Workshop Recommendations for Axis I Pain-Related TMD Diagnoses

1. The Axis I TMD Pain Screener⁴⁵ is a simple, reliable, and valid self-report instrument used to assess for the presence of any pain-related TMD, with sensitivity and specificity ≥ 0.95.⁴⁶ For screening for pain-related TMD, the full six item version has sufficient reliability for assessing individuals, such as in a clinical setting, whereas a three-item version is suitable for assessment of a population in research settings. The DC/TMD Symptom Questionnaire (DC/TMD SQ) provides the necessary history for rendering a specific diagnosis in conjunction with the new DC/TMD painrelated diagnostic algorithms.

2. The changes in the diagnostic procedures for the pain diagnoses in the new DC/TMD, as compared to the corresponding disorders in the RDC/TMD, are summarized in Table 5. In the new DC/TMD, myalgia represents what was called myofascial pain in the RDC/TMD. The term myofascial pain now describes two new DC/TMD diagnoses: myofascial pain and myofascial pain with referral. Further detail regarding these changes can be found in the Examination Specifications.⁴⁷ The diagnostic algorithms in the new DC/TMD for arthralgia and myalgia now include criteria for modification of pain by function, movement, or parafunction; these criteria are also included in the TMD Pain Screener. The clinical examination includes provocation tests for TMJ arthralgia of pain with any jaw movement (ie, opening, lateral, and protrusive) and TMJ palpation. For myalgia, the tests include pain with opening jaw movements and palpation of the temporalis and masseter muscles. Pain from these provocation tests must replicate the patient's pain complaint.

   Table 5

   From RDC/TMD to DC/TMD: Comparison of Diagnostic Procedures for Pain-Related TMD

   	RDC/TMD	DC/TMD
   HISTORY (applicable to all pain-related TMD)
   Presence of masticatory system pain
   Headache of any type in temporal region
   Pain or headache modification with jaw movement, function, or parafunction
   EXAMINATION
   Arthralgia
   Confirmation of location of pain in the joint
   Pain with joint palpation
   • Lateral pole
   • Around lateral pole
   • Posterior site
   Pain with range of motion
   Familiar pain with palpation or range of motion
   Myalgia (“Myofascial pain” in RDC/TMD)
   Confirmation of location of pain in a masticatory muscle
   Pain with muscle palpation (required sites)
   • Temporalis
   • Masseter
   • Posterior mandibular region
   • Submandibular region
   • Lateral pterygoid area
   • Temporalis tendon
   Pain with maximum unassisted or assisted opening
   Familiar pain with palpation or opening
   Local myalgia (new diagnosis)
   Sustained palpation with no identification of spreading pain or referral patterns
   Myofascial pain (new diagnosis)
   Sustained palpation with identification of spreading pain but no referral patterns
   Myofascial pain with referral (new diagnosis)
   Sustained palpation with identification of referral patterns (spreading pain may also be present)
   Headache attributed to TMD (new diagnosis)
   Confirmation of location of headache in temple area
   Familiar headache with palpation or range of motion

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3. The disorder of myofascial pain with limited opening, as described in the RDC/TMD, is eliminated.

4. For the new DC/TMD, muscle pain diagnoses are organized into four major subclasses: myalgia, tendonitis, myositis, and spasm (see Table 4). Myalgia is further subdivided into three mutually exclusive types of myalgia: (1) local myalgia, defined as pain localized to the site of palpation; (2) myofascial pain, defined as pain spreading beyond the site of palpation but within the boundary of the muscle being palpated; and (3) myofascial pain with referral, defined as pain at a site beyond the boundary of the muscle being palpated. The diagnostic criteria for myalgia and one of its types, myofascial pain with referral, have criterion validity and are listed in Table 2. The palpation pressure for myalgia is 1 kg for 2 seconds, but to differentiate the three types of myalgia, the duration of the 1 kg of palpation pressure is increased to 5 seconds to allow more time to elicit spreading or referred pain, if present.⁴⁷ The diagnostic criteria for local myalgia and myofascial pain, which have content validity but for which criterion validity has not been established, are presented in Table 2 for completeness; their respective validity estimates will be posted on the Consortium website after they are established.⁴⁸ If a diagnosis of myalgia is desired, and no distinction between the three types is needed, then the more general diagnostic procedures as described in Table 2 are sufficient.

Workshop Recommendations for Axis I TMJ Disc Displacement (DD) and Degenerative Joint Disease (DJD)

1. The clinical procedures for assessing DD with reduction, DD without reduction without limited opening, and DJD lead to clinical diagnoses based on procedures that exhibit low sensitivity but good to excellent specificity. Consequently, for treatment decision-making in selective cases, confirmation of a provisional clinical diagnosis requires imaging. In contrast, the clinical procedures for assessing DD without reduction with limited opening have acceptable sensitivity and specificity, and the clinical evaluation may be sufficient for the initial working diagnosis.

2. The changes made to the diagnostic procedures in the new DC/TMD for DD and DJD as compared to the RDC/TMD are summarized in Table 6. Further detail regarding these changes can be found in the Examination Specifications.⁴⁷ TMJ noise by history is a recommended criterion for the intra-articular disorders of DD with reduction and DJD. This history criterion may be met by the patient's report of any joint noise (click or crepitus) during the 30 days prior to the examination, or by the patient's detection of any joint noise with jaw movements during the clinical examination. In addition, a diagnosis of DD with reduction requires examiner detection of clicking, popping, or snapping noises during the examination. Establishing a diagnosis of DJD necessitates examiner detection of crepitus (eg, crunching, grinding, or grating noises) during the examination. For DJD, no distinction between fine versus coarse crepitus is made. Finally, for DD without reduction, an assisted opening measurement (including the amount of vertical incisal overlap) of < 40 mm yields the subtype of “with limited opening,” while the measurement ≥ 40 mm yields the subtype of “without limited opening,” and joint noises, if present, do not affect the diagnosis of DD without reduction as long as the required criteria for DD without reduction are met.

   Table 6

   From RDC/TMD to DC/TMD: Comparison of Diagnostic Procedures for Disc Displacements and Degenerative Joint Disease with New History-Based Diagnosis of Subluxation

   	RDC/TMD	DC/TMD
   HISTORY
   “In last 30 days, any noise present” applicable to disc displacement with reduction with and without intermittent locking, and degenerative joint disease
   “In last 30 days, jaw locks with limited mouth opening and then unlocks” applicable to disc displacement with reduction with intermittent locking
   “Ever have jaw lock or catch so that it would not open all the way” and “interfered with eating” applicable to disc displacement without reduction with and without limited opening
   “In last 30 days, when you opened your mouth wide, jaw locked or caught so that it would not close all the way” applicable to subluxation
   EXAMINATION
   Disc displacement with reduction
   Report by patient of any joint noise (click or crepitus)
   Click detection (# of opening/closing cycles required for click)	2 of 3	1 of 3
   Click detection during lateral and protrusive movements
   5mm vertical distance between reciprocal clicks
   Elimination of click in protrusive position
   Disc displacement with reduction with intermittent locking
   Disc displacement without reduction with limited opening
   Unassisted opening* ≤ 35mm and assisted opening ≤ 4mm more than unassisted opening
   Assisted opening* < 40mm
   Contralateral movements < 7mm and/or uncorrected deviation to the ipsilateral side on opening
   Absence of noise, or noise not meeting criteria for disc displacement with reduction
   Disc displacement without reduction without limited opening
   Unassisted opening* > 35mm and assisted opening > 4mm more than unassisted opening
   Assisted opening* ≥ 40mm
   Contralateral and protrusive movements ≥ 7mm
   Noise not meeting criteria for disc displacement with reduction
   Degenerative joint disease
   Report by patient of any joint noise (click or crepitus)
   Crepitus (only coarse) with palpation
   Crepitus (either fine or coarse) with palpation

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   ^*Measurement of opening includes interincisal opening plus vertical incisal overlap.

3. DD with reduction with intermittent locking and TMJ subluxation are included as new disorders. The diagnostic algorithms for these disorders include specific criteria from the patient history, including current intermittent locking with limited opening for DD with reduction with intermittent locking and jaw locking in the wide-open position for TMJ subluxation.

4. Nomenclature change: The terms osteoarthritis and osteoarthrosis are considered to denote subclasses of DJD.

Workshop Recommendations for Axis I Headache Disorders

“Headache attributed to TMD” is included as a new disorder type to replace “Headache or facial pain attributed to temporomandibular joint (TMJ) disorder“ as described in the International Classification of Headache Disorders II (ICHD- 2).⁴⁹ The diagnostic algorithm for headache attributed to TMD has been previously published⁵⁰ and has been incorporated into the beta version of the ICHD-3 (See Table 5).⁵¹

Workshop Recommendations for Axis II Evaluation

It is well recognized that patients’ cognitive, emotional, and behavioral responses to pain are quite independent of the source of their pain, so the workgroup recommended instruments currently used in other areas of medicine to assess the psychosocial functioning associated with any pain condition. In addition, the Jaw Functional Limitation Scale (JFLS) was selected to assess jaw function specific to TMD. The criteria used to select the additional Axis II instruments were reliability, validity, interpretability, patient and clinician acceptability, patient burden, and feasibility, as well as availability of translated versions for different languages and cultures. All areas of biopsychosocial assessment with the recommended instruments are available from the Consortium⁵² and are summarized in Table 7.

1. Axis II screeners. Five simple self-report screening instruments are included for detection of pain-relevant psychosocial and behavioral functioning. The Patient Health Questionnaire-4 (PHQ-4) is a short, reliable, and valid screening instrument for detecting “psychological distress” due to anxiety and/or depression in patients in any clinical setting.⁵³ A cutoff of > 6, suggesting moderate psychological stress, should be interpreted as warranting observation, while a cutoff of > 9, suggesting severe psychological distress, should be interpreted as warranting either further assessment or referral.⁵³ The Graded Chronic Pain Scale (GCPS) is a short, reliable, and valid instrument that assesses pain intensity and pain-related disability.¹⁰ The two GCPS subscales are: (1) Characteristic Pain Intensity (CPI), which reliably measures pain intensity, with ≥ 50/100 considered “high intensity,” and (2) the pain-disability rating, which is based on number of days that pain interferes with activity and on extent of interference with social, work, or usual daily activities. High pain and high interference, or moderate to severe disability (classified as Grades 3 or 4), should be interpreted as disability due to pain, warranting further investigation, and suggests that the individual is experiencing significant impact from the TMD on his or her life. The third instrument is a pain drawing of the head, jaw, and body, and it allows the patient to report the location of all pain complaints.^54,55 Widespread pain suggests the need for comprehensive assessment of the patient. The fourth instrument is the reliable and valid short form (eight items) of the JFLS that assesses global limitations across mastication, jaw mobility, and verbal and emotional expression.^56,57 The fifth instrument is the Oral Behaviors Checklist (OBC), which assesses the frequency of oral parafunctional behaviors.^58,59

2. Comprehensive Axis II instruments. The instruments to be used when indicated by clinical specialists or researchers in order to obtain a more comprehensive evaluation of psychosocial functioning are listed in Table 7 and follow the Initiative on Methods, Measurement, and Pain Assessment in Clinic Trials (IMMPACT) recommendations.⁶⁰ Those recommendations include assessment of pain intensity, physical functioning (both general and disease-specific), and emotional functioning. In addition to measuring pain intensity and pain disability (via GCPS, as described previously) and disease-specific physical functioning (via the 20-item version of the JFLS), the new DC/TMD includes new measures for a more comprehensive assessment of emotional functioning. This assessment uses the PHQ-9⁶¹ for depression (with cutoffs of 5, 10, 15, and 20 representing, respectively, mild, moderate, moderately severe, and severe levels of depression) and Generalized Anxiety Disorder-7 (GAD-7)⁶² for anxiety (with cutoffs of 10 and 15 representing, respectively, moderate and severe levels of anxiety). Finally, like the RDC/TMD, the new DC/ TMD retains a measure for physical symptoms by using the PHQ-15⁶³ (with cutoffs of 5, 10, and 15 representing, respectively, low, medium, and high somatic symptom severity) due to the overwhelming importance of overall symptom reporting in individuals with TMD.⁶⁴ The pain drawing and the OBC are also components of the comprehensive assessment.

Table 7

Recommended Axis II Assessment Protocol

Domain	Instrument	No. of items	Screening	Comprehensive
Pain intensity	Graded Chronic Pain Scale (GCPS)	3
Pain locations	Pain drawing	1
Physical function	Graded Chronic Pain Scale (GCPS)	4
Limitation	Jaw Functional Limitation Scale-short form (JFLS)	8
	Jaw Functional Limitation Scale-long form (JFLS)	20
Distress	Patient Health Questionnaire-4 (PHQ-4)	4**
Depression	Patient Health Questionnaire-9* (PHQ-9)	9**
Anxiety	Generalized Anxiety Disorder-7 (GAD-7)	7**
Physical symptoms	Patient Health Questionnaire-15* (PHQ-15)	15
Parafunction	Oral Behaviors Checklist (OBC)	21

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^*The RDC/TMD depression and non-specific physical symptoms instruments could be substituted for the PHQ-9 and PHQ-15, respectively, if continuity with legacy data is important.

^**Each of the PHQ-4, PHQ-9, and GAD-7 include one additional item beyond the number listed above; the additional item is a global reflective question regarding functional interference due to any of the endorsed symptoms on that instrument.

Data Collection Forms and Examination Specifications

A short, focused new DC/TMD Symptom Questionnaire (DC/TMD SQ)⁶⁵ was developed to assess pain characteristics as well as history of jaw noise, jaw locking, and headache. The DC/TMD SQ provides the necessary history for the Axis I diagnostic criteria. The new DC/TMD operational specifications for the clinical tests, examination forms, DC/TMD SQ, and biobehavioral assessment instruments can be downloaded from the Consortium website³⁸ and used without copyright infringement.

Validity of the Newly Recommended DC/TMD Axis I Diagnostic Algorithms

Sufficient data from the Validation Project existed to provide a credible estimate of the criterion validity for myalgia as a class with sensitivity of 0.90 (95% confidence limits of 0.87 and 0.94) and specificity of 0.99 (0.97, 1.00). Myofascial pain with referral as a type of myalgia showed sensitivity of 0.86 (0.79, 0.94) and specificity of 0.98 (0.97, 0.99). Finally, arthralgia had sensitivity of 0.89 (0.84, 0.92) and specificity of 0.98 (0.95, 0.99). Among the intracapsular diagnoses, excellent validity was confirmed for DD without reduction with limited opening, with sensitivity of 0.80 (0.63, 0.90) and specificity of 0.97 (0.95, 0.98). The validity for the other disc displacements was inadequate: DD with reduction had sensitivity of 0.34 (0.28, 0.41) and specificity of 0.92 (0.89, 0.94); DD with reduction with intermittent locking showed sensitivity of 0.38 (0.24, 0.54) and specificity of 0.98 (0.96, 0.99); and disc displacement without reduction without limited opening exhibited sensitivity of 0.54 (0.44, 0.62) and specificity of 0.79 (0.74, 0.83). The sensitivity of the recommended clinical criteria for DJD was 0.55 (0.47, 0.62) and specificity was 0.61 (0.56, 0.65). The total width of all confidence intervals was < 0.20, except for disc displacement with reduction with intermittent locking for which the total interval was 0.30.

Features of the DC/TMD History and Examination Protocol

The criterion for a patient report of pain modified— that is, made better or worse—by jaw function, movement, or parafunction is now a requirement for all pain-related TMD diagnoses; this feature is shared with other musculoskeletal pains.^66,67 Questions regarding pain modification are integral to the history and are derived from the TMD Pain Screener or from the more comprehensive DC/TMD SQ that contains all of the history questions required for the new DC/TMD diagnostic algorithms.^45,46,65 Pain modification is especially important in differential diagnosis in a broader clinical setting when comorbid conditions may be present, especially other pain conditions of the trigeminal system.

The clinical provocation of “familiar pain” has proved useful in the assessment of other orthopedic and pain disorders.^68–74 The rationale is that the clinician needs to provoke the patient's pain complaint in order for a positive examination response to be clinically meaningful. A patient report of familiar pain is required with pain provoked by jaw movement and/ or palpation to diagnose all pain-related TMD, including arthralgia, myalgia, the three types of myalgia, and headache attributed to TMD. Familiar pain is pain that is like or similar to the pain that the patient has been experiencing. The intent is to replicate the patient's chief complaint of pain(s) in such a way that the patient describes the provoked pain in the same way— because it is the same type of pain. This criterion minimizes false-positive findings from pain-provoking tests in asymptomatic patients and incidental findings in symptomatic patients. Similarly, a report of “familiar headache“ is required from the examination as part of the diagnostic algorithm for “Headache attributed to TMD.” It must, however, be emphasized that the presence of familiar pain is not associated exclusively with the diagnoses of arthralgia, myalgia, and the three types of myalgia, as other conditions may cause familiar pain during jaw movement or from palpation of jaw structures such as muscle or joint. For example, infection and rheumatoid disease affecting the TMJ can result in the report of familiar pain from movement and/or palpation of the associated structures. In order for the criterion of familiar pain to lead logically to the specified diagnosis, the signs must explain the symptoms; the symptom history, or additional assessment, must effectively rule out other competing diagnoses.⁷⁵

For myalgia and the three types of myalgia diagnoses, palpation of only the temporalis and masseter muscles is required; mandatory palpation of the temporalis tendon, lateral pterygoid area, submandibular region, and posterior mandibular region has been eliminated because of poor reliability,^76–78 and not examining these areas does not significantly affect the validity of these diagnoses.²⁷ For example, the lateral pterygoid area is commonly tender in non-cases, leading to false positives when the RDC/TMD are used.⁷⁶ It is also uncommon for these other sites to be painful to palpation when the masseter or temporalis muscles are not, but they may be included as part of the examination when clinically indicated or for specific research questions. For the same reason, palpation of the posterior aspect of the TMJ through the external auditory meatus has also been eliminated but can be used when indicated.

TMJ noises can be difficult to detect, even with auscultation using a stethoscope, and may be sporadically present. In addition, the data of the Validation Project have demonstrated that patient differentiation of noises such as clicking, crunching, grinding, or grating noises (ie, crepitus) was an inconsistent source of clinical information. Typically, such information gathering requires reviewing these noises with the patient and then carefully interpreting their responses. These data confirm the most reliable approach is based on patient detection of any such noise within the last 30 days or patient detection of any noise occurring with jaw movements during the clinical examination. Whether to use “last 30 days” or a different period is addressed in the footnote in Table 3. The distinction between coarse and fine crepitus was omitted, as these sounds are not reliably distinguished and the distinction does not contribute to the diagnostic accuracy of DJD.

Changes to Original RDC/TMD Pain Diagnoses

The original RDC/TMD diagnosis of myofascial pain with limited opening has not yet demonstrated unique clinical utility and was eliminated in the new DC/TMD. The remaining original RDC/TMD diagnosis of myofascial pain has been reorganized in the new DC/TMD into two new disorders with criterion validity: myalgia (as a subclass of muscle pain disorders) and myofascial pain with referral (as a type of myalgia); see Table 4. Although the diagnostic criteria for local myalgia and myofascial pain, as types of myalgia, have content validity, the criterion validity has not been established. Myofascial pain with referral is a distinct clinical disorder with central convergence accounting for the referral of pain to other anatomical sites.^79–81 Referred pain has clinical utility for, at a minimum, differential diagnosis regarding the identification of pain in other anatomical locations, including pain referred to the teeth that is shown ultimately to be pain of muscular origin.

“Headache attributed to TMD” is a new Axis I diagnostic classification.⁸² Tension-type headache (TTH) and migraine have been associated with TMD.^19,83–90 In particular, TTH and TMD share many symptoms,^19,90,91 although this may not imply identical pathophysiology or underlying mechanisms.^88,91,92 A subgroup of headache patients experience increased headache following masticatory system overuse such as clenching of the teeth.^88,89,92,93 Longitudinal studies have found that the development of TMD was accompanied by an increase in headache and that the presence of TMD at baseline predicted the onset of headache.^94,95 Finally, treatment of the masticatory system has also been associated with a report of decreased headaches.^96–98 These findings suggest that some headaches may be secondary to TMD.

Frequency of TTH⁹⁹ and migraine correlate with functional disability and are a useful patient characterization,^100–102 and increased frequency of headaches in the temples is associated with increased symptoms of pain-related TMD.¹⁰² Future research will explore whether frequency of pain when used to subclassify headache attributed to TMD, TMJ arthralgia, and TMD myalgia improves the identification of patients with more complex pain problems. Consequently, frequency and duration of “jaw pain” is assessed by the DC/TMD Symptom Questionnaire— Long Form that was developed for the TMJ Impact Project; this is available on the Consortium website.¹⁰³

Changes to Original RDC/TMD TMJ Diagnoses

A diagnostic category of DD with reduction with intermittent limited opening (ie, episodic self-limiting “closed lock”) was included in the new DC/TMD. This is a common, clinically significant “mechanical” joint disorder that can require treatment. Another newly included diagnostic category is the mechanical joint disorder of TMJ dislocation characterized by “open lock” of the jaw and typically diagnosed based on patient history. If the patient is able to reduce this dislocation, it is termed “subluxation,” and if the dislocation requires an interventional reduction, it is termed “luxation.” Sufficient data were only available to assess the diagnostic validity of subluxation.¹⁰⁴

The low sensitivity for the diagnostic algorithms for DD and DJD suggests these criteria be limited to providing provisional diagnoses. For example, for a diagnosis of DD with reduction, a positive history of noise and the presence clinically of clicking noises (as specified) effectively rules in the diagnosis due to the high specificity of the criteria, while a negative finding can be associated with false negatives due to low sensitivity. Consequently, some DD with reduction will not have clinically detectable noise or will have fewer clicks or different types of noise, and the disorder will not be diagnosed using the clinical criteria.¹⁰⁵ Based on available data, DD with reduction is highly prevalent and is probably without clinical consequence unless pain occurs with the noise, or functional limitations such as limited opening or interference in mastication are present. Nevertheless, imaging using MRI is required for a definitive diagnosis of TMJ DD, and CT imaging is required for a definitive diagnosis of DJD. The single diagnostic exception is DD without reduction with limited opening (ie, “closed lock”), which shows good diagnostic validity without imaging (ie, sensitivity 80%; specificity 97%). However, the criteria for DD without reduction with limited opening have not been assessed in subjects with other causes of limited opening such as adhesions, coronoid hyperplasia, or muscle contracture. The need for a definitive DD diagnosis, and thus the indication to use imaging, is based on whether the information gained will change the patient's treatment plan or prognosis. Reliable imaging criteria for these disorders are available.¹⁰⁶

Taxonomic Classification Structure and Classification of the Less Common TMD

A comprehensive taxonomic system is presented in Table 4. The diagnostic criteria for the less common TMD were derived, in part, from the best available definitions for those disorders included in existing AAOP guidelines. This was augmented by a review of the literature for diagnostic criteria defining other disorders not identified in the AAOP guidelines. The comprehensive taxonomic system and criteria for these disorders is available⁴³ and will be continually updated on the Consortium website as new information emerges. These AAOP-based diagnostic criteria were developed by clinicians and researchers according to their experience and the literature.⁴⁰ Although these criteria have content validity, their criterion validity has not been assessed, so special caution should accompany their use clinically. Treatment decisions based on these diagnoses should be undertaken with careful consideration of all risks and benefits associated with the resulting care plan.

Nomenclature

Since the terms osteoarthrosis and osteoarthritis have not been consistently used in medicine, these terms were subclassified under the broader term DJD. Use of DJD is also endorsed by the American Association of Oral and Maxillofacial Surgeons.¹⁰⁷ When pain co-occurs with DJD, the additional diagnosis of arthralgia can be used—as is the case with DD. A former diagnosis of osteoarthritis by the RDC/TMD is now dually coded as degenerative joint disease and joint pain (ie, arthralgia).

Changes to Original RDC/TMD Axis II

IMMPACT guidelines for clinical trials assessing pain recommend that patients be assessed for pain intensity and emotional functioning as well as general and disease-specific physical functioning.⁶⁰ These four domains are assessed using the core Axis II instruments of GCPS (pain intensity subscale), PHQ-4 (emotional functioning), GCPS (general physical functioning by using the pain interference subscale), and JFLS (disease-specific physical functioning). Domains that bridge behavior with Axis I and are of direct utility for the clinician and researcher have been added. The biopsychosocial model of pain recognizes that pain is not purely a sensory process but that it is always accompanied by cognitive, emotional, and behavioral aspects which influence how a patient reacts to and reports pain, and which, in turn, result in coping strategies that may be helpful or harmful in maintaining adequate functioning.^22,23 If these coping strategies are harmful, they can contribute to the development of chronic pain. Indeed, a set of psychosocial factors such as anxiety, depressed mood, psychological distress, fear-avoidance beliefs, catastrophic thoughts, passive coping strategies, and social isolation have been recognized as risk factors for the development of chronic pain in musculoskeletal disorders.^108–110 Similar risk factors have also been identified for chronicity in individuals with TMD. ^{18,64,111,112}

In addition, psychosocial factors are at least as important for the treatment outcome as are initial pain intensity and physical diagnoses.^113,114 The expansion of Axis II instruments for the new DC/TMD allows for identification of patients’ psychosocial and behavioral status in order to identify factors that, if present, must be addressed from the beginning of any treatment in an attempt to decrease suffering and increase functioning. In addition, early biobehavioral intervention appears to reduce the risk of patients developing persistent or chronic pain.^109,115 Core risk factor assessment instruments include the OBC to identify maladaptive parafunctional behaviors and pain drawings to readily identify presence of widespread pain or other regional pain conditions. Frequent parafunctional behaviors may operate at several levels, including that of possibly repetitive trauma to the masticatory system, and appear to be significant predictors for TMD onset and are strongly associated with chronic TMD pain.^116,117 In addition, the presence of significant psychosocial distress should be considered as a particularly important comorbid condition contributing to TMD onset as well as being associated with chronic TMD pain.^64,118

Widespread pain suggests potential systemic disorders, including rheumatic diseases and/or central sensitization (eg, fibromyalgia), suggesting the need for further medical assessment. It is therefore advisable that the core set of Axis II instruments be used routinely in all clinical assessments. Use of the Axis II instruments in the clinical setting will permit assessment of the biobehavioral constructs currently known to be relevant to pain disorders and thereby lead to appropriate interventions as guided by the patient's status.^18,21

An in-depth evaluation of the patient's psychosocial status is important for all research studies comparing TMD treatment modalities. Axis II psychosocial factors have better prognostic value than Axis I physical diagnoses.^18,112 Research that does not take into account these important risk factors cannot improve our understanding of TMD and of which treatments work and why.²⁴

Clinical Application of the New DC/TMD

The comprehensive evaluation necessary to design a specific patient's care plan is beyond the scope of this article. The reader is referred to an example of a clinical assessment protocol⁷⁵ that can be used, in conjunction with the new DC/TMD, to rule out other orofacial pathology, including odontogenic pathology, trigeminal autonomic dysfunction cephalalgias, other headache disorders, and neuropathic pain disorders. An “unusual” presentation such as swelling, warmth and redness, autonomic signs, or sensory or motor deficiencies warrants high suspicion, since these are not typical TMD signs. The new DC/TMD is an effective and efficient adjunct to well-developed clinical reasoning skills, keeping in mind that the history must lead to a provisional diagnosis, and the clinical examination, augmented when indicated by other assessment tools, is needed to confirm or refute this provisional diagnosis. The validity of the diagnostic criteria revolves around use of reliable clinical tests; several versions of the clinical procedures are available on the Consortium website.⁴⁷ Finally, multiple diagnoses are permitted: one of the muscle pain diagnoses (eg, myalgia or one of three types of myalgia), as well as diagnoses for each joint, including a joint pain diagnosis, any one of four disc displacement diagnoses, a degenerative joint disorder diagnosis, and/or a subluxation diagnosis.

In addition to the formal new DC/TMD diagnoses for the common disorders, other diagnoses listed in Table 4 may be required to fully capture all findings; for example, a lateral pterygoid spasm could coexist with a myalgia of the other masticatory muscles, resulting in two muscle diagnoses.

The new DC/TMD assessment protocol has both screening and confirmatory tests for the most common Axis I physical diagnoses and for Axis II contributing factors (Table 8). The Axis I TMD Pain Screener is recommended for all patients in any clinical setting.⁴⁶ A positive screen is followed by further evaluation to arrive at the specific TMD pain-related diagnoses. The Axis II screening instruments consist of 41 questions from the PHQ-4, GCPS, OBC, and JFLS (short form), as well as a pain drawing, with minimal burden to the patient and clinician^10,53; their use is recommended when triage indicates a pain disorder is present, and their use should be considered mandatory in cases of persistent pain lasting 6 months or longer or in the presence of prior unsuccessful treatment(s). Overall, the Axis II screening instruments identify barriers to treatment response, contributors to chronicity, and targets for further intervention.^15,16 Positive findings with these screening instruments require further investigation using the comprehensive Axis II assessment instruments listed in Table 7; or, to establish a definitive diagnosis, referral is required to the patient's physician or a qualified mental health provider, ideally a health psychologist or psychiatrist.¹¹⁹

The final two Axis II instruments can be used with any patient. The OBC assesses for the presence of parafunctional behaviors that may be a form of trauma to the masticatory system.¹²⁰

Likewise, the JFLS can be used to identify jaw-related functional limitations that may be present in any patient and then can be used to document changes over time. Axis II instruments and their application are discussed more fully elsewhere.^28,29,121 All Axis II instruments are available on the Consortium website.

Adjunctive Tests

The new DC/TMD provides the core provocation tests necessary for the diagnosis of masticatory muscle and TMJ pain, but false positives and negatives can occur. Adjunctive tests may include static and dynamic tests, joint play tests such as compression and distraction, bitetests, “end-feel” tests, clenching tests, and palpation of the other masticatory muscles that are not part of the core criteria.^122–128 Even though these tests did not improve overall validity of the diagnostic algorithms, they may, nevertheless, be useful in specific circumstances in which the history suggests a pain-related TMD and the formal new DC/TMD examination protocol is negative.^{27,126,128,129} When used, these adjunctive tests must also provoke familiar pain. Occlusal tests also did not contribute to the diagnostic validity of any of the TMD, but occlusal factors including intercuspal occlusal contacts, open bite, and the slide from centric relation to maximum intercuspal position can all be affected by DD and DJD,¹³⁰ and documentation of occlusal status during initial assessment is warranted. The history and clinical examination remains the cornerstone for TMD diagnosis, and all adjunctive tests, including electronic diagnostic instruments, require assessment for their diagnostic accuracy and evidence of incremental validity for a true positive diagnosis of TMD prior to being recommended for clinical use.^131–133

Patient Advocacy

The workshop at Miami in 2009 had the benefit of obtaining patient advocate input. A paradigm shift was advocated from a doctor-based assessment to patient-reported assessment. In short, patients want their symptom experience to be a more central part of the assessment and treatment recommendations. For example, limited mouth opening has been traditionally assessed using less than 40 mm as a “cut-off”; a recent population-based study involving more than 20,000 individuals supports this cutoff.¹³⁴ An alternative perspective is to ask patients if they perceive a limitation in their opening independent of this “cutoff.” Ultimately, what the patient believes, feels, and reports is as important as what the clinician is able to observe and measure.

Research performed by the Validation Project Research Group was supported by NIH/NIDCR U01-DE013331. The development of the examination specifications in support of the diagnostic criteria was also supported by NIH/NIDCR U01-DE017018 and U01-DE019784. Reliability assessment of Axis I diagnoses was supported by U01-DE019784. Workshop support was provided by the International Association for Dental Research, Canadian Institute for Health Research, International RDC/ TMD Consortium Network, Medotech, National Center for Biomedical Ontology, Orofacial Pain Special Interest Group of the International Association for the Study of Pain, and Journal of Oral Rehabilitation. The authors thank the American Academy of Orofacial Pain for their support; Terrie Cowley, president of the TMJ Association, for her participation in the Miami workshop; and Dr Vladimir Leon-Salazar for his assistance with finishing the manuscript. The Taxonomy Committee was composed of JeanPaul Goulet, Thomas List, Richard Ohrbach (chair), and Peter Svensson. The authors report no conflicts of interest related to this study.