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.

Abstract The present cross-sectional study aimed to analyze the relationship between awake bruxism and fatigue of masticatory muscles in healthy young adults. For this purpose, 121 graduate students participated in this study. Frequency of awake bruxism was collected for 7 consecutive days by ecological momentary assessment (EMA) using an online survey (mentimeter). Muscle fatigue was tested one day after EMA assessment, which consisted of voluntarily and continuously clenching at 30% (kgf/cm2) of maximum bite force (MBF) until exhaustion. The percentage of change in MBF after the clenching task, as compared to the MBF before the clenching task was measured. The average frequency of awake bruxism was 45.5% during 7 days. Sustained clenching resulted in a significant reduction in MBF values in the total sample (p < 0.05). Nevertheless, no significant correlation was found between frequency of awake bruxism behaviors and percent of change in MBF and endurance time during the fatigue test. Therefore, it can be concluded that young healthy adults present a relatively high frequency of awake bruxism behaviors that do not seem to impact the degree of masticatory muscle fatigue.

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.

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.

Abstract This study aimed to evaluate whether the presence of awake bruxism was associated with temporomandibular dysfunction symptoms, pain threshold at pressure, pain vigilance, oral health-related quality of life (OHRQoL), and anxiety and depression symptoms in patients undergoing orthodontic treatment. Methodology This observational study followed patients who had started receiving orthodontic treatment for six months. The following variables were measured three times (at baseline, one month, and six months): pressure pain threshold (PPT) in the right and left masseter, anterior temporalis, and temporomandibular joint (TMJ), and right forearm; pain vigilance and awareness questionnaire; and shortened form of the oral health impact profile (OHIP-14). Anxiety and depression symptoms were measured using the Beck anxiety inventory and the Beck depression inventory, respectively. The patients were divided into two main groups according to the presence (n=56) and absence (n=58) of possible awake bruxism. The multi-way analysis of variance (ANOVA) was applied on the date (p=0.050). Results TMJ and/or muscle pain were not observed in both groups. Time, sex, age group, and awake bruxism did not affect the PPT in the masticatory muscles and pain vigilance (p>0.050). However, the primary effect of awake bruxism was observed when anxiety (ANOVA: F=8.61, p=0.004) and depression (ANOVA: F=6.48, p=0.012) levels were higher and the OHRQoL was lower (ANOVA: F=8.61, p=0.004). Conclusion The patients with self-reported awake bruxism undergoing an orthodontic treatment did not develop TMJ/masticatory muscle pain. The self-reported awake bruxism is associated with higher anxiety and depression levels and a poorer OHRQoL in patients during the orthodontic treatment.

Abstract Disc displacement with reduction (DDWR) is one of the most common intra-articular disorders of the temporomandibular joint (TMJ). Factors related to the etiology, progression and treatment of such condition is still a subject of discussion. This literature review aimed to address etiology, development, related factors, diagnosis, natural course, and treatment of DDWR. A non-systematic search was conducted within PubMed, Scopus, SciELO, Medline, LILACS and Science Direct using the Medical Subjective Headings (MeSH) terms “temporomandibular disorders”, “temporomandibular joint”, “disc displacement” and “disc displacement with reduction”. No time restriction was applied. Literature reviews, systematic reviews, meta-analysis and clinical trials were included. DDWR is usually asymptomatic and requires no treatment, since the TMJ structures adapt very well and painlessly to different disc positions. Yet, long-term studies have shown the favorable progression of this condition, with no pain and/or jaw locking occurring in most of the patients.

Abstract Studies to assess the effects of therapies on pain and masticatory muscle function are scarce. Objective To investigate the short-term effect of transcutaneous electrical nerve stimulation (TENS) by examining pain intensity, pressure pain threshold (PPT) and electromyography (EMG) activity in patients with temporomandibular disorder (TMD). Material and Methods Forty patients with myofascial TMD were enrolled in this randomized placebo-controlled trial and were divided into two groups: active (n=20) and placebo (n=20) TENS. Outcome variables assessed at baseline (T0), immediately after (T2) and 48 hours after treatment (T1) were: pain intensity with the aid of a visual analogue scale (VAS); PPT of masticatory and cervical structures; EMG activity during mandibular rest position (MR), maximal voluntary contraction (MVC) and habitual chewing (HC). Two-way ANOVA for repeated measures was applied to the data and the significance level was set at 5%. Results There was a decrease in the VAS values at T1 and T2 when compared with T0 values in the active TENS group (p<0.050). The PPT between-group differences were significant at T1 assessment of the anterior temporalis and sternocleidomastoid (SCM) and T2 for the masseter and the SCM (p<0.050). A significant EMG activity reduction of the masseter and anterior temporalis was presented in the active TENS during MR at T1 assessment when compared with T0 (p<0.050). The EMG activity of the anterior temporalis was significantly higher in the active TENS during MVC at T1 and T2 when compared with placebo (p<0.050). The EMG activity of the masseter and anterior temporalis muscle was significantly higher in the active TENS during HC at T1 when compared with placebo (p<0.050). Conclusions The short-term therapeutic effects of TENS are superior to those of the placebo, because of reported facial pain, deep pain sensitivity and masticatory muscle EMG activity improvement.

ABSTRACT Low pressure Pain Threshold (PPT) is considered a risk factor for Temporomandibular Disorders (TMD) and is influenced by psychological variables. Objectives To correlate deep pain sensitivity of masticatory muscles with prosthetic factors and Oral-Health-Related Quality of Life (OHRQoL) in completely edentulous subjects. Material and Methods A total of 29 complete denture wearers were recruited. The variables were: a) Pressure Pain Threshold (PPT) of the masseter and temporalis; b) retention, stability, and tooth wear of dentures; c) Vertical Dimension of Occlusion (VDO); d) Oral Health Impact Profile (OHIP) adapted to orofacial pain. The Kolmogorov-Smirnov test, the Pearson Product-Moment correlation coefficient, the Spearman Rank correlation coefficient, the Point-Biserial correlation coefficient, and the Bonferroni correction (α=1%) were applied to the data. Results The mean age (standard deviation) of the participants was of 70.1 years (9.5) and 82% of them were females. There were no significant correlations with prosthetic factors, but significant negative correlations were found between the OHIP and the PPT of the anterior temporalis (r=-0.50, 95% CI-0.73 to 0.17, p=0.005). Discussion The deep pain sensitivity of masticatory muscles in complete dentures wearers is associated with OHRQoL, but not with prosthetic factors.

OBJECTIVES:This cross-sectional study aimed to evaluate the influence of Primary Headache (PH) on efficacy of a Temporomandibular Disorders (TMD) conservative therapy and its association with the presence of self-reported parafunctional habits.SAMPLE AND METHODS:Sample was composed of 400 medical records, divided into four groups: I) Muscular TMD (n=64); II) Muscular TMD+PH (n=48); III) Muscular TMD+Articular TMD (n=173); IV) Muscular TMD+Articular TMD+PH (n=115). All groups had undergone a TMD therapy for three months with a stabilization appliance and counseling for habits and behavioral changes, with no specific headache management. Current pain intensity and existence or not of self-reported bruxism were assessed. Repeated measures ANOVA and Chi-Square test followed by Odds were used for statistical analysis, with a significance level of 5%.RESULTS:results of this study showed that: (1) A conservative therapy with stabilization appliance and counseling for habits and behavioral changes was effective in the TMD pain relief; (2) Groups with an additional diagnosis of PH had worsened the pain improvement significantly; and (3) no association between the presence of self-reported bruxism and PH was found.CONCLUSIONS:this study could elucidate the important effect that headache may have on the TMD management.

JUSTIFICATIVA E OBJETIVOS: Na grande maioria dos casos, o tratamento das disfunções temporomandibulares deve ser um processo não invasivo, interdisciplinar e integrativo. Dentro da medicina tradicional chinesa, a acupuntura é uma ótima ferramenta que visa a terapia e cura dessas doenças. O objetivo deste estudo foi conduzir uma revisão crítica da literatura para verificar a eficácia da acupuntura tradicional chinesa no tratamento da disfunção temporomandibular do tipo muscular, bem como identificar os principais acupontos. CONTEÚDO: Foi realizada uma pesquisa nas bases de dados Pubmed, LILACS, Scielo e Cochrane para identificar artigos científicos relevantes para o estudo. Os artigos foram selecionados no período de janeiro de 2000 a maio de 2013. Encontrou-se um total de 125 artigos, sendo que 21 foram incluídos. O tratamento de acupuntura isolado ou como terapia complementar, ou ainda comparado com outras técnicas, se mostrou superior e eficiente na melhora da dor e da função de pacientes com disfunção temporomandibular, e os pontos de acupuntura mais citados foram IG4, E6, E7 e F3. CONCLUSÃO: Este estudo demonstrou que a acupuntura é uma técnica recomendada pela literatura nacional e internacional para o tratamento de disfunções temporomandibulares de origem muscular, promovendo alivio e/ou redução total da intensidade dolorosa, melhora nos movimentos mandibulares e na função oral e diminuição da hiperatividade muscular dos músculos da mastigação.

BACKGROUND AND OBJECTIVES: For most cases, temporomandibular disorders should be treated by a non-invasive, interdisciplinary and integrative process. In traditional Chinese medicine, acupuncture is an excellent tool aiming at treating and healing this disease. This study was a critical literature review to observe the efficacy of traditional Chinese acupuncture to treat muscular temporomandibular disorders and to identify primary acupoints. CONTENTS: Pubmed, LILACS, Scielo and Cochrane databases were queried to identify scientific articles relevant for the study. Articles were selected from January 2000 to May 2013. A total of 125 articles were found and 21 were included. Acupuncture treatment alone or as additional therapy, or even compared to other techniques, was superior and effective to improve pain and function of patients with temporomandibular disorders and most commonly used acupoints were IG4, E6, E7 and F3. CONCLUSION: This study has shown that acupuncture is a technique recommended by national and international literature to treat muscular temporomandibular disorders, promoting pain relief and/or total intensity, improvement of joint movements and oral function and decrease of masticatory muscles hyperactivity.

A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO) patients. The computerized search included the main databases (MEDLINE, EMBASE, and Cochrane Library). The studies included used the following quantitative sensory testing (QST) methods: mechanical detection threshold (MDT), mechanical pain threshold (MPT) (pinprick), pressure pain threshold (PPT), dynamic mechanical allodynia with a cotton swab (DMA1) or a brush (DMA2), warm detection threshold (WDT), cold detection threshold (CDT), heat pain threshold (HPT), cold pain detection (CPT), and/or wind-up ratio (WUR). The publications meeting the inclusion criteria revealed that only mechanical allodynia tests (DMA1, DMA2, and WUR) were significantly higher and pain threshold tests to heat stimulation (HPT) were significantly lower in the affected side, compared with the contralateral side, in AO patients; however, for MDT, MPT, PPT, CDT, and WDT, the results were not significant. These data support the presence of central sensitization features, such as allodynia and temporal summation. In contrast, considerable inconsistencies between studies were found when AO patients were compared with healthy subjects. In clinical settings, the most reliable evaluation method for AO in patients with persistent idiopathic facial pain would be intraindividual assessments using HPT or mechanical allodynia tests.

Um grande número de distúrbios pode provocar limitação no grau de abertura bucal. As condições mais comuns relacionadas com esse problema são aquelas que envolvem a articulação temporomandibular (ATM) e músculos mastigatórios, em que, além da limitação, a dor facial é um achado comum. Distúrbios congênitos ou de desenvolvimento da mandíbula também são possíveis causas para limitação de abertura bucal, embora possuam uma baixa prevalência. A hiperplasia do processo coronóide (HPC) é um exemplo dessas causas, caracterizada por um desenvolvimento excessivo do processo coronóide, em que o movimento mandibular torna-se limitado pela impacção dessa mesma estrutura na parte posterior do osso zigomático. Esta condição é rara, indolor, geralmente bilateral e progressiva, afetando principalmente homens. O diagnóstico de HPC é feito por meio dos sinais clínicos de abertura bucal limitada associado com exames de imagem, especialmente a radiografia panorâmica e tomografia computadorizada (TC). O tratamento é exclusivamente cirúrgico. O objetivo desse artigo é apresentar um caso de paciente do sexo masculino com hiperplasia bilateral do processo coronóide, inicialmente diagnosticado com deslocamento de disco sem redução bilateral, e tratado com sucesso com coronoidectomia intraoral. Assim, é enfatizada a importância do diagnóstico diferencial para um correto diagnóstico e, consequentemente, estratégias efetivas de tratamento.

A large number of disorders affecting the masticatory system can cause restriction of mouth opening. The most common conditions related to this problem are those involving the temporomandibular joint (TMJ) and the masticatory muscles, when facial pain also is an usual finding. Congenital or developmental mandibular disorders are also possible causes for mouth opening limitation, although in a very small prevalence. Coronoid process hyperplasia (CPH) is an example of these cases, characterized by an excessive coronoid process growing, where mandibular movements become limited by the impaction of this structure on the posterior portion of the zygomatic bone. This condition is rare, painless, usually bilateral and progressive, affecting mainly men. Diagnosis of CPH is made based on clinical signs of mouth opening limitation together with imaging exams, especially panoramic radiography and computerized tomography (CT). Treatment is exclusively surgical. This paper presents a case of a male patient with bilateral coronoid process hyperplasia, initially diagnosed with bilateral disk displacement without reduction, and successfully treated with intraoral coronoidectomy. It is emphasized the importance of differential diagnosis for a correct diagnosis and, consequently, effective management strategy.