Diagnostic Criteria for Temporomandibular Disorders (DC/TMD): Polish assessment instruments.

The article presents the Polish version of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), the process of document translation and cultural adaptation.

Whole-genome methylation profiling reveals regions associated with painful temporomandibular disorders and active recovery processes.

ABSTRACT: Temporomandibular disorders (TMDs), collectively representing one of the most common chronic pain conditions, have a substantial genetic component, but genetic variation alone has not fully explained the heritability of TMD risk. Reasoning that the unexplained heritability may be because of DNA methylation, an epigenetic phenomenon, we measured genome-wide DNA methylation using the Illumina MethylationEPIC platform with blood samples from participants in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) study. Associations with chronic TMD used methylation data from 496 chronic painful TMD cases and 452 TMD-free controls. Changes in methylation between enrollment and a 6-month follow-up visit were determined for a separate sample of 62 people with recent-onset painful TMD. More than 750,000 individual CpG sites were examined for association with chronic painful TMD. Six differentially methylated regions were significantly ( P < 5 × 10 -8 ) associated with chronic painful TMD, including loci near genes involved in the regulation of inflammatory and neuronal response. A majority of loci were similarly differentially methylated in acute TMD consistent with observed transience or persistence of symptoms at follow-up. Functional characterization of the identified regions found relationships between methylation at these loci and nearby genetic variation contributing to chronic painful TMD and with gene expression of proximal genes. These findings reveal epigenetic contributions to chronic painful TMD through methylation of the genes FMOD , PM20D1 , ZNF718 , ZFP57 , and RNF39 , following the development of acute painful TMD. Epigenetic regulation of these genes likely contributes to the trajectory of transcriptional events in affected tissues leading to resolution or chronicity of pain.

The Chronic Overlapping Pain Condition Screener.

Ten Chronic Overlapping Pain Conditions (COPCs) are currently recognized by the National Institutes of Health Pain Consortium (eg, irritable bowel syndrome, chronic migraine headache, and chronic low back pain). These conditions affect millions of Americans; however, assessing these conditions, their co-occurrence, and their relationship to treatment has proven challenging due to time constraints and a lack of standardized measures. We present a Chronic Overlapping Pain Condition-Screener (COPC-S) that is logic-driven, efficient, and freely available in electronic format to nonprofit entities. Thirty experts were convened to identify and modify self-report criteria for each COPC as well as criteria that trigger the administration of the diagnostic criteria from a body map and a brief series of questions. Their recommendations were then programmed into the Research Electronic Data Capture platform and refined for comprehensibility and ease of use by patient focus groups. The electronic screener and physician-administered criteria were both administered to patients with known COPCs in a counter-balanced fashion to determine the level of agreement between methods. The expert panel identified screening items/body map regions and diagnostic criteria for all 10 COPCs. Patients found the content comprehensible and the platform easy to use. Cohen's Kappa statistics suggested good agreement between the electronic COPC-S and criteria administered by a physician (κ = .813). The COPC-S is an efficient tool for screening multiple COPCs and has applicability to research studies, clinical trials, and clinical practice. PERSPECTIVE: Assessing COPCs remains a challenge for researchers and clinicians. The COPC-S is an efficient and logic-driven electronic tool that allows for the rapid screening assessment of 10 COPCs. The instrument may have utility in research and clinical settings.

Constructing the brief diagnostic criteria for temporomandibular disorders (bDC/TMD) for field testing.

BACKGROUND: Despite advances in temporomandibular disorders' (TMDs) diagnosis, the diagnostic process continues to be problematic in non-specialist settings. OBJECTIVE: To complete a Delphi process to shorten the Diagnostic Criteria for TMD (DC/TMD) to a brief DC/TMD (bDC/TMD) for expedient clinical diagnosis and initial management. METHODS: An international Delphi panel was created with 23 clinicians representing major specialities, general dentistry and related fields. The process comprised a full day workshop, seven virtual meetings, six rounds of electronic discussion and finally an open consultation at a virtual international symposium. RESULTS: Within the physical axis (Axis 1), the self-report Symptom Questionnaire of the DC/TMD did not require shortening from 14 items for the bDC/TMD. The compulsory use of the TMD pain screener was removed reducing the total number of Axis 1 items by 18%. The DC/TMD Axis 1 10-section examination protocol (25 movements, up to 12 sets of bilateral palpations) was reduced to four sections in the bDC/TMD protocol involving three movements and three sets of palpations. Axis I then resulted in two groups of diagnoses: painful TMD (inclusive of secondary headache), and common joint-related TMD with functional implications. The psychosocial axis (Axis 2) was shortened to an ultra-brief 11 item assessment. CONCLUSION: The bDC/TMD represents a substantially reduced and likely expedited method to establish (grouping) diagnoses in TMDs. This may provide greater utility for settings requiring less granular diagnoses for the implementation of initial treatment, for example non-specialist general dental practice.

Associations Between Temporomandibular Pain and Biobehavioral Variables in Dental Students in Response to an External Stressor.

AIMS: To assess changes in temporomandibular disorder (TMD) pain and multiple biobehavioral variables relevant to TMDs in response to an external stressor. METHODS: Self-reported data using online DC/TMD questionnaires were collected from volunteer dentistry graduate students. Data collection was performed on two occasions: during a non-exam period of the semester and during the subsequent exam period. Changes in the proportion of students with pain, differences in pain grade, and severity of biobehavioral status were measured and compared over the two periods. The association between severity of non-exam-period biobehavioral status and pain presence was also tested to assess whether biobehavioral variables can predict pain occurrence or persistence. Chi-square test, Wilcoxon signed-rank test, ANOVA, and Kruskal-Wallis tests were used for data analysis. P < .05 was considered significant. RESULTS: Of the 213 enrolled students, 102 remained after data reduction. In the non-exam period, the proportion of individuals with pain was 24.5%; in the exam period, the proportion was 54.9%, and more students had a higher pain grade. The severity of all biobehavioral variables was higher in the exam period, but there was no association between changes in the presence of pain and changes in biobehavioral variables. Higher anxiety and parafunction levels were found in those who reported pain on both occasions. CONCLUSION: Exam periods initiate readily measurable changes in the psychologic status of many students, as well as alterations in their temporomandibular pain. Higher levels of anxiety and oral behaviors during non-exam periods seem to be predictors for persisting pain.

Non-esterified erythrocyte linoleic acid, arachidonic acid, and subjective sleep outcomes.

OBJECTIVE: This study investigated whether non-esterified erythrocyte omega-6 PUFAs were associated with subjective assessment of sleep quality and duration, and risk for obstructive sleep apnea. METHODS: In this secondary analysis of the cross-sectional OPPERA-II study, 538 adults completed the Pittsburgh Sleep Quality Index (PSQI), reported their usual hours of sleep, and answered STOP screening questions for obstructive sleep apnea. Circulating non-esterified erythrocyte concentrations of omega-6 PUFA linoleic acid and arachidonic acid were quantified by liquid chromatography tandem mass spectroscopy. Sleep outcomes were dichotomized as poor (PSQI ≤5) vs good (PSQI ≥6) sleep quality, insufficient or excessive (≤6 or >9 h) vs good (7-9 h) sleep duration, and high (≥2 affirmative responses) vs low (<2 affirmative responses) risk for obstructive sleep apnea. Non-esterified omega-6 PUFAs and the continuous covariates of body mass index, Short Form (SF) 12 Health Survey Physical and Mental Component scores and resting measures of systolic and diastolic blood pressure were standardized for multivariable analysis. Categorical covariates were study site, age, sex, and race/ethnicity. Multivariable-adjusted logistic regression first estimated odds ratios (OR) and 95% confidence limits (CL) for sleep outcomes using linoleic acid as the main exposure. Analysis was then repeated using arachidonic acid as the main exposure. RESULTS: In the multivariable-adjusted model, each standard deviation increase in non-esterified erythrocyte linoleic acid was associated with higher odds of poor sleep quality (OR=1.2, 95% CL: 1.1, 1.5), insufficient or excessive sleep (OR= 1.3, 95% CL: 1.1, 1.6) and high-risk for obstructive sleep apnea (OR=1.3, 95% CL: 1.1, 1.6). Likewise, for each standard deviation increase in non-esterified erythrocyte arachidonic acid, odds increased of poor sleep quality (OR=1.2, 95% CL: 1.1, 1.5), and insufficient or excessive sleep (OR=1.2, 95% CL: 1.1, 1.5). Odds of being high risk for obstructive sleep apnea increased with greater circulating arachidonic acid, but the association did not reach statistical significance (OR=1.1, 95% CL: 0.9, 1.4). CONCLUSION: Non-esterified erythrocyte linoleic acid and arachidonic acid were associated with poor sleep quality and insufficient or excessive sleep duration. Linoleic acid, but not arachidonic acid, was also associated with high risk for obstructive sleep apnea.

Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for adolescents.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for use in adults is in use worldwide. Until now, no version of this instrument for use in adolescents has been proposed. OBJECTIVE: To present comprehensive and short-form adaptations of the adult version of DC/TMD that are appropriate for use with adolescents in clinical and research settings. METHODS: International experts in TMDs and experts in pain psychology participated in a Delphi process to identify ways of adapting the DC/TMD protocol for physical and psychosocial assessment of adolescents. RESULTS: The proposed adaptation defines adolescence as ages 10-19 years. Changes in the physical diagnosis (Axis I) include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for adolescents, (ii) adding two general health questionnaires, one for the adolescent patient and one for their caregivers and (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire. Changes in the psychosocial assessment (Axis II) include (i) adapting the language of the Graded Chronic Pain Scale to be developmentally appropriate for adolescents, (ii) adding anxiety and depression assessment that have been validated for adolescents and (iii) adding three constructs (stress, catastrophizing and sleep disorders) to assess psychosocial functioning in adolescents. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II for adolescents, is appropriate to use in clinical and research settings. This adapted first version for adolescents includes changes in Axis I and Axis II requiring reliability and validity testing in international settings. Official translations of the comprehensive and short-form to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

Remarks on "Temporomandibular Disorders: Priorities for Research and Care": how will Chile advance? / Observaciones sobre trastornos temporomandibulares: prioridades de investigación y atención: ¿cómo avanzará Chile?

Temporomandibular disorders (TMDs) are complex multi-system disorders for which common traditional dental-centric approaches to research and care unfortunately continue to prevail. A committee appointed by the National Academies of Sciences, Engineering and Medicine (NAM) of the United States of America summarized important recommendations regarding the urgent need to transform, from the predominantly biomedical model, the research, professional education/training, and patient care for TMDs into the biopsychosocial model that is standard in the rest of pain medicine. The release of the Consensus Study Report identifies eleven short-term and long-term recommendations regarding gaps and opportunities oriented towards the situation in the US, which are equally applicable to the situation in Chile. The first four recommendations focus on basic and translational research, public health research and strengthening clinical research. The next three recommendations concern risk assessment, diagnostics, and dissemination of clinical practice guidelines and care metrics to improve patient care and expand its access. Recommendations eight to ten propose Centers of Excellence for Temporomandibular Disorders and Orofacial Pain Treatment, improving professional school education, and expanding specialized continuing education for healthcare providers. The eleventh recommendation focuses on patient education and stigma reduction. This article highlights the published recommendations and addresses what should be considered by Chilean professionals, as a first step of a major effort to shift TMD research, treatment, and education paradigms for the years to come.

Los trastornos temporomandibulares son complejos trastornos multisistémicos para los que, lamentablemente, siguen prevaleciendo los enfoques tradicionales odontocéntricos comunes de la investigación y la atención. Un comité designado por las Academias Nacionales de Ciencias, Ingeniería y Medicina de los Estados Unidos de América resumió importantes recomendaciones relativas a la urgente necesidad de transformar, desde el modelo predominantemente biomédico, la investigación, la educación/formación profesional y la atención al paciente para los trastornos temporomandibulares en el modelo biopsicosocial que es estándar en el resto de la medicina del dolor. La publicación del informe del estudio de consenso identifica once recomendaciones de corto y largo plazo respecto a brechas y oportunidades orientadas a la situación en Estados Unidos, que son igualmente aplicables a la situación en Chile. Las primeras cuatro recomendaciones se centran en la investigación básica y traslacional, la investigación en salud pública y el fortalecimiento de la investigación clínica. Las tres recomendaciones siguientes se refieren a la evaluación de riesgos, el diagnóstico y la difusión de guías de práctica clínica y métricas asistenciales para mejorar la atención de los pacientes y ampliar su acceso. Las recomendaciones octavas a décima proponen centros de excelencia para el tratamiento de los trastornos temporomandibulares y el dolor orofacial, la mejora de la formación en los centros profesionales y la ampliación de la formación continua especializada para los profesionales sanitarios. La undécima recomendación se centra en la educación de los pacientes y la reducción del estigma. Este artículo destaca las recomendaciones publicadas y aborda lo que debiesen considerar los profesionales chilenos, como primer paso hacia un gran esfuerzo por cambiar los paradigmas de investigación, tratamiento y educación sobre los trastornos temporomandibulares para los próximos años.

Observaciones sobre trastornos temporomandibulares: prioridades de investigación y atención: ¿cómo avanzará Chile? / Remarks on "Temporomandibular Disorders: Priorities for Research and Care": how will Chile advance?

Los trastornos temporomandibulares son complejos trastornos multisistémicos para los que, lamentablemente, siguen prevaleciendo los enfoques tradicionales odontocéntricos comunes de la investigación y la atención. Un comité designado por las Academias Nacionales de Ciencias, Ingeniería y Medicina de los Estados Unidos de América resumió importantes recomendaciones relativas a la urgente necesidad de transformar, desde el modelo predominantemente biomédico, la investigación, la educación/formación profesional y la atención al paciente para los trastornos temporomandibulares en el modelo biopsicosocial que es estándar en el resto de la medicina del dolor. La publicación del informe del estudio de consenso identifica once recomendaciones de corto y largo plazo respecto a brechas y oportunidades orientadas a la situación en Estados Unidos, que son igualmente aplicables a la situación en Chile. Las primeras cuatro recomendaciones se centran en la investigación básica y traslacional, la investigación en salud pública y el fortalecimiento de la investigación clínica. Las tres recomendaciones siguientes se refieren a la evaluación de riesgos, el diagnóstico y la difusión de guías de práctica clínica y métricas asistenciales para mejorar la atención de los pacientes y ampliar su acceso. Las recomendaciones octavas a décima proponen centros de excelencia para el tratamiento de los trastornos temporomandibulares y el dolor orofacial, la mejora de la formación en los centros profesionales y la ampliación de la formación continua especializada para los profesionales sanitarios. La undécima recomendación se centra en la educación de los pacientes y la reducción del estigma. Este artículo destaca las recomendaciones publicadas y aborda lo que debiesen considerar los profesionales chilenos, como primer paso hacia un gran esfuerzo por cambiar los paradigmas de investigación, tratamiento y educación sobre los trastornos temporomandibulares para los próximos años.

Temporomandibular disorders (TMDs) are complex multi-system disorders for which common traditional dental-centric approaches to research and care unfortunately continue to prevail. A committee appointed by the National Academies of Sciences, Engineering and Medicine (NAM) of the United States of America summarized important recommendations regarding the urgent need to transform, from the predominantly biomedical model, the research, professional education/training, and patient care for TMDs into the biopsychosocial model that is standard in the rest of pain medicine. The release of the Consensus Study Report identifies eleven short-term and long-term recommendations regarding gaps and opportunities oriented towards the situation in the US, which are equally applicable to the situation in Chile. The first four recommendations focus on basic and translational research, public health research and strengthening clinical research. The next three recommendations concern risk assessment, diagnostics, and dissemination of clinical practice guidelines and care metrics to improve patient care and expand its access. Recommendations eight to ten propose Centers of Excellence for Temporomandibular Disorders and Orofacial Pain Treatment, improving professional school education, and expanding specialized continuing education for healthcare providers. The eleventh recommendation focuses on patient education and stigma reduction. This article highlights the published recommendations and addresses what should be considered by Chilean professionals, as a first step of a major effort to shift TMD research, treatment, and education paradigms for the years to come.

Circulating Polyunsaturated Fatty Acids and Pain Intensity in Five Chronic Pain Conditions.

Pain intensity is well-known to be influenced by a wide range of biobehavioral variables. Nutritional factors, however, have not been generally considered for their potential importance. This cross-sectional study examined associations between erythrocyte omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and pain intensity in 605 adults. Pain intensity was computed on a 0 to 100 numeric rating scale from questions about 5 chronic pain conditions: orofacial pain, headache, low back pain, irritable bowel syndrome, and bodily pain. For each pain condition, multiple linear regression tested the hypothesis that a higher ratio of n-6 arachidonic acid to the sum of n-3 eicosapentaenoic acid and docosahexaenoic acid (AA/(EPA+DHA) was associated with greater pain intensity. In covariate-adjusted analysis, orofacial pain intensity increased 5.7 points (95% CI: 1.4, 9.9) per unit increase in n-6/n-3 PUFA ratio. Likewise, a 1 unit increase in n-6/n-3 PUFA ratio was associated with significant increases in pain intensity (range 5-8 points) of headache pain, low back pain, and bodily pain, but not abdominal pain. Separate multiple linear regression models investigated the independent strength of association of individual PUFAs to the intensity of each pain condition. Overall, n-3 docosahexaenoic acid was most strongly, and inversely, associated with pain intensity. PERSPECTIVE: A higher ratio of n-6/n-3 long-chain polyunsaturated fatty acids was associated greater pain intensity for orofacial pain, headache, low back pain, and bodily pain, but not abdominal pain. The n-6/n-3 PUFA ratio was more consistently associated with pain intensity than any individual constituent of the long-chain PUFA ratio.

Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for children.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) are used worldwide in adults. Until now, no adaptation for use in children has been proposed. OBJECTIVE: The aim of this study was to present comprehensive and short-form adaptations of Axis I and Axis II of the DC/TMD for adults that are appropriate for use with children in clinical and research settings. METHODS: Global Delphi studies with experts in TMDs and in pain psychology identified ways of adapting the DC/TMD for children. RESULTS: The proposed adaptation is suitable for children aged 6-9 years. Proposed changes in Axis I include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for children, (ii) adding a general health questionnaire for children and one for their parents, (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire and (iv) modifying the clinical examination protocol. Proposed changes in Axis II include (i) for the Graded Chronic Pain Scale, to be developmentally appropriate for children, (ii) adding anxiety and depression assessments that have been validated in children and (iii) adding three constructs (stress, catastrophising and sleep disorders) to assess psychosocial functioning in children. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II, for children aged 6-9 years, is appropriate for use in clinical and research settings. This adapted the first version for children includes changes in Axis I and Axis II changes requiring reliability and validity testing in international settings. Official translations to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

A rose by another name? Characteristics that distinguish headache secondary to temporomandibular disorder from headache that is comorbid with temporomandibular disorder.

ABSTRACT: Co-occurring pain conditions that affect overlapping body regions are complicated by the distinction between primary vs secondary pain conditions. We investigate the occurrence of headache and painful temporomandibular disorder (TMD) in a community-based, cross-sectional study of US adults in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA-II) study. A specific goal was to determine whether headache attributed to TMD is separable from primary headache. Using DC/TMD and International Classification of Headache Disorders-third edition criteria, 3 groups of individuals were created: (a) headache without TMD; (b) headache comorbid with TMD; and (c) headache attributed to TMD. Regression models compared study groups according to demographic and comorbid characteristics, and post hoc contrasts tested for differences. Descriptive statistics and Cohen d effect size were computed, by group, for each predictor variable. Differences in continuous predictors were analyzed using one-way analysis of variance. Nearly all demographic and comorbid variables distinguished the combined headache and TMD groups from the group with headache alone. Relative to the reference group with primary headache alone, markers related to headache, TMD, somatic pain processing, psychosocial, and health conditions were substantially greater in both headache comorbid with TMD and headache attributed to TMD, attesting to their qualitative similarities. However, effect sizes relative to the reference group were large for headache comorbid with TMD and larger again for headache attributed to TMD, attesting to their separability in quantitative terms. In summary, the presence of overlapping painful TMD and headache adds substantially to the biopsychosocial burden of headache and points to the importance of comprehensive assessment and differential management.

Psychological therapies for temporomandibular disorders (TMDs).

BACKGROUND: Temporomandibular disorders (TMDs) are a group of musculoskeletal disorders affecting the jaw. They are frequently associated with pain that can be difficult to manage and may become persistent (chronic). Psychological therapies aim to support people with TMDs to manage their pain, leading to reduced pain, disability and distress. OBJECTIVES: To assess the effects of psychological therapies in people (aged 12 years and over) with painful TMD lasting 3 months or longer. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched six bibliographic databases up to 21 October 2021 and used additional search methods to identify published, unpublished and ongoing studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of any psychological therapy (e.g. cognitive behaviour therapy (CBT), behaviour therapy (BT), acceptance and commitment therapy (ACT), mindfulness) for the management of painful TMD. We compared these against control or alternative treatment (e.g. oral appliance, medication, physiotherapy). DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We reported outcome data immediately after treatment and at the longest available follow-up. We used the Cochrane RoB 1 tool to assess the risk of bias in included studies. Two review authors independently assessed each included study for any risk of bias in sequence generation, allocation concealment, blinding of outcome assessors, incomplete outcome data, selective reporting of outcomes, and other issues. We judged the certainty of the evidence for each key comparison and outcome as high, moderate, low or very low according to GRADE criteria. MAIN RESULTS: We identified 22 RCTs (2001 participants), carried out between 1967 and 2021. We were able to include 12 of these studies in meta-analyses. The risk of bias was high across studies, and we judged the certainty of the evidence to be low to very low overall; further research may change the findings. Our key outcomes of interest were: pain intensity, disability caused by pain, adverse events and psychological distress. Treatments varied in length, with the shortest being 4 weeks. The follow-up time ranged from 3 months to 12 months. Most studies evaluated CBT.   At treatment completion, there was no evidence of a benefit of CBT on pain intensity when measured against alternative treatment (standardised mean difference (SMD) 0.03, confidence interval (CI) -0.21 to 0.28; P = 0.79; 5 studies, 509 participants) or control (SMD -0.09, CI -0.30 to 0.12; P = 0.41; 6 studies, 577 participants). At follow-up, there was evidence of a small benefit of CBT for reducing pain intensity compared to alternative treatment (SMD -0.29, 95% CI -0.50 to -0.08; 5 studies, 475 participants) and control (SMD -0.30, CI -0.51 to -0.09; 6 studies, 639 participants). At treatment completion, there was no evidence of a difference in disability outcomes (interference in activities caused by pain) between CBT and alternative treatment (SMD 0.15, CI -0.40 to 0.10; P = 0.25; 3 studies, 245 participants), or between CBT and control/usual care (SMD 0.02, CI -0.21 to 0.24; P = 0.88; 3 studies, 315 participants). Nor was there evidence of a difference at follow-up (CBT versus alternative treatment: SMD -0.15, CI -0.42 to 0.12; 3 studies, 245 participants; CBT versus control: SMD 0.01 CI - 0.61 to 0.64; 2 studies, 240 participants). There were very few data on adverse events. From the data available, adverse effects associated with psychological treatment tended to be minor and to occur less often than in alternative treatment groups. There were, however, insufficient data available to draw firm conclusions. CBT showed a small benefit in terms of reducing psychological distress at treatment completion compared to alternative treatment (SMD -0.32, 95% CI -0.50 to -0.15; 6 studies, 553 participants), which was maintained at follow-up (SMD -0.32, 95% CI -0.51 to -0.13; 6 studies, 516 participants). For CBT versus control, only one study reported results for distress and did not find evidence of a difference between groups at treatment completion (mean difference (MD) 2.36, 95% CI -1.17 to 5.89; 101 participants) or follow-up (MD -1.02, 95% CI -4.02 to 1.98; 101 participants). We assessed the certainty of the evidence to be low or very low for all comparisons and outcomes. The data were insufficient to draw any reliable conclusions about psychological therapies other than CBT. AUTHORS' CONCLUSIONS: We found mixed evidence for the effects of psychological therapies on painful temporomandibular disorders (TMDs). There is low-certainty evidence that CBT may reduce pain intensity more than alternative treatments or control when measured at longest follow-up,  but not at treatment completion. There is low-certainty evidence that CBT may be better than alternative treatments, but not control, for reducing psychological distress at treatment completion and follow-up. There is low-certainty evidence that CBT may not be better than other treatments or control for pain disability outcomes.  There is insufficient evidence to draw conclusions about alternative psychological therapeutic approaches, and there are insufficient data to be clear about adverse effects that may be associated with psychological therapies for painful TMD.  Overall, we found insufficient evidence on which to base a reliable judgement about the efficacy of psychological therapies for painful TMD. Further research is needed to determine whether or not psychological therapies are effective, the most effective type of therapy and delivery method, and how it can best be targeted. In particular, high-quality RCTs conducted in primary care and community settings are required, which evaluate a range of psychological approaches against alternative treatments or usual care, involve both adults and adolescents, and collect measures of pain intensity, pain disability and psychological distress until at least 12 months post-treatment.

A commentary on Temporomandibular disorders: priorities for research and care - bridging from the US to the UK.

In January 2019, the United States National Academy of Medicine initiated a comprehensive study of the status of current knowledge and clinical practices associated with temporomandibular disorders (TMDs). The National Academy of Sciences, which includes the National Academy of Medicine, was chartered by the US Government in the late 1800s as a non-profit institution working outside of government in order to provide unbiased, objective opinions on matters including healthcare. In this brief paper, we will discuss the open access 2020 report Temporomandibular disorders: priorities for research and care, available online. While the main focus of this report was the situation of TMDs in the US, the evidence base, authorship, expertise and literature scope was international and the findings therefore are at least in part generalisable to and important for the UK.The authors of this commentary were directly involved in the National Academy process, with RO a panel member, JD a consultant and CG one of 15 reviewers of the draft report. There was a wide variety of clinical and research fields involved in gathering the evidence and constructing the report. In addition, there was extensive involvement from affected patients with TMDs and their families, which is critical because their perspective is typically omitted in textbooks and professional consensus meetings.

Circulating polyunsaturated fatty acids, pressure pain thresholds, and nociplastic pain conditions.

OBJECTIVE: Polyunsaturated fatty acids (PUFAs) play a role in pain regulation. This study sought to determine whether free PUFAs found in red blood cells also play a role in nociceptive processing. We examined associations between circulating PUFAs and nociceptive thresholds to noxious mechanical stimuli. We also determined whether nociceptive thresholds were associated with nociplastic pain conditions. METHODS: This cross-sectional study used stored red bloods cells and data from 605 adult participants in the OPPERA-2 study of chronic overlapping pain conditions. In OPPERA-2 adults completed quantitative sensory testing in which pressure algometry measured deep muscular tissue sensitivity at six anatomical sites. Standardized protocols classified adults for presence or absence of five nociplastic pain conditions: temporomandibular disorder, headache, low back pain, irritable bowel syndrome and fibromyalgia. Liquid chromatography tandem mass spectroscopy quantified erythrocyte PUFAs. We conducted three sets of analyses. First, a multivariable linear regression model assessed the association between n-6/n-3 PUFA ratio and the number of overlapping nociplastic pain conditions. Second, a series of 36 multivariable linear regression models assessed covariate-adjusted associations between PUFAs and nociceptive thresholds at each of six anatomical sites. Third, a series of 30 multivariable linear regression models assessed covariate-adjusted associations between nociceptive thresholds at six anatomical sites and each of five pain conditions. RESULTS: In multiple linear regression, each unit increase in n-6/n-3 PUFA ratio was associated with more pain conditions (ß = 0.30, 95% confidence limits: 0.07, 0.53, p = 0.012). Omega-6 linoleic acid and arachidonic acid were negatively associated with lower nociceptive thresholds at three and at five, respectively, anatomical sites. In contrast, omega-3 alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and the n-6/n-3 PUFA ratio were not associated with nociceptive thresholds at any site. Pain cases had significantly lower nociceptive thresholds than non-case controls at all anatomical sites. CONCLUSION: A higher n-6/n-3 PUFA ratio was associated with more pain conditions. Omega-6 PUFAs may promote a generalized upregulation of nociceptive processing.

Circulating Omega-6 and Omega-3 Polyunsaturated Fatty Acids in Painful Temporomandibular Disorder and Low Back Pain.

Preclinical studies demonstrate opposing effects of long-chain polyunsaturated fatty acid (PUFA) metabolites on inflammation and nociception. Omega-6 (n-6) PUFAs amplify both processes while omega-3 (n-3) PUFAs inhibit them. This cross-sectional study examined relationships between PUFAs in circulating erythrocytes and 2 chronic idiopathic pain conditions: temporomandibular disorder (TMD) and low back pain in a community-based sample of 503 U.S. adults. Presence or absence of TMD and low back pain, respectively, were determined by clinical examination and by responses to established screening questions. Liquid chromatography-tandem mass spectrometry quantified PUFAs. In multivariable logistic regression models, a higher ratio of n-6/n-3 long-chain PUFAs was associated with greater odds of TMD (odds ratio ((OR) = 1.75, 95% confidence limits (CL): 1.16, 2.64) and low back pain (OR = 1.63, 95% CL: 1.07, 2.49). Higher levels of the pronociceptive n-6 long-chain arachidonic acid (AA) were associated with a greater probability of both pain conditions for women, but not men. Higher levels of the antinociceptive long-chain n-3 PUFAs eicosapentaenoic and docosahexaenoic acids were associated with a lower probability of both pain conditions for men, but not women. As systemic inflammation is not a hallmark of these conditions, PUFAs may influence idiopathic pain through other mechanisms. PERSPECTIVE: This cross-sectional clinical study found that a higher ratio of circulating n-6/n-3 long-chain PUFAs was associated with greater odds of 2 common chronic overlapping pain conditions. This suggests that the pro and antinociceptive properties of n-6 and n-3 PUFAs, respectively, influence pain independently of their well-established inflammatory pathways.

Ratio of Omega-6/Omega-3 Polyunsaturated Fatty Acids Associated With Somatic and Depressive Symptoms in People With Painful Temporomandibular Disorder and Irritable Bowel Syndrome.

Somatic symptom disturbance is among the strongest predictors of painful temporomandibular disorder (TMD). Related psychological constructs, such as anxiety and depression, respond therapeutically to omega-3 polyunsaturated fatty acids (PUFAs) in clinical trials. This cross-sectional study investigated associations between the omega-6/omega-3 PUFA ratio and somatic symptom disturbance and depressive symptoms in a community-based sample of 501 adults and determined whether these associations differed between adults with and without TMD or irritable bowel syndrome (IBS). Liquid chromatography tandem mass spectrometry quantified PUFAs in circulating erythrocytes. Somatic symptoms and depression were quantified using Symptom Checklist-90-Revised subscales. Presence or absence of TMD and IBS, respectively, were determined by clinical examination and Rome III screening questions. The standardized beta coefficient for the omega-6/omega-3 long-chain PUFA ratio was 0.26 (95% confidence limits (CL): 0.08, 0.43) in a multivariable linear regression model in which somatic symptom disturbance was the dependent variable. When modelling depressive symptoms as the dependent variable, the standardized beta coefficient was 0.17 (95% CL:0.01, 0.34). Both associations were stronger among TMD cases and IBS cases than among non-cases. Future randomized control trials that lower the omega-6/omega-3 PUFA ratio could consider somatic or depressive symptoms as a therapeutic target for TMD or IBS pain. PERSPECTIVE: In people with TMD or IBS, a high n-6/n-3 PUFA ratio was positively associated with somatic symptom disturbance and depressive symptoms. Both measures of psychological distress were elevated in people with painful TMD and IBS. Future randomized clinical trials will determine whether lowering the n-6/n-3 ratio is therapeutic for pain.