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.

Preoperative anxiety induces chronic postoperative pain by activating astrocytes in the anterior cingulate cortex region

SUMMARY OBJECTIVE The study aims to explore the relationship between preoperative anxiety and chronic postoperative pain. METHODS A total of forty rats were divided into four groups, control, single-prolonged stress alone, Hysterectomy alone, and SPS+ Hysterectomy. The paw withdrawal mechanical thresholds (PWMT) were examined. qRT-PCR and western blotting assay were performed to detect the GFAP expression in astrocytes isolated from the anterior cingulate cortex (ACC) region. In addition, the long-term potentiation (LTP) in ACC was examined. RESULTS Rats in the SPS group or the Hysterectomy alone group had no significant effect on chronic pain formation, but SPS can significantly induce chronic pain after surgery. Astrocytes were still active, and the LTP was significantly increased three days after modeling in the SPS+Hysterectomy group. CONCLUSIONS anxiety can induce chronic pain by activating astrocytes in the ACC region.

RESUMO OBJETIVO O objetivo deste estudo é explorar a relação entre a ansiedade no pré-operatório e a dor crônica no pós-operatório. MÉTODOS Um total de 40 ratos foram divididos em quatro grupos: controle, estresse prolongado (SPS), histerectomia e SPS + histerectomia. Os limiares de retirada da pata em resposta a estímulo mecânico (PWMT) foram examinados. Ensaios qRT-PCR e imunoenzimáticos (western blotting) foram realizados para detectar a expressão de GFAP em astrócitos isolados da região do córtex cingulado anterior (CCA). Além disso, a potenciação de longa duração (LTP) no CCA também foi examinada. RESULTADOS Os ratos no grupo de estresse prolongado e no grupo de histerectomia não apresentaram nenhum efeito significativo na formação de dor crônica. Porém, o estresse prolongado foi capaz de induzir dor crônica significativamente após a cirurgia. Três dias após o modelo, o grupo de SPS + histerectomia ainda apresentava astrócitos ativos e LTP significativamente maior. CONCLUSÃO A ansiedade pode provocar dor crônica através da ativação de astrócitos na região do CCA.

Identification of key genes and pathways involved in response to pain in goat and sheep by transcriptome sequencing

PURPOSE: This aim of this study was to investigate the key genes and pathways involved in the response to pain in goat and sheep by transcriptome sequencing. METHODS: Chronic pain was induced with the injection of the complete Freund's adjuvant (CFA) in sheep and goats. The animals were divided into four groups: CFA-treated sheep, control sheep, CFA-treated goat, and control goat groups (n = 3 in each group). The dorsal root ganglions of these animals were isolated and used for the construction of a cDNA library and transcriptome sequencing. Differentially expressed genes (DEGs) were identified in CFA-induced sheep and goats and gene ontology (GO) enrichment analysis was performed. RESULTS: In total, 1748 and 2441 DEGs were identified in CFA-treated goat and sheep, respectively. The DEGs identified in CFA-treated goats, such as C-C motif chemokine ligand 27 (CCL27), glutamate receptor 2 (GRIA2), and sodium voltage-gated channel alpha subunit 3 (SCN3A), were mainly enriched in GO functions associated with N-methyl-D-aspartate (NMDA) receptor, inflammatory response, and immune response. The DEGs identified in CFA-treated sheep, such as gamma-aminobutyric acid (GABA)-related DEGs (gamma-aminobutyric acid type A receptor gamma 3 subunit [GABRG3], GABRB2, and GABRB1), SCN9A, and transient receptor potential cation channel subfamily V member 1 (TRPV1), were mainly enriched in GO functions related to neuroactive ligand-receptor interaction, NMDA receptor, and defense response. CONCLUSIONS: Our data indicate that NMDA receptor, inflammatory response, and immune response as well as key DEGs such as CCL27, GRIA2, and SCN3A may regulate the process of pain response during chronic pain in goats. Neuroactive ligand-receptor interaction and NMDA receptor as well as GABA-related DEGs, SCN9A, and TRPV1 may modulate the process of response to pain in sheep. These DEGs may serve as drug targets for preventing chronic pain.

Secondary hyperalgesia occurs regardless of unilateral or bilateral knee osteoarthritis involvement in individuals with mild or moderate level / A hiperalgesia secundária ocorre independentemente do envolvimento unilateral ou bilateral da osteoartrite de joelho em indivíduos com doença leve ou moderada

ABSTRACT Background: Secondary hyperalgesia in individuals with less severe levels of knee osteoarthritis remains unclear. The objective of this study was to measure the pressure pain threshold of individuals with mild or moderate knee osteoarthritis and compare with no osteoarthritis. Methods: Ten healthy controls and 30 individuals with mild or moderate knee osteoarthritis divided into two groups (unilateral and bilateral involvement) were included. Dermatomes in lumbar levels (L1, L2, L3, L4 and L5) and sacral level (S1 and S2), myotomes (vastus medialis, vastus lateralis, rectus femoris, adductor longus, tibialis anterior, peroneus longus, iliacus, quadratus lumborum, and popliteus muscles), and sclerotomes in lumbar levels (L1-L2, L2-L3, L3-L4, L4-L5 supraspinous ligaments), over the L5-S1 and S1-S2 sacral areas, pes anserinus bursae, and at the patellar tendon pressure pain threshold were assessed and compared between individuals with and without knee osteoarthritis. Results: Knee osteoarthritis groups (unilateral and bilateral) reported lower pressure pain threshold compared to the control group in most areas (dermatomes, myotomes, and sclerotomes). There were no between group differences in the supra-spinous ligaments and over the L5-S1 and S1-S2 sacral areas of the sclerotomes. No difference was seen between knee osteoarthritis. Conclusion: These findings suggest that individuals with mild to moderate knee osteoarthritis had primary and secondary hyperalgesia, independent of unilateral or bilateral involvement. These results suggest that the pain have to be an assertive focus in the clinical practice, independent of the level of severity or involvement of knee osteoarthritis.

RESUMO Introdução: A ocorrência de hiperalgesia secundária em indivíduos com níveis menos graves de osteoartrite de joelho ainda é incerta. O objetivo deste estudo foi medir o limiar de dor à pressão (LDP) de indivíduos com osteoartrite de joelho (OAJ) leve ou moderada e comparar com indivíduos sem osteoartrite. Métodos: Foram incluídos 10 controles saudáveis e 30 indivíduos com OAJ leve ou moderada, divididos em dois grupos (envolvimento unilateral e bilateral). Foi avaliado e comparado o LDP em dermátomos (L1, L2, L3, L4, L5, S1 e S2), miótomos (músculos vasto medial, vasto lateral, reto femoral, adutor longo, tibial anterior, fibular longo, ilíaco, quadrado lombar e poplíteo) e esclerótomos (ligamentos supraespinais L1-L2, L2-L3, L3-L4, L4-L5), sobre as áreas sacrais L5-S1 e S1-S2, bolsa anserina e tendão patelar entre os indivíduos com e sem OAJ. Resultados: Os grupos OAJ (unilateral e bilateral) relataram menor LDP em comparação com o grupo controle na maior parte das áreas (dermátomos, miótomos e esclerótomos). Não houve diferenças entre os grupos nos ligamentos supraespinais e ao longo das áreas sacrais L5-S1 e S1-S2 dos esclerótomos. Não foi observada qualquer diferença entre os indivíduos com OAJ. Conclusão: Esses achados sugerem que os indivíduos com OAJ leve a moderada tinham hiperalgesia primária e secundária, independentemente do acometimento unilateral ou bilateral. Esses resultados sugerem que a dor precisa ser um foco assertivo na prática clínica, independentemente do grau de gravidade ou envolvimento da OAJ.

Cerebrospinal fluid-contacting nucleus mediates nociception via release of fractalkine

Increasing evidence suggests that the cerebrospinal fluid-contacting nucleus (CSF-contacting nucleus) mediates the transduction and regulation of pain signals. However, the precise molecular mechanisms remain unclear. Studies show that release of fractalkine (FKN) from neurons plays a critical role in nerve injury-related pain. We tested the hypothesis that release of FKN from the CSF-contacting nucleus regulates neuropathic pain, in a chronic constriction injury rat model. The results show that FKN is expressed by neurons, via expression of its only receptor CX3CR1 in the microglia. The levels of soluble FKN (sFKN) were markedly upregulated along with the increase in FKN mRNA level in rats subjected to chronic constriction injury. In addition, injection of FKN-neutralizing antibody into the lateral ventricle alleviated neuropathic pain-related behavior followed by reduction in microglial activation in the CSF-contacting nucleus. The results indicate that inhibition of FKN release by the CSF-contacting nucleus may ameliorate neuropathic pain clinically.

Avaliação dos efeitos do tratamento ortodôntico sobre limiares de dor, hábitos orais parafuncionais e qualidade de vida / Evaluation of orthodontic treatment effects on pain thresholds, parafunctional oral habits and quality of life

O objetivo dessa tese foi avaliar alguns desses fatores, verificar a influência da ortodontia sobre alterações oclusais, limiares de dor à pressão da região orofacial, hábitos orais parafuncionais, e percepção de qualidade de vida. Foram selecionados 111 pacientes com idade entre 13 e 55 anos e ausência de sintomas de DTM que iniciaram terapia ortodôntica corretiva. O experimento foi dividido em três etapas: t1 (no momento da instalação do aparelho), t2 (2 meses após o início do tratamento), e t3 (6 meses após o início do tratamento). Em todas etapas os pacientes foram examinados clinicamente para avaliação oclusal e seus limiares de dor à pressão foram avaliados com um algômetro digital. Também foram aplicados questionários sobre hábitos orais parafuncionais (OBC) e percepção de saúde oral na qualidade de vida (OHIP-14br). Foram feitas comparações a respeito de cada variável quantitativa considerando os três tempos de avaliação por meio de Análise de variância (ANOVA) a um critério. O teste t foi utilizado para avaliar diferenças entre as médias das variáveis quantitativas no tempo inicial (t1) e tempo final (t3) de avaliação. Para avaliar o efeito da ortodontia sobre variáveis qualitativas oclusais foi utilizado o teste exato de Fisher. Foram considerados estatisticamente significantes aqueles resultados que apresentaram nível de significância igual ou menor que 0,05. Nenhum dos 111 pacientes desenvolveram sintomas de DTM até o momento final de avaliação. Não foram observadas mudanças oclusais quantitativas significativas (p>0,05) entre t1 e t3, no entanto os fatores qualitativos como mudanças nos padrões oclusais foram alterados significativamente (p<0,05). O tratamento ortodôntico não alterou os limiares de dor à pressão, mas foi observado um aumento significativo (p<0,05) nos escores de OHIP entre os períodos t1 e t3. O tratamento ortodôntico também não aumentou ou diminuiu a presença de hábitos orais parafuncionais, e não foram encontradas diferenças entre sexo e Limear de Dor a Pressão (LDP) nos indivíduos que possuíam mais ou menos hábitos. No entanto, pacientes mais velhos relataram maiores escores de OBC, e foi encontrada correlação entre pacientes com maiores escores de OBC e menores escores para o OHIP. O estudo concluiu que a movimentação ortodôntica não teve efeito sobre limiares de dor na região orofacial e não influencia na presença de hábitos orais parafuncionais. No entanto, o tratamento ortodôntico teve um efeito positivo sobre a percepção de saúde oral na qualidade de vida.(AU)

The aim of this thesis was to evaluate some of these factors, examining the influence of orthodontics on occlusal changes, pain pressure thresholds of the orofacial region, parafunctional oral habits, and the perception of quality of life. 111 patients aged 13 to 55 that showed no signs or symptoms of TMD and began orthodontic treatment were selected. The experiment was divided into three phases: t1 (when the orthodontic device was installed), t2 (two months after the installation), and t3 (six months after the start of the treatment). At all phases, the patients were examined clinically for occlusal evaluation and their pain pressure thresholds were assessed with an analog algometer. They were also applied questionnaires on parafunctional oral habits (OBC) and perception of oral health on the quality of life (OHIP-14br). Comparisons were made with respect to each quantitative variable considering the three phases of evaluation through a one-way analysis of variance (ANOVA) for each variable. The t test was used to assess differences between the means of quantitative variables at baseline (T1) and the final evaluation (t3). To evaluate the effect of orthodontics on occlusal qualitative variables Fisher's exact test was used. Statistical significance was considered for those results with a significance level equal to or less than 0.05. None of the 111 patients developed symptoms of TMD within the evaluation time. No significant occlusal quantitative changes were observed (p> 0.05) between t1 and t3, however the qualitative factors considered as occlusal patterns were significantly changed (p <0.05). Orthodontic treatment did not alter pain pressure thresholds but a significant increase (p <0.05) in scores of OHIP was observed between phases t1 and t3. Orthodontic treatment did not increase or decrease the pesence of parafunctional oral habits, and no differences were found between sex and LDP in individuals who possessed more/less parafunctional habits. However, older patients reported higher OBC scores, and correlation was found between patients with higher OBC scores and lower scores for OHIP. The study concluded that orthodontic treatment did not have an effect on orofacial pain hresholds, nor the presence of parafunctional oral habits. The perception of oral health on quality of life improved significantly with treatment and patients with lessparafunctional oral habits presented a better quality of life.(AU)

Comparative evaluation of somatosensory mechanisms involved in orofacial somatic, visceral and neuropathic pain / Avaliação comparativa dos mecanismos somatossensoriais envolvidos na gênese das dores orofaciais de origem somática, visceral e neuropática

Orofacial pain conditions can be classified into somatic, visceral or neuropathic pain. Somatic pain is triggered by a noxious stimulus generally inducted by peripheral traumas, such as dental implants surgeries (IMP). Visceral pain initiates within internal body tissues and is normally triggered by inflammation, as in inflammatory toothaches (IT). The third condition is neuropathic pain, which results from persistent injury to the peripheral nerve as in Atypical Odontalgia (AO). The aims of this study were: 1- to investigate somatosensory abnormalities, using mechanical, painful, and electrical quantitative sensory testing (QST), in somatic (IMP patients), visceral (IT) and neuropathic pain (AO); 2- to quantify how accurately QST discriminates an IT or AO diagnosis; and 3- to investigate the influence implant surgeries or pulpectomy may have on somatosensory system and sensory nerve fibers. Sixty subjects were divided in three groups: IMP (n = 20), IT (n = 20) and AO group (n = 20). A sequence of five QSTs and the Conditioned Pain Modulation Test (CPM) were performed one month and three months after dental implant surgery (IMP group) or pulpectomy (IT group). AO group was evaluated only at baseline. QST comprehended Mechanical Detection Threshold (MDT), Mechanical Pain Threshold (MPT), Dynamical Mechanical Allodynia (DMA), Current Perception Threshold (CPT) for A-beta (frequency of 2000Hz), A-delta (250Hz) and C fibers (5Hz) and Temporal Summation Test (TS). "Z" score transformation were applied to the data, and within and between groups were statistically analyzed using two-way ANOVA. In addition, the receiver operating characteristic curve analysis, diagnostic accuracy, sensitivity, specificity, likelihood ratios, and diagnostic odds ratio of QSTs were calculated (α = 5%). The findings of this study proved that: 1- loss of function for touch threshold and electrical threshold of C fibers is present in inflammatory toothache; 2- allodynia, hyperalgesia, gain of function for touch and pain thresholds and impaired pain modulation is detected in atypical odontalgia; 3- some QSTs may be used as complementary tests in the differential diagnosis of atypical odontalgia and inflammatory toothache with strong accuracy; 4- the most accurate QSTs for differential diagnosis between subjects with AO and IT were MDT, MPT and DMA where touch threshold forces > 1 g/mm2 and pain threshold forces > 10g/mm2 can be used to accurately discriminate AO from IT; and 5- no somatosensory modification is found after implant surgery and reduced electrical threshold in C fiber is found for patients with inflammatory toothache after 3 months of pulpectomy.(AU)

As dores orofaciais podem ser classificadas em dores somáticas, viscerais ou neuropáticas. A dor somática está relacionada a um estímulo nocivo evidente, geralmente associada a um trauma periférico, como por exemplo, nas cirurgias de implantes (IMP). As dores viscerais têm origem dentro dos órgãos e cavidades internas do corpo e são ativadas pela inflamação, como no exemplo da dor de dente do tipo Pulpite Aguda (PA). A terceira condição é a dor neuropática, que resulta de uma lesão persistente ao nervo periférico, como ocorre na Odontalgia Atípica (OA). Os objetivos deste estudo foram: 1- avaliar as alterações somatossensoriais, por meio do uso de Testes Sensoriais Quantitativos (TSQ) mecânicos, dolorosos e elétricos em dores somáticas (pacientes IMP), viscerais (PA) e neuropáticas (OA); 2- quantificar a acurácia dos TSQs na descriminação diagnóstica de uma PA ou OA; e 3- investigar alterações somatossensoriais e nas fibras nervosas sensoriais após cirurgia de instalação de implantes dentários ou pulpectomia. Sessenta sujeitos foram divididos em três grupos: IMP (n = 20), PA (n = 20) e OA (n = 20). Uma sequência de cinco TSQs e o teste de Controle da Modulação da Dor (CMD) foram realizados um mês e três meses após cirurgia de implantes (grupo IMP) ou pulpectomia (grupo PA). No grupo OA, os testes foram realizados somente uma vez no início do estudo. Os TSQs englobaram o Limiar de Detecção Mecânica (LDM), Limiar de Dor Mecânica (LDoM), Alodinia Mecânica Dinâmica (AMD), Limiar de Percepção de Corrente (LPC) para fibras A-beta (frequência de 2000Hz), A-delta (250Hz) e C (5 Hz), e o teste de Somação Temporal (ST). A transformação em escores de "Z" foi aplicada aos dados, e diferenças intra e inter-grupos foram analisadas usando ANOVA de medidas repetidas. Ainda, a acurácia diagnóstica dos TSQs foi medida por meio da sensibilidade, especificidade, razão de verossimilhança e razão de chances para diagnóstico (α = 5%). Os resultados deste estudo mostraram que: 1- perda da função em limiar táctil e limiar elétrico de fibras C está presente na Pulpite Aguda; 2- alodinia, hiperalgesia, ganho de função nos limiares de tato e de dor, e modulação da dor prejudicada são encontrados em pacientes com odontalgia atípica; 3- alguns TSQs podem ser usados como testes diagnósticos complementares ao diagnóstico diferencial entre PA e OA; 4- os TSQs com maior acurácia para o diagnóstico diferencial entre indivíduos com PA e OA foram LDM LDoM e AMD, onde uma força maior que 1 g/mm2 para limiar de tato e maior que 10 g/mm2 para limiar de dor podem ser usados com precisão; e 5- nenhuma alteração somatossensorial é encontrada após cirurgia de implantes e uma redução no limiar elétrico em fibras C é encontrado em pacientes com PA após 3 meses da pulpectomia.(AU)

Avaliação do limiar de dor a pressão (LDP) e fadiga mastigatória em indivíduos submetidos à cirurgia bariátrica: análise da inatividade mastigatória / Evaluation of pressure pain threshold (PPT) and masticatory fatigue in patients undergoing bariatric surgery: analysis of masticatory inactivity

O objetivo deste estudo foi avaliar o limiar de dor a pressão (LDP) e a percepção de dor orofacial através do teste de fadiga mastigatória após um período de inatividade da mastigação. Estudo caracterizado como de coorte, prospectivo e observacional. Composto por 30 indivíduos obesos mórbidos, divididos em dois grupos. Experimental (GE) (n=15) que foram submetidos a cirurgia bariátrica e Controle (GC) (n=15) que se apresentavam na fase pré cirúrgica. O Limiar de Dor a Pressão e a Escala de Análise Visual (EAV) foram adotados como testes para compor a avaliação de fadiga mastigatória. Os dados foram registrados em dois tempos distintos para ambos os grupos, com um intervalo de 37 dias entre as coletas. No entanto, apenas o GE foi submetido a inatividade mastigatória. Empregou-se o teste de Shapiro-Wilk para avaliar a normalidade dos dados e adotou-se ANOVA mista de medidas repetidas (dados paramétricos) e o teste de Friedman (dados não paramétricos) para identificar diferenças intragrupos e para comparar os valores de LDP observados antes e depois da cirurgia bariátrica foram empregados o teste t de Student para amostras pareadas (dados paramétricos) e o teste de Wilcoxon pareado (dados não paramétricos) considerando-se uma probabilidade de erro do tipo I () de 0,05. Para o GE, os níveis do LDP apresentaram uma redução significativa e a percepção de dor aumentou durante o teste de fadiga mastigatória quando avaliado após o período de inatividade da mastigação. Outro dado observado foi a não recuperação dos níveis do LDP e EAV após a o teste de fadiga, no qual os níveis não retornaram aos registros iniciais como no período pré cirúrgico. Diante dos dados avaliados no teste de fadiga mastigatória, o Limiar de Dor a Pressão apresentou reduções significativas, caracterizando o aumento da sensibilidade à palpação nos músculos avaliados, após o período de inatividade mastigatória de 37 dias. Ao passo que houve aumento na percepção de dor orofacial dos pacientes obesos mórbidos no mesmo período de avaliação.(AU)

The aim of this study was to evaluate the pressure pain threshold (PPT) and the perception of orofacial pain through masticatory fatigue test after a period of inactivity of mastication. Study characterized as a cohort, prospective, observational. Composed of 30 morbid obese subjects, separated into two groups: Experimental (EG) (n = 15) were submitted to bariatric surgery and Control (CG) (n = 15) pre surgical procedure. The Pressure Pain Threshold and Visual Analysis Scale (VAS) have been adopted as testing to compose the evaluation of masticatory fatigue. Data were recorded at two different times for both groups, with an interval of 37 days between the analyses. However only the EG was subjected to masticatory inactivity. The Shapiro-Wilk test was employed to assess the normality of the data and adopted mixed repeated measures ANOVA (parametric data) and the Friedman test (nonparametric data) to identify intergroup differences and to compare the PPT values observed before and after bariatric surgery were used the Student t test for paired samples (parametric data) and Wilcoxon test (nonparametric data) considering a probability of error type I () of 0.05. For EG, the PPT levels showed a significant reduction and the perception of pain increased during the masticatory fatigue test when evaluated after a period of inactivity of mastication. Another fact observed was the non-recovery of the PPT and VAS levels after the fatigue test, in which the levels did not return to the original records as the surgical pre surgical procedure. According the data evaluated in the masticatory fatigue test, the pain threshold to pressure showed significant reductions, featuring increased tenderness to palpation in the muscles evaluated after masticatory inactivity period of 37 days. Whereas there was an increase in the perception of orofacial pain of morbidly obese patients in the same period of evaluation.(AU)

Avaliação da influência do tratamento ortodôntico em sinais e sintomas de disfunção temporomandibular, no relato de bruxismo, na hipervigilância à dor e nos sintomas de ansiedade e depressão / Evaluation of orthodontic treatment on signs and symptoms of temporomandibular dysfunction, bruxism, pain hypervigilance, anxiety and depression

Novos estudos são necessários para elucidar com maior clareza o impacto da ortodontia na saúde dos músculos mastigatórios e das articulações temporomandibulares. A associação do estudo de sinais e sintomas de DTM com a investigação dos fatores psicossociais apresentam perspectivas promissoras, assim como o conhecimento da presença de hábitos parafuncionais. Entender como os fatores psicossociais interferem nos resultados dos tratamentos clínicos pode trazer contribuições enriquecedoras para a odontologia. Um modelo que tem sido aceito no entendimento da etiologia das DTM é o modelo biopsicossocial, que envolve uma combinação de fatores biológicos, psicológicos e sociais. Segundo essa perspectiva, entende-se que um problema biológico pode ter antecedentes psicológicos, assim como consequências comportamentais. O objetivo deste trabalho é avaliar a influência da ortodontia no desenvolvimento de sinais e sintomas de disfunção temporomandibular, no relato de bruxismo, na hipervigilância à dor e nos sintomas de depressão e ansiedade. 111 pacientes iniciando tratamento ortodôntico foram examinados em 3 sessões: t1 (no momento da instalação do aparelho), t2 (dois meses após a instalação), e t3 (seis meses após o início do tratamento). Nas 3 sessões os pacientes foram examinados clinicamente para avaliação oclusal, limiares de dor à pressão e aplicações de questionários de bruxismo, hipervigilância, depressão e ansiedade. Foram feitas comparações a respeito de cada variável quantitativa considerando os três tempos de avaliação através de Análise de variância (ANOVA) a um critério. O teste t foi utilizado para avaliar diferenças entre as médias das variáveis quantitativas no tempo inicial (t1) e tempo final (t3) de avaliação. Para avaliar o efeito da ortodontia sobre variáveis qualitativas oclusais foi utilizado o teste exato de Fisher. Foram considerados estatisticamente significantes aqueles resultados que apresentaram nível de significância igual ou menor que 0,05. O presente estudo demonstrou que a ortodontia não interfere no surgimento de sinais e sintomas de disfunção temporomandibular, sendo que não houve diferenças na presença de ruído articular e no LDP em nenhum dos sítios durante os períodos avaliados. Os resultados apontaram que nos grupos que não possuíam bruxismo do sono (controle), houve um aumento no relato de bruxismo em vigília após o início da ortodontia. Considerando o grupo de pacientes com maiores sintomas de ansiedade, encontrou-se maior presença de relato de bruxismo em vigília. Por último, os resultados demonstraram que a ortodontia não alterou os escores do questionário de hipervigilância à dor e os sintomas de ansiedade e depressão.(AU)

Further studies are needed to elucidate more clearly the impact of orthodontics on the health of the masticatory muscles and temporomandibular joints. The study of the association of signs and symptoms of TMD with psychosocial factors have promising prospects, as well as the presence of parafunctional habits. Understanding how psychosocial factors affect the results of clinical treatments can bring great contributions to dentistry. A model that has been accepted in the understanding of the etiology of TMD is the biopsychosocial model, which involves a combination of biological, psychological and social factors. From this perspective, it is understood that a biological problem may have psychological backgrounds, as well as behavioral consequences. The objective of this study is to evaluate the influence of orthodontics in the development of signs and symptoms of temporomandibular disorders, the report of bruxism, hypervigilance to pain, and symptoms of depression and anxiety. 111 patients initiating orthodontic treatment were examined in 3 sessions: t1 (at the time of orthodontic appliance installation), t2 (two months after installation), and t3 (six months after the start of the treatment). In the three sessions, patients were examined clinically for occlusal evaluation, pain pressure thresholds were measured, and bruxism, hypervigilance, depression and anxiety questionnaires were applied. Comparisons were made with respect to each quantitative variable considering the three phases of evaluation through a multi-way analysis of variance (ANOVA). The t test was used to assess differences between means of quantitative variables at the initial time (t1) and end time (t3) evaluation. To evaluate the effect of orthodontics on occlusal qualitative variables we used Fisher's exact test. This study showed that orthodontics does not interfere with the appearance of signs and symptoms of temporomandibular dysfunction, and there were no differences in the presence of articular noise and LDP on any of the sites during the evaluation period. The results showed that the group that did not reported sleep bruxism (control), showed an increase in the reporting of awake bruxism after the start of orthodontics. Considering the group of patients with higher anxiety symptoms, we found a greater presence of daytime bruxism report. Finally, the results showed that orthodontics did not alter the scores of pain hypervigilance questionnaire and symptoms of anxiety and depression.(AU)

Deep pain sensitivity is correlated with oral-health-related quality of life but not with prosthetic factors in complete denture wearers

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.

Linhas de pesquisa em enfermagem: destaques filosóficos e epistemológicos / Research lines in nursing: phylosophical and epistemological highlights / Lineas de investigación en enfermería: destaques filosoficos y espistemologicos

RESUMONeste texto trata-se de explicar a investigação científica quanto às Linhas de Pesquisa e Prioridades de Enfermagem, com base na aplicação da teoria do conhecimento e como tangível à Subjetividade e à Objetividade no que concerne aos termos categoriais integrados na literatura como profissional, assistencial e organizacional.Objetivo:elucidar destaques filosóficos e epistemológicos mediante considerações significativas, essenciais, em favor da causalidade de questões no interesse da Enfermagem.Método:abordagem fundamentada nas proposições teóricas de Johannes Hessen, com referência a outros autores expertos no tema.Resultados:esclarecimento de aspectos substantivos e implicações adjetivas não só no interesse da investigação, ressaltando os significados essenciais do assunto, condizente com as elaborações de dissertações de mestrado e teses de doutorado de Enfermagem.Conclusão:trata-se de uma contribuição valiosa para esclarecer melhor detalhes da construção do conhecimento na temática e problemática do assunto posto em causa, as linhas de pesquisa em enfermagem.

ABSTRACTIn this paper scientific investigation is explained as related to the Nursing Research Lines and Priorities based on the theory of knowledge application and as tangible to Subjectivity and Objectivity on what relates to the integrated categorical terms in the literature as professional, caring and organizational.Objective:to elucidate philosophical and epistemological highlights in the face of meaningful, essential considerations, in favor of question causalities of interest to Nursing.Method:the reality approach is founded on the theoretical propositions of Johannes Hessen, with held attention to conceptions of other recognized authors.Results:one can state the exposition value to clarify substantive aspects and adjective implications, not only of interest to investigation, but just to pinpoint the essential meanings on the subject related to elaborated thesis and dissertations (Marters' and Doctoral).Conclusion:represents a valuable contribution to better clarify details on knowledge construction and on the subject theme under discussion.

RESUMENTratase de explicar la investigación científica cuanto a las Líneas de Investigación y Prioridades de Enfermería, en base de la aplicación de la teoría del conocimiento y como tangible a la Subjetividad y a la Objetividad en que concierne a los termos categorías integrados en la literatura como profesional, asistencial y organizacional.Objetivo:elucidar destaques filosóficos y epistemológicos mediante consideraciones en favor de la casualidad de cuestiones en el interés de la Enfermería.Método:es fundamentado en las proposiciones teóricas de Johannes Hessen y de otros autores consagrados.Resultados:clareamiento de aspectos sustantivo e implicaciones adjetivas no sólo el interés de la investigación, resaltando los significados esenciales del asunto coincidido con las elaboraciones de disertaciones y tesis (Maestría y Doctorado de Enfermería).Conclusión:texto representa una contribución valiosa para esclarecer mejor detalles de la construcción del conocimiento en la temática y problemática del asunto puesto en causa.

The role of sensitization in musculoskeletal shoulder pain

Introduction: Peripheral and central sensitization are neurophysiological processes that can prolong painful conditions. Painful shoulder conditions are often persistent, perhaps due to the presence of sensitization.Method:This manuscript summarizes six studies that have evaluated those with musculoskeletal shoulder pain for the presence of sensitization.Results:All six manuscripts report evidence of peripheral sensitization, while central sensitization was described in five of the studies. The chronicity of symptoms in subjects who were included in the studies is probably influencing this finding. The primary somatosensory test used to assess sensitization in these studies was Pressure Pain Threshold, a test for lowered nociceptive thresholds.Discussion:It appears that peripheral sensitization manifests consistently in those with musculoskeletal shoulder pathology, probably due to the inflammatory processes related to tissue injury. Central sensitization, while not universally present, was reported in a majority of the manuscripts. Because central sensitization is thought to be a key step on the pathway to chronic pain, evidence for its presence in those with shoulder pain is significant. Clinicians should expect the presence of sensitization with shoulder pathology and make appropriate choices about interventions so as not to exacerbate pain.

Systematic analysis of the nociceptive blink reflex: reliability and association with psychological factors / Análise sistemática do reflexo de piscar nociceptivo: confiabilidade e associação com fatores psicológicos

The present study aimed to estimate the reliability of the nociceptive blink reflex (nBR) and to evaluate the possible association between the nBR and various pain-related psychological measures: the Anxiety Sensitivity Index-3 (ASI-3), the Fear of Pain Questionnaire III (FPQ-III), the Pain Vigilance and Awareness Questionnaire (PVAQ), the Somatosensory Amplification Scale (SSAS), the Pain Catastrophizing Scale (PCS) and the Situational Pain Catastrophizing Scale (S-PCS). Twenty-one healthy participants were evaluated in two sessions. The nBR was elicited by a so-called "nociceptive-specific" electrode placed over the entry zone of the right supraorbital (V1R), infraorbital (V2R) and the mental (V3R) nerve and left infraorbital (V2L) nerve. The outcomes were: (a) individual electrical sensory (I0) and pain thresholds (IP); b) root mean square (RMS), area-under-thecurve (AUC) and onset latencies of R2 responses; and c) stimulus-evoked pain on a 0-10 numerical rating scale. The questionnaires ASI-3, FPQ-III, PVAQ, SSAS, PCS and S-PCS were also applied. Intraclass Correlation Coefficients (ICCs) and Kappa statistics were computed as a measure of the reliability (α=5%). Besides, Pearson correlation coefficient was used to associate the average of nBR measurements among all sites and the questionnaires. The significance level was set up after a Bonferroni correction (adjusted α=0.8%). ICCs were fair to excellent in 82% of the psychophysical measures and in 86% of V1R, V2R and V2L nBR parameters, whereas the V3R showed poor reliability in 52%. ICCs for intrarater reliability were fair to excellent in 70% of measurements (V3R showed the lowest values) and in 75% of interrater measurements. All kappa values showed at least fair agreement and the majority of the nBR measures (93%) were considered to have moderate to excellent reliability. There was no correlation for any pair of variables considering the adjusted significance level (p>0.008) and only a single significant correlation considering the standard significance level (p < 0.05), where the pain intensity (NRS) at 50% of IP presented a positive and small to moderate correlation with the PCS (r = 0.43, p = 0.047). The nBR and its associated psychophysical measures can be considered a sufficiently reliable test to assess the trigeminal nociceptive function. On the other hand, it seems not associated with psychological factors in healthy participants.

O presente estudo teve como objetivo estimar a confiabilidade do reflexo de piscar nociceptivo (nBR, sigla em inglês) e avaliar a possível associação entre o nBR e várias medidas psicológicas relacionadas à dor: o Anxiety Sensitivity Index-3 (ASI-3), o Fear of Pain Questionnaire III (FPQ-III), o Pain Vigilance and Awareness Questionnaire (PVAQ), o Somatosensory Amplification Scale (SSAS), o Pain Catastrophizing Scale (PCS) e o Situational Pain Catastrophizing Scale (S-PCS) (siglas e nomes em inglês). Vinte e um participantes saudáveis foram avaliados em 2 sessões. O nBR foi estimulado por meio de um eletrodo "nociceptivo específico" posicionado na zona de entrada do nervo supraorbital direito (V1D, sigla em inglês), infraorbital direito (V2D) e esquerdo (V2E) e mentual direito (V3R). As variáveis analisadas foram: a) limar elétrico sensorial (I0) e doloroso (IP); b) raíz quadrática média (RMS, sigla em inglês), área sobre a curva (AUC, sigla em inglês) e as latências da respostas R2; e c) dor provocada pelo estímulo em uma escala numérica de O a 10. Os questionários ASI-3, FPQ-III, PVAQ, SSAS, PCS e S-PCS também foram aplicados. Coeficiente de Correlação Intraclasse (ICC, sigla em inglês) e estatística Kappa foram calculados como medidas da confiabilidade (α=5%). Além disso, coeficiente de correlação de Pearson foi usado para associar a média do nBR entre todos os sítios de avaliação e os questionários. O nível de significância foi ajustado após correção de Bonferroni (α ajustado=0.8%). ICCs foram razoáveis à excelentes em 82% das medidas psicofísicas e em 86% dos parâmetros do nBR em V1D, V2D e V2E, enquanto que 52% das medidas em V3D apresentaram pobre confiabilidade. ICCs para confiabilidade intra-examinador foram razoáveis à excelente em 70% das medições (V3D apresentou os menores valores) e em 75% das medidas inter-examinadores. Todos os coeficientes Kappa apresentaram pelo menos razoável concordância e a maioria das medidas do nBR (93%) foram consideradas moderadas à excelente em termos de confiabilidade. Não houve correlação para nenhum par de variáveis considerando os valores ajustados de significância (p>0,008) e somente foi constatada uma correlação significante considerando o nível de significância padrão (p<0,005), em que a intensidade de dor em 50% do IP apresentou uma correlação positiva entre pequena e moderada com o PCS. O nBR e suas medidas psicofísicas associadas pode ser considerado um teste com suficiente confiabilidade para avaliar a função nociceptiva trigeminal. Por outro lado, parece que o nBR não está associado com fatores psicológicos em participantes saudáveis.

Quantitative methods for somatosensory evaluation in atypical odontalgia

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.

Do Diabetic Patients with Acute Coronary Syndromes Have a Higher Threshold for Ischemic Pain? / Pacientes Diabéticos com Síndromes Coronárias Agudas têm um Limiar Maior para a Dor Isquêmica?

Background: Data from over 4 decades have reported a higher incidence of silent infarction among patients with diabetes mellitus (DM), but recent publications have shown conflicting results regarding the correlation between DM and presence of pain in patients with acute coronary syndromes (ACS). Objective: Our primary objective was to analyze the association between DM and precordial pain at hospital arrival. Secondary analyses evaluated the association between hyperglycemia and precordial pain at presentation, and the subgroup of patients presenting within 6 hours of symptom onset. Methods: We analyzed a prospectively designed registry of 3,544 patients with ACS admitted to a Coronary Care Unit of a tertiary hospital. We developed multivariable models to adjust for potential confounders. Results: Patients with precordial pain were less likely to have DM (30.3%) than those without pain (34.0%; unadjusted p = 0.029), but this difference was not significant after multivariable adjustment, for the global population (p = 0.84), and for subset of patients that presented within 6 hours from symptom onset (p = 0.51). In contrast, precordial pain was more likely among patients with hyperglycemia (41.2% vs 37.0% without hyperglycemia, p = 0.035) in the overall population and also among those who presented within 6 hours (41.6% vs. 32.3%, p = 0.001). Adjusted models showed an independent association between hyperglycemia and pain at presentation, especially among patients who presented within 6 hours (OR = 1.41, p = 0.008). Conclusion: In this non-selected ACS population, there was no correlation between DM and hospital presentation without precordial pain. Moreover, hyperglycemia correlated significantly with pain at presentation, especially in the population that arrived within 6 hours from symptom onset. .

Fundamento: Dados de mais de 4 décadas relataram maior incidência de infarto silencioso entre os pacientes com diabetes mellitus (DM), mas publicações recentes mostraram resultados conflitantes quanto à correlação entre DM e presença de dor em pacientes com síndromes coronárias agudas (SCA). Objetivo: Nosso objetivo principal foi analisar a associação entre dor precordial e DM na chegada ao hospital. Análises secundárias avaliaram a associação entre hiperglicemia e dor precordial na apresentação, e o subgrupo de pacientes que se apresentaram em até 6 horas após o início dos sintomas. Métodos: Analisamos um registro prospectivo de 3.544 pacientes com SCA internados em unidade coronária de um hospital terciário. Desenvolvemos modelos multivariados para ajustar potenciais fatores de confusão. Resultados: Os pacientes com dor precordial eram menos propensos a ter DM (30,3%) do que aqueles sem dor (34,0 %, p não ajustado = 0,029), mas essa diferença não foi significativa após ajuste multivariado, para a população global (p = 0,84), e para o subgrupo de pacientes que se apresentaram dentro do período de 6 horas após o início dos sintomas (p = 0,51). Em contraste, a dor precordial era mais provável entre os pacientes com hiperglicemia (41,2% vs. 37,0% sem hiperglicemia, p = 0,035) na população total, e também entre aqueles que se apresentaram no período de 6 horas (41,6% vs. 32,3%, p = 0,001). Modelos ajustados mostraram uma associação independente entre hiperglicemia e dor na apresentação, especialmente entre os pacientes que se apresentaram no período de até 6 horas (OR = 1,41, p = 0,008). Conclusão: Nesta população não-selecionada com SCA, não houve correlação entre DM e a ...

Influence of different frequencies of transcutaneous electrical nerve stimulation on the threshold and pain intensity in young subjects / As influências de diferentes frequências da estimulação elétrica nervosa transcutânea no limiar e intensidade de dor em indivíduos jovens

Objective To investigate the effects of different transcutaneous electrical nerve stimulation frequencies in nociception front of a pressure pain threshold and cold in healthy individuals. Methods Twenty healthy subjects were divided into four groups, all of which have gone through all forms of electrical stimulation at different weeks. Assessments were pre and post-therapy, 20 and 60 minutes after stimulation. To evaluate the pressure pain threshold, an algometer was used with one tapered tip, pressing the hypothenar region until voluntary report the word “pain”. Cold pain intensity was assessed by immersion in water at 5°C for 30 seconds; at the end, the subject was asked to quantify the pain intensity on a Visual Analog Scale for Pain. For electrical stimulation, two electrodes were used near the elbow, for 20 minutes, with an intensity strong, but not painful. The frequency was in accordance with the group: 0Hz (placebo); 7Hz; 100Hz; and 255Hz. Results Both for the assessment of pressure pain threshold as the cold pain intensity, there was no significant difference (p>0.05). Conclusion We conclude that the use of transcutaneous electrical nerve stimulation on dermatomes C6 to C8 produced no significant change in pressure pain threshold or cold discomfort. .

Objetivo Investigar os efeitos de diferentes frequências da estimulação elétrica nervosa transcutânea na nocicepção, frente a um estímulo doloroso pressórico e ao frio, em indivíduos saudáveis. Métodos Participaram 20 indivíduos saudáveis, divididos em 4 grupos, sendo que todos passaram por todas as formas de eletroestimulação, em semanas diferentes. As avaliações ocorreram nos seguintes períodos: pré-aplicação, pós-aplicação, 20 e 60 minutos após a eletroestimulação. Para avaliar o limiar de dor à pressão, foi utilizado um algômetro com ponta afilada, pressionando na região hipotenar, até o voluntário relatar a palavra “dor”. A intensidade de dor ao frio foi avaliada por meio de imersão em água a 5°C, durante 30 segundos; ao final, pediu-se para que o indivíduo quantificasse a intensidade álgica em uma Escala Visual Analógica de Dor. Para a eletroestimulação, foram utilizados dois eletrodos próximos ao cotovelo, durante 20 minutos, com intensidade referida como forte, porém não dolorosa. A frequência esteve de acordo com o grupo: 0Hz (placebo); 7Hz; 100Hz; e 255Hz. Resultados Tanto para a avaliação do limiar de dor à pressão quanto da intensidade ao frio, não houve diferença significativa (p>0,05). Conclusão O uso da estimulação elétrica nervosa transcutânea, sobre os dermátomos de C6 a C8, não produziu alteração significativa no limiar de dor à pressão e nem no desconforto ao frio. .

Evaluation of sensitivity, motor and pain thresholds across the menstrual cycle through medium-frequency transcutaneous electrical nerve stimulation

OBJECTIVES: The aim of this study was to identify variations in nervous thresholds in different phases of the menstrual cycle in eumenorrheic women and users of oral contraceptives. METHOD: An observational study was performed including 56 volunteers, consisting of 30 eumenorrheic women who were non-users of oral contraceptives and 26 users of oral contraceptives. An electrical stimulator was employed to assess their nervous thresholds, with pulses applied at a fixed frequency of 2,500 Hz, modulated at 50 Hz, with phase variances of 20 μs, 50 μs and 100 μs. Sensitivity, motor and pain thresholds were evaluated during five menstrual cycle phases: phase 1 - menstrual, phase 2 - follicular, phase 3 - ovulatory, phase 4 - luteal and phase 5 - premenstrual. RESULTS: The results indicated low sensitivity thresholds of 100 μs for non-users of oral contraceptives and 50 μs for oral contraceptive users in phase 5. Low motor thresholds of 20 μs, 50 μs and 100 μs were observed for non-users of oral contraceptives in phase 5, while that of oral contraceptive users was 100 μs. Finally, a low pain threshold of 100 μs was observed in phase 5, but only in the oral contraceptive group. CONCLUSION: Nervous thresholds vary systematically across the phases of the menstrual cycle, with or without the use of oral contraceptives. These variations should be taken into account during research performed in women. .

Quantitative sensory testing in trigeminal traumatic neuropathic pain and persistent idiopathic facial pain / Teste sensitivo quantitativo em dor neuropática trigeminal pós-traumática e dor facial idiopática persistente

The objective of this article was to investigate, with a systematic protocol of quantitative sensory testing, patients with persistent idiopathic facial pain (PIFP) and others with trigeminal traumatic neuropathic pain (TTN) compared to controls. Thirty patients with PIFP, 19 with TTN, and 30 controls were evaluated on subjective numbness and dysesthesia and with a systematic protocol of quantitative sensory testing for thermal evaluation (cold and warm), mechanical detection (touch and pinpricks for mechanical pain), superficial pain thresholds, and corneal reflex. We found that PIFP and TTN had numbness and dysesthesia higher than controls (p<0.001 and p=0.003), and that in both of them mechanical pain by pinpricks detection was abnormal intra and extra orally at the mandibular branch (p<0.001). Cold, warm, and tactile detections and pain thresholds were similar among the groups. Corneal reflex was abnormal in TTN (p=0.005). This study supports neuropathic mechanisms involving pain processing in PIFP and that the criterion on absence of sensorial variations in PIFP should be revised.

O objetivo deste artigo foi investigar, com um protocolo sistemático de testes sensitivos quantitativos, pacientes com dor facial idiopática persistente (DFIP) e outros com dor neuropática trigeminal traumática (DNTT) comparado aos controles. Trinta pacientes com DFIP, 19 com DNTT e 30 controles foram avaliados quanto à dormência e à disestesia subjetiva e por meio de um protocolo sistemático de testes sensitivos quantitativos, que incluiu avaliação térmica (frio e quente), detecção mecânica (táctil e alfinetes), limites de dor superficial e reflexo córneo-palpebral. Foi observado que os pacientes apresentaram mais dormência e disestesia do que os controles (p<0,001 e p=0,003), além de mais anormalidades intra e extraorais no ramo mandibular (p<0,001). As alterações de calor, frio, dor e tato foram semelhantes entre os grupos. O reflexo córneo-palpebral foi anormal somente no grupo com DNTT (p=0,005). Este estudo suporta mecanismos de dor neuropática envolvidos no processamento da DFIP, e o critério de ausência de variações sensoriais nesta deve ser revisto.

An improved experimental model for peripheral neuropathy in rats

A modification of the Bennett and Xie chronic constriction injury model of peripheral painful neuropathy was developed in rats. Under tribromoethanol anesthesia, a single ligature with 100% cotton glace thread was placed around the right sciatic nerve proximal to its trifurcation. The change in the hind paw reflex threshold after mechanical stimulation observed with this modified model was compared to the change in threshold observed in rats subjected to the Bennett and Xie or the Kim and Chung spinal ligation models. The mechanical threshold was measured with an automated electronic von Frey apparatus 0, 2, 7, and 14 days after surgery, and this threshold was compared to that measured in sham rats. All injury models produced significant hyperalgesia in the operated hind limb. The modified model produced mean ± SD thresholds in g (19.98 ± 3.08, 14.98 ± 1.86, and 13.80 ± 1.00 at 2, 7, and 14 days after surgery, respectively) similar to those obtained with the spinal ligation model (20.03 ± 1.99, 13.46 ± 2.55, and 12.46 ± 2.38 at 2, 7, and 14 days after surgery, respectively), but less variable when compared to the Bennett and Xie model (21.20 ± 8.06, 18.61 ± 7.69, and 18.76 ± 6.46 at 2, 7, and 14 days after surgery, respectively). The modified method required less surgical skill than the spinal nerve ligation model.