Search

Aims The aims of this critical review were to: (i) assess the factors that differentiate acute from chronic temporomandibular disorders (TMD) pain; (ii) assess the risk factors associated with the transition from acute to chronic TMD pain; and (iii) summarize and appraise the studies. Method The databases used were MEDLINE, Embase, and Cochrane Database of Systematic Reviews. Eligible studies included articles comparing acute to chronic TMD pain, and cohort studies assessing the risk factors implicated in the transition from acute to chronic TMD pain. Results Seven articles were selected: one case-control study, three cross-sectional studies, and three cohort studies. These studies found that psychological factors were more common in chronic than acute TMD pain patients; however, these factors did not increase the transition risk in the multivariable model. Myofascial and baseline pain intensity were associated with the transition from acute to chronic TMD pain at a 6-month follow-up. Due to methodological weaknesses in the available literature, more research is required to establish the risk factors implicated in the transition from acute to chronic TMD pain. Conclusion This review found some evidence that myofascial pain is associated with the transition risk from acute to chronic TMD pain at a 6-month follow-up and that pain intensity at baseline is associated with more intense TMD pain 6 months later. . There is insufficient evidence to draw conclusions about the role of demographics and psychological disorders as independent risk factors.

Aims To investigate whether a shortened dental arch (SDA), as identified by reduced posterior occlusal contacts, is a risk factor for the progression of temporomandibular joint (TMJ) intra-articular disorders (ID), as identified using imaging techniques. Methods This multisite, prospective observational study with a mean follow-up period of 7.9 years had a sample of 345 participants with at least 1 temporomandibular disorder (TMD) diagnosis at baseline. SDA was defined as reduced occlusal posterior support due to lack of occlusal intercuspal contacts in the molar region on the left and/or right side. SDA was assessed at baseline and at follow-up with metalized Mylar Tape. The presence or absence of a TMJ ID and the specific TMJ ID diagnoses for baseline and follow-up images were established by a calibrated, blinded radiologist at each of three sites by using bilateral magnetic resonance imaging for soft tissue imaging for disc displacement and by bilateral multidetector computed tomography or cone beam computed tomography for hard tissue imaging for degenerative joint diseases. Wilcoxon rank sum test and linear regression analyses were used to test for an impact of SDA on TMJ ID status. Results At baseline, TMJ ID status of either side was not significantly affected by the presence of SDA on the ipsilateral or contralateral side of the jaw (all P > .05). Furthermore, the presence or absence of SDA at baseline was also not a significant predictor for progression of the TMJ ID status between baseline and follow-up (all P > .05). Conclusion The findings of this study suggest that there is no significant effect of SDA on progression of TMJ ID.

Aims: To investigate, in individuals with pain-related temporomandibular disorder (TMD), the association of long-term pain intensity with baseline health-related quality of life (HRQoL) and jaw functional limitation. Methods: Of 513 cases with baseline pain-related TMD (masticatory muscle and/or temporomandibular joint [TMJ] pain), 273 were reevaluated after 8 years, and 258 of them had complete baseline data for Jaw Functional Limitation Scale (JFLS) scores and HRQoL measured by the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores of the 12-item Short Form Health Survey and follow-up data for Characteristic Pain Intensity (CPI) from the Graded Chronic Pain Scale. Secondary analyses of existing data quantified the effects of primary (PCS, MCS) and secondary (JFLS) predictors on follow-up CPI by using multivariable linear regression. Sensitivity analyses considered differences between the included participants (n = 258) and those who were not included (n = 255) by using inverse probability weighting. Interactions of baseline predictors with age, sex, and baseline CPI were evaluated using multivariable linear regression. Results: The score for baseline PCS, but not MCS or JFLS, was associated with follow-up CPI (P = .012). One standard deviation (SD = 9.0)-higher baseline PCS score predicted an overall 3.2-point-lower follow-up CPI (95% confidence interval -5.8 to -0.7) after adjusting for age, sex, MCS, JFLS, and baseline CPI scores. However, the effect of PCS score was not uniform: the association between PCS and follow-up CPI scores was statistically significant for participants with baseline CPI ≥ 51.3/100 and clinically significant for participants with baseline CPI ≥ 68.7/100. Adjustment for TMD treatments and sensitivity analyses had negligible effect. Conclusion: In participants with moderate to severe baseline TMD pain intensity, higher baseline physical HRQoL predicted lower TMD pain intensity at 8 years follow-up. PCS score could contribute to a multifactorial long-term TMD pain prediction model.

Self-management (SM) programmes are commonly used for initial treatment of patients with temporomandibular disorders (TMD). The programmes described in the literature, however, vary widely with no consistency in terminology used, components of care or their definitions. The aims of this study were therefore to construct an operationalised definition of self-management appropriate for the treatment of patients with TMD, identify the components of that self-management currently being used and create sufficiently clear and non-overlapping standardised definitions for each of those components. A four-round Delphi process with eleven international experts in the field of TMD was conducted to achieve these aims. In the first round, the participants agreed upon six principal concepts of self-management. In the remaining three rounds, consensus was achieved upon the definition and the six components of self-management. The main components identified and agreed upon by the participants to constitute the core of a SM programme for TMD were as follows: education; jaw exercises; massage; thermal therapy; dietary advice and nutrition; and parafunctional behaviour identification, monitoring and avoidance. This Delphi process has established the principal concepts of self-management, and a standardised definition has been agreed with the following components for use in clinical practice: education; self-exercise; self-massage; thermal therapy; dietary advice and nutrition; and parafunctional behaviour identification, monitoring and avoidance. The consensus-derived concepts, definitions and components of SM offer a starting point for further research to advance the evidence base for, and clinical utility of, TMD SM.

Background In this executive summary, the authors describe a protocol for assessing patients with temporomandibular disorder (TMD). It is based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for clinical and research applications. Methods The DC/TMD was developed using published Axis I physical diagnoses for the most common TMDs. Axis I diagnostic criteria were derived from pertinent clinical TMD signs and symptoms. Axis II consists of psychosocial and behavioral questionnaires already in the public domain. A panel of experts vetted and modified the Axis I and Axis II diagnostic protocols. Recommended changes were assessed for diagnostic accuracy by using the Validation Project’s data set, which formed the basis for the development of the DC/TMD. Results Axis I diagnostic criteria for TMD pain-related disorders have acceptable validity and provide definitive diagnoses for pain involving the temporomandibular joint (TMJ) and masticatory muscles. Axis I diagnostic criteria for the most common TMJ intra-articular disorders are appropriate for screening purposes only. A definitive diagnosis for TMJ intra-articular disorders requires computed tomography or magnetic resonance imaging. Axis II questionnaires provide valid assessment of psychosocial and behavioral factors that can affect management of TMD. Conclusions The DC/TMD provides a questionnaire for the pain history in conjunction with validated clinical examination criteria for diagnosing the most common TMDs. In addition, it provides Axis II questionnaires for assessing psychosocial and behavioral factors that may contribute to the onset and perpetuation of the patient’s TMD. Practical Implications The DC/TMD is appropriate for use in clinical and research settings to allow for a comprehensive assessment of patients with TMD.

Aims: To quantify the practice patterns of Japanese dentists in the management of pain related to temporomandibular disorders (TMD) and to identify specific characteristics that are significantly associated with the decision to perform occlusal adjustment for TMD-related pain. Methods: A cross-sectional study was conducted consisting of a questionnaire survey of dentists affiliated with the Dental Practice-Based Research Network Japan (JDPBRN) (n = 148). Participants were asked how they diagnosed and treated TMD-related pain. Associations between dentist characteristics and the decision to perform occlusal adjustment were analyzed via multiple logistic regression. Results: A total of 113 clinicians responded to the questionnaire (76% response rate), and 81% of them (n = 89) had treated TMD during the previous year. Dentists treated an average of 1.9 ± 1.8 (mean ± SD) patients with TMD-related pain per month. Most JDPBRN dentists used similar diagnostic protocols, including questions and examinations. The most frequent treatments were splints or mouthguards (96.5%), medications (84.7%), and self-care (69.4%). Occlusal adjustment for TMD-related pain was performed by 58% of the participants. Multiple logistic regression analysis identified two factors significantly associated with the decision to perform occlusal adjustment: dentist lack of confidence in curing TMD-related acute pain (odds ratio [OR] 5.60; 95% confidence interval [CI] 1.260 to 24.861) and proportion of patients with severe TMD-related pain (OR 0.95; 95% CI 0.909 to 0.999). Conclusion: The most common treatments for TMD-related pain were reversible treatments; however, over half of the dentists performed occlusal adjustment for TMD-related pain. The results of this study suggest that an evidence-practice gap exists for occlusal adjustment for TMD-related pain.

A previous randomized controlled trial (RCT) by Schiffman et al. (2007)15 compared four treatments strategies for temporomandibular joint (TMJ) disc displacement without reduction with limited mouth opening (closed lock). In this parallel group RCT, 106 patients with magnetic resonance imaging (MRI)-confirmed TMJ closed lock were randomized between medical management, non-surgical rehabilitation, arthroscopic surgery, and arthroplasty. Surgical groups also received rehabilitation post-surgically. The current paper reassesses the effectiveness of these four treatment strategies using outcome measures recommended by the International Association of Oral and Maxillofacial Surgeons (IAOMS). Clinical assessments at baseline and at follow-up (3, 6, 12, 18, 24, and 60 months) included intensity and frequency of TMJ pain, mandibular range of motion, TMJ sounds, and impairment of chewing. TMJ MRIs were performed at baseline and 24 months, and TMJ tomograms at baseline, 24 and 60 months. Most IAOMS recommended outcome measures improved significantly over time (P ≤ 0.0003). There was no difference between treatment strategies relative to any treatment outcome at any follow-up (P ≥ 0.16). Patient self-assessment of treatment success correlated with their ability to eat, with pain-free opening ≥35 mm, and with reduced pain intensity. Given no difference between treatment strategies, non-surgical treatment should be employed for TMJ closed lock before considering surgery.

There is a need to expand the current temporomandibular disorders' (TMDs) classification to include less common but clinically important disorders. The immediate aim was to develop a consensus-based classification system and associated diagnostic criteria that have clinical and research utility for less common TMDs. The long-term aim was to establish a foundation, vis-à-vis this classification system, that will stimulate data collection, validity testing and further criteria refinement. A working group [members of the International RDC/TMD Consortium Network of the International Association for Dental Research (IADR), members of the Orofacial Pain Special Interest Group (SIG) of the International Association for the Study of Pain (IASP), and members from other professional societies] reviewed disorders for inclusion based on clinical significance, the availability of plausible diagnostic criteria and the ability to operationalise and study the criteria. The disorders were derived from the literature when possible and based on expert opinion as necessary. The expanded TMDs taxonomy was presented for feedback at international meetings. Of 56 disorders considered, 37 were included in the expanded taxonomy and were placed into the following four categories: temporomandibular joint disorders, masticatory muscle disorders, headache disorders and disorders affecting associated structures. Those excluded were extremely uncommon, lacking operationalised diagnostic criteria, not clearly related to TMDs, or not sufficiently distinct from disorders already included within the taxonomy. The expanded TMDs taxonomy offers an integrated approach to clinical diagnosis and provides a framework for further research to operationalise and test the proposed taxonomy and diagnostic criteria.

The longitudinal course of temporomandibular joint (TMJ) disc displacement (DD) and degenerative joint disease (DJD) has never been conclusively described with magnetic resonance imaging and computed tomography, respectively. This 8-y observational study’s objective was to assess the longitudinal stability of DD and DJD among 401 subjects. The Validation Project provided baseline measures; follow-up was performed in the TMJ Impact Project. With magnetic resonance imaging, 2 radiologists rendered a consensus diagnosis of normal/indeterminate, DD with reduction, or DD without reduction. Computed tomography consensus diagnoses included normal/indeterminate, grade 1 DJD, or grade 2 DJD. Radiologist reliability was assessed by kappa; a Hui-Walter model was used to estimate, after accounting for diagnostic disagreement, the frequency of diagnostic progression and reversal. Permutation tests were used to test the statistical influence of concurrent baseline diagnoses on diagnostic changes at follow-up. Of 789 baseline joint-specific soft tissue diagnoses of DD, 598 (76%) joints showed no change; 109 (14%) demonstrated progression; and 82 (10%) had reversal. Of 794 joints with baseline joint-specific hard tissue diagnoses of DJD, progression was observed in 122 (15%) joints, no change in 564 (71%), and reversal in 108 (14%). Radiologist reliability (kappa) was 0.73 (95% CI, 0.64 to 0.83) for DD and 0.76 (95% CI, 0.68 to 0.83) for DJD. After accounting for the influence of diagnostic disagreement, progression of hard tissue diagnoses in the right TMJ occurred in 15.2% of subjects (95% CI, 10.5% to 20.8%) and reversal in 8.3% (95% CI, 4.9% to 12.3%); results were similar for soft tissue diagnoses and the left TMJ. Concurrent baseline soft tissue diagnoses were associated with hard tissue diagnostic changes at follow-up ( P < 0.0001). Baseline hard tissue diagnoses showed no statistical association with soft tissue changes at follow-up ( P = 0.11). Longitudinally, 76% of baseline TMJ soft tissue diagnoses and 71% of the baseline hard tissue diagnoses remained stable. Diagnostic reversal and progression were confirmed for both soft and hard tissues.

Background The authors conducted a survey to characterize the strategies used by general dentists to manage pain related to temporomandibular muscle and joint disorders (TMJDs) and to assess the feasibility of conducting a randomized controlled trial (RCT) to determine the effectiveness of these strategies. Methods Dentists from three dental practice-based research networks (PBRNs) (The Dental Practice-Based Research Network, Practitioners Engaged in Applied Research and Learning Network and Northwest Practice-based REsearch Collaborative in Evidence-based DENTistry) agreed to participate in this survey. Results Of 862 dentists surveyed, 654 were general dentists who treated TMJDs; among these, 80.3 percent stated they would participate in a future RCT. Dentists treated an average of three patients with TMJD-related pain per month. Splints or mouthguards (97.6 percent), self-care (85.9 percent) and over-the-counter or prescribed medications (84.6 percent) were the treatments most frequently used. The treatments dentists preferred to compare in an RCT were splint or mouthguard therapy (35.8 percent), self-care (27.4 percent) and medication (17.0 percent). Conclusions Most general dentists treat TMJD-related pain, and initial reversible care typically is provided. It is feasible to conduct an RCT in a dental PBRN to assess the effectiveness of splint or mouthguard therapy, self-care or medication for the initial management of painful TMJD. Clinical Implications There is an opportunity to do an RCT in a dental PBRN, which could lead to the development of evidence-based treatment guidelines for the initial treatment of TMJD-related pain by primary care dentists.

The development of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) (1)involved expanding the taxonomy for all TMDs (2) in order to propose for future validation DC for empirically supported TMDs that were not part of the DC/ TMD structure. This expanded taxonomy offers an integrated approach to clinical diagnosis and providesa framework for operationalising and testing the proposed taxonomy and diagnostic criteria in future research. During expansion of the taxonomy, researchers identified several challenges in the diagnosis of some disorders, so the International RDC/TMD ConsortiumNetwork planned a workshop to discuss criterion improvements for five of the disorders and the biobehavioural domain.

Temporomandibular disorders (TMD) affect 5% to 12% of the United States population. This article discusses common conditions related to temporomandibular joints, including disc displacements, inflammatory disturbances, loose joint bodies, traumatic disturbances, and developmental conditions. Also addressed are the appropriate imaging modalities and diagnostic criteria for TMD.

Objective The aim of this study was to characterize self-reported sleep quality (SQ) in cases with temporomandibular disorder (TMD) and to compare their results with those of healthy controls. Methods The Pittsburgh Sleep Quality Index (PSQI) was used to measure SQ in a convenience sample of 609 TMD cases and 88 controls. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I diagnostic nomenclature was used, but Axis I diagnoses were based on the consensus of two reliable criterion examiners and not the RDC/TMD algorithms. The PSQI scores for TMD cases were calculated also for the RDC/TMD Axis II measures assessing chronic pain and disability, depression, and nonspecific physical symptoms. PSQI scores of the TMD cases were compared with those from controls. Results TMD cases with one to five TMD diagnoses ( n = 609) had a mean PSQI score of 7.0 [95% confidence interval (CI) = 6.7–7.4]. In comparison, the mean score was 5.2 (95% CI = 4.6–5.9) for control subjects. For the subset of TMD cases with pain-free diagnoses ( n = 113), the PSQI score was similar to controls with 5.1 (95% CI = 4.5–5.6), whereas it was significantly different for cases with pain-related diagnoses 7.5 (95% CI = 6.6–8.3; n = 87). Although the number of TMD diagnoses and participant age had some influence on SQ, psychosocial status, and pain-related impairment assessed with RDC/TMD Axis II measures had the strongest association with SQ, in particular, dysfunctional chronic pain. Conclusion SQ is impaired in TMD patients with pain-related diagnoses, and even more in those with dysfunctional pain. This relationship between sleep and pain suggests that SQ should be assessed in TMD pain patients, especially in those with significant Axis II involvement.

Background Available screening instruments for identifying temporomandibular disorders (TMDs) exhibit methodological or logistic limitations. The authors conducted a study to develop and assess the validity of a self-report instrument in screening patients for pain-related TMDs.

The research diagnostic criteria for temporomandibular disorders (RDC/TMD) have been employed internationally since 1992 for the study of temporomandibular muscle and joint disorders (TMD). This diagnostic protocol incorporates a dual system for assessment of TMD for Axis I physical diagnoses as well as Axis II psychological status and pain-related disability. Because the reliability and criterion validity of RDC/TMD had not yet been comprehensively characterised, the National Institute of Dental and Craniofacial Research funded in 2001 the most definitive research to date on the RDC/TMD as a U01 project entitled, 'Research Diagnostic Criteria: Reliability and Validity'. The results of this multi-site collaboration involving the University of Minnesota, the University of Washington, and the University at Buffalo were first reported at a pre-session workshop of the Toronto general session of the International Association of Dental Research on 2 July 2008. Summaries of five reports from this meeting are presented in this paper including: (i) reliability of RDC/TMD Axis I diagnoses based on clinical signs and symptoms; (ii) reliability of radiographic interpretations used for RDC/TMD Axis I diagnoses; (iii) reliability of self-report data used for RDC/TMD Axis I diagnoses; (iv) validity of RDC/TMD Axis I diagnoses based on clinical signs and symptoms; and (v) proposed revisions of the RDC/TMD Axis I diagnostic algorithms.

For individuals with temporomandibular joint (TMJ) disc displacement without reduction with limited mouth opening (closed lock), interventions vary from minimal treatment to surgery. In a single-blind trial, 106 individuals with TMJ closed lock were randomized among medical management, rehabilitation, arthroscopic surgery with post-operative rehabilitation, or arthroplasty with post-operative rehabilitation. Evaluations at baseline, 3, 6, 12, 18, 24, and 60 months used the Craniomandibular Index (CMI) and Symptom Severity Index (SSI) for jaw function and TMJ pain respectively. Using an intention-to-treat analysis, we observed no between-group difference at any follow-up for CMI (p ≥ 0.33) or SSI (p ≥ 0.08). Both outcomes showed within-group improvement (p < 0.0001) for all groups. The findings of this study suggest that primary treatment for individuals with TMJ closed lock should consist of medical management or rehabilitation. The use of this approach will avoid unnecessary surgical procedures.

The aim of this study was to determine the association between more advanced stages of temporomandibular joint (TMJ) intra-articular disorders (“TMJ intra-articular status”), representing a transition from normal joint structure to TMJ disc displacement with and without reduction (DDwR and DDwoR) to degenerative joint disease (DJD), and patient-reported outcomes of jaw pain, function, and disability (“TMD impact”). This cross-sectional study included 614 cases from the RDC/TMD Validation Project with at least one temporomandibular disorder (TMD) diagnosis. TMJ intra-articular status was determined by 3 blinded, calibrated radiologists using magnetic resonance imaging and computed tomography as one of normal joint structure, DDwR, DDwoR, or DJD, representing the subject’s most advanced TMJ diagnosis. TMD impact was conceptualized as a latent variable consisting of 1) pain intensity (Characteristic Pain Index from the Graded Chronic Pain Scale [GCPS]), 2) jaw function (Jaw Functional Limitation Scale), and 3) disability (Disability Points from GCPS). A structural equation model estimated the association of TMJ intra-articular status with the latent measure TMD impact as a correlation coefficient in all TMD cases ( n = 614) and in cases with a TMD pain diagnosis ( n = 500). The correlations between TMJ intra-articular status and TMD impact were 0.05 (95% confidence interval [CI], −0.04 to 0.13) for all TMD cases and 0.07 (95% CI, −0.04 to 0.17) for cases with a pain diagnosis, which are neither statistically significant nor clinically relevant. Conceptualizing worsening of TMJ intra-articular disorders as 4 stages and characterizing impact from TMD as a composite of jaw pain, function, and disability, this cross-sectional study found no clinically significant association. Models of TMJ intra-articular status other than ours (normal structure → DDwR → DDwoR → DJD) should be explored.

Temporomandibular disorders (TMD) are a significant public health problem affecting approximately 5% to 12% of the population.1 TMD is the second most common musculoskeletal condition (after chronic low back pain) resulting in pain and disability.1 Pain-related TMD can impact the individual's daily activities, psychosocial functioning, and quality of life. Overall, the annual TMD management cost in the USA, not including imaging, has doubled in the last decade to $4 billion.1 Patients often seek consultation with dentists for their TMD, especially for pain-related TMD. Diagnostic criteria for TMD with simple, clear, reliable, and valid operational definitions for the history, examination, and imaging procedures are needed to render physical diagnoses in both clinical and research settings. In addition, biobehavioral assessment of pain-related behavior and psychosocial functioning—an essential part of the diagnostic process—is required and provides the minimal information whereby one can determine whether the patient's pain disorder, especially when chronic, warrants further multidisciplinary assessment. Taken together, a new dual-axis Diagnostic Criteria for TMD (DC/TMD) will provide evidence-based criteria for the clinician to use when assessing patients, and will facilitate communication regarding consultations, referrals, and prognosis.2 The research community benefits from the ability to use well-defined and clinically relevant characteristics associated with the phenotype in order to facilitate more generalizable research. When clinicians and researchers use the same criteria, taxonomy, and nomenclature, then clinical questions and experience can be more easily transferred into relevant research questions, and research findings are more accessible to clinicians to better diagnose and manage their patients. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) have been the most widely employed diagnostic protocol for TMD research since its publication in 1992.3 This classification system was based on the biopsychosocial model of pain4 that included an Axis I physical assessment, using reliable and well-operationalized diagnostic criteria, and an Axis II assessment of psychosocial status and pain-related disability. The intent was to simultaneously provide a physical diagnosis and identify other relevant characteristics of the patient that could influence the expression and thus management of their TMD. Indeed, the longer the pain persists, the greater the potential for emergence and amplification of cognitive, psychosocial, and behavioral risk factors, with resultant enhanced pain sensitivity, greater likelihood of additional pain persistence, and reduced probability of success from standard treatments.5 The RDC/TMD (1992) was intended to be only a first step toward improved TMD classification, and the authors stated the need for future investigation of the accuracy of the Axis I diagnostic algorithms in terms of reliability and criterion validity—the latter involving the use of credible reference standard diagnoses. Also recommended was further assessment of the clinical utility of the Axis II instruments. The original RDC/TMD Axis I physical diagnoses have content validity based on the critical review by experts of the published diagnostic approach in use at that time and were tested using population-based epidemiologic data.6 Subsequently, a multicenter study showed that, for the most common TMD, the original RDC/TMD diagnoses exhibited sufficient reliability for clinical use.7 While the validity of the individual RDC/TMD diagnoses has been extensively investigated, assessment of the criterion validity for the complete spectrum of RDC/TMD diagnoses had been absent until recently.8 For the original RDC/TMD Axis II instruments, good evidence for their reliability and validity for measuring psychosocial status and pain-related disability already existed when the classification system was published.9–13 Subsequently, a variety of studies have demonstrated the significance and utility of the original RDC/TMD biobehavioral measures in such areas as predicting outcomes of clinical trials, escalation from acute to chronic pain, and experimental laboratory settings.14–20 Other studies have shown that the original RDC/TMD biobehavioral measures are incomplete in terms of prediction of disease course.21–23 The overall utility of the biobehavioral measures in routine clinical settings has, however, yet to be demonstrated, in part because most studies have to date focused on Axis I diagnoses rather than Axis II biobehavioral factors.24 The aims of this article are to present the evidence-based new Axis I and Axis II DC/TMD to be used in both clinical and research settings, as well as present the processes related to their development.

Background With the advent of magnetic resonance imaging, or MRI, clinicians and researchers have sophisticated techniques by which to assess the anatomy of the temporomandibular joint, or TMJ. Imaging is indicated when the results will affect the patient's care beyond that which can be gained from a complete clinical assessment. One of the primary indications for treatment of patients with temporomandibular disorders, or TMDs, is jaw pain, including TMJ pain. Therefore, it is necessary to assess whether MRI-depicted TMJ findings are associated with TMJ pain. This study assessed the relationship between TMJ pain and clinical and MRI findings. Methods Subjects consisted of 85 patients with unilateral jaw pain in the area of the TMJ. The contralateral, nonpainful TMJ served as the matched control. All patients underwent a complete stomatognathic examination that included palpation of both TMJs. No care was given and no anti-inflammatory medications were prescribed until bilateral MRIs were obtained within one week. Results The authors found significant relationships between the side of reported jaw pain and the patient's report that palpation of the TMJ was painful and between the side of reported pain and the presence of MRI-detected effusions. The authors found no relationship between the side of reported pain and the presence of a disk displacement, or DD, or between the presence of effusions and DD on either side of the jaw. Conclusion Although MRI-depicted effusions of the TMJ were associated with reports of TMJ pain, there was a high level of false-positive and false-negative findings. The results indicate that palpation of the TMJ is more accurate than MRI-depicted effusions in identifying the TMJ as the source of pain for patients with unilateral jaw pain. Clinical Implications The results of this study suggest that palpation of the TMJ is superior to MRI in identifying the joint as the source of pain. Therefore, the most cost-effective and valid test to determine if the TMJ is a source of jaw pain is a complete clinical assessment.

Aims: We assessed and compared the diagnostic accuracy of two sets of diagnostic criteria for headache secondary to temporomandibular disorders (TMD). Methods: In 373 headache subjects with TMD, a TMD headache reference standard was defined as: self-reported temple headache, consensus diagnosis of painful TMD and replication of the temple headache using TMD-based provocation tests. Revised diagnostic criteria for Headache attributed to TMD were selected using the RPART (recursive partitioning and regression trees) procedure, and refined in half of the data set. Using the remaining half of the data, the diagnostic accuracy of the revised criteria was compared to that of the International Headache Society’s International Classification of Headache Diseases (ICHD)-II criteria A to C for Headache or facial pain attributed to temporomandibular joint (TMJ) disorder. Results: Relative to the TMD headache reference standard, ICHD-II criteria showed sensitivity of 84% and specificity of 33%. The revised criteria for Headache attributed to TMD had sensitivity of 89% with improved specificity of 87% ( p Conclusion: Having significantly better specificity than the ICHD-II criteria A to C, the revised criteria are recommended to diagnose headache secondary to TMD.

The purpose of this study was to examine the possible association of signs and symptoms of temporomandibular disorders relative to headache. Fifty-six sequential patients referred to the Headache Institute of Minnesota for evaluation and treatment of migraine and tension headaches were examined for signs and symptoms of temporomandibular disorders. The results of the examination of headache patients were compared to patients suffering from myofascial pain dysfunction and/or TMJ internal derangements from the TMJ and Craniofacial Pain Clinic at the University of Minnesota. Finally the migraine and tension headache patients were compared to each other and an asymptomatic population. Results indicate that patients with temporomandibular disorders exhibit significantly more jaw dysfunction and pericranial muscle tenderness than migraine and tension headache patients. Migraine and tension headache patients were found to have similar amounts of pericranial muscle tenderness. Migraine and tension headache patients exhibited significantly more pericranial and neck muscle tenderness than a general population.

The relationship of the frequency of temple headache to signs and symptoms of temporomandibular joint (TMJ) disorders (TMD) was investigated in a subset of a larger convenience sample of community TMD cases. The study sample included 86 painful TMD, nonheadache subjects; 309 painful TMD subjects with varied frequency of temple headaches; and 149 subjects without painful TMD or headache for descriptive comparison. Painful TMD included Research Diagnostic Criteria for Temporomandibular Disorders diagnoses of myofascial pain, TMJ arthralgia, and TMJ osteoarthritis. Mild to moderate-intensity temple headaches were classified by frequency using criteria based on the International Classification of Headache Disorder, 2nd edition, classification of tension-type headache. Outcomes included TMD signs and symptoms (pain duration, pain intensity, number of painful masticatory sites on palpation, mandibular range of motion), pressure pain thresholds, and temple headache resulting from masticatory provocation tests. Trend analyses across the painful TMD groups showed a substantial trend for aggravation of all of the TMD signs and symptoms associated with increased frequency of the temple headaches. In addition, increased headache frequency showed significant trends associated with reduced PPTs and reported temple headache with masticatory provocation tests. In conclusion, these findings suggest that these headaches may be TMD related, as well as suggesting a possible role for peripheral and central sensitization in TMD patients.

To evaluate the psychometric properties of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) biobehavioral (Axis II) screening instruments.Participants with Axis I TMD diagnoses (n = 626) completed the Axis II instruments (Depression, Nonspecific Physical Symptoms, Graded Chronic Pain) and other instruments assessing psychological distress, pain, and disability at three study sites. Internal consistency, temporal stability, and convergent/discriminant validity of the Axis II measures were assessed. To assess criterion validity of Nonspecific Physical Symptoms and Depression instruments as screeners, 170 participants completed a structured psychiatric diagnostic interview.The Axis II instruments showed very good to excellent internal consistency (Cronbach's alpha coefficients = 0.80 to 0.95). Their convergent (correlation range 0.3 to 0.9) and discriminant (range 0.0 to 0.6) validity were generally supported, although Nonspecific Physical Symptoms was more strongly associated with depressive than with somatic symptoms. Temporal stability was high for characteristic pain intensity (Lin's correlation concordance coefficient [CCC] = 0.91), interference (CCC = 0.89), and chronic pain grade (weighted kappa = 0.87), and fair to good for Depression and Nonspecific Physical Symptoms (CCC = 0.63 to 0.78). The Depression instrument normal versus moderate to severe cutoff point was good at identifying current-year depression and dysthymia diagnoses (sensitivity 87%, specificity 53%). Nonspecific Physical Symptoms did not have high utility for detecting psychiatric disorders (sensitivity 86%, specificity 31%).The Axis-II Depression and Graded Chronic Pain instruments have clinically relevant and acceptable psychometric properties for reliability and validity and utility as instruments for identifying TMD patients with high levels of distress, pain, and disability that can interfere with treatment response and course of Axis I disorders.

This study investigated the association between occlusion, oral habits and stress relative to the level of mandibular dysfunction in the total population and in specific diagnostic subgroups (normal, joint disorder, muscle disorder and joint/muscle disorder). A total of 269 nursing students were given a questionnaire and examination. The questionnaire included items to calculate an oral habit index and a social readjustment rating scale. The examination included items to calculate an occlusal index, two craniomandibular indices and a diagnostic criteria for specific subgroups. In the total population there was a positive association between mandibular dysfunction and three postulated risk factors. The total population was then divided into diagnostic subgroups. There was a positive association between the degree of mandibular dysfunction and parafunctional habits for normals, muscle disorders and joint/muscle disorders. There was a positive association between mandibular dysfunction and occlusion for normals only. Finally there was a positive association between mandibular dysfunction and stress for muscle disorders only. The results suggest that associations between postulated aetiologic factors and mandibular dysfunction vary depending on whether the subjects have a muscle and/or joint disorder. Since all associations were weak, other possible risk factors need to be investigated.

The psychometric properties of the modified Symptom Severity Index were investigated to assess the relationships among dimensions of pain in temporomandibular disorders (TMD). The 15-item instrument is composed of ordinal scales assessing five pain dimensions (intensity, frequency, duration, unpleasantness and difficulty to endure) as experienced in three locations (temple, temporomandibular joint (TMJ), masseter). In 108 closed-lock subjects, Cronbach's alpha was used to measure internal consistency resulting in 31 of the 105 pair-wise comparisons >or=0.71. Multilevel exploratory factor analysis was used to assess dimensionality between items. Two factors emerged, termed temple pain and jaw pain. The jaw pain factor comprised the TMJ and masseter locations, indicating that subjects did not differentiate between these two locations. With further analysis, the jaw pain factor could be separated into temporal aspects of pain (frequency, duration) and affective dimensions (intensity, unpleasantness, endurability). Temple pain could not be further reduced; this may have been influenced by concurrent orofacial pains such as headache. Internal consistency was high, with alphas >or=0.92 for scales associated with all factors. Excellent test-retest reliability was found for repeat testing at 2-48 h in 55 subjects (Intra-class correlation coefficients = 0.97, 95%CI 0.96-0.99). In conclusion, the modified Symptom Severity Index has excellent psychometric properties for use as an instrument to measure pain in subjects with TMD. The most important characteristic of this pain is location, while the temporal dimensions are important for jaw pain. Further research is needed to confirm these findings and assess relationships between dimensions of pain as experienced in other chronic pain disorders.

Although most cases of temporomandibular muscle and joint disorders (TMJD) are mild and self-limiting, about 10% of TMJD patients develop severe disorders associated with chronic pain and disability. It has been suggested that fibromyalgia and widespread pain play a significant role in TMJD chronicity. This paper assessed the effects of fibromyalgia and widespread pain on clinically significant TMJD pain (GCPS II-IV). Four hundred eighty-five participants recruited from the Minneapolis/St. Paul area through media advertisements and local dentists received examinations and completed the Graded Chronic Pain Scale (GCPS) at baseline and at 18 months. Baseline widespread pain (OR: 2.53, P = .04) and depression (OR: 5.30, P = .005) were associated with onset of clinically significant pain (GCPS II-IV) within 18 months after baseline. The risk associated with baseline fibromyalgia was moderate, but not significant (OR: 2.74, P = .09). Persistence of clinically significant pain was related to fibromyalgia (OR: 2.48, P = .02) and depression (OR: 2.48, P = .02). These results indicate that these centrally generated pain conditions play a role in the onset and persistence of clinically significant TMJD. Perspective Fibromyalgia and widespread pain should receive important consideration when evaluating and developing a treatment plan for patients with TMJD.

Pigmented villonodular synovitis (PVNS) is a benign, yet locally aggressive proliferative lesion most commonly found in joints of the long bones; it rarely presents in the temporomandibular joint (TMJ). The authors report a case of PVNS involving the TMJ and review similar cases reported in the English literature. This is the first case of PVNS with long-term follow-up of 11 years to include imaging studies. A 36-year-old male with symptoms suggestive of a temporomandibular disorder (TMD) presented with a progressive preauricular/parotid swelling and restricted mandibular range of motion. Imaging suggested a lesion with an aggressive course due to tissue displacement and destruction proximal to the lesion. A multidisciplinary team performed complete excision of the lesion with immediate reconstruction. PVNS often presents with similar symptoms to a TMD, but must be distinguished from symptomatic TMD as it can be highly destructive. Owing to its aggressive nature and potential for recurrence, complete and early extirpation and long-term follow-up with advanced imaging is indicated.

To test in vitro and in vivo the reliability and accuracy of a new algometer, the pressure algometer for palpation (PAP), for measuring pressure pain thresholds (PPTs) and to compare its features with those of a commercially available pressure algometer.For in vitro accuracy testing, 6 repeated measurements were made at 8 defined test weights from 0.5 to 5 lb. In vivo validity testing compared the PAP to a standard instrument, the hand-held Somedic algometer, at 16 sites including the masticatory muscles, the temporomandibular joints, and the frontalis (as the control site) in 15 temporomandibular disorder (TMD) cases and 15 controls. Intraexaminer reliability was also assessed for both algometers.In vitro reliability was high, with coefficients of variation of5% and a single-measurement standard deviation of 2.1 kPa. Accuracy was also high, with PAP measurements correlating with test weights at r = .99 (P.001). Repeated measures reliability in vivo was high, with intraclass correlation estimates of 0.73 to 0.96 for the PAP and 0.78 to 0.99 for the Somedic algometer. PPT values correlated moderately between the 2 devices (r ranged from 0.38 to 0.66; Por = .05) and were consistently higher for the PAP at all sites (P.001). Differences between controls and TMD cases were also significant for both algometers (P.006).Both the PAP and the Somedic algometer showed high reliability. Concurrent validity was demonstrated by statistically significant correlations between the devices. Both showed equally high capacity for differentiating TMD cases from controls. The PAP yielded significantly higher PPTs than the Somedic algometer.

To test the effect of glucosamine hydrochloride (glucosamine-HCl) on the proteoglycan (PG) concentration of the articular disc of non-arthritic temporomandibular joints (TMJs) in rabbits.Twenty-four of 48 New Zealand white 10- to 12-week-old male rabbits (2.2 kg average) were injected with the irritant chymopapain in the knee joint. Both groups of 24 rabbits were divided into 3 groups of 8 animals. The rabbits were fed a control diet or a diet supplemented with glucosamine-HCl incorporated at a level to provide 20 mg/kg (approximating the recommended dose 500 mg/tid/70 kg man) or 100 mg/kg, for 8 weeks. Sulfated glycosaminoglycans (GAGs) were assayed in protease K digests of the TMJ articular disc by dimethylmethylene blue method to quantify PG concentration. The groups were compared with 2-way analysis of variance.Glucosamine-HCl did not cause a significant change in the PG concentration of the TMJ articular disc (P.8). There was also no detectable effect of chymopapain injection to the knee joint on the TMJ (P.07) and no interaction between glucosamine-HCl treatment and chymopapain injection (P.3).Glucosamine-HCl has no effect on PG concentration of the articular disc of non-arthritic TMJ in rabbits.

Purpose: The purpose of this study was to determine the long-term objective and subjective outcomes of temporomandibular joint (TMJ) implant surgery for the treatment of painful TMJ disc displacement using temporary Silastic (Dow Corning Corporation, Midland, MI), permanent Silastic, or Proplast (Vitek, Houston, TX) implants to replace the disc. These cases were compared with other cases of the same diagnosis treated with either nonsurgical rehabilitation or nonimplant surgery involving discectomy or disc repair procedures. Materials and Methods: A cross-sectional study was conducted among 466 patients who received treatment for unilateral or bilateral TMJ disc displacement before January 1, 1990. The 5 treatment groups noted above were compared for long-term outcomes. Objective outcome measurements for jaw function were performed using a calibrated examiner and the Craniomandibular Index (CMI). Subjective (self-reported) outcomes were obtained relative to jaw function (Mandibular Function Impairment Questionnaire [MFIQ]), symptom severity (Symptom Severity Index [SSI]), and the impact of pain (Global Pain Impact [GPI] scale). Results: The results, adjusted for gender, baseline tomogram score, and baseline symptom scores, showed that the nonsurgical rehabilitation group (n = 159) and the group having TMJ surgery without implants (n = 149) had statistically better results than the group who underwent surgery with a Proplast implant (n = 94). These between-group differences included both objective signs (CMI), and subjective reports of jaw function (MFIQ), symptom severity (SSI), and global pain impact (GPI). The MFIQ score associated with the nonsurgical rehabilitation group was also statistically better than for the Silastic implant groups, including both the temporary (n = 31) and permanent (n = 33) implants. Clinical differences between groups were slight. Conclusion: This study suggests that the use of interpositional disc implants in TMJ surgery is not associated with improved outcomes when compared with nonimplant surgery or nonsurgical rehabilitation. © 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:1400-1411, 2002

To compare the relative effectiveness of a benzodiazepine (clonazepam), a muscle relaxant (cyclobenzaprine), and a placebo for the treatment of jaw pain upon awakening, when each is combined with the recommended nonpharmacological components of initial medical management.Forty-one subjects were recruited with a diagnosis of myofascial pain based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All subjects were given education about TMD and a self-care program. Subjects were randomized into 1 of 3 groups: clonazepam (0.5 mg/night), cyclobenzaprine (10 mg/night), or placebo. The primary outcome measure was the subjects' average intensity of jaw pain upon awakening over the prior week. This was recorded with a visual analog scale at pretreatment and at the completion of the 3-week trial. A secondary outcome measure was sleep quality based on the Pittsburg Sleep Quality Index.Within-group changes showed a statistically significant (P.001) decrease in jaw pain upon awakening for all 3 groups. Between-group differences demonstrated a statistically significant difference (P.016) between cyclobenzaprine and placebo, and between cyclobenzaprine and clonazepam. There was no significant effect on sleep quality in any group.This study suggests that cyclobenzaprine is statistically superior to either placebo or clonazepam when added to self-care and education for the management of jaw pain upon awakening. Based on the subjects' report of sleep quality, these medications failed to significantly improve sleep in the short term.

Background This study assessed the dimensional structure of sleep quality with the Pittsburgh Sleep Quality Index (PSQI) and investigated its psychometric properties in cases with temporomandibular disorders (TMD). Methods A convenience sample of 609 TMD cases (age: 37.1 ± 13.1 yrs, 18–67 yrs, 85% female) of the multi-center Validation Project meeting Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and with sufficient PSQI data were included in this study. To investigate PSQI scores’ dimensionality, exploratory factor analysis was used. Factors were identified using the Scree plot. To investigate internal consistency, Cronbach’s alpha was calculated. Analyses were separately performed for TMD cases with (N = 496) and TMD cases withouta pain-related diagnosis (N = 113). Results The mean PSQI score for all TMD cases was 7.1 ± 4.0 units, range: 0–19. The exploratory factor analysis identified one factor for cases with at least one pain-related TMD diagnosis as well as one factor for cases with a pain-free TMD diagnosis that explained 41% of the variance in cases with pain-related TMD and 37% in cases with pain-free TMD. Internal consistency for PSQI scores was alpha of 0.75 in cases with pain-related TMD, alpha of 0.66 in cases with pain-free TMD and alpha = 0.75 for all TMD cases. Conclusions Sleep quality in TMD patients is a unidimensional construct and can therefore be represented by one summary score; a finding that is in line with previous reports in TMD patients.

It has been suggested that MRI-depicted effusions identify patients with TMJ arthralgia. The Research Diagnostic Criteria (RDC) propose a pressure-pain threshold (PPT) of 1 pound for the identification of TMJ arthralgia. The hypotheses in this study were that: (1) there is no association between MRI-depicted effusions and TMJ arthralgia, and (2) a PPT of 1 pound does not discriminate between subjects with and those without arthralgia. Thirty females with TMJ disc displacement with reduction were divided into two groups based on the presence or absence of the self-report of TMJ pain. Bilateral TMJ PPTs and MRIs were obtained. Increasing palpation pressure from 1 to 3 pounds increased the sensitivity for identifying arthralgia from 22% to 100%, with a corresponding decrease in the specificity from 100% to 81%. The sensitivity and specificity of effusions for identifying arthralgia were 85% and 28%, respectively. These results suggest that the use of palpation pressures greater than 1 pound is a valid test for TMJ arthralgia. However, TMJ effusions lack adequate specificity for identifying TMJ arthralgia and were not associated with pain.

Schiffman EL, Look JO, Hodges JS, Swift JQ, Decker KL, Hathaway KM, et al. (2007). Randomized effectiveness study of four therapeutic strategies for TMJ closed lock. J Dent Res 86:58-63. (doi: 10.1177/154405910708600109)

Alternative therapies are used by many people, and the dental literature has reported that some alternative therapies are comparable to splint therapy in the effective treatment of masticatory myofascial pain. The authors review the efficacy of alternative therapies and discuss their clinical implications. This review is intended to help dental practitioners to select alternative therapies they can use with or instead of splint therapy for treating patients who have a primary diagnosis of myofascial pain.

Temporomandibular joint internal derangement (TMJ ID) is the most common intra-articular TM disorder and can progress from TMJ ID with reduction to TMJ ID without reduction. It is not known whether this anatomical progression is associated with increasing levels of mandibular dysfunction. The objective of this study was to determine whether the level of clinically detectable mandibular dysfunction was related to the stage of TMJ ID. Two clinicians examined 42 subjects prior to bilateral TMJ arthrographic evaluation. The level of mandibular dysfunction was calculated by Helkimo's Clinical Dysfunction Index (Di) and the Craniomandibular Index (CMI). Statistical analysis revealed that the level of mandibular dysfunction as determined by the Di and CMI was not related to the arthrographic presence or absence of TMJ ID. Therefore, the clinician cannot assume that the level of mandibular dysfunction is directly related to the absence or presence of TMJ ID. Epidemiologically, the CMI and Di can be used only for estimation of the degree of mandibular dysfunction, since they do not provide direct information on a specific TM disorder.

Background Current methods for identifying patients with pain hypersensitivity are sufficiently complex to limit their widespread application in clinical settings. We assessed the reliability and validity of a simple multi-modal vibrotactile stimulus, applied using an electric toothbrush, to evaluate its potential as a screening tool for central sensitization. Methods Fourteen female temporomandibular disorders (TMD) subjects with myofascial pain (RDC/TMD Ia or Ib) and arthralgia (RDC/TMD IIIa) were compared to 13 pain-free controls of matched age and gender. Vibrotactile stimulus was performed with an electric toothbrush, applied with 1 pound pressure for 30 seconds in four locations: over the lateral pole of the temporomandibular joint, masseter, temporalis, and mid-ventral surface of forearm. Pain intensity (0–10) was recorded following the stimulus at 0, 15, 30, and 60 seconds. Test-retest reliability was assessed with measurements from 8 participants, taken 2–12 hours apart. Case versus control differentiation involved comparison of area under the curve (AUC). A receiver operating characteristic (ROC) curve was used to determine cutoff AUC scores for maximum sensitivity and specificity for this multi-modal vibrotactile stimulus. Results Test-retest reliability resulted in an ICC of 0.87 for all 4 pooled sites. ROC-determined AUC cutoff scores resulted in a sensitivity of 57% and specificity of 92% for all 4 pooled sites. Conclusion The electric toothbrush stimulus had excellent test-retest reliability. Validity of the scores was demonstrated with modest sensitivity and good specificity for differentiating TMD pain patients from controls, which are acceptable properties for a screening test.

A cross-sectional study of prevalence of temporomandibular joint (TMJ) internal derangements, muscle disorders, and associated TM signs and symptoms was completed on 269 female nursing students. The prevalence of specific stages of internal derangements of the TMJ and muscle disorders was estimated, using established diagnostic criteria. The levels of dysfunction and symptomatology associated with each diagnosis were estimated with previously established indexes. When subjects with symptoms were asked if they had previous treatment for a TMJ problem, 6.7% responded positively. When subjects with symptoms who had not had treatment were asked why they had not sought treatment, most responded that it was not a problem or they could live with the symptoms. Thus, most subjects with clinically detectable dysfunction are functioning adequately without significant symptoms and do not need treatment.

Internal derangements of the temporomandibular joint (TMJ) have gained increased recognition as a potential source of pain and dysfunction of the masticatory system. The objective of this study was to evaluate the reliability of clinicians in predicting an arthrographic diagnosis of articular disc position in a typical patient population presenting for TMJ arthrographic evaluation. Two clinicians utilized a brief history, clinical examination (including evaluation of mandibular movement and TMJ auscultation), and tomographic TMJ imaging in evaluating 60 patients. The radiologist subsequently performed the arthrographic procedures on 102 TMJs (18 unilateral and 42 bilateral). Diagnostic agreement was determined for all possible diagnostic categories including: normal disc position, TMJ internal derangement with reduction, TMJ internal derangement without reduction/acute, TMJ internal derangement without reductionlchronic, and osteoarthrosis. The significance of the diagnostic agreement between the clinicians and arthrography was evaluated with a Kappa Statistical Test, which showed good reliability. For epidemiological studies, it was concluded that clinical and tomographic evaluation would provide sufficient reliability for determination of the presence and stage of TMJ internal derangement. However, in a specific clinical situation, a difficult diagnostic problem may require the use of arthrography, depending on the impact of the diagnosis on subsequent treatment decisions.

Epidemiological investigations about the prevalence of TMJ ID and osteoarthritis have largely reported the symptoms and signs associated with these disorders without specific criteria to establish the diagnosis. In this study, specific diagnostic criteria have been developed, using historical, clinical and tomographic items that are predictive of the presence and stage of TMJ internal derangement. The diagnostic criteria were compared to arthrotomography to assess their diagnostic accuracy. Overall, the percent agreement was 75%. The predictability of specific stages of TMJ ID varied. Overall, sensitivity and specificity of the criteria were acceptable. The diagnosis of osteoarthritis was predicted only with tomography. Utilization of these diagnostic criteria in epidemiological studies is valid due to their high overall predictiveness when applied to a large population.

The Craniomandibular Index (CMI) was developed to provide a standardized measure of severity of problems in mandibular movement, TMJ noise, and muscle and joint tenderness for use in epidemiological and clinical outcome studies. The instrument was designed to have clearly defined objective criteria, simple clinical methods, and ease in scoring; it is divided into the Dysfunction Index and the Palpation Index. Inter-rater reliability (three raters) and intra-rater reliability (19 patients examined twice by one rater) were tested to determine whether the instrument has operational definitions sufficiently precise to allow for consistency in use between different raters and with one rater over time. Intraclass Correlation Coefficient for inter-rater reliability was 0.84 for the Dysfunction Index, 0.87 for the Palpation Index, and 0.95 for the CMI. Correlation for intra-rater reliability was 0.92 for the Dysfunction Index, 0.86 for the Palpation Index, and 0.96 for the CMI. These results support the reliability of the CMI for use in epidemiological and clinical studies. Users are cautioned about the subjectivity of numerous items within the CMI and the strict methodological guidelines that must be followed in order to assure accuracy and reproducibility of results.

The CMI appears to be valid for use in clinical studies, but users must be aware of its numerous potential errors and its associated strict methodologic guidelines to ensure accuracy and reproducibility of results. The subjective nature of some items demands that the same rater who is unaware of the management status of the patient perform both evaluations. If multiple raters are used, it is recommended that the raters discuss all items, and compare scoring of demonstration subjects before the study and use a pressure algometer for muscle palpation.