Nutrition and chronic musculoskeletal pain: A narrative review and directions for temporomandibular disorder research and management.

BACKGROUND: Recent evidence suggests neuro-immune mechanisms may link dietary patterns to chronic painful conditions (CPC). In the research field of oro-facial pain (OFP), studies focuses primarily on dietary mechanical limitations due to pain and dysfunction. OBJECTIVE: This narrative review aimed to overview the role of nutrition on CPC, with emphasis on temporomandibular disorder (TMD), enlightening OFP researcher on dietary assessment possibilities and providing directions for studies in the field of OFP and nutrition. METHODS: A PubMed database search was performed using the MeSH and non-MeSH descriptors: "temporomandibular joint disorder"; "orofacial pain"; "musculoskeletal pain"; "chronic pain disorders"; "nutrition"; "diet"; "dietary therapy"; "dietary intake" and "inflammation". No time restrictions were applied. Literature reviews, systematic reviews, meta-analyses and clinical and pre-clinical trials were included. RESULTS: Exogenous oxidants from unhealthy dietary patterns may contribute to peripheral and central pro-inflammatory immune signalling leading to peripheral and central sensitization. Furthermore, diets rich in bioactive compounds are suggested to contribute to pain management of CPC. High dietary intake of ultra-processed foods impacts the quality of the diet and shows adverse health outcomes. In this context, the role of nutrition on TMD remains overlooked. CONCLUSION: Considering diet may influence CPC, allied with the scarcity of studies evaluating the role of nutrition on TMD, well-designed clinical trials based on dietary assessments and measurements capable of evaluating food quality, UPF consumption and nutrient adequacy-added to serum nutrient levels evaluation-are suggested.

Influence of psychometric and sleep quality features on painful mechanical sensitivity and pain modulation in patients with temporomandibular disorders.

Investigating the collective impact of psychometric properties and sleep quality on pain sensitivity in temporomandibular disorder (TMD) patients could improve clinical management strategies. OBJECTIVE: Assessing whether combined psychometric properties and sleep quality impact painful mechanical sensitivity and pain modulation in TMD patients. MATERIALS AND METHODS: A cross-sectional study using secondary data analysis of 77 TMD patients and 101 controls. All participants completed questionnaires characterizing their psychometric profile (anxiety, depression, stress and catastrophizing) and sleep quality, alongside psychophysical tests for painful mechanical sensory (mechanical pain threshold (MPT), pressure pain threshold (PPT), and wind-up ratio (WUR)) and conditioned pain modulation (CPM). Participants were grouped into "High distress" or "Low distress" categories based on psychometric properties and sleep quality using hierarchical cluster and k-means analyses. Multiple linear regression evaluated the influence of TMD, age, and the distress cluster on MPT, WUR, PPT, and CPM in masseter and thenar muscles. Differences were statistically significant when p < 0.05. RESULTS: The presence of TMD was the strongest predictor of mechanical painful sensitivity in the trigeminal region (MPT[F(3,174) = 51.902;p < .001;R2 = .463]; TMD presence (ß = -.682) / PPT[F(3,174) = 15.573;p < .001;R2 = .198] TMD presence (ß = -.452), and extra-trigeminal (MPT[F(3,174) = 35.897;p < .001;R2 = .382] TMD (ß = -.647) / CPM [F(3,174) = 4.106;p < .05;R2 = .050] TMD presence (ß = .197). Furthermore, neither the high distress group nor the low distress group were able to significantly influence the variation of the values of any of the psychophysical variables evaluated (p > .05). CONCLUSIONS: There is not a significant influence of impairment clusters based on psychological variables and sleep quality on painful mechanical sensitivity and pain modulation, regardless of the presence of TMD. CLINICAL RELEVANCE: This outcome suggests that psychosocial factors and sleep quality may not play a decisive role in the sensory-discriminative aspect of pain, particularly concerning painful TMD.

Botulinum toxin-A effects on pain, somatosensory and psychosocial features of patients with refractory masticatory myofascial pain: a randomized double-blind clinical trial.

The antinociceptive effect of BoNT-A have been well documented in animal studies; however, results of few but well-designed randomized placebo-controlled clinical trials about BoNT-A efficacy in masticatory myofascial pain (MFP) are inconsistent. Therefore, the present randomized, double-blind, placebo-controlled clinical trial evaluated the efficacy of BoNT-A in patients with refractory MFP. Twenty-eight patients with pain reduction of less than 30% despite conservative treatment and with an average pain intensity of > 50 mm on the visual analogue scale (VAS) participated. Patients were randomly assigned to receive a total of 80 U of BoNT-A or saline solution (SS) injected into the masseter and anterior temporalis muscles. Pain intensity (VAS), quantitative sensory testing (QST), conditioned pain modulation (CPM), and psychosocial status were examined. Follow-up was performed at 1 and 6 months. For repeated-measure comparisons between evaluation times, Friedman test with Bonferroni correction was used for pain and somatosensory variables and the Wilcoxon test for the psychosocial variables. The Mann-Whitney test was used for all comparisons between groups. The BoNT-A group had a significant decrease in pain intensity at follow-ups compared with the SS group (p < 0.001). QST assessment revealed higher pressure pain threshold values in the masseter muscle for BoNT-A group compared to SS (p < 0.03) at all follow-ups. No differences were found for mechanical pain threshold and wind-up ratio values (p > 0.05) in the entire study. The BoNT-A group presented the most efficient CPM effect (p < 0.03) only at the 1 month follow-up in the masseter muscle. There was a significant time effect for BoNT-A in all psychosocial variables (p < 0.05) and a drug effect in the Central Sensitization Inventory (p < 0.01), Pittsburgh Sleep Quality Index (p < 0.004), and Healthy Survey 36 (p < 0.05) at 6 months follow-up. The study demonstrates that a single injection-session of BoNT-A has positive effects on the hall pain spectrum of patients with refractory masticatory myofascial pain.

Prediction of duloxetine efficacy in addition to self-management in painful temporomandibular disorders: A randomised, placebo-controlled clinical trial.

BACKGROUND: Conditioned pain modulation (CPM) is a potential predictor of treatment response that has not been studied in temporomandibular disorders (TMD). OBJECTIVES: We conducted a randomised, double-blind, placebo-controlled trial (RCT) of duloxetine in addition to self-management (SM) strategies to investigate its efficacy to reduce pain intensity in painful TMD patients. Moreover, we investigated whether baseline CPM would predict the duloxetine efficacy to reduce TMD pain intensity. METHODS: Eighty participants were randomised to duloxetine 60 mg or placebo for 12 weeks. The primary outcomes were the change in the pain intensity from baseline to week-12 and CPM-sequential paradigm at baseline. Safety, physical and emotional functioning outcomes were also evaluated. RESULTS: Of 80 participants randomised, 78 were included in intention-to-treat analysis. Pain intensity decreased for SM-duloxetine and SM-placebo but did not differ between groups (p = .82). A more efficient CPM was associated with a greater pain intensity reduction regardless of the treatment group (p = .035). Physical and emotional functioning did not differ between groups, but adverse events (p = .014), sleep impairment (p = .003) and catastrophizing symptoms (p = .001) were more prevalent in SM-duloxetine group. CONCLUSION: This study failed to provide evidence of a beneficial effect of adding duloxetine to SM strategies for treatment of painful TMD. Nonetheless, this RCT has shown the feasibility of applying pain modulation assessment to predict short-term treatment response in painful TMD patients, which confirms previous finds that CPM evaluation may serve a step forward in individualising pain treatment.

Divergence between confidence and knowledge of endodontists regarding non-odontogenic pain.

INTRODUCTION: This study aimed to assess the self-reported levels of confidence and knowledge related to non-odontogenic pain among a group of Brazilian endodontists. METHODOLOGY: A total of one hundred and forty-six endodontists affiliated with the Brazilian Society of Endodontics participated in the survey. The questionnaire, distributed via email or WhatsApp, contained inquiries designed to gauge self-perceived confidence and knowledge concerning non-odontogenic pain. The practitioners were categorized into four groups based on their self-reported familiarity with various orofacial pain types, classified as either sufficient or insufficient, and on their engagement in ongoing educational programs related to orofacial pain. Data were analyzed by Chi-Square Test and Fischer's exact test (p<0.05). RESULTS: Overall, self-reported confidence about non-odontogenic pain was high, especially for endodontists who considered their knowledge about orofacial pain sufficient, regardless of whether they had (71.1% - 97.8%) or not (35.7% - 96.4%) been continuously involved in education courses on orofacial pain. In general, self-reported knowledge about non-odontogenic pain was insufficient (0% - 42%), except in the question about how they would act in cases of pain that persists beyond the normal healing time after an endodontic procedure (70.6% - 81.9%). In general, endodontists are confident in their diagnosis and treatment of non-odontogenic pain. Nonetheless, this confidence did not correlate with a commensurate knowledge depth of. Thus, specialization courses in endodontics should highly consider training and qualifying these professionals in the diagnosis of non-odontogenic pain.

Experimental pain thresholds and psychosocial features across menstrual cycle in myofascial orofacial pain compared to healthy individuals: cross-sectional study / Limiares de dor experimental e características psicossociais ao longo do ciclo menstrual na dor miofascial orofacial em comparação com indivíduos saudáveis: estudo transversal

ABSTRACT BACKGROUND AND OBJECTIVES: The hormonal impact on pain perception during the menstrual cycle is a major focus of study, and further elucidation in temporomandibular disorders (TMD) field is necessary. Thus, this cross-sectional study evaluated experimental pain thresholds, psychosocial features, and clinical pain report on TMD women across menstrual cycle versus healthy controls. METHODS: A total of 220 women's clinical files were screened, with 80 selected and divided into control group (healthy individuals, n=40) and TMD group (myofascial pain, n=40). Regarding the menstrual cycle phases, the files were divided into Pre-Luteal and Luteal. The Perceived Stress Scale (PSS), Pain Catastrophizing Scale (PCS), Mechanical Pain Threshold (MPT), Wind-up (WUR), Pressure Pain Threshold (PPT), Conditioned Pain Modulation (CPM) and Visual Analogue Scale (VAS) were analyzed at a 5% significance level, by Two-Way ANOVA test and post hoc Tukey test. RESULTS: PSS and PCS were significantly different between TMD and control group (p<0.001), regardless of menstrual cycle. Healthy individuals in the Luteal phase presented higher MPT values compared to the other phases (p<0.001). PPT showed significant difference across menstrual phases (p=0.022), but no differences in multiple comparisons. VAS values showed no difference between menstrual cycle phases (p=0.376). CONCLUSION: Finally, healthy individuals in the Luteal phase have higher MPT and PPT values on the orofacial region. Pain report in patients with TMD showed no difference throughout the menstrual cycle, showing that small alterations on experimental pain thresholds may not be clinically relevant. The presence of chronic pain seems to be more related to psychosocial features than hormonal fluctuations.

RESUMO JUSTIFICATIVA E OBJETIVOS: O impacto do ciclo menstrual na percepção da dor é um foco importante de estudo, sendo necessária uma maior elucidação na disfunção temporomandibular (DTM). Assim, este estudo transversal avaliou limiares de dor experimental, características psicossociais e relatos de dor em mulheres com DTM ao longo do ciclo menstrual, comparadas com controles saudáveis. MÉTODOS: 220 prontuários de mulheres foram analisados, sendo 80 selecionados para os grupos de controle (saudáveis, n=40) e DTM (dor miofascial, n=40). Nas fases do ciclo menstrual, as pacientes foram divididas nas categorias Pré-Luteal e Luteal. Os instrumentos Escala de Estresse Percebido (PSS), Escala de Pensamentos Catastróficos (PCS), Limiar de Dor Mecânica (MPT), Wind-up Ratio (WUR), Limiar de Dor à Pressão (PPT), Modulação Condicionada da Dor (CPM) e Escala analógica visual (EAV) foram analisados com nível de significância de 5%, pelos testes ANOVA de dois fatores e Tukey post hoc. RESULTADOS: As escalas PSS e PCS foram significativamente diferentes entre os grupos DTM e controle (p<0,001), independentemente do ciclo menstrual. Indivíduos saudáveis na fase luteal apresentaram MPT maior em comparação com outras fases (p,0,001). O PPT mostrou diferença significativa entre as fases menstruais (p=0,022), sem diferença nas comparações múltiplas. Os valores da EAV não apresentaram diferença entre as fases menstruais (p=376). CONCLUSÃO: Indivíduos saudáveis na fase luteal têm MPT e PPTl maior na região orofacial. Os relatos de dor em pacientes com DTM não mostraram diferença ao longo do ciclo menstrual, indicando que pequenas alterações nos limiares experimentais podem ser clinicamente relevantes. A presença de dor crônica parece estar mais relacionada com características psicossociais do que com flutuações hormonais.

Ecological Momentary Assessment of Awake Bruxism Behaviors: A Scoping Review of Findings from Smartphone-Based Studies in Healthy Young Adults.

BACKGROUND: The recent introduction of ecological momentary assessment (EMA) smartphone-based strategies has allowed achieving some interesting data on the frequency of different awake bruxism (AB) behaviors reported by an individual in the natural environment. OBJECTIVE: The present paper aims to review the literature on the reported frequency of AB based on data gathered via smartphone EMA technology. METHODS: On September 2022, a systematic search in the Pubmed, Scopus and Google Scholar databases was performed to identify all peer-reviewed English-language studies assessing awake bruxism behaviors using a smartphone-based Ecological Momentary Assessment. The selected articles were assessed independently by two authors according to a structured reading of the articles' format (PICO). RESULTS: A literature search, for which the search terms "Awake Bruxism" and "Ecological Momentary Assessment" were used, identified 15 articles. Of them, eight fulfilled the inclusion criteria. The results of seven studies using the same smartphone-based app reported a frequency of AB behaviors in the range between 28.3 and 40% over one week, while another investigation adopted a different smartphone-based EMA approach via WhatsApp using a web-based survey program and reported an AB frequency of 58.6%. Most included studies were based on convenience samples with limited age range, highlighting the need for more studies on other population samples. CONCLUSIONS: Despite the methodological limits, the results of the reviewed studies provide a standpoint for comparison for future studies on the epidemiology of awake bruxism behaviors.

Catastrophizing and Hypervigilance Influence Subjective Sleep Quality in Painful TMD Patients

Aims: To determine sleep quality and associated factors in a group of patients with painful TMDs. Methods: The medical records of 80 patients with arthralgia and/or myofascial pain were reviewed and compared to a healthy control group. Data about sex, age, subjective pain, physical activity, social activity, subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]), pain vigilance (Pain Vigilance and Awareness Questionnaire [PVAQ]), and pain catastrophizing (Pain Catastrophizing Scale [PCS]) were collected. Relationships between PSQI, age, pain intensity, PVAQ, and PCS in the TMD group were also analyzed. Data from the control group were used to transform the PSQI results into T-scores, which were then used to divide the TMD group into two subgroups: normal and impaired sleep. Results: TMD patients presented a significantly higher (P < .001) PSQI score than the control group. Also, in the TMD group, there was a low to moderate correlation between PSQI and pain intensity and a significant correlation between PVAQ and PCS. The impaired sleep group presented a significantly higher (P < .001) PSQI T-score than the normal sleep group. Univariate analysis showed that subjective pain, social activity, and the PCS total and subscale scores differed significantly between the different PSQI T-score groups. The comparison between TMD pain patients and control subjects showed a significantly higher prevalence of T-score discordance in almost all PSQI components in TMD patients with impaired sleep. Conclusion: Subjective sleep quality in painful TMD patients could be associated with and influenced by psychosocial factors (catastrophizing and hypervigilance), social activity, and pain intensity.

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.

Influence of genetic polymorphisms on mechanical pain sensitivity and endogenous pain modulation of trigeminal and spinal areas.

BACKGROUND: Previous evidence indicates significant association between genetic polymorphisms and phenotypes related to pain sensitivity in patients with temporomandibular disorders (TMD). Despite the important advances in cataloguing diverse factors such as sleep disorders, anxiety and depression, the interrelated mechanisms of painful TMD aetiopathogenesis still need investigation. OBJECTIVES: This case-control study aimed to evaluate the influence of genetic polymorphisms (rs6296, rs6295, rs1799971, rs4680, rs4633, rs4818) and psychosocial factors on the mechanical pain sensitivity and endogenous pain modulation in women with painful TMD and asymptomatic controls. METHODS: We evaluated six independent variables: anxiety levels, depression, stress, sleep quality, pain catastrophising and genetic polymorphisms, and four dependent variables: mechanical pain threshold (MPT), pressure pain threshold (PPT), wind-up ratio (WUR) and conditioned pain modulation (CPM) collected at masseter (trigeminal) and hand (spinal) areas in a sample of 95 painful TMD patients and 85 controls. A regression model was used to test the possible effect of the independent variables on dependent variables. RESULTS: The regression model was significant for MPT (F11,168  = 9.772; R2  = .390). Painful TMD diagnoses and sleep quality were associated with trigeminal MPT (B coefficient = -.499; and B coefficient = -.211, respectively). WUR was associated with rs6295 and rs6746030, respectively, for the spinal and the trigeminal area. CONCLUSION: Genetic polymorphisms had a slight contribution to endogenous pain modulation as indicated by the significant association with WUR but did not contribute to mechanical pain sensitivity. On the other hand, the presence of painful TMD and the sleep quality contributed significantly to mechanical pain sensitivity.

Divergence between confidence and knowledge of endodontists regarding non-odontogenic pain

Abstract This study aimed to assess the self-reported levels of confidence and knowledge related to non-odontogenic pain among a group of Brazilian endodontists. Methodology A total of one hundred and forty-six endodontists affiliated with the Brazilian Society of Endodontics participated in the survey. The questionnaire, distributed via email or WhatsApp, contained inquiries designed to gauge self-perceived confidence and knowledge concerning non-odontogenic pain. The practitioners were categorized into four groups based on their self-reported familiarity with various orofacial pain types, classified as either sufficient or insufficient, and on their engagement in ongoing educational programs related to orofacial pain. Data were analyzed by Chi-Square Test and Fischer's exact test (p<0.05). Results Overall, self-reported confidence about non-odontogenic pain was high, especially for endodontists who considered their knowledge about orofacial pain sufficient, regardless of whether they had (71.1% - 97.8%) or not (35.7% - 96.4%) been continuously involved in education courses on orofacial pain. In general, self-reported knowledge about non-odontogenic pain was insufficient (0% - 42%), except in the question about how they would act in cases of pain that persists beyond the normal healing time after an endodontic procedure (70.6% - 81.9%). In general, endodontists are confident in their diagnosis and treatment of non-odontogenic pain. Nonetheless, this confidence did not correlate with a commensurate knowledge depth of. Thus, specialization courses in endodontics should highly consider training and qualifying these professionals in the diagnosis of non-odontogenic pain.

Long-Term Effects of a Single Application of Botulinum Toxin Type A in Temporomandibular Myofascial Pain Patients: A Controlled Clinical Trial.

This study assessed the long-term effects of botulinum toxin type A (BoNT-A) in subjective pain, pain sensibility, and muscle thickness in persistent myofascial temporomandibular-disorder pain (MFP-TMD) patients. Fourteen female subjects with persistent MFP received BoNT-A treatment with different doses (10U-25U for temporalis muscle and 30U-75U for masseter muscle). The treatment was injected bilaterally in the masseter and anterior temporalis muscles in a single session. Clinical measurements included: self-perceived pain (VAS), pain sensibility (PPT), and muscles thickness (ultrasonography). Follow-up occurred 1, 3, 6, and 72 months after treatment for VAS and PPT and 1, 3, and 72 months for ultrasonography. For statistical analysis, the Friedman test with the Bonferroni test for multiple comparisons as a post hoc test was used for non-parametric repeated measures comparisons among the evaluation times. A 5% probability level was considered significant in all tests. VAS values presented a significant decrease throughout the study (p < 0.05). Regarding PPT values, a significant increase was found when comparing baseline data with post-treatment follow-ups (p < 0.05), and even though a significant decrease was found in muscle thickness when baseline values were compared with the 1- and 3-months assessments, no differences were found when compared with the 72 months follow-up (p > 0.05). A single injection of BoNT-A presents long-term effects in reducing pain in persistent MFP-TMD patients, and a reversibility of adverse effects on masticatory-muscle thickness.

Primary headache and myofascial pain: a data based study / Cefaleia primária e dor miofascial: um estudo baseado em dados

Aim: This study aimed to evaluate the relationship be-tween the presence of primary headaches and myofascial pain in orofacial patients. Materials and methods: Six hundred and ninety-nine records of patients seeking treatment in a specialized orofacial pain clinic were assessed. The primary diagnostic categories of heada-che and myofascial pain were recorded. Data analyses were carried out by Pearson Chi-square and Logistic Regression, with a p-value of 0.05. Results: Average age of patients was 34.6 years. Females constituted 82.8% of the sample. A relationship between the presence of tension-type headache and myofascial pain was found (p=0.00); however, this relationship was not found for the presence of migraine and myofascial pain (p>0.05). Discussion: Tension-type headaches may be triggered or perpetuated by trigger points in orofacial structures. Conclusion: It can be concluded that trigger points in myofascial pain patients can play an important role in the genesis of tension-type headache.

Objetivo: Este estudo avaliou a relação entre a presença de cefaleia primária e dor miofascial em pacientes orofaciais. Materiais e métodos: Foram avaliados 699 prontuários de pacientes que buscavam atendimento em clínica especiali-zada em dor orofacial. As categorias diagnósticas primárias de cefaleia e dor miofascial foram registradas. A análise dos dados foi realizada pelo Qui-quadrado de Pearson e Regressão Logística, com valor de p=0,05. Resultados: A idade média dos pacientes foi de 34,6 anos. O sexo feminino constituiu 82,8% da amostra. Foi encontrada relação entre a presença de cefaleia do tipo tensional e dor miofascial (p = 0,00); en-tretanto, essa relação não foi encontrada para a presença de enxaqueca e dor miofascial (p> 0,05). Discussão: As cefaleias primárias do tipo tensionais podem ser desencadeadas ou perpetuadas por pontos-gatilhos nas estruturas orofaciais. Conclusão: Pode-se concluir que os pontos-gatilhos em pacientes com dor miofascial podem desempenhar um papel importante na gênese da cefaleia do tipo tensional.

Who is the individual that will complain about temporomandibular joint clicking?

BACKGROUND: Understanding the profile of the individual complaining of TMJ clicking can help in the clinical approach of these patients. OBJECTIVE: To identify clinical variables associated with individuals who complain about and seek treatment for TMJ clicking. METHODS: Seventy-two individuals, composed the sample: Group 1 - patients with a complaint of TMJ clicking who sought treatment; (n = 36); Group 2 - individuals with TMJ clicking who have no complaints about it (n = 36). Three categories of data were evaluated: clinical (gender; age; side of TMJ clicking; TMJ pain; self-reported level of bother; previous TMJ clicking information); somatosensory (mechanical pain threshold [MPT], wind-up ratio [WUR], pressure pain threshold [PPT]); and, psychosocial (Pain Vigilance and Awareness Questionnaire [PVAQ]; Pain Catastrophising Scale [PCS]; Tampa Scale for Kinesiophobia for Temporomandibular Disorders [TSK/TMD]); The Perceived Stress Scale (PSS); The State-Trait Anxiety Inventory (STAI). RESULTS: Group 1 was composed mostly of female patients, with TMJ pain, without previous orientation about the condition, bothered by the clicking, with lower PPT and higher scores in the PVAQ, PCS, TKS/TMD, PSS and STAI scales than Group 2. The groups did not differ significantly for side of TMJ clicking, age, MPT and WUR. CONCLUSION: Individuals who have a TMJ clicking complaint and seek treatment are mostly female, have TMJ pain, have not received previous orientation about TMJ clicking, are bothered by the clicking, have a lower pain threshold and higher scores of hypervigilance, catastrophising, kinesiophobia, stress and anxiety than people with TMJ clicking who do not report it.

The hierarchy of different treatments for myogenous temporomandibular disorders: a systematic review and network meta-analysis of randomized clinical trials.

The best treatment modality for the management of painful temporomandibular disorders of muscular origin (M-TMD) with predictable outcomes based on solid evidence is still not well defined. Thus, the aim of this network meta-analysis (NMA) was to identify the best treatment for adult patients with M-TMD. An electronic search was undertaken from the inception of each database to August 2018, to identify randomized clinical trials (RCTs), which are comparing two or more of the following treatment modalities in patients with M-TMD: counseling therapy; occlusal appliances; manual therapy; laser therapy; dry needling; intramuscular injection of local anesthesia (LA) or botulinum toxin-A (BTX-A); muscle relaxants; hypnosis/relaxation therapy; oxidative ozone therapy; and placebo or no treatment. Primary outcome variables were the reduction of pain and mechanical sensitivity. The secondary outcome was the maximal mouth opening (MMO). The quality of evidence was rated according to Cochrane's tool for assessing risk of bias. Standardized mean difference was used to analyze via frequentist network meta-analysis (NMA), using STATA software. 52 RCTs were included in this NMA. At the most follow up moments, manual therapy, counseling therapy, occlusal splints therapy, and needling using BTX-A or LA as well as dry needling significantly decreased post-treatment pain intensity in M-TMDs, when compared to placebo.  At short term (≤5 months), the four highest-ranked treatments for post-treatment pain reduction were manual therapy (83.5%, low quality evidence), ozone therapy (75.7%, very low quality evidence),counseling  therapy (71.2%, moderate quality), and occlusal appliances  (71.7%,moderate quality evidence). When intermediate term (≥6 months)was considered, BTX-A (85.8%, very low quality evidence) , counseling therapy(80%, low quality evidence), occlusal appliances  (62.8%, low quality evidence) and hypnosis (50.6%, very low quality evidence) were the four highest-ranked treatments.  This NMA reveals that manual therapy can be considered the most effective treatment for M-TMD, followed by counseling treatment, intramuscular injection of LA, and occlusal appliances  . However, considering the limitations of the studies included, and the scarce of strong evidence, the present findings should be interpreted cautiously.

Oral behaviors, bruxism, malocclusion and painful temporomandibular joint clicking: is there an association?

The present cross-sectional case-control study aimed to determine if there is an association between specific oral behaviors, sleep bruxism (SB), awake bruxism (AB), and painful temporomandibular joint (TMJ) clicking. Ninety individuals were dived into three groups; Group 1 (n = 30): painful TMJ clicking; Group 2 (n = 30): painless TMJ clicking; and Group 3 (n = 30): control group. The following clinical data were studied: oral behaviors (unilateral chewing, gum chewing, nail biting, foreign objects biting, leaning with jaw against the hand, and sleeping in a position that pressures the jaw), SB, AB (including the frequency in 10 days, evaluated by ecological momentary assessment), and malocclusions investigated based on clinical inspections (anterior open bite, posterior cross-bite, abnormal overbite/overjet, occlusal guidance, mediotrusive and/or laterotrusive interferences, retruded contact position to maximum intercuspation slide, missing posterior teeth). All statistical tests (Kolmogorov-Smirnov, chi-square, and one-way ANOVA) were performed with a 5% significance level. Group 1 had the highest frequency of and a significant association with leaning with jaw in the hand, sleeping position that pressures the jaw, gum chewing, nail biting, and AB (p<0.05). Gum chewing, nail biting, and AB were associated with Group 2 only when compared to Group 3 (p<0.05). No significant difference among groups was found for other behaviors (unilateral chewing and foreign objects biting), SB, and all malocclusions (p>0.05). It can be concluded that patients with painful TMJ clicking had a higher frequency of and a significant association with some specific harmful behaviors and AB.

Association of sleep quality and psychological aspects with reports of bruxism and TMD in Brazilian dentists during the COVID-19 pandemic.

BACKGROUND: Dentists are exposed to contamination by SARS-CoV-2 due to dental interventions, leading to a state of alert and potential risk of negative impact in mental health and sleep quality, associated with Temporomandibular Disorder (TMD) and bruxism. OBJECTIVE: to evaluate the psychosocial status, sleep quality, symptoms of TMD, and bruxism in Brazilian dentists (DSs) during the COVID-19 pandemic. METHODOLOGY: The sample (n=641 DSs) was divided into three groups (quarantined DSs; DSs in outpatient care; and frontline professionals), which answered an electronic form containing the TMD Pain Screening Questionnaire (Diagnostic Criteria for Temporomandibular Disorders - DC/TMD), the Pittsburgh Sleep Quality Index (PSQI), the Depression, Anxiety and Stress Scale (DASS-21), and the sleep and awake bruxism questionnaire. ANOVA test and Mann Whitney post-test were used, with Bonferroni adjustment (p<0.016) and a 95% confidence level. RESULTS: Probable TMD was found in 24.3% (n=156) of the participants, while possible sleep and awake bruxism were diagnosed in 58% (n=372) and 53.8% (n=345) of them, respectively. Among all variables evaluated, only symptoms of depression were significantly greater in the quarantined DSs group when compared to those who were working at the clinical care (p=0.002). Working DSs were significantly less likely (OR=0.630, p=0.001) to have depressive symptoms. Those who were not worried or less worried about the pandemic were less likely to experience stress (OR=0.360), anxiety (OR=0.255), and poor sleep quality (OR=0.256). Sleep had a strong positive and moderate correlation with psychological factors on frontline workers and DSs in outpatient care, respectively. CONCLUSION: The results suggest confinement may have a more negative impact on the life of DSs than the act of being actively working. The concern about Covid-19 and poor sleep quality was significantly prevalent and may negatively affect the quality of life of DSs. Thus, further research on the topic is needed.

Effects of acute mental stress on conditioned pain modulation in temporomandibular disorders patients and healthy individuals.

BACKGROUND: Stress is a contributing factor to painful temporomandibular disorders (TMD). Nevertheless, the underpinnings of this relationship are not fully understood. OBJECTIVE: To investigate the effects of acute mental stress on conditioned pain modulation (CPM) in TMD patients compared with healthy individuals. METHODOLOGY: Twenty women with chronic myofascial TMD diagnosed according to the RDC/TMD and 20 age-matched healthy women had the CPM assessed before and after a stressful task using the Paced Auditory Serial Addition Task (PASAT) in a single session. Subjective stress response was assessed with the aid of visual analog scale (VAS). Pressure pain threshold (PPT) on masseter muscle was the test stimulus (TS) and immersion of the participant's hand on hot water was the conditioning stimulus (CS) - CPM-sequential paradigm. RESULTS: Healthy individuals reported PASAT are more stressful when compared with TMD patients and the stress task did not affect the CPM in neither group. Nonetheless, a negative correlation was observed between change in CPM and change in TS from baseline to post-stress session, which indicates that the greater the increase in PPT after the stress task, the greater was the decrease in CPM magnitude. The correlation was strong for healthy controls (r=- 0.72, p<0.001) and moderate for TMD patients (r=- 0.44, p=0.047). CONCLUSIONS: The correlation between the change in CPM and the TS change following the stress task may possibly indicate an overlapping pathway between stress-induced analgesia/hyperalgesia and descending pain inhibition.

Botulinum toxin type A and acupuncture for masticatory myofascial pain: a randomized clinical trial.

BACKGROUND: BoNT-A has been widely used for TMD therapy. However, the potential benefits compared to dry needling techniques are not clear. OBJECTIVE: this study aimed to compare the immediate effects of botulinum toxin type A (BoNT-A) injections and Acupuncture in myofascial temporomandibular disorders (TMD) patients. METHODOLOGY: 54 women were divided into three groups (n=18). AC patients received four sessions of traditional acupuncture, being one session/week during 20-min. BoNT-A patients were bilaterally injected with 30U and 10U in masseter and anterior temporal muscles, respectively. Moreover, a control group received saline solution (SS) in the same muscles. Self-perceived pain was assessed by visual analog scale, while pressure pain threshold (PPT) was verified by a digital algometer. Electromyographic evaluations (EMG) of anterior temporal and masseter muscles were also measured. All variables were assessed before and 1-month after therapies. The mixed-design two-way repeated measures ANOVA and Tukey's post-hoc tests were used for analysis, considering a=0.05. RESULTS: Self-perceived pain decreased in all groups after one month of therapy (P<.001). BoNT-A was not better than AC in pain reduction (P=0.05), but both therapies were more effective in reducing pain than SS (P<0.05). BoNT-A was the only treatment able to improve PPT values (P<0.05); however, a severe decrease of EMG activity was also found in this group, which is considered an adverse effect. CONCLUSION: after one month of follow-up, all therapies reduced the self-perceived pain in myofascial TMD patients, but only BoNT-A enhanced PPT yet decreased EMG.