Influence of awake bruxism behaviors on fatigue of the masticatory muscles in healthy young adults.

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.

Influence of awake bruxism behaviors on fatigue of the masticatory muscles in healthy young adults

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.

The association of self-reported awake bruxism with anxiety, depression, pain threshold at pressure, pain vigilance, and quality of life in patients undergoing orthodontic treatment.

INTRODUCTION: 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.

The association of self-reported awake bruxism with anxiety, depression, pain threshold at pressure, pain vigilance, and quality of life in patients undergoing orthodontic treatment

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.

Experimental Psychological Stress on Quantitative Sensory Testing Response in Patients with Temporomandibular Disorders.

AIMS: To assess the modulatory effects of experimental psychological stress on the somatosensory evaluation of myofascial temporomandibular disorder (TMD) patients. METHODS: A total of 20 women with myofascial TMD and 20 age-matched healthy women were assessed by means of a standardized battery of quantitative sensory testing. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical pain threshold (MPT), wind-up ratio (WUR), and pressure pain threshold (PPT) were performed on the facial skin overlying the masseter muscle. The variables were measured in three sessions: before (baseline) and immediately after the Paced Auditory Serial Addition Task (PASAT) (stress) and then after a washout period of 20 to 30 minutes (poststress). Mixed analysis of variance (ANOVA) was applied to the data, and the significance level was set at P = .050. RESULTS: A significant main effect of the experimental session on all thermal tests was found (ANOVA: F > 4.10, P < .017), where detection tests presented an increase in thresholds in the poststress session compared to baseline (CDT, P = .012; WDT, P = .040) and pain thresholds were reduced in the stress (CPT, P < .001; HPT, P = .001) and poststress sessions (CPT, P = .005; HPT, P = .006) compared to baseline. In addition, a significant main effect of the study group on all mechanical tests (MPT, WUR, and PPT) was found (ANOVA: F > 4.65, P < .037), where TMD patients were more sensitive than healthy volunteers. CONCLUSION: Acute mental stress conditioning can modulate thermal sensitivity of the skin overlying the masseter in myofascial TMD patients and healthy volunteers. Therefore, psychological stress should be considered in order to perform an unbiased somatosensory assessment of TMD patients.

Collagenous matrix as a predictor for bone formation: a digital technique for collagen quantification

The collagenous matrix plays a fundamental role in the process of bone regeneration, so it is essential to study how it is primarily formed in situations in which critical bone defects are created. Objective: this study seeks to quantify the collagenous matrix formed in critical bone defects in the calvaria of mice over the process of bone regeneration promoted by the association of poly(lactide-co-glycolide) (PLGA) porous scaffolds and stem cells from deciduous teeth (SCDT). In addition, this study attempted to establish a precise protocol for the digital quantification of collagen through a histological method. Materials and method: Nine Wistar rats were used, in which critical defects of 8.0 mm of diameter were made in their calvarium. The animals were divided into three groups (n = 9): I ­ PLGA scaffolds; II ­ PLGA scaffolds/SCDT; III ­ PLGA scaffolds/SCDT maintained in osteogenic medium for 13 days. Within sixty postoperative days, calvaria were removed for histometric analysis following a digital protocol. A specific digital analysis method was designed for this study, in which a more precise quantification and differentiation between collagen fibers and non-collagenous tissue was possible, excluding factors that would normally alter the results. Results: it was noted that the association of PLGA scaffolds and SCDT maintained in osteogenic medium resulted in collagen matrix formation statistically higher than the other groups (p<0.05). Conclusion: the protocol designed for collagen quantification was precise and efficient, producing methodologically standardized results.

Determination of normative values for mechanical quantitative sensory tests in the orofacial region / Determinação de valores normativos para testes quantitativos sensoriais mecânicos na região orofacial

Um novo conceito de tratamento de síndromes dolorosas baseada em mecanismos de dor é baseado na hipótese de que diferentes sinais clínicos refletem alterações em diversos mecanismos de geração de dor. Para analisar estes mecanismos, em 2006, o DFNS (German Research Network on Neuropathic Pain) criou um protocolo padronizado de testes quantitativos sensoriais (QST) para uma avaliação quantitativa de mecanismos de geração de dor, criando valores de referência para mão, pé e face (músculo masseter). No entanto, ainda há falta de valores de referência para alguns testes quantitativos em diversas importantes regiões orofaciais como o músculo temporal anterior e a mucosa oral. Este estudo buscou determinar valores normativos dos QSTs nessas regiões e avaliou a eficácia de um estímulo condicionante (CPM) na percepção da dor por meio de dois estímulos teste (PPT e MPT). 60 sujeitos saudáveis (30 homens/30 mulheres) foram examinados com os testes de sensibilidade tátil (MDT), limiar de dor mecânico (MPT), somação temporal (WUR), limiar de dor à pressão (PPT) e condicionamento modulatório da dor (CPM), afim de determinar valores normativos na população. Os pacientes foram examinados em sessão única por um único examinador treinado sob o protocolo desenvolvido pelo DFNS. Para avaliação estatística dos dados da CPM uma análise de variância (ANOVA) foi utilizada comparando os fatores sítio (2 níveis), tempo (2 níveis) e sexo (2 níveis) entre os dois estímulos teste (MPT e PPT). Os valores de referência para QST foram comparados por uma ANOVA multi-vias considerando os fatores sítio (3 níveis), lado (2 níveis), e sexo (2 níveis) (α=5%). MDT e MPT mostraram efeitos principais de sítio (p<0,001), em que a mucosa apresentou os maiores limiares para MDT e menos limiares para MPT, quando comparada à mão e temporal anterior. PPT demonstrou efeitos principais de sítio e sexo. Limiares de dor à pressão do músculo temporal foram menores comparados com a mão (p<0,001) e homens apresentaram maiores limiares que as mulheres em todos os sítios. O teste WUR não apresentou nenhum efeito de sexo, sítio ou lado examinado. Os dois estímulos teste da CPM (MPT e PPT) foram capazes de produzir maiores limiares quando comparados aos estímulos não condicionados (p<0,001). Um maior número significativo de sujeitos respondeu positivamente a estimulação CPM no músculo temporal (p=0,002) para ambos estímulos teste. O estudo concluiu que o perfil sensorial avaliados por meio de QSTs pode ser influenciado pela região de exame e sexo. O efeito da CPM foi igualmente positivo para ambos estímulos teste. No entanto, seu grau de resposta depende da região avaliada.(AU)

Modern concepts for the treatment of pain patients are based on the hypothesis that different clinical signs and symptoms reflect different underlying pathophysiological mechanisms of pain generation. To analyze these mechanisms, in 2006, the DFNS (German Research Network on Neuropathic Pain) developed a standardized protocol of quantitative sensory testing (QST) for a quantitative evaluation of pain generating mechanisms, creating reference values for hand, foot and face (masseter muscle) sites. However, there is a lack of orofacial reference values for the temporalis muscle and maxillary gingiva. This study aimed to determine reference values for QST protocol in the orofacial region and evaluate the effectiveness of two test stimuli during conditioned pain modulation (CPM) test. Sixty participants (30 men/30 women) were examined through the tests of mechanical detection (MDT), mechanical pain (MPT), wind-up ratio (WUR), pressure pain threshold (PPT) and conditioned pain modulation (CPM), to determine reference values in healthy subjects. Individuals were examined in a single session by a trained examiner under the protocol developed by the DFNS (2006). The CPM statistical evaluation was done by a multi-way analysis of variance (ANOVA) within the factors site (2 levels), time (2 levels), and sex (2 levels); comparing the absolute values of MPT and PPT. QST reference values comparison was made by a multi-way withinsubjects ANOVA performed considering the factors site (3 levels), side (2 levels) and sex (2 levels) (α=5%). MDT and MPT showed main effects of site (p<0.001), where the maxillary gingiva presented the highest thresholds for MDT and lowest MPT thresholds. In addition, PPT values of the anterior temporalis were lower than the hand (p<0.001). PPT (p<0.001) showed main effects of sex, where men presented higher thresholds. WUR did not show any main effects of sex, site or side. Both CPM test-stimulus (PPT and MPT) were capable of producing significantly higher thresholds during conditioning stimulus when compared to baseline thresholds (p<0.001). Temporalis CPM respondents were significantly higher (p=0.002) than hand respondents for both QSTs. The study concluded that orofacial QST profile of healthy participants could be influenced by the test site and sex. The CPM does not differ considering PPT and MPT as test stimuli, but the test site can influence its effects.(AU)