Effect of low-level LASER therapy versus CAD/CAM Michigan splint on patients with Temporomandibular Muscle Disorders: a randomized clinical trial / Efeito da terapia LASER de baixa potência versus placa de Michigan CAD/CAM em pacientes com Distúrbios Temporomandibulares musculares: um ensaio clínico randomizado

Objective: This study aimed to evaluate the efficacy and sustainability of using low level LASER therapy and CAD/CAM Michigan splint on improving the range of mandibular movements, muscle activity and reducing the pain. Material and Methods: 56 female patients were randomly divided into two groups. Group A: Patients received applications of low-level LASER therapy using semiconductor InGaAsp diode LASER type 940 nm with continuous mode of operation, applied for 180 sec per session for 12 sessions. Group B: Patients received Michigan splint of 2 mm thickness constructed on their upper teeth, the splint was 3D digitally printed. Electromyography was used to evaluate muscle activity, visual analogue scale was used to evaluate the pain intensity, ARCUS digma facebow was used to evaluate range of mandibular movements, and maximum mouth opening was taken using a millimeter ruler. They were measured before the beginning of the treatment, and at three and six month follow-up periods. Results: The results revealed that both low-level LASER therapy and Michigan splint reduce the myofascial pain, improved the range of the mandibular movements, and the muscles activity, but the effect of the low-level LASER therapy was more profound and sustainable. After 6 months from the beginning of the treatment, changes in masseter muscle activity (P= 0.001; effect size= 1.757), pain intensity (P= 0.003; effect size= 3), and range of mandibular movement (P= 0.001, effect size= 1.729) differed significantly between the two groups. Conclusions: Low-level LASER therapy had a better and more sustainable effect on reducing the pain intensity and improving the muscle activity as well as the mandibular movement when compared to Michigan splint (AU)

Objetivo: Este estudo teve como objetivo avaliar a eficácia e a durabilidade do uso da terapia LASER de baixa potência e da placa de Michigan CAD/CAM na melhora da amplitude dos movimentos mandibulares, atividade muscular e redução da dor. Material e Métodos: 56 pacientes do sexo feminino foram divididos aleatoriamente em dois grupos. Grupo A: os pacientes receberam aplicações de terapia LASER de baixa potência utilizando diodo semicondutor InGaAsp LASER tipo 940 nm em modo contínuo de operação, aplicado por 180 segundos por sessão durante 12 sessões. Grupo B: os pacientes receberam a placa de Michigan com uma espessura de 2 mm confeccionada sobre a arcada superior, a placa foi impressa digitalmente em 3D. A eletromiografia foi utilizada para avaliar a atividade muscular, a escala visual analógica foi utilizada para avaliar a intensidade da dor, o arco facial ARCUS digma foi utilizado para determinar a amplitude dos movimentos mandibulares e a abertura máxima da boca foi medida com uma régua milimétrica. Todas as medidas foram realizadas antes do início do tratamento e nos períodos de acompanhamento de três e seis meses. Resultados: Os resultados revelaram que tanto a terapia LASER de baixa potência como a placa de Michigan reduziram a dor miofascial, aumentaram a amplitude dos movimentos mandibulares e melhoraram a atividade muscular, mas o efeito da terapia LASER de baixa potência foi mais profundo e duradouro. Após 6 meses do início do tratamento, as alterações na atividade do músculo masseter (P= 0. 001; tamanho do efeito= 1,757), intensidade da dor (P= 0,003; tamanho do efeito= 3), e amplitude de movimento mandibular (P= 0,001, tamanho do efeito= 1,729) diferiram significativamente entre os dois grupos. Conclusão: A terapia com LASER de baixa potência teve um efeito melhor e mais duradouro na redução da intensidade da dor e na melhora da atividade muscular, bem como do movimento mandibular, quando comparada à placa de Michigan(AU)

Relación entre contactos mediotrusivos con la articulación temporomandibular y la oclusión / Relationship between mediotrusive contacs, the temporomandibular joint and occlusion

Los contactos mediotrusivos son aquellos contactos oclusales que se encuentran entre las vertientes in- ternas de las cúspides linguales maxilares y las inter- nas de las cúspides bucales mandibulares del lado de no trabajo durante los movimientos de lateralidad. Estos contactos mediotrusivos podría desencadenar trastornos temporomandibulares, afectando la oclu- sión y la articulación temporomandibular. El objetivo de este estudio es analizar las caracterís- ticas y la relación entre los contactos mediotrusivos con la articulación temporomandibular y la oclusión en pacientes que consultan al Servicio de Oclusión y ATM del Hospital Odontológico de la Facultad de Odontología de la Universidad Nacional del Nordeste (AU)

Mediotrusive contacts are those occlusal contacts that are found between the internal slopes of the maxillary lingual cusps and the internal slopes of the mandibular buccal cusps on the non-working side during laterality movements. These mediotrusive contacts could trigger temporomandibular disorders affecting occlusion and temporomandibular joint. The objective of this study was to analyze the characteristics and relationship of mediotrusive contacts with occlusion and the temporomandibular joint, in patients who consult the Occlusion and TMJ Service of the Dental Hospital of the Faculty of Dentistry of the National University of the Northeast (AU)

Ultra-Low Frequency Transcutaneous Electrical Nerve Stimulation on Pain Modulation in a Rat Model with Myogenous Temporomandibular Dysfunction.

Masticatory myofascial pain (MMP) is one of the most common causes of chronic orofacial pain in patients with temporomandibular disorders. To explore the antinociceptive effects of ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS) on alterations of pain-related biochemicals, electrophysiology and jaw-opening movement in an animal model with MMP, a total of 40 rats were randomly and equally assigned to four groups; i.e., animals with MMP receiving either ULF-TENS or sham treatment, as well as those with sham-MMP receiving either ULF-TENS or sham treatment. MMP was induced by electrically stimulated repetitive tetanic contraction of masticatory muscle for 14 days. ULF-TENS was then performed at myofascial trigger points of masticatory muscles for seven days. Measurable outcomes included maximum jaw-opening distance, prevalence of endplate noise (EPN), and immunohistochemistry for substance P (SP) and µ-opiate receptors (MOR) in parabrachial nucleus and c-Fos in rostral ventromedial medulla. There were significant improvements in maximum jaw-opening distance and EPN prevalence after ULF-TENS in animals with MMP. ULF-TENS also significantly reduced SP overexpression, increased MOR expression in parabrachial nucleus, and increased c-Fos expression in rostral ventromedial medulla. ULF-TENS may represent a novel and applicable therapeutic approach for improvement of orofacial pain induced by MMP.

Análise de diferentes tarefas para normalização do sinal elétrico do músculo orbicular da boca pela contração voluntária máxima: estudo piloto / Analysis of different tasks to normalize the electrical signal of the orbicularis oris muscle by maximum voluntary contraction: pilot study

RESUMO Objetivo pesquisar a atividade elétrica do músculo orbicular da boca em quatro diferentes tarefas isométricas e indicar a mais apropriada para utilização como referência na normalização do sinal elétrico do músculo orbicular da boca pela contração voluntária máxima. Métodos participaram do estudo 22 indivíduos, sendo dez do sexo masculino e 12 do feminino, com idades entre 20 e 33 anos. A atividade elétrica das porções superior e inferior do músculo orbicular da boca foi registrada durante a realização das seguintes tarefas isométricas: protrusão labial com fechamento, protrusão labial sem fechamento, contrarresistência com a placa de resistência labial e preensão de lábios. A ordem de realização das tarefas foi randomizada entre os participantes. Os dados foram comparados entre as tarefas, para cada seguimento labial. Resultados no segmento marginal superior, a tarefa com maior média e mediana de amplitude foi preensão labial, embora sem diferença significativa entre tarefas. O menor coeficiente de variação foi obtido na tarefa de contrarresistência com a placa de resistência labial. No segmento marginal inferior, a tarefa com maior média e mediana de amplitude foi protrusão labial com fechamento, que também teve o menor coeficiente de variação e diferença significativa entre as tarefas protrusão labial com fechamento e preensão, sendo os maiores valores obtidos na primeira. Conclusão indica-se como referência para a normalização do sinal elétrico do músculo orbicular da boca, pela contração voluntária máxima, a tarefa de protrusão labial com fechamento.

ABSTRACT Purpose To verify the electrical activity of the orbicularis oris in four different isometric tasks and to indicate the most appropriate task for use as a reference in the normalization of the electrical signal of the orbicularis oris muscle by maximum voluntary contraction. Methods Twenty-two individuals participated in the study, of which 10 were male and 12 were female, with ages ranging from 20 to 33 years. The electrical activity of the upper and lower parts of orbicularis oris muscle was recorded during the following isometric tasks: lip protrusion with bilabial closure; lip protrusion without bilabial closure; the counter resistance using the plate of labial resistance and lips prehension. The order of the tasks was randomized among participants. Data were compared between tasks for each lip part. Results in the upper marginal segment, the task with the highest mean and median amplitude was lip prehension, although there was no significant difference between tasks. The lowest coefficient of variation was obtained in the counter resistance task with the plate of labial resistance. In the lower marginal segment, the task with the highest mean and median amplitude was labial protrusion with lips closure, which also had the lowest coefficient of variation. In this segment, there was a significant difference between labial protrusion with lips closure and prehension, with the highest values obtained in the first task. Conclusion lip protrusion with bilabial closure is suggested as reference for the normalization of the electrical signal of the orbicularis oris muscle, by maximum voluntary contraction.

Osteoartrosis de ATM: recuperar la función / TMJ Osteoarthrosis: recover function

Objetivo: evaluar la rehabilitación funcional de la ATM en pacientes con osteoartrosis, con abordaje neuromuscular. La osteoartrosis se caracteriza por la degeneración del cartílago articular y la cortical ósea, que conduce a dolor e inmovilidad. Se incluyó a 8 mujeres entre 20 y 42 años de edad con dolor en la región orofacial, signos de oclusión disfuncional e imágenes compatibles con trastornos degenerativos en ATM. Clínicamente se evaluó el dolor y la oclusión y, mediante tecnología electrónica, se obtuvieron datos objetivos de los movimientos de apertura-cierre y lateralidades, la velocidad de apertura-cierre mandibulares y de los ruidos articulares. Las mediciones fueron realizadas al inicio y al finalizar el tratamiento de estabilización mandibular con una ortosis neuromuscular. Para determinar la significación estadística se utilizaron el Student`s test de comparaciones múltiples y el análisis de varianza, ANOVA, de un factor. Las diferencias entre medias se consideraron significativas con p <0.05. Los resultados demostraron ausencia de dolor en el 100% de los casos al primer mes de tratamiento. Se incrementaron la apertura bucal (6,73 mm promedio), ambas lateralidades (P=0.0023), velocidad en apertura y en cierre (no estadísticamente significativo). Después de estabilizar la mandíbula se redujo la frecuencia de los ruidos. En conclusión, la oclusión dental disfuncional es el principal factor etiológico de la artrosis de la ATM. El establecimiento de una oclusión fisiológica produce la descompresión de la ATM, aumenta el rango de los movimientos mandibulares y disminuye significativamente el dolor (AU)

Objective: to evaluate the functional rehabilitation of the TMJ in patients with osteoarthritis, with a neuromuscular approach. Osteoarthrosis is characterized by degeneration of articular cartilage and bone cortex, which leads to pain and immobility. Eight women between 20 and 42 years of age with pain in the orofacial region, signs of dysfunctional occlusion, and images consistent with degenerative TMJ disorders were included. Clinically, pain and occlusion were evaluated and, using electronic technology, objective data were obtained on the opening-closing movements and lateralities, the opening-closing speed of the jaws and joint noises. Measurements were made before and at the end of the mandibular stabilization treatment with a neuromuscular orthosis. To determine the statistical significance, the Student`s multiple comparisons test and the analysis of variance, ANOVA, of one factor were used. The differences between means were considered significant with p <0.05. The results showed absence of pain pain in 100% of cases in the first month of treatment. Mouth opening (6.73 mm average), both lateralities (P = 0.0023), opening and closing speed (not statistically significant) were increased. After stabilizing the jaw the noise frequency value was reduced. In conclusion, dysfunctional dental occlusion is the main etiologic factor of TMJ osteoarthritis. Establishing a physiological occlusion causes TMJ decompression, increases the range of mandibular movements, and significantly decreases pain (AU)

Alternativas de tratamiento para pacientes jóvenes con pérdida de estructura dentaria. Parte 2: caso clínico / Treatment alternatives for young patients with loss of dental structure. Part 2: a clinical case

El objetivo de este artículo es presentar una alternativa de tratamiento rehabilitador para pacientes jóvenes con gran pérdida de estructura dental, vinculada a lesiones de origen no bacteriano. Se presenta el caso clínico de un paciente de sexo masculino, de 39 años de edad, que acudió a la Cátedra de Odontología Integral Adultos de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA) relatando síntomas compatibles con hipersensibilidad dentaria y fatiga de los músculos masticadores. Al mismo tiempo, manifestó disconformidad con el aspecto estético de su sonrisa. Teniendo en cuenta la gran pérdida de sustancia en sus piezas dentarias producida por hábitos parafuncionales (bruxismo), se realizó una rehabilitación oral adhesiva con cerámicas utilizando el protocolo de abordaje terapéutico sugerido por la Cátedra. En pacientes que presentan severos desgastes (AU)

The mechanism of beneficial effect of radiofrequency therapy on masticatory muscles in temporomandibular disorders - a literature review.

Temporomandibular disorders (TMD) is one of the most common problem in contemporary dentistry. It is a term covering dysfunction of the masticatory muscles and the temporomandibular joints. Patients are suffering from severe pain, followed by limited mandibular opening and sounds in the temporomandibular joints during jaw movement. TMD influences the quality of life because the symptoms can become chronic and difficult to manage. Radiofrequency waves (RF) are electromagnetic waves with low energy and high frequency. They provide pain relief without causing significant damage to the nervous tissue. The RF therapy is commonly used for physiotherapeutic treatment of skeletal muscle relaxation, as a supportive therapy. The rehabilitation effect of these waves is based on diathermy by means of high-voltage quick alternating current. RF has also found application in physical therapy, as a therapeutic tool for various types of chronic pain syndromes. The aim of this literature review is to show the beneficial effect of radiofrequency waves on the pain of the masticatory muscles in the course of TMD.

Evaluation of the effectiveness of infrared light-emitting diode photobiomodulation in children with sleep bruxism: Study protocol for randomized clinical trial.

BACKGROUND: Sleep bruxism is a masticatory muscle activity characterized as rhythmic (phasic) or nonrhythmic (tonic). In children and adolescents, etiological factors, such as breathing pattern and sleep quality, have recently been addressed in studies investigating sleep bruxism. New therapies for adults, such as botulinum toxin, have been investigated, but such techniques are not applicable for individuals in the growth and development phase. METHODS: The participants will be 76 children, which will be randomly allocated to a control group, that is group 1, absence of bruxism; group 2, children with bruxism treated with infrared light-emitting diode (LED); and group 3, bruxism treated with occlusal splint. All participants will be submitted to a clinical evaluation to evaluate muscle activity and salivary biomarkers, before and after treatments. Muscle activity will be verified by electromyography of muscles mastication, masseter and temporal, and salivary biomarkers observed will be cortisol and dopamine levels. DISCUSSION: Photobiomodulation therapy has piqued the interest of researchers, as this noninvasive method has demonstrated positive results in problems related to muscle tissues. This document describes the protocol for a proposed study to evaluate morphological and psychosocial aspects in children and adolescents with awake bruxism and their responses to photobiomodulation therapy with infrared LED. CLINICAL TRIALS:.

Heterogeneity and shifts in distribution of muscle weakness in myasthenia gravis.

The distribution of muscle weakness in myasthenia gravis (MG) patients with acetylcholine receptor (AChR) antibodies is highly variable. As muscle groups respond differently to therapeutic interventions, it is important to acknowledge this variability. We analysed the distribution of muscle weakness in 225 AChR MG patients over time. On the basis of combinations of muscle weakness, seven phenotypes were defined: 'ocular' (O), 'bulbar' (B), 'neck/limbs/respiratory' (NLR), or a combination (O+B, O+NLR, B+NLR and O+B+NLR). MG remained restricted to ocular weakness in 5%, whereas 7% never had ocular weakness. At last follow-up, ocular or bulbar weakness had resolved more frequently than NLR weakness (40%, 38% and 25%; p = 0.003, respectively). Patients with O, B or OB phenotype at baseline had a higher age at onset and were more frequently male than patients with NLR, ONLR, BNLR or OBNLR phenotype (52.7 ±â€¯17.5 vs. 44.0 ±â€¯18.9; p = 0.007 and 64% vs. 37%; p = 0.002, respectively). MG patients have heterogeneous distributions of muscle weakness and frequently shift between phenotypes. The phenotypic variations found in AChR MG suggest that also other factors aside from the AChR antibody mediated immune response are of importance in determining the disease expression in MG.

Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation.

INTRODUCTION: Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. OBJECTIVE: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. METHODOLOGY: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. RESULTS: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. CONCLUSION: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Photobiomodulation with simultaneous use of red and infrared light emitting diodes in the treatment of temporomandibular disorder: study protocol for a randomized, controlled and double-blind clinical trial.

INTRODUCTION: Temporomandibular disorder (TMD) is considered the main cause of orofacial pain of non-dental origin, and a public health problem. The symptomatology is muscular and/or articular pain, restriction of the mandibular range of motion, and changes in the mandibular movement pattern. Due to its complexity there are already treatments using various forms of therapy. Photobiomodulation using light sources, such as low-level laser or light emitting diodes (LED), with different wavelengths, in a single or combined form, allows one more therapeutic resource to be explored. The objective of this study is to evaluate the effects of photobiomodulation with the simultaneous use of red and infrared LEDs, on pain, range of mandibular movements, and on the electrical activity of masticatory muscles in individuals with TMD. METHODS: A randomized, controlled, double-blind clinical trial is proposed, which will involve 33 individuals (n = 11 per group) of both sexes, ages 18 to 45 years in 3 groups: LED group; placebo group; and control group, submitted to 6 non-consecutive sessions of photobiomodulation totaling 2 weeks of treatment. The Research Diagnostic Criteria for Temporomandibular Disorders-RDC/TMD will be used to assess and determine the participants' TMD. The pain will be assessed using the Visual Analog Scale - VAS, the mandibular range of motion will be determined with the aid of a digital caliper, and the electrical activity of the masticatory muscles will be verified by electromyography. A mixed plate of 18 red LEDs-660 nm and 18 infrared LEDs-850 nm with power of 3.5 mW per LED, 4.45 mW/cm, radiant exposure of 5.35 J/cm, will be used for photobiomodulation. The irradiated area will be 14.13 cm, and energy of 75.6 J, in the TMJ region and in the bilateral masseter and temporal muscles. Participants from all groups will be reassessed after the first therapeutic intervention, and at the end of treatment. DISCUSSION: We expect the use of photobiomodulation with LEDs, infra and red, to reduce pain, improve temporomandibular joint function in patients with TMD, and thus improve the general conditions of the patient.

Effects of unilateral nasal obstruction on the characteristics of jaw-closing muscles in growing rats.

OBJECTIVES: Mouth breathing caused by nasal obstruction (owing to abnormal pressure of masticatory muscles) affects craniofacial growth and development. The influence of unilateral nasal obstruction on jaw-closing muscles was investigated in rats to reveal one of the etiologic mechanisms. MATERIALS AND METHODS: Forty 8-day-old male Wistar rats were used in this study. Experimental rats were subjected to left-sided nasal obstruction by burning the external nostril tissue at the age of 8 days. Pulse oxygen saturation was recorded each week. Morphologic changes were evaluated by staining with hematoxylin and eosin (to assess the cross-sectional area) and by adenosine triphosphatase activity staining (to assess the myosin heavy chain isoform composition). Immunohistochemical and reverse transcription quantitative real-time polymerase chain reaction analyses of tumor necrosis factor-α and glucose transporter 4 were carried out at 5 and 9 weeks of age. RESULTS: The cross-sectional area of the jaw-closing muscles was lower in the experimental group at 9 weeks of age. The percentage of myosin heavy chain-2a in masseter muscles was increased in the experimental group compared with the control group. An increase in the tumor necrosis factor-α messenger RNA and protein levels and a decrease in the glucose transporter 4 messenger RNA and protein levels at 5 and 9 weeks of age in the jaw-closing muscles in the experimental group were noted. CONCLUSIONS: Unilateral nasal obstruction could affect the morphology and contractile characteristics of jaw-closing muscles during growth in rats.

The association between a mixing ability test and patient reported chewing ability in patients treated for oral malignancies.

INTRODUCTION: Mastication has been assessed in several ways in the past. Both patients reported and objective assessment methods have been developed. The University Medical Center (UMC) Utrecht has developed a mixing ability test (MAT) using a two-coloured wax tablet. The present study investigates the association between the mixing ability test and a chewing related questionnaire in patients treated for oral malignancies. PATIENTS AND METHODS: In a cohort study, patients treated for oral malignancies were assessed 4-6 weeks before and 4-6 weeks after treatment, as well as 6 months, 1 year and 5 years after treatment. The mixing ability test was assessed using 10 and 20 chewing strokes and was compared to seven questions about several aspects of mastication. Regression analysis was performed and density plots were drawn for statistical analysis. RESULTS: One hundred and twenty-three patients were included in this study. The questionnaire was less predictive for the 10-chewing stroke test and the test was less discriminatory for different food types than the 20-chewing stroke mixing ability test. Three questions about the ability to chew solid, soft and thickened liquid food types were found to be significantly predictive for the 20-chewing stroke test. Threshold values on the mixing ability index were around 20 for the ability to chew solid food types and 24 for soft food types. CONCLUSION: The 10-chewing stroke mixing ability test is less suitable than 20-chewing strokes for patients with and treated for oral cancer. The 20-chewing stroke mixing ability test has a fair association with self-reported outcomes.

Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation

Abstract Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. Objective: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. Methodology: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. Results: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. Conclusion: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Photobiomodulation versus light-emitting diode (LED) therapy in the treatment of temporomandibular disorder: study protocol for a randomized, controlled clinical trial.

BACKGROUND: Temporomandibular disorder (TMD) is described as a subgroup of orofacial pain with a set of signs and symptoms that involve the temporomandibular joint, masticatory muscles, ears, and neck. TMD can occur unilaterally or bilaterally and approximately 70% of the population is affected with at least one sign. The disorder progresses with orofacial pain, muscle pain involving the masticatory and cervical muscles, joint noises (clicks and pops), joint block, mandibular dysfunction, and headache. The etiology can be abnormal occlusion and/or posture, trauma involving local tissues, repetitive microtrauma, parafunctional habits, and an increase in emotional stress. Studies have demonstrated that phototherapy is an efficient option for the treatment of TMD, leading to improvements in pain and orofacial function. METHODS: The aim of the proposed study is to compare the effects of two sources of photobiomodulation in individuals with TMD. A randomized, controlled, double-blind, clinical trial is proposed, which will involve 80 individuals aged 18-65 years allocated to either a laser group or light-emitting diode (LED) group submitted to 12 sessions of phototherapy. The Research Diagnostic Criteria for TMDs will be used to evaluate all participants. Pain will be measured using the visual analog scale and maximum vertical mandibular movement will be determined with the aid of digital calipers. DISCUSSION: This study compares the effects of two modalities of laser therapy on the pain and orofacial function of patients with TMD dysfunction. Photobiomodulation and LED therapy are treatment options for reducing the inflammatory process and pain as well as inducing the regeneration of the target tissue. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03257748 . Registered on 8 August 2017.

Observation of Effects of Different Surgical Treatments on Unilateral Masticatory Muscle Spasm.

BACKGROUND: Unilateral masticatory muscle spasm is a rare disease without a generally accepted and efficacious treatment plan. OBJECTIVE: We sought to compare the effects of different surgical treatments on unilateral masticatory muscle spasm. METHODS: A retrospective analysis of the surgical treatment and effects of 10 cases of unilateral masticatory muscle spasm occurred between February 2010 and September 2016. Three cases underwent complete amputation of the trigeminal motor branch, 3 cases underwent partial amputation of the trigeminal motor branch, and 4 cases received only vascular decompression. All patients were followed up by telephone interview after surgery. RESULTS: In the simple vascular decompression group, 3 cases were cured and 1 was cured after a delay. Of these 3 cases, 1 case became aggravated 2 years after the operation, 1 case became aggravated 5 years after the operation, and 1 case showed no change during the follow-up period. In the partial amputation group, 2 cases were cured and 1 case was alleviated. Of the 2 patients who were cured, 1 suffered recurrence 2 years later, while the other case showed no recurrence during the follow-up period. In the complete amputation group, 1 case was cured with a delay and 2 cases were cured immediately with no recurrence during the follow-up. Mild atrophy of the temporal muscle occurred gradually with no restriction of the mouth opening in 2 cases. CONCLUSIONS: Complete amputation of the trigeminal nerve did achieve better effects than pure microvascular decompression and partial amputation of the trigeminal motor branch, but it may lead to mild temporal muscle atrophy.

Comparative effectiveness of photobiomodulation and manual therapy alone or combined in TMD patients: a randomized clinical trial

Abstract The effectiveness of photobiomodulation (PBM) and manual therapy (MT), alone or combined (CT), were evaluated in pain intensity, mandibular movements, psychosocial aspects, and anxiety symptoms of temporomandibular disorder (TMD) patients. Fifty-one TMD patients were randomly assigned to three groups: the PBM group (n = 18), which received PBM with 808 nm, 100 mW, 13.3 J/cm2, and 4 J per point; the MT group (n=16) for 21 minutes each session on masticatory muscles and temporomandibular joint TMJ; and the CT group (n = 17), applied during twelve sessions. Seven evaluations were performed in different moments using visual analogue scale (VAS), Research Diagnosis Criteria for Temporomandibular Disorders (RDC/TMD) Axis I and II, and Beck anxiety inventory (BAI). All groups demonstrated reductions in pain and improvement in jaw movements during treatment and at follow-up (< 0.001). The assessment of psychosocial aspects of TMD, comparing baseline and follow-up in all treatment groups, revealed that treatment did not promote modification in the intensity of chronic pain (p > 0.05). However, depression symptoms showed a reduction in PBM and CT groups (p≤0.05). All treatments promoted reduction in physical symptoms with and without pain and enhancement of jaw disabilities (p ≤ 0.05). MT promotes improvement in 5 functions, PBM in 2, and CT in 1 (p < 0.001). BAI analysis revealed that all treatments lead to a reduction in anxiety symptoms (p≤0.05). All protocols tested were able to promote pain relief, improve mandibular function, and reduce the negative psychosocial aspects and levels of anxiety in TMD patients. However, the combination of PBM and MT did not promote an increase in the effectiveness of both therapies alone.

[Sleep bruxism : state of the art and management]. / Bruxisme nocturne : actualités et prise en charge.

Although well studied since the 50's, bruxism remains a largely unknown pathology. Its origin is complex, mixing psychological as well as neurological, odontological and hypnic aspects. However, the few analyzes performed on this topic have allowed to set convincing etiopathological hypotheses, including central dysregulation of the dopaminergic system as well as of the neuro-masticatory system. To avoid harmful consequences as headaches, temporomandibular disorders and premature dental scuffs / fractures, it is mandatory to diagnose bruxism as early as possible. For this purpose, and in addition to anamnestic and clinical data, the practitioner can confirm diagnosis with polysomnography, including electromyographic study of masticatory muscles and audiovisual recording. Some orthodontic, pharmacological and psychological solutions have already proved efficient. Nevertheless, a better knowledge of causative neurobiological mechanisms would allow to foresee etiology-based treatments.

Le bruxisme reste, à l'heure actuelle, une pathologie relativement mal connue, bien que déjà étudiée depuis le début des années 50. Son origine est complexe, impliquant des composantes psychologiques, neurologiques, odontologiques et hypniques. Les quelques analyses réalisées à ce sujet ont, toutefois, permis de mettre en avant certaines hypothèses étiopathogéniques convaincantes, notamment un dérèglement central du système dopaminergique et du système neuromasticateur. Un diagnostic rapide de l'affection permettra de réduire ses complications (céphalées, désordres temporomandibulaires, abrasion et fractures dentaires prématurées). Au-delà de l'anamnèse et de l'examen clinique, le praticien pourra confirmer le diagnostic par polysomnographie, incluant une étude électromyographique des muscles masticateurs et un enregistrement audiovisuel. Certaines solutions orthodontiques, pharmacologiques et psychologiques ont déjà prouvé leur efficacité. Néanmoins, une meilleure connaissance des mécanismes neurobiologiques incriminés permettrait d'envisager un traitement étiologique.

Surface electromyography before and after orthognathic surgery and condylectomy in active laterognathia: a case report.

BACKGROUND: Condylar hyperplasia is a rare bone disease characterised by excessive development of mandibular condyle, which can lead to the development of asymmetric facial deformity together with malocclusion, mandibular deviation, TMJ and masticatory musculoskeletal system dysfunction. There is not a treatment protocol universally accepted. In order to determine the correct management, treatment and intervention timing of these patients, morphological examinations should be coupled with functional assessments. CASE REPORT: In the present case report, morphological (bone scintigraphy; orthopantomography; posteroanterior and lateral cephalograms; 3D facial photographs) and functional (surface electromyography of masseter and temporalis muscles) quantitative data of a 20-year-old male patient affected by unilateral condylar hyperplasia are presented. The patient underwent a surgical treatment with high unilateral condylectomy associated to a maxillary Le Fort I osteotomy; as well as orthodontic treatment before and after surgery. Facial morphology and masticatory muscles activity were assessed before surgery and followed-up 6, 12 and 24 months after surgery. Twenty-four months after surgery, all electromyographic values were normal, and soft-tissue facial asymmetry was negligible at 3D assessment. CONCLUSION: Surface electromyography joins a set of clinical and morphological diagnostic tests that help the surgeon in planning the operation and managing the post-surgical patient.