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.

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.

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.

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.

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

Abstract 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.

Evaluation of the influence of experimental psychological stress on the quantitative sensory testing response in temporomandibular disorders patients / Avaliação da influência de estresse psicológico experimental na resposta de testes sensoriais quantitativos em pacientes com disfunção temporomandibular

Background: Quantitative sensory testing (QST) is a promising method for assessing the mechanisms that contribute to the development and maintenance of painful Temporomandibular Disorders (TMD). All QST responses rely on the participant´s perception; therefore a number of cognitive and psychological factors are known to directly influence results, including psychological stress. Aims: To assess the effects of experimental psychological stress on QST response in TMD patients and healthy volunteers. Methods: 20 women with myofascial TMD and 20 healthy women underwent a standardized QST protocol, including cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical pain threshold (MPT), pressure pain threshold (PPT) and wind up ratio (WUR) at the masseter muscle. QST was conducted before and after to the Paced Auditory Serial Addition Task (PASAT), inducing acute psychological stress. ANOVA with repeated measures was performed to assess the effect of group and time on the reported stress and absolute values of QST. The significance level was set at 5% (p=0.050). Furthermore, Z-score profiles were generated. Results: The PASAT induced a significant stress reaction (p<0.001). After exposure to experimental stress, both healthy volunteers and TMD patients showed increase in thermal detection threshold (CDT: F=4.25, p=0.017 and WDT: F=4.10, p=0.020) and decrease in thermal pain threshold (CPT: F=11.2, p<0.001 and HPT: F=8.13, p<0.001) when compared to baseline. However, stress did not induce significant changes in MPT, PPT or WUR in both groups (p>0.050). Conclusion: The experimental psychological stress induces thermal hypoesthesia and thermal hyperalgesia on masticatory muscle, regardless of the presence of TMD painful. Overall, these findings emphasize the importance of considering the psychological stress when judging QST findings.(AU)

Contextualização: Teste sensorial quantitativo (QST) é um método promissor para avaliar os mecanismos que contribuem para o desenvolvimento e manutenção das Disfunções Temporomandibulares (DTM) dolorosas. As respostas de QST dependem da percepção do participante; portanto, uma série de fatores cognitivos e psicológicos, como o estresse, podem influenciar os resultados. Objetivo: Avaliar a influência do estresse psicológico experimental na resposta de QST em pacientes com DTM e voluntários saudáveis. Métodos: 20 mulheres com DTM (Dor Miofascial) e 20 mulheres saudáveis foram submetidas a um protocolo padronizado de QST, incluindo limiar de detecção ao frio (CDT), limiar de detecção ao calor (WDT), limiar de dor ao frio (CPT), limiar de dor ao calor (HPT), limiar de dor mecânica (MPT), limiar de dor a pressão (PPT) e somação temporal de dor (WUR) na região de masseter. QST foi realizado antes e após teste de estresse psicológico laboratorial denominado Paced Auditory Serial Addition Task (PASAT). ANOVA foi realizada para avaliar o efeito de grupo e tempo sobre o estresse relatado e valores de QST a um nível de significância de 5% (p = 0,050). Ademais, perfis Z-score foram gerados. Resultados: PASAT induziu aumento significativo no relato de estresse (p <0,001). Após exposição ao estresse experimental, ambos os grupos apresentaram aumento nos limiares de detecção térmicos (CDT: F = 4,25, p = 0,017 e WDT: F = 4,10, p = 0,020) e redução dos limiares de dor térmicos (CPT: F= 11,2, p <0,001 e HPT: F = 8,13, p <0,001) quando comparados com valores iniciais. Entretanto, o estresse não induziu mudanças significativas em MPT, PPT ou WUR (p> 0,050). Conclusão: O estresse psicológico experimental induz hipoestesia térmica e hiperalgesia térmica na musculatura mastigatória independente da presença de DTM dolorosa. Esses achados enfatizam a importância de considerar o estresse psicológico do particpante ao interpretar os resultados de QST.(AU)

Desinfecção do sistema de água de equipamentos odontológicos com clorexidina / Disinfection of dental unit waterline with chlorexidine

Introdução: A água utilizada em procedimentos odontológicos pode apresentar- se contaminada, sendo fonte de infecção para profissionais e pacientes. Objetivo: Comparar a efetividade da clorexidina 0,1% e do hipoclorito de sódio 1% na desinfecção do sistema de água de equipamentos odontológicos. Método: Três equipamentos odontológicos sofreram desinfecção com clorexidina; e três, com hipoclorito de sódio mediante acionamento da seringa tríplice durante dois minutos. Amostras de água coletadas antes, após a desinfecção e no final do dia foram analisadas microbiologicamente. Amostras do filtro de abastecimento também foram analisadas. Resultados: As amostras coletadas antes da desinfecção mostraram altos níveis de contaminação (>500 UFC/ml). Após emprego dos desinfetantes, estas apresentaram-se nos padrões recomendados pela American Dental Association – ADA (<200 UFC/ml). A água do filtro de abastecimento também estava dentro dos limites estabelecidos pela ADA. Conclusão: Clorexidina 0,1% mostrou-se tão efetiva quanto hipoclorito de sódio 1% na desinfecção do sistema de água de equipamentos odontológicos.

Introduction: The water used in dental procedures may be contaminated and source of infection for patients and dental staff. Objective: The aim of this study was to compare the effectiveness chlorhexidine 0.1% and sodium hypochlorite 1% in the disinfection of dental unit waterline. Method: Three dental units were disinfection with chlorhexidine and three with sodium hypochlorite by flushing the triple syringe for two minutes. Water samples collected before and after disinfection and in the end of the day were analyzed microbiologically. Samples of the supply filter were also analyzed. Results: Samples collected before disinfection showed high levels of contamination (> 500 CFU / ml). After use of disinfectants, the samples were within the recommended standards by the American Dental Association – ADA (< 200 CFU / ml). The water supply filter was also within the limits established by the ADA. Conclusion: Chlorhexidine 0.1% was effective as sodium hypochlorite 1 % for the disinfection of dental unit waterlines.

Avaliação da eficácia da clorexidina na desinfecção do sistema de água odontológica / Chlorhexidine efficacies evaluation on disinfection of dental unit waterline

Introdução: A água utilizada nos procedimentos odontológicos apresenta-se contaminada e pode causar infecção cruzada. Objetivos: Neste estudo, investigou-se a qualidade da água de equipos odontológicos e a ação de diferentes concentrações de clorexidina na redução da contaminação. Métodos: Os parâmetros de contaminação utilizados foram o da American Dental Association e do Ministério da Saúde. Realizou-se análise bacteriológica em amostras de água de 17 seringas tríplices para verificar a qualidade microbiológica da água tratada ou não com clorexidina in vitro. Testaram-se concentrações de clorexidina 0,4%; 0,2%; 0,1%. Utilizou-se clinicamente clorexidina 0,1% na desinfecção do sistema de água por um minuto em 13 equipos e realizou-se nova análise bacteriológica da água. Resultados: Todos os grupos-controles apresentaram níveis elevados de contaminação, 100% dos grupos tratados in vitro com clorexidina e dos equipos que sofreram desinfecção com clorexidina 0,1% apresentaram-se descontaminados. Conclusão: Clorexidina 0,1% foi efetiva na redução da contaminação da água odontológica.

Introduction: The water used in dental procedures is contaminated and can cause crossed infection. Objective: This study investigates the quality of water on dental units and the action of different concentrations of chlorhexidine in the reduction of this contamination. Method: The contamination parameters used were the American Dental Association and the Brazilian Health State Department. It was executed a bacteriological analysis of water samples from 17 air-water syringes to verify the microbiological quality of water treated or not with chlorhexidine in vitro. It was examined concentrations of 0.4%; 0.2%; 0.1%. One percent chlorhexidine was used, clinically, in disinfection of dental unit waterline for one minute in 13 dental units and a new bacteriological analysis of water was made. Results: All control groups showed high levels of contamination, 100% of groups with chlorhexidine in vitro and all dental units who suffered disinfection with 0.1% chlorhexidine were free of contamination. Conclusion: One percent chlorhexidine was effective in reducing contamination of the dental water.