMD subgroups is now part of the
DC/TMD based on sufficient data from the Validation
Project.7 The inter-examiner reliability of the DC/TMD
algorithms was tested in 46 patients by 6 examiners,
implementing the TMJ Impact Project.7
The improvements, together with the meticulous-
ly executed and discussed methodology, do deserve
compliments. Given the International RDC/TMD
Consortium Network’s request5,7,10 to the larger TMD
community to provide input and discussion regarding
the future of RDC/TMD research, the authors of the
present Focus Article were motivated to critically as-
sess the DC/TMD and to offer a positive contribution
for improvement of its Axis I, as was the case for a
previous publication.11 Hence, the aim of this article is
to discuss the DC/TMD from the perspective of the
RDC/TMD and the Validation Project, under consid-
eration of the claim for immediate implementation in
clinical and research settings.
This Focus Article only addresses the Axis I com-
ponent of the (R)DC/TMD. Aspects of Axis II are dis-
cussed in the context of Axis I.
DC/TMD and RDC/TMD Axes I in
Clinical and Research Settings
On two previous occasions, various aspects of the
RDC/TMD were reviewed by two of the present au-
thors, and suggestions for improvement were pre-
sented.11,12 The most important suggestions are
summarized in Table 1. Some of these suggestions
have been adopted in the revised RDC/TMD and in
the DC/TMD, and others have been put aside. All
operationalized changes from the RDC/TMD to the
DC/TMD have been described in the DC/TMD publi-
cation.7 This Focus Article will focus on four aspects
from the perspective of their clinical application:
(1) familiar pain; (2) TMD categories; (3) palpation;
and (4) diagnoses.
Familiar Pain
One important suggestion for improvement of the
RDC/TMD was related to reproduction of the main
complaint.11,12 The principal challenge of making a
diagnosis in patients with putative TMD signs and
symptoms is to relate the complaints of the patient
to the affected structures.13,14 Consequently, in the
revised RDC/TMD as well as in the DC/TMD al-
gorithms, the construct of “familiar pain” was intro-
duced.15, 21 Familiar pain is defined as “pain similar to
or like what he/she had been experiencing from the
target condition outside the examination setting.”15
This distinction is critical because tenderness on
palpation of the masticatory muscles or TMJs may
also be elicited in individuals without TMD or in pa-
tients with other pain conditions; hence, a distinction
is made between familiar pain and any other pains in
the particular region being investigated. The original
RDC/TMD myofascial pain algorithm made a classi-
fication in the presence of any pain with a minimum
of 3 out of 20 painful sites and at least 1 painful pal-
pation site on the same side as the ongoing pain,
but without the condition for familiar pain. With such
criteria, a reliable myofascial pain or TMJ arthralgia
classification cannot be established, and overdiag-
nosis of myofascial pain may instead be the result. In
fact, the prevalence of group I diagnoses was about
45% lower when the number of painful palpation
sites on the side of the ongoing pain was at least
three as opposed to at least one (76% vs 31.4%,
respectively).16
Table 1 Previous Suggestions for Updating the
RDC/TMD11,1 2 and Their Endorsement
for the DC/TMD7
Suggested changes
Endorsement
Yes No
Reproduction of the main complaint 3
Additional clinical subgroups
(eg, disc displacement with catching)
3
Update of disc displacement criteria 3
Inclusion of other clinical tests 3
Fewer muscle palpation sites 3
Additional palpation techniques 3
Exclusion of extra- and intraoral palpation sites 3
Re-evaluation of group I, II, and III algorithms 3
Restriction to calibrated examiners and
research purposes
3
Identification of pathology or other sources of
orofacial pain first, before applying RDC/TMD
3
Steenks et al
Journal of Oral & Facial Pain and Headache 9
The introduction of the construct of familiar pain
has significantly improved the reliability of the test
results for the revised RDC/TMD myofascial pain
algorithm.6 It may be discussed, however, wheth-
er familiar pain provoked by palpation—in the RDC/
TMD, revised RDC/TMD, and DC/TMD (operational-
ized as pressure)—is equivalent to pain provoked by
functional loading of the masticatory structures, as is
the case during muscular stretching or mastication
of hard or tough foods. Hence, the presence of both
conditions (pain on palpation and during mandibular
function) seems more adequate as a criterion to ap-
ply in the confirmation of TMD.
TMD Categories
Additional categories were proposed by the authors
of the DC/TMD to meet the objective of using this
classification system in clinical settings. The most im-
portant previously missing category, which had been
formerly suggested as an addition to the RDC/TMD,
is “disc displacement with catching,”11 now identified
as “disc displacement with reduction with intermittent
locking.” The categories “subluxation,” “headache at-
tributed to TMD,” and three subcategories of myalgia
have been supplemented. The utility of the three my-
algia subgroups has been questioned elsewhere by
some authors of the DC/TMD,17,18 and the categories
“subluxation” and “headache attributed to TMD” will
be discussed below. The RDC/TMD diagnosis “my-
ofascial pain with limited opening” was eliminated as
a separate category, but the RDC/TMD Validation
Project provided no explanation for this decision. This
latter RDC/TMD diagnosis should be re-introduced
for the reasons outlined below.
Disc displacement criteria were also revised.
Criteria that are widely used clinically for disc dis-
placement with reduction (ie, the elimination of a
click while opening and closing with the mandible
in protrusion; loudness of a closing click with coun-
terforce on the mandible19, 20) have been abandoned.
TMJ clicking on either opening or closing the jaw now
qualifies for disc displacement with reduction.
Palpation
The number of muscles to be palpated in the DC/
TMD has been reduced compared to the RDC/TMD.
Both the temporalis and masseter muscles seem
logical sites to palpate because these muscles are
the most clinically relevant and are the only jaw mus-
cles accessible to extraoral palpation. Palpation in its
original (and broad) sense is an examination for the
purpose of diagnosing disease or illness; it provides
information about the areas of pain, wind-up phe-
nomena, hypersensitivity, and tender spots that may
provoke symptoms. During muscle palpation, the cli-
nician assesses stiffness, tissue texture, the contrast
of the muscle tone between contraction and relax-
ation, symptoms provoked by muscle palpation, and
the reaction to palpation during muscle stretch and
muscle contraction. The relevant tissues should be
palpated not only for tenderness, but also for tissue
changes, such as induration.
In the DC/TMD, the technique mandated for mus-
cle palpation does not fully comply with the original
description in the RDC/TMD, as it is restricted to as-
sessing the intensity of pain originating from a muscle
site after pressing for a certain amount of time with
a defined amount of force (1 kp). In order to classify
three muscle pain–related conditions, the elicited
pain is further evaluated as to its location and dis-
tribution on the basis of palpations of 2 and 5 sec-
onds, respectively. The rationale for choosing 2 and
5 seconds has not been explained, nor has the time
period between these two palpations been specified.
Furthermore, palpation to obtain an insight into tis-
sue characteristics or to detect pathology is still not
an issue; instead, pain provocation is the only char-
acteristic assessed, albeit supplemented by confir-
mation of its location and by the construct of familiar
pain. In order to use the information gained from this
palpation methodology in clinical practice, other clin-
ical conditions and diagnoses need to be excluded
beforehand.
Surprisingly, palpation of supplemental muscle
sites that are anatomically not accessible is still en-
dorsed in the DC/TMD protocol and includes the
amount of palpation pressure21 despite the evidence
for the inaccessibility of these muscles, as is the
case for the lateral pterygoid muscle22 and the poste-
rior digastric muscle.23 In the new protocol, pressure
in the posterior mandibular region is now carried out
medially at the posterior aspect of the mandibular
angle and at the medial wall of the mandible, proba-
bly aiming at the attachment of the medial pterygoid
muscle. Yet, the region behind the posterior aspect
of the mandibular ramus contains many structures
that may easily produce pain when pressure is ap-
plied even among symptom-free individuals, which
may include non-TMD patients. The tendon of the
temporalis muscle is the only clinically relevant and
accessible intraoral palpation site in the DC/TMD;
however, pressure on this structure is usually un-
pleasant, even in healthy individuals. Hence, instruc-
tions for palpation of supplemental muscle sites (ie,
the lateral pterygoid, posterior digastric, and poste-
rior mandibular region) should be omitted from the
clinical protocol.21
Palpation of the TMJs in the DC/TMD differs from
the RDC/TMD description. The rationale behind
palpation “around the lateral pole of the condyle”15
is not mentioned. This method has neither been de-
scribed nor used in other TMD protocols, thereby
10 Volume 32, Number 1, 2018
Steenks et al
lacking content validity. Well-established methods
to assess pain originating from the TMJ, in particular
from its posterior structures,24 have been abandoned,
but “can be used when indicated.”7 Yet, the corre-
sponding indication has not been provided. More
importantly, when following the pain-related TMD al-
gorithms, palpation of the lateral pole of the condyle
during jaw opening is now critical in the distinction
between articular and muscular pain (arthralgia vs
myalgia), as the location of the pain has become a
major criterion in the DC/TMD protocol. However,
overlap of articular and muscular structures (the deep
portion of the masseter muscle with the anterior part
of the joint capsule) makes such a distinction some-
times difficult, especially in a protruded mandibular
position mandated for palpation of the posterior part
of the TMJs as part of palpation around the lateral
pole.21 Since protrusion by itself may provoke pain,
palpation without protrusion via the external auditory
meatus needs to be carried out as well. The rationale
behind these proposed procedures is unclear. In how
many cases will anterior, superior, and/or inferior pal-
pation be positive when posterior palpation is neg-
ative? In addition, one should always recall that the
site of the pain may not always be the source of the
pain, especially in the distinction between articular
and muscular pain when the pain-related TMD and
headache algorithm is used.
Besides these aspects, correlation between dig-
ital examination of the lateral pole of the TMJ and the
range of mandibular motion to assess condylar slid-
ing during opening and closing of the jaw and in ex-
cursive mandibular movements is lacking in the DC/
TMD. Again, the focus is on pain provocation, not on
other qualities.
Clinicians typically use a systematic approach in
their assessment and continuously match the obtained
information with other findings. Taking a history is more
than asking questions and documenting the patient’s
answers. While taking the history, aspects such as
general appearance, state of nutrition, symmetry, head
posture, speech, skin condition, and engagement in
oral habits can be observed. Pain provocation through
pressure only contributes a small amount to the diag-
nostic process. Pressure to establish pain intensity
receives too much emphasis in the DC/TMD over oth-
er aspects of the physical examination, such as pain
provocation by mandibular movements or palpation as
a tool for detecting pathologies.
Diagnoses
In clinical practice, patients with pain and dysfunc-
tion of the masticatory system may have all kinds of
alternative or additional conditions. The following two
citations from the RDC/TMD Validation Project4 and
the DC/TMD6 may serve as examples:
The study attempted to exclude subjects
with other forms of regional pain including
odontogenic pain, any specific craniofacial
neuralgia, nonspecific neuropathic pain,
and pain arising from recent trauma in
addition to pain associated with fibromyalgia,
rheumatoid arthritis…these findings should
be viewed as preliminary data to be taken into
consideration for future study designs.4
The reader is advised that before applying the
revised algorithms, it is necessary to assess
for and rule out other pathology, including
the conditions that are listed in the exclusion
criteria for the RDC/TMD Validation Project.6
In this sense, the DC/TMD is an improvement
compared to the RDC/TMD. Nonetheless, it would
have been beneficial to cite this latter remark in the
Introduction or to position it as a disclaimer at the
beginning of the DC/TMD publication and in the
assessment instruments on the RDC/TMD web-
site with a specific reference to the different types
of odontalgia, as they represent the most frequent
orofacial pains. This would also reflect the necessi-
ty of beginning any examination with an open mind.
The assumption at the beginning of a clinical assess-
ment that a non-specific TMD is playing a role in a
particular patient suggests that many clinicians may
not consider other sources of pain and dysfunction
of the masticatory system. The possible flaws that
may result from such a strategy are illustrated in
case reports published in the dental literature.25–40
The scope of the DC/TMD is much narrower than
the open mind that clinicians should have when con-
fronted with patients with putative TMD signs and
symptoms. As the DC/TMD authors themselves in-
dicate, the values for diagnostic sensitivity and spec-
ificity need to be looked at with great care, because
“the study was not designed to provide estimates in
patients with comorbidities.”15
The DC/TMD may serve as an adjunct to other
existing protocols aiming to exclude other pathol-
ogies.4,6 As soon as all other pathologies (not only
pain-related) have been excluded, including the dif-
ferent forms of odontalgia41 and systemic diseases
(eg, fibromyalgia, rheumatoid arthritis), the resultant
potential “nonspecific” TMD may be classified follow-
ing (an updated version of) the DC/TMD or any other
validated protocol that a clinician is using or is familiar
with.42
It should also be noted that in clinical practice the
reliability of classification of subcategories is expect-
ed to be lower than that of the DC/TMD, which was
developed by highly calibrated examiners with ongo-
ing training.
Steenks et al
Journal of Oral & Facial Pain and Headache 11
In summary, the DC/TMD has undoubtedly im-
proved upon the original RDC/TMD. However, this
new classification and diagnostic scheme is high-
ly pain oriented, and (dys)function does not receive
much attention. Palpation, operationalized as pres-
sure on tissues of the masticatory muscles and the
TMJs, still plays a dominant role in classification.
Finally, the statement that the RDC/TMD has served
the community well does not agree with the out-
come of the Validation Project.5 Overdiagnosis (eg,
myofascial pain) and overtreatment may well have
resulted from this classification. On the other hand,
underdiagnosis may also have been a consequence
of the strict application of the RDC/TMD criteria, for
instance in individuals with (deep) temporomandibu-
lar pain in the absence of relevant findings during the
clinical examination.
DC/TMD Axis I and the Validation
Project
In addition to the general concerns regarding the
DC/TMD proper, the Validation Project—which was
the basis for the DC/TMD—also merits discussion.
The following discussion will focus on six relevant as-
pects: (1) the Axis I TMD pain screener; (2) the test
population characteristics; (3) the utility of additional
subgroups; (4) the reference standard; (5) pain and
(dys)function; and (6) the algorithms.
Axis I TMD Pain Screener
An Axis I pain screener was introduced by Gonzalez
et al43 as a simple, reliable, and valid self-report in-
strument in the DC/TMD that “. . . will allow clinicians
to identify more readily—and cost-effectively—most
patients with painful TMD conditions for whom ear-
ly and reliable identification would have a significant
effect on the diagnosis, treatment, and prognosis.”43
Pain and stiffness in the jaw in the morning and
pain-related changes in the jaw during certain activi-
ties (such as chewing hard or tough food), mandibu-
lar movements (such as yawning), and parafunctions
(such as jaw clenching) are included in the TMD
pain screener, but these functional activities may
provoke non–TMD-related pain as well. Therefore,
although the screener can be important in patient
care in general dental practice (for instance, when a
patient has to be referred to a TMD specialist or is a
likely candidate for intervention43), it is crucial to be
cautious with this module. Still, the study population
used to provide test characteristics of the screener
was a selection of cases and controls originating
from the Validation Project. This is a selected TMD
population, not an open population in which screen-
ing is indicated. Because of this, the groups to be
compared are restricted to painful TMD patients (as
established by the criterion examiners) and healthy
controls, nonpainful TMD patients, and TMD patients
with headache (pain vs no pain and pain vs head-
ache). The high values for diagnostic sensitivity and
specificity are based on these obvious aspects. Any
consultation with patients encompasses and starts
with questions like those included in the screening
evaluation, so its additional value is questionable. It
will certainly not select or triage patients for being
candidates for intervention or select TMD patients
in a nonselected population with similar high posi-
tive and negative predictive values, as found in the
study that resulted from circularity in the design (ie,
the questions in the screener are similar to those in
the reference standard examination). The results of
the investigation by Gonzalez et al43 on the reliability
and validity of the pain-screening questionnaire are
too positive as well, because an optimized prediction
model will reach a certain level of correctness solely
due to the number of random variables as predictors.
A part of the model performance is “for free,” but also
meaningless. This phenomenon is known as the op-
timism of a prediction model.44 Hence, the TMD pain
screener should not be used in clinical settings as
proposed.7 Any additional pain conditions need to
be ruled out first. The patient group in the investiga-
tion by Gonzalez et al also consisted of a subgroup
with odontalgia, and the logistics of this investigation
did not allow the inclusion of values for sensitivity,
specificity, negative predictive value, and positive
predictive value for this subgroup in comparison to
TMD pain or headache or to patients without pain.43
Other authors have suggested the inclusion of a den-
tal pain group as well in order to “discriminate dental
pain patients from TMD pain patients.”45 The use of
clinical tests for TMD pain in such a context is not
compliant with clinical practice because in patients
presenting with orofacial pain, the dentist will evalu-
ate the presence of odontalgia first by using primarily
dental tests. TMD pain tests are not relevant for this
purpose. Because toothache is the most prevalent
source of pain in the face and jaw, the discrimina-
tion between TMD pain and odontalgia (as well as
other possible sources of pain) belongs to the very
first phase of the diagnostic process. It is advised,
therefore, to specifically mention odontalgia in the
disclaimer because this condition needs other tests
for confirmation (also see below).
Test Population Characteristics
In selecting the study population, the procedures6
followed the Standards for Reporting of Diagnostic
Accuracy (STARD) requirements,46 beginning with:
“Are the test results in patients with the target con-
dition different from the results in healthy people?”6
12 Volume 32, Number 1, 2018
Steenks et al
If so, a second question needs to be answered: “Are
patients with specific results more likely to have the
target condition than similar patients with other test
results?”6 Due to the relatively large number of indi-
viduals who were invited to participate in the inves-
tigation by telephone, advertisement, or flyer (thus
qualifying as community cases [n = 359, 72%]15 as
opposed to clinic cases [n = 141, 28%]
15), too few
comorbid conditions were prevalent in the study
sample to answer this question.6 This challenges the
generalizability of the study results. Patients with pain
and dysfunction of the masticatory system due to
other pathologies were excluded from the study pop-
ulation because their sample size was too small. The
sensitivity and specificity presented in the RDC/TMD
Validation Project are expected to be less favorable in
other settings, for instance, in a dental practice.
The population characteristics also differ from a
clinical setting with respect to the duration of the pain
complaints (averages range from 100 to 126 months),
suggesting an exaggeration in the number of patients
diagnosed with persistent temporomandibular pain.
Chronicity and its associated comorbidity are more
prevalent in dental clinics focused on special needs
than in a general dental practice, thus jeopardizing
the generalizability of the reported results.
Another selection bias may be the low threshold
for having at least one of the three cardinal TMD symp-
toms; ie, jaw pain, limited mandibular movement (in
most cases, restricted jaw opening), and TMJ noise.15
This is important, since in recent studies high preva-
lence rates of TMD-related pain conditions were found
when the RDC/TMD was used. For example, in an in-
vestigation analyzing factors associated with TMD pain
in adolescents, group I and group III RDC/TMD diag-
noses were selected to detect TMD pain, and a preva-
lence of 25.5% was found.47 Apart from using a global
system to classify patients, it would be mandatory to
define having TMD in epidemiologic studies similarly,
relying on similar operationalized criteria worldwide.
However, when the criteria result in such high preva-
lence values, the RDC/TMD may not be representa-
tive for patients in general dentistry. A statement about
low treatment need for most TMD cases is necessary
when using other criteria that unveil all TMD cases,
including those without a treatment need.
It is well known that in the general population,
treatment need for TMD is much lower than its prev-
alence.48 In the RDC/TMD Validation Project pop-
ulation, 40% of the community cases received five
diagnoses, and almost 50% of the community were
non–pain-related TMD individuals with two diagno-
ses.15 Considering that nonpatients did not demand
therapy, the number of subgroup categories is unex-
pectedly high. In an earlier study, 30% of a pain-free
population received a TMD pain diagnosis accord-
ing to the RDC/TMD.45 It seems that the RDC/TMD
criteria and the associated multiple diagnosis system
render too many diagnoses, thereby raising doubt as
to the validity of the RDC/TMD and probably the DC/
TMD, given the major role of pain on palpation in both
classifications. Yet, it is still the patient report about
her/his perception of pain during mandibular function
that is the first requirement for making a (R)DC/TMD
diagnosis; tenderness on palpation alone does not
qualify for a (R)DC/TMD pain diagnosis.
Due to the low threshold for being a case, the
study group in the Validation Project contained many
community cases without a treatment demand. In
future study groups, the reliability of classified con-
ditions needs to be tested in TMD patients with a
concomitant demand for therapy in order to better
simulate clinical patients.
Utility of Additional Subgroups
In the DC/TMD, pain-related TMD include the sub-
group “headache attributed to TMD.”7 Unfortunately,
the relevance of the distinction between headache
and myalgia is not explained. Headache in the re-
gion of the anterior portions of the temporalis mus-
cle(s) can result from various pain sources. The
DC/TMD unambiguously states that “a diagnosis
of pain-related TMD (eg, myalgia or TMJ arthralgia)
must be present and is established using valid diag-
nostic criteria.”7 But what is the need for the sepa-
rate subgroup for headache attributed to TMD when
the pain has already been classified as TMD-related
pain? Should a subgroup “otalgia attributed to TMD”
be supplemented as well? Pain in the temporalis re-
gion may present in conjunction with arthralgia; is it
then tension-type headache or myalgia in the tempo-
ralis region in conjunction with arthralgia? It seems
more appropriate to use “myalgia (in the temporalis
region)” in such cases. In the IHS classification this
subgroup makes sense, but not in the DC/TMD.
Subluxation is an additional DC/TMD category. In
the literature, the term “subluxation” has raised much
confusion because it has been defined in a highly
variable way.49 Other conditions, such as mandibu-
lar hypermobility and disc dislocation, have been de-
scribed similarly. In 87% of the general population (in
some individuals more expressed than in others), the
condyle moves beyond the inferior crest of the artic-
ular eminence during maximum jaw opening without
any hindrance in jaw closure or any other TMJ-related
symptomatology.50 This phenomenon is neither a hy-
permobility disorder nor is it known to be a predictor
of dislocation. Conversely, clinically relevant condi-
tions are (habitual) dislocations (luxation, open lock)
with condylar sliding beyond the lower crest of the
eminence and with the mandible in an elastic fixation
in the wide-open position.
Steenks et al
Journal of Oral & Facial Pain and Headache 13
Perceived clicking or popping at the end of jaw
opening requires further evaluation by the clinician in
order to assess whether the symptom is related to
the condyle moving beyond the crest or to clicking in
the final phase of jaw opening due to a disc displace-
ment. Therapeutically, neither condition needs more
than explanation and advice for the patient; therefore,
it would be better to eliminate the subgroup “sublux-
ation” and to use “luxation” instead when it relates
to a single event. The term “habitual luxation,” on the
other hand, should be used in cases in which dislo-
cations occur more frequently, regardless of whether
the patient or the examiner needs to maneuver the
jaw. In sum, it is suggested to omit the myalgia sub-
groups, the subluxation subgroup, and the headache
attributed to TMD subgroup.
Reliance on the DC/TMD in patients with re-
stricted jaw opening in association with myalgia
apparently does not result in a correct diagnosis.
In contrast to the RDC/TMD, the DC/TMD no lon-
ger includes this condition, although it is a prevalent
clinical entity. A more than 5-mm difference between
assisted and unassisted jaw opening (“soft endfeel”)
in combination with familiar pain, as well as a jaw
opening of less than 40 mm and normal range of
motion values for the horizontal movements, are in-
dicative for the group “myofascial pain with limited
mouth opening.” These considerations support the
need for the former diagnostic RDC/TMD group to
be re-introduced.
Regarding the expanded TMD taxonomy, which
was published separately from the DC/TMD,51 the
DC/TMD is oscillating between two thoughts. On the
one hand, a diagnosis is only made after excluding all
other pain-related and non–pain-related pathologies.
On the other hand, it has been suggested to include
in the DC/TMD (at a later stage) specific but less
common TMD conditions, which have been listed in
the expanded taxonomy.51 However, when the DC/
TMD is used at the initial consultation, the history,
physical examination, and presented algorithms are
inadequate to diagnose these specific conditions.
Besides, inspection as part of the physical examina-
tion is lacking, which is very important for conditions
mentioned in the expanded taxonomy, such as neo-
plasms or growth disturbances. Simple algorithms
like those used in the DC/TMD will never yield any
of the conditions mentioned in the expanded tax-
onomy. Therefore, it is advised that the DC/TMD
be restricted to the most common pain-related and
intra-articular manifestations of TMD.
Reference Standard
In assessments of patients, the validity of an instru-
ment is as important as its reliability. An instrument
can be highly reliable, but not valid. The DC/TMD
publication has stated that “validity of diagnostic
criteria revolves around the use of reliable clinical
tests.”7 Undoubtedly, the validity critically depends
on the reliability of the clinical tests when using cri-
terion examiners as a reference standard and test
examiners for evaluation of the criterion validity of the
index tests.15 Using this method, the tables present-
ed in the DC/TMD publications5–7 in fact represent
calculations of reliability. Circularity has been avoid-
ed as much as possible15; nevertheless, the test ex-
aminers and the criterion examiners, by knowing and
using the algorithms, are not independent, thus lead-
ing to a certain degree of circularity. In conditions
such as TMD, it is impossible to use an independent
reference standard when biomarkers are not avail-
able. The help of imaging techniques for the criterion
examiners is not useful, since the association be-
tween symptoms and imaging results is low.52 While
the method of using two random samples of one
specific population under study is a proper valida-
tion procedure, the strength of the model in another
population (external validity) is still unknown. A refer-
ence standard for TMD does not exist, and so values
for diagnostic characteristics—such as sensitivity,
specificity, positive predictive value, and negative
predictive value—should not be used. Therefore, it is
advisable to limit the presented data to the concept
of reliability of clinical entities.
The reliability of the assessment of various TMD
symptoms and classification of subgroups following
the RDC/TMD has been found to be unacceptable.
In a multicenter study, major differences in clinical
TMD subgroups existed even among highly calibrat-
ed examiners, despite broad categories.2,3 Percent
agreement, heavily inflated through agreement by
chance and clustering into myofascial pain, disc
displacement, and degenerative joint disorder, was
able to yield positive results leading to the authors’
conclusion that the results supported the use in
clinical research and decision-making (clinical prac-
tice).2 However, only categories such as (muscle- or
joint-associated) pain and no pain (intraclass coeffi-
cient [ICC] 0.72) and diagnosis vs no diagnosis (ICC
0.78) reached sufficiently acceptable values to have
clinical utility.2
Similar results were obtained in the Validation
Project of the RDC/TMD3: The reliability of the re-
vised RDC/TMD Axis I diagnoses was found to be
excellent, with κ values > 0.75 only for all myofascial
pain subgroups. Considerable uncertainty existed
for the other groups. Compared with the RDC/TMD
Validation Project, the DC/TMD reliability values were
based on a relatively small sample of 46 individuals
(92 TMJs).7 Considering this limited data, immediate
implementation of the DC/TMD procedures in clinical
practice is not advised.
14 Volume 32, Number 1, 2018
Steenks et al
Pain and Dysfunction
In both the DC/TMD and the RDC/TMD, pain and
dysfunction are evaluated separately. This nonclini-
cal dichotomy is necessary to be able to compose
the simple classification algorithms. However, just as
Axis I and Axis II are constructs in the same patient,
both pain and dysfunction need to be assessed in
their mutual relation. The concept of replication of the
main complaint is based on this principle, among oth-
ers. The number of the resultant multiple diagnoses is
high after pain and dysfunction are assessed sepa-
rately in cases and controls (see above); nonetheless,
patients may not be sufficiently characterized through
the summation of the maximum of five Axis I classi-
fications permitted for a single patient. Moreover,
the management plan does not always differ among
subgroups.
In contrast, assessing pain and dysfunction in
their mutual relation provides additional information
about the underlying substrate (eg, myofascial pain
with limited jaw opening), as opposed to assessment
of pain and dysfunction as separate entities. Multiple
diagnoses are still possible when assessed together
in the same patient, but the clinician is better able
to grade the identified signs and symptoms and
thereby to determine the patient-specific therapeutic
need than with the mere use of multiple independent
diagnoses.
The construct “familiar” (as used in the term "fa-
miliar pain") can be used for any symptom that is part
of the patient’s complaint. In the case of a painful
click during jaw opening as reported by the patient,
it is necessary to ensure a clear communication be-
tween the patient and the examiner; in particular, it
should be assessed whether the click is due to an
anterior disc displacement or to the condyle popping
beyond the inferior crest of the articular eminence, as
well as whether pain is elicited at the moment of the
phenomenon (eg, pain-free clicking vs painful click-
ing). It is not adequate to assess pain and clicking
separately.
The nonclinical dichotomy of assessing pain and
function separately has yet other consequences. In
the DC/TMD, pain drawings indicating the location(s)
of a patient’s pain are used. The drawings show a
full body (front and back) template, a head and neck
(left and right, but not the shoulders) template, and an
intraoral template. The drawings and the assessment
of impairments of mandibular function are part of Axis
II, but this is in fact Axis I physical information. It is
crucial for the treatment provider in clinical settings
to assess all pain locations as Axis I information be-
cause this information is relevant for prognosis and
therapy.53 Other consequences of assessing pain
and dysfunction separately are that palpation is re-
stricted to one dimension: pain on pressure. Joint
locking is assessed for reduction and unlocking;
however, whether a pain report is linked to mandibu-
lar function is not evaluated.
Patterns of signs and symptoms mandatory for
defining TMD subgroups that are absent in patients
are likely to disturb diagnostic accuracy. One example
is the pattern of deflexion of the mandible to the af-
fected side upon mandibular opening movement; this
is highly predictable for an acute unilateral disc dis-
placement without reduction, while a clinical finding
not fitting this pattern raises doubt with regard to this
diagnosis. Another example is a jaw opening of less
than 20 mm, which is atypical for nonspecific TMD,
but not part of a disclaimer. Hence, clinically relevant
pattern recognition is absent in the DC/TMD.
Teaching clinicians to think of pain and dysfunc-
tion as separate entities provides them with a false
start in the process of clinical reasoning. Clinicians
tend to stick to a first impression and often forget to
keep an open mind at the first consultation, as well
as during the subsequent management of their pa-
tients. Diagnostic error is defined as “the failure to (a)
establish an accurate and timely explanation of the
patient’s health problem(s) or (b) communicate that
explanation to the patient.”54 Anchoring (the tendency
to lock onto salient features in the patient’s initial pre-
sentation and to fail to adjust this initial impression in
light of subsequent information) and premature clo-
sure (the tendency to accept the first answer that ex-
plains the facts at hand without considering whether
there might be a different or better solution) are fre-
quent biases in clinical practice.53 Using the oversim-
plified TMD pain screener and examining the patient
from the viewpoint of the separate entities pain and
dysfunction in general dental practice are bound to
increase this type of diagnostic error.
Algorithms
The evolution of the original 1992 RDC/TMD algo-
rithms was tested in the Validation Project. The results
led to the revised RDC/TMD algorithms presented in
2010. Workshops held in different parts of the world
and involving members of the International RDC/TMD
Consortium Network and the IASP Orofacial Pain
Special Interest Group produced the current DC/
TMD algorithms. It is beyond the scope of this Focus
Article to identify all differences among the three ver-
sions; however, due to the additional myalgia sub-
groups and the arthralgia subgroup, modifications of
the pain-related DC/TMD algorithms are larger than
those between the original and revised RDC/TMD al-
gorithms. The same holds true for the disc displace-
ment and degenerative joint disease algorithms.
In the DC/TMD, several subgroups still lack values
for diagnostic accuracy. This is due to major changes
in the transition of the revised RDC/TMD to the DC/
Steenks et al
Journal of Oral & Facial Pain and Headache 15
TMD. The process for providing subgroup diagnos-
tic accuracy has been less clearly described than the
process of transition to the revised RDC/TMD. It was
stated that “sufficient data from the Validation Project
existed to provide a credible estimate of the criterion
validity.”7 This concerned the validity of the newly rec-
ommended DC/TMD Axis I diagnostic algorithms7;
however, it is not clear which “sufficient data” were
used. With so many of its components still being de-
veloped, the prompt implementation of the DC/TMD
should not be based on this limited information.
Another aspect that deserves attention is the
number of positive test results in the case of repet-
itive diagnostic procedures: In the DC/TMD this is
one out of three, whereas in the original RDC/TMD
this was two out of three. Probabilistic (Bayesian)
reasoning implies that the presence (or absence) of
findings (ie, positive vs negative tests) can raise the
likelihood of a condition.53 A symptom is more stable
when it is tested positively in three out of three tests.
In this strict interpretation, a two out of three outcome
would be interpreted as a negative overall test result.
Hence, the reliability of the subgroup classification
based on a set of positive tests will increase in pro-
portion to the percent of positive responses. Would
it, therefore, not be preferable to require at least two
out of three positive test results, as in the RDC/TMD,
or even three out of three positive test results for re-
search purposes, which would be a better indication
of homogenous patient groups? In research a patient
can be excluded for a test or a trial, but in the clinic,
patients need to be accommodated. Using one out
of three positive test results may be sufficient in a
clinical setting, particularly to avoid too many patients
finding themselves undiagnosed.
The DC/TMD algorithms need to be simple in or-
der to generate the classified TMD conditions, but at
the cost of a limited scope regarding clinical reality. For
example, in the history level (Symptom Questionnaire
item 3), replacement of regional pain with wisdom
tooth pain (representing regional pain modified by jaw
opening) would lead to the category “myalgia” in the
pain-related TMD algorithm. Although the muscles
may be sore, they certainly do not require therapy in
such a case, and the necessarily simple DC/TMD al-
gorithm may lead the clinician’s reasoning in the wrong
direction. More “AND” statements in the pain-related
algorithms may result in increased diagnostic accu-
racy. In the myalgia subgroup, “familiar pain from jaw
opening” (exam item 4) during examination is expected
to be accompanied by the similar “familiar pain on mas-
ticatory muscle palpation, 2 secs” (exam item 9). In the
context of probabilistic reasoning, “AND” is more ap-
propriate than “OR.” Similarly, it seems more appropri-
ate to connect “arthralgia on jaw opening” (exam item
4) to “jaw horizontal movements” (exam item 5) with
“AND” instead of “OR.” Other “AND/OR” statements
in these algorithms need further consideration as well.
Likewise, “pain modified with mandibular function”
is preferred over “pain modified with jaw movement,
function, or parafunction,” because it is questionable
whether patients can reproduce parafunction on com-
mand. Since mandibular function includes jaw move-
ment, the latter term can be eliminated from the phrase.
Furthermore, at the history and examination levels for
intra-articular disorders, prior jaw locking at closed
jaw does not really describe the actual condition; “jaw
locking with limited opening” is preferred. A “maneu-
ver required to open the mouth” in disc displacement
with intermittent locking could preferably be stated as
a “maneuver required to unlock the joint.”
Crepitus in conjunction with putative degener-
ative joint disease may be confirmed by computer
tomography21 (CT) or by cone beam computed to-
mography (CBCT); a reference to the specific indi-
cation is necessary. However, the need for imaging
when the only symptoms and signs are TMJ noise is
highly questionable. Exclusion of clinically relevant
pathologies is the main indication for TMJ imaging.
In the body of the text of the DC/TMD, pain modi-
fication in a patient report is described as “pain made
better or worse” by loading the masticatory system (ie,
through function, movement, or parafunction).7 However,
pain modification also relates to pain that was previous-
ly absent but is induced by diagnostic manipulations, as
indicated in the legend of Table 2 in the DC/TMD. Both
descriptions should receive equal emphasis.
Neck pain is frequently part of the history in pa-
tients with TMD. Following the DC/TMD, the examin-
er considers pain referral from the neck and shoulder
region as TMD pain because these regions do not
otherwise receive diagnostic attention. Moreover,
due to the overlap in symptom profiles of TMD and
cervical spine disorders and its consequences with
regard to sensitization, the examiner may not be
aware of manifestations of malignancies, fracture, or
rheumatic disease in the neck and shoulder area.
Suggestions
The DC/TMD offers much perspective for future de-
velopment in research settings and represents a dis-
tinct improvement over the RDC/TMD; however, the
remarks made here and previously11 lead to the con-
clusion that the DC/TMD is not yet adequate for use in
clinical settings. Therefore, suggestions for improve-
ment are offered in Table 2. Theoretically, research
can be directed toward determining proper reliabil-
ity and validity and to studies using the DC/TMD in
clinical TMD research. More advanced versions of a
better validated Axis I system may be used for TMD
16 Volume 32, Number 1, 2018
Steenks et al
research on clinical care. The latest research agenda
proposed in a commentary55 drafted by a subgroup
of the authors of the DC/TMD, in combination with
the present suggestions, may serve as recommenda-
tions. The contents of this commentary also under-
pin the lack of urgency to implement the DC/TMD in
clinical practice. DC/TMD projects that are executed
in a stepped order of research before research on
its clinical application will provide the best possible
evidence for the TMD community. TMD patients will
also benefit most when this stepped strategy is used.
One may wonder, though, whether a one-size-fits-
all strategy (one system for both research and clinical
care) is desirable, since research and management
of patients are different processes. The statement
that the core of the DC/TMD can be supplemented
by any other desired examination is correct, but also
somewhat misleading. The presented diagnostic ac-
curacy is no longer valid when other tests are used
in the decision-making process of subgroup classi-
fication next to the core algorithms; for example, a
cut-off value for limited jaw opening may be relevant
as a research question, but may not be relevant in
clinical care at all. Separating pain and dysfunction is
probably acceptable for research, but not in clinical
practice.
Figures on reliability of the DC/TMD in a larger
test population are also needed. In future Axis I reli-
ability studies, patients with TMD but without a treat-
ment demand should not be included. As long as the
DC/TMD is advocated to be used in clinical settings,
a disclaimer should be added indicating that before
applying the revised algorithms it is necessary to as-
sess for and rule out all other pathologies.
More certainty can be expected from three out of
three positive tests in research settings. One out of
three is the very minimum in clinical measurement.
Assessing condylar sliding by palpation and correlat-
ing this information with the degree of jaw opening
better informs the clinician about the source of a
jaw-opening limitation than measuring only the inter-
incisal distance (plus the vertical overbite). Palpation
should include examination of the tissues with the fin-
gertips by touch and not only by the pain pressure
procedure, and nonaccessible muscles should no
longer be a part of the protocol. Several DC/TMD
subgroups need to be evaluated for retention, recon-
sideration, or omission.
Because of overlap between signs and symp-
toms of TMD and cervical spine disorders, clinicians
should be advised to include within their diagnostic
scheme the probability of a cervical spine disorder
as an additional condition in patients with pain and
dysfunction of the masticatory system. Both the
RDC/TMD and the DC/TMD ignore this aspect.
Studies have shown that both questionnaires and
orthopedic tests of the masticatory system may be
used to distinguish between TMD and cervical spine
disorders, while orthopedic testing of the cervical
spine is of minor importance.56,57 Hence, the ques-
tions, drawings, and tests in the DC/TMD protocol
should include the neck and shoulder girdle region
in order to provide an orientation needed for prop-
er referral of the patient to a specialist competent in
Table 2 Suggestions for Improvement of the DC/TMD
Avoid using pain screener to select patients with TMD or candidates for intervention.
Include individuals with treatment demand in Axis I validation studies.
Use the construct “familiar” for all signs and symptoms in the assessment of putative TMD.
Include extra- and intra-oral inspections in the protocol.
Include clinical tests on neck and shoulder girdle.
Include a list of atypical signs and symptoms for nonspecific TMD.
Include a disclaimer for excluding other pain-related conditions first before considering nonspecific TMD.
Abandon nonaccessible muscle palpation sites.
Do not use pain location as a critical decision for subgroup allocation.
Use additional palpation techniques for assessment of tissue characteristics.
Include more robust algorithms for determination of subgroups (more “AND” statements; three out of three criteria met).
Include correlation of condylar sliding and incisal measurement of jaw opening.
Include the subgroup “myofascial pain with limited opening” (use difference of assisted and unassisted jaw opening > 5 mm).
Exclude subluxation subgroup and the need for maneuvering the mandible by the patient.
Exclude palpation around the lateral pole.
Do not differentiate temporalis myalgia and headache attributed to TMD.
Assess pain and dysfunction in their mutual relation.
Consider pain locations and limitation in function as Axis I information.
Provide information for dealing with patients not exhibiting all requirements of the DC/TMD classification (eg, patients reporting TMJ or
masticatory muscle pain in the absence of tenderness on palpation) and provide a list of signs and symptoms occurring in patients with
TMD/orofacial pain.
Steenks et al
Journal of Oral & Facial Pain and Headache 17
dealing with problems involving the head, neck, and
shoulder girdle. Patients and clinicians may expect
a more mature DC/TMD version before immediate
implementation is proclaimed. Researchers have an
even broader responsibility in exposing patients and
subjects to the DC/TMD, which are presently not yet
ready for clinical application.
Conclusions
The DC/TMD represents an improvement over the
RDC/TMD; however, there is a need to consider
further aspects of the DC/TMD before its immedi-
ate and general implementation in clinical settings.
Suggestions for improvement are made in this Focus
Article. It is difficult to support the DC/TMD Axis I
as long as several of its components are still being
developed. It would be wise to focus research efforts
on further development of the system itself. Given the
vast number of pathologies mimicking nonspecific
TMD and the necessity to exclude other pathologies
first, expanding the DC/TMD to include less common
TMD conditions and disorders appears to be too am-
bitious to be credible and clinically appropriate.
Acknowledgments
The authors report no conflicts of interest.
References
1. Dworkin SF, LeResche L. Research diagnostic criteria for
temporomandibular disorders: Review, criteria, examina-
tions and specifications, critique. J Craniomandib Disord
1992;6:301–3 55.
2. John MT, Dworkin SF, Mancl LA. Reliability of clinical temporo-
mandibular disorder diagnoses. Pain 2005;118:61–69.
3. Look JO, John MT, Tai F, et al. The Research Diagnostic
Criteria For Temporomandibular Disorders. II: Reliability of
Axis I diagnoses and selected clinical measures. J Orofac Pain
2010;24:25–34.
4. Truelove E, Pan W, Look JO, et al. The Research Diagnostic
Criteria for Temporomandibular Disorders. III: Validity of Axis I
diagnoses. J Orofac Pain 2010;24:35–47.
5. Schiffman E, Ohrbach R. The many faces of persistent orofa-
cial muscle pain. J Oral Facial Pain Headache 2015;29:208.
6. Schiffman EL, Ohrbach R, Truelove EL, et al. The Research
Diagnostic Criteria for Temporomandibular Disorders. V:
Methods used to establish and validate revised Axis I diagnos-
tic algorithms. J Orofac Pain 2010;24:63–78.
7. Schiffman E, Ohrbach R, Truelove E, et al. Diagnostic Criteria
for Temporomandibular Disorders (DC/TMD) for Clinical and
Research Applications: Recommendations of the International
RDC/TMD Consortium Network and Orofacial Pain Special
Interest Group. J Oral Facial Pain Headache 2014;28:6–27.
8. de Leeuw R, Klasser GD (eds). Orofacial Pain: Guidelines for
Assessment, Diagnosis, and Management, ed 5. Chicago:
Quintessence, 2013.
9. Headache Classification Committee of the International
Headache Society (IHS). The International Classification of
Headache Disorders, 3rd edition (beta version). Cephalalgia
2013;33:629–808.
10. Anderson GC, Gonzalez YM, Ohrbach R, et al. The Research
Diagnostic Criteria for Temporomandibular Disorders. VI:
Future directions. J Orofac Pain 2010;24:79–88.
11. Steenks M, de Wijer A. Validity of the Research Diagnostic
Criteria for Temporomandibular Disorders Axis I in clinical and
research settings. J Orofac Pain 2009;23:9–16.
12. Steenks MH, de Wijer A. Research Diagnostic Criteria for
Temporomandibular Disorders: Need for an update of Axis
I [abstract]. Marrakech: Annual Meeting of the European
Academy of Craniomandibular Disorders, 2007.
13. Steenks MH, de Wijer A. Die strukturbezogene untersu-
chung des kauapparates. In: Steenks MH, de Wijer A (eds.).
Kiefergelenksfehlfunktionen aus Physiotherapeutischer und
Zahnmedizinscher Sicht: Diagnose und Therapie. Berlin:
Quintessenz, 1991:109–132.
14. Steenks MH, de Wijer A, Bosman F. Orthopedic diagnostic
tests for temporomandibular and cervical spine disorders. J
Back Musculoskelet Rehabil 1996;6:135–153.
15. Schiffman EL, Truelove EL, Ohrbach R, et al. The Research
Diagnostic Criteria for Temporomandibular Disorders. I:
Overview and methodology for assessment of validity. J Orofac
Pain 2010;24:7–24.
16. Yap AU, Dworkin SF, Chua EK, List T, Tan KB, Tan HH.
Prevalence of temporomandibular disorder subtypes, psycho-
logic distress, and psychosocial dysfunction in Asian patients.
J Orofac Pain 2003;17:21–28.
17. Lobbezoo F, Visscher CM, Naeije M. Some remarks on the
RDC/TMD Validation Project: Report of an IADR/Toronto-2008
workshop discussion. J Oral Rehabil 2010;37:779–783.
18. Sve nss on P, M ich elo tti A, L obb ezo o F, Li st T. The ma ny f ace s of
persistent orofacial muscle pain. J Oral Facial Pain Headache
2015;29:207–208.
19. Huddleston Slater JJ, Lobbezoo F, Van Selms MK, Naeije
M. Recognition of internal derangements. J Oral Rehabil
2004;31:851–854.
20. Huddleston Slater JJ, Lobbezoo F, Chen YJ, Naeije M. A com-
parative study between clinical and instrumental methods for
the recognition of internal derangements with a clicking sound
on condylar movement. J Orofac Pain 2004;18:138–147.
21. Ohrbach R, Gonzalez Y, List T, Michelotti A, Schiffman
E. Diagnostic Criteria for Temporomandibular Disorders
(DC/TMD) Clinical Examination Protocol. Version: June 2,
2013. https://ubwp.buffalo.edu/rdc-tmdinternational/tmd-
assessmentdiagno si s/dc-tmd/. Accessed 13 November 2017.
22. Türp JC, Minagi S. Palpation of the lateral pterygoid region in
TMD—Where is the evidence? J Dent 2001;29:475–483.
23. Türp JC, Arima T, Minagi S. Is the posterior belly of the digas-
tric muscle palpable? A qualitative systematic review of the lit-
erature. Clin Anat 2005;18:318–322.
24. Okeson JP. Bell’s Oral and Facial Pain, ed 7. Chicago:
Quintessence, 2014.
25. Brown RS, Johnson CD, Fay RM. The misdiagnosis of tem-
poromandibular disorders in lateral pharyngeal space infec-
tions—Two case reports. Cranio 1994;12:194–198.
26. Domnitz JM, Swintak EF, Schriver WR , Shereff RH. Myofascial
pain syndrome masquerading as temporomandibular joint
pain. Oral Surg Oral Med Oral Pathol 1977;43:11–17.
27. DuPont JD. Unhealed extraction sites mimicking TMJ pain.
Gen Dent 2000;48:82–85.
18 Volume 32, Number 1, 2018
Steenks et al
28. Freudlsperger C, Kurth R, Werner MK, Hoffmann J, Reinert S.
Condylar metastasis from prostatic carcinoma mimicking tem-
poromandibular disorder: A case report. Oral Maxillofac Surg
2012;16:79–82.
29. Gingrass DJ, Sadeghi EM. Osteochondroma of the mandibular
condyle mimicking TMJ syndrome: Clinical and therapeutic ap-
praisal of a case. J Orofac Pain 1993;7:214–219.
30. Gobetti JP, Türp JC. Fibrosarcoma misdiagnosed as a tem-
poromandibular disorder: A cautionary tale. Oral Surg Oral
Med Oral Pathol Oral Radiol Endod 1998;85:404–409.
31. Keith DA, Glyman ML. Infratemporal space pathosis mimicking
TMJ disorders. J Am Dent Assoc 1991;122:59–61.
32. Lader E. Lyme disease misdiagnosed as a temporomandibular
joint disorder. J Prosthet Dent 1990;63:82–85.
33. Muñoz M, Goizueta C, Gil-Díez JL, Díaz FJ. Osteocartilaginous
exostosis of the mandibular condyle misdiagnosed as tem-
poromandibular joint dysfunction. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod 1998;85:494–495.
34. Orhan K, Orhan AI, Oz U, Pekiner FN, Delilbasi C.
Misdiagnosed fibrosarcoma of the mandible mimicking tem-
poromandibular disorder: A rare condition. Oral Surg Oral
Med Oral Pathol Oral Radiol Endod 2007;104:e26–e29.
35. Park W, Nam W, Park HS, Kim HJ. Intraosseous lesion in
mandibular condyle mimicking temporomandibular disorders:
Report of 3 cases. J Orofac Pain 2008;22:65–70.
36. Reiter S, Winocur E, Goldsmith C, Emodi-Perlman A, Gorsky
M. Giant cell arteritis misdiagnosed as temporomandibular
disorder: A case report and review of the literature. J Orofac
Pain 2009;23:360–365.
37. Scolozzi P, Becker M, Lombardi T. Mandibular condylar me-
tastasis mimicking acute internal derangement of the temporo-
mandibular joint. J Can Dent Assoc 2012;78:c77.
38. Reiter S, Gavish A, Winocur E, Emodi-Perlman A, Eli I.
Nasopharyngeal carcinoma mimicking a temporomandibular
disorder: A case report. J Orofac Pain 2006;20:74–81.
39. Menezes AV, Lima MP, Mendonca JE, Haiter-Neto F, Kurita LM.
Breast adenocarcinoma mimicking temporomandibular disor-
ders: A case repor t. J Contemp Dent Pract 2008;9:100–106.
40. Pang KM, Park JW. Masticator y muscle pain and progressive
mouth opening limitation caused by amyotrophic lateral sclero-
sis: A case r eport. J Oral Fa cial Pain Headache 2015;29:91–96.
41. Türp JC, Hugger A, Löst C, Nilges P, Schindler HJ, Staehle
HJ. Suggestion for a classification of odontalgias [in German].
Schmerz 2009;23:448–460.
42. Lobbezoo-Scholte AM, de Wijer A, Steenks MH, Bosman F.
Interexaminer reliability of six orthopaedic tests in diagnostic
subgroups of craniomandibular disorders. J Oral Rehabil 1994;
21:273–285.
43. G onzalez YM, Schiffman E, Gordon SM, et al. Development of a
brief and effective temporomandibular disorder pain screening
questionnaire: Reliability and validity. J Am Dent Assoc 2011;
142:1183–1191.
44. Steyerberg EW. Over fitting and optimism in prediction mod-
els. In: Steyerberg EW (ed). Clinical Prediction Models: A
Practical Approach to Development, Validation, and Updating.
New York: Springer, 2009:83–100.
45. Visscher CM, Naeije M, De Laat A, et al. Diagnostic accuracy
of temporomandibular disorder pain tests: A multicenter study.
J Orofac Pain 2009;23:108–114.
46. Bossuyt PM, Reitsma JB, Bruns DE, et al. Towards complete
and accurate reporting of studies of diagnostic accuracy:
The STARD initiative. Standards for Reporting of Diagnostic
Accuracy. Clin Chem 2003;49:1–6.
47. Fernandes G, van Selms MK, Gonçalves DA, Lobbezoo F,
Camparis CM. Factors associated with temporomandibular
disorde rs pain in adoles cents. J Oral Re habil 2015;42:113–119.
48. De Kanter R J, Käyser AF, Battis tuzzi PG, Truin GJ, Van ‘ t Hof MA.
Demand and need for treatment of craniomandibular dysfunction
in the Dutch adult population. J Dent Res 1992;71:1607–1612.
49. Boering G. Temporomandibular Joint Arthrosis: An Analysis
of 400 Cases [in Dutch] [dissertation]. Groningen, The
Netherlands: University of Groningen, 1966.
50. Derksen A A, Buchner R. Some observations concerning dislo-
cations of the temporomandibular joint [in Dutch]. Ned Tijdschr
Tandheelkd 1966;73:846–856.
51. Peck CC, Goulet JP, Lobbezoo F, et al. E xpanding the ta xono-
my of the diagnostic criteria for temporomandibular disorders.
J Oral Rehabil 2014;41:2–23.
52. Petersson A. What you can and cannot see in TMJ imag-
ing—An overview related to the RDC/TMD diagnostic system.
J Oral Rehabil 2010;37:771–778.
53. Palla S. Neurocognition and neuroplasticity: What does it
all mean for clinical practice? J Oral Facial Pain Headache
201 5;2 9 :113 –114 .
54. National Academies of Sciences, Engineering, and Medicine.
Improving Diagnosis in Health Care. Washington, D.C.:
National Academies, 2015.
55. Michelotti A, Alstergren P, Goulet JP, et al. Next steps in develop-
ment of the Diagnostic Criteria for Temporomandibular Disorders
(DC/TMD): Recommendations from the International RDC/
TMD Consortium Network workshop. J Oral Rehabil 2016;43:
453–467.
56. de Wijer A, de Leeuw JR, Steenks MH, Bosman F. Tem-
poromandibular and cervical spine disorders. Self-reported signs
and symptoms. Spine (Phila Pa 1976) 1996;21:1638–1646.
57. de Wijer A, Steenks MH, Bosman F, Helders PJ, Faber J.
Symptoms of the stomatognathic system in temperomandibular
and cervical spine disorders. J Oral Rehabil 1996;23:733–741.
