Bichectomy Surgery and EMG Masticatory Muscles Function in Adult Women: A Longitudinal Study.

AIM: This longitudinal study aimed to evaluate the electromyographic activity of the masseter and temporal muscles in adult women who underwent buccal fat removal. MATERIALS AND METHODS: The sample consisted of 20 healthy adult women with no temporomandibular dysfunction and normal occlusion, who were assessed before, 30, and 60 days after the surgery. The electromyographic signal of the masseter and temporal muscles was captured through mandibular tasks including rest, protrusion, right and left laterality, and maximum voluntary contraction with and without parafilm. The results obtained were tabulated and the Shapiro-Wilk normality test was performed, which indicated a normal distribution. Statistical analysis was performed using the repeated measures test (p < 0.05). RESULTS: Significant differences were observed between time periods in maximum voluntary contraction for the left masseter muscle (p = 0.006) and in maximum voluntary contraction with parafilm for the right temporal (p = 0.03) and left temporal (p = 0.03) muscles. CONCLUSION: Bichectomy surgery did not modify the electromyographic activity of the masseter and temporal muscles during the rest task but may have influenced variations in the electromyographic signal during different mandibular tasks after 60 days of surgery, suggesting compensatory adaptations and functional recovery. CLINICAL SIGNIFICANCE: Understanding the impact of buccal fat removal surgery on the stomatognathic system function provides insights into postoperative functional recovery and potential compensatory adaptations, guiding clinical management and rehabilitation strategies for patients undergoing such procedures. How to cite this article: Cardoso AHDLS, Palinkas M, Bettiol NB, et al. Bichectomy Surgery and EMG Masticatory Muscles Function in Adult Women: A Longitudinal Study. J Contemp Dent Pract 2024;25(3):207-212.

Lower limb balance, ankle dorsiflexion, orofacial tissue pressure, and occlusal force of rugby players.

This cross-sectional study examined the lower limb balance, ankle dorsiflexion, orofacial tissue pressure, and occlusal strength of rugby players. Twenty-six participants were divided into groups: rugby players (n â€‹= â€‹13) and healthy sedentary adults (n â€‹= â€‹13). Participants underwent an analysis of lower limb balance using a composite score (Y-Balance Test). Ankle dorsiflexion was measured using the Lunge Test. The Iowa Oral Performance Instrument was employed to measure orofacial tissue pressure. Bite force was measured with a dynamometer, and T-Scan assessed occlusal contact distribution. Data were analyzed using the t-test (p â€‹< â€‹0.05) and ANCOVA with age and weight as covariates, where it is possible to verify that these factors did not influence the results obtained. Significant differences were observed in the balance of the right (p â€‹= â€‹0.07) and left (p â€‹= â€‹0.02) lower limbs, where rugby players had lower composite scores. There were significant differences in the right (p â€‹= â€‹0.005) and left (p â€‹= â€‹0.004) lunges, with rugby players showing lower values, as well as lower tongue pressure (p â€‹= â€‹0.01) and higher lip pressure (p â€‹= â€‹0.03), with significant differences to sedentary participants. There was no significant difference in molar bite force and distribution occlusal contacts between groups. Rugby seems to reduce lower limb displacement, cause ankle hypomobility, lead to changes in orofacial tissues, particularly the tongue and lips. This study is significant for identifying significant differences between rugby players and sedentary individuals, providing new insights into the impact of rugby on health and performance, which can benefit sports training and injury prevention.

Magnification in preclinical procedures: effect on muscle activity and angular deviations of the neck and trunk.

Objectives: This study aimed to assess the effects of different magnification systems on the angular deviations of the neck and trunk and the muscle activities of the upper back and neck during preclinical cavity preparation. Methods: This was an experimental laboratory study, with the angular deviations from the neutral positions of the neck and trunk and the activities of the bilateral upper back (the descending and ascending trapezius) and neck (sternocleidomastoid) muscles as the dependent variables. The independent variables were the different magnification systems used (Simple, Galilean, and Keplerian loupes, with direct vision as the control) and prepared teeth (teeth 16, 26, 36, and 46). A dental mannequin phantom head with artificial resin teeth was used, and Class I cavity preparations for composite resin were performed on teeth 16, 26, 36, and 46 using a 1012 round diamond bur at low speed. To analyze the angular deviations, the postures adopted during the procedure were recorded using a tripod-mounted camera positioned to provide a lateral view of the operator. A trained researcher measured the angular deviations using the software entitled "Software for Postural Assessment"-SAPO (version 0.69). Bilateral muscle activity was assessed using surface electromyography. Descriptive statistical analysis was performed, and after verifying the assumptions of normality and homoscedasticity, two-way analysis of variance and the Tukey and Games-Howell post-hoc tests were used to compare the data (α=0.05). Results: The angular deviation from the neutral position of the neck was found to be significantly higher during cavity preparations performed with the naked eye and the Simple loupe, irrespective of the prepared tooth. With regard to tooth location, the angular deviation of the neck was significantly greater during cavity preparation on teeth 16 and 26, and the angular deviation of the trunk was significantly greater during cavity preparation on tooth 26, regardless of the magnification system used. There were significant differences in right sternocleidomastoid muscle activity between the Simple, Galilean, and Keplerian loupes, with activity being the lowest for the Galilean loupe (p = 0.008). There were no significant differences in left sternocleidomastoid muscle activity between the loupes, regardless of the prepared tooth (p = 0.077). The activities of the bilateral descending trapezius and the right ascending trapezius muscles were significantly lower when the Galilean loupe was used (p < 0.010). Conclusion: These results suggest that the Galilean loupe resulted in lower muscle activity in the neck and back regions and that the Galilean and Keplerian loupes resulted in less angular deviations of the neck and trunk during cavity preparation.

Impact of obesity on the structures and functions of the stomatognathic system: A morphofunctional approach.

OBJECTIVE: The prevalence of obesity is increasing significantly worldwide, raising great concern among health professionals. This observational study evaluated the electromyographic activity and thickness of the masseter and temporalis muscles, in addition to the maximum molar bite force, in obese and eutrophic subjects. METHODS: Sixty subjects were divided into three groups: I (7-12 years), II (13-20 years), III (21-40 years) and sex: with 10 men and 10 women for each group. Electromyographic recordings of the masticatory muscles were obtained during mandibular tasks. The masticatory muscles thicknesses were obtained at rest and during dental clenching. The maximum molar bite forces were measured on the right and left sides. The difference in outcome measures between the groups and sex was analyzed using Mann-Whitney U test (p < 0.05) and analysis of covariance (ANCOVA). RESULTS: Electromyographic activity in the masseter and temporal muscles consistently displayed lower levels in obese subjects of both sexes across all three age groups during mandibular tasks. Additionally, greater thickness of the masticatory muscles was observed in obese subjects of both sexes across all three age groups. Obese women in Group II displayed higher values of molar bite force, both on the right and left sides, compared to eutrophic women. On the other hand, women in Group III exhibited higher values of molar bite force on the right side in comparison to eutrophic women. CONCLUSIONS: This study underscores the potential impact of obesity on the morphofunctional aspects of the stomatognathic system in subjects aged 7 to 40 years.

Lycopene enhances bone neoformation in calvaria bone defects of ovariectomized rats.

Osteoporosis can affect a significant part of the population and fractures are the most common complications associated with this disease, leading to high public health costs. Thus, the prevention of fractures is relevant to individuals with signs and symptoms as well as to the health system. Postmenopausal osteoporosis has been associated with oxidative stress, emphasizing the importance of an efficient defense system to maintain bone health. Lycopene is a carotenoid with antioxidant properties that may stimulate osteoblastogenesis and inhibit osteoclastogenesis. The purpose of this investigation was to analyze the influence of lycopene in the bone neoformation of calvaria defects in ovariectomized rats utilizing the concentration of 45 mg/kg. Wistar Hannover female rats were divided into ovariectomized and sham groups. The ovariectomized animals received 45 mg/kg lycopene (OvxL) or water (Ovx) by daily gavage the day after ovariectomy/sham surgery for 16 weeks. Twelve weeks after ovariectomy, there were performed 5-mm calvaria defects followed by euthanasia after 4 weeks. Samples of bone tissue were collected to perform morphological and morphometrical analysis of the neoformed bone area, and percentage with Software Image J. Morphological evaluation showed mature bone with more osteocytes in the group OVxL when compared to the other groups. The morphometrical analysis demonstrated a significant increase of bone neoformation in the group OvxL (p<0.05). The data obtained suggest that lycopene benefits bone repair in the absence of estrogenic hormones.

Effect of finger rest positions on upper limb muscle activity during pre-clinical procedures.

Objectives: This study aimed to observe the effect of different finger rest positions on the muscular activity of the hand, forearm, arm, shoulder, thorax, and neck, as well as on the angular deviation from the neutral position of the neck, trunk, upper arm, and forearm on the working side during pre-clinical procedures. Methods: An experimental laboratory study was performed. Response variables were muscle activation of the abductor pollicis, brachioradialis, biceps brachii, deltoid, pectoralis major, and right sternocleidomastoid muscles and angular deviation from the neutral position of the neck, trunk, arm, and forearm during simulated clinical procedures. Independent variable was finger-rest position during cavity preparation (no finger rest, usual rest, and ergonomic rest). Class I cavity preparations (N = 120) were performed on artificial first molars (16, 26, 36, and 46) (N = 120). Muscular activation was assessed by surface electromyography and angular deviations using Software for Postural Assessment (SAPO) version 0.69. One-way analysis of variance and Tukey's or Games-Howell's post-hoc tests were performed (α = 0.05). Results: For the sternocleidomastoid muscle, there was no statistically significant difference between the different rest positions. For the deltoid muscle, work with no finger rest resulted in greater muscle activation (p < 0.001) during work on tooth 36. Regarding the pectoralis major and right brachioradialis muscles, we observed that for both teeth 16 and 26, working with ergonomic rest showed less muscle activation. Muscle activation of the right biceps brachii was higher for work with no rest in both the upper and lower arches, differing significantly only from the usual rest in tooth 16 (p < 0.001), usual rest and ergonomic rest in teeth 26 and 46 (p < 0.001), and only ergonomic rest in tooth 36 (p = 0.044). In the right abductor pollicis muscle, work with ergonomic rest resulted in less muscle activation for cavity preparation in teeth 16, 26, and 36, which was significantly different from work with no rest (p = 0.029, p < 0.001, and p = 0.013, respectively). Regarding angular deviation, it was observed that for tooth 16, there was a greater angular deviation of the arm when performing cavity preparations with no finger rest. For teeth 26 and 46, the ergonomic finger rest provided lower angular deviation from the neutral position of the right arm. For tooth 36, ergonomic rest provided less angular deviation from the neutral neck position. Conclusion: In general, the use of non-active finger rest during simulated cavity preparations, regardless of the type of rest, provided less muscle activation and angular deviation from the neutral position of the body's upper extremity when performing pre-clinical procedures.

Lycopene enhances bone neoformation in calvaria bone defects of ovariectomized rats

Abstract Osteoporosis can affect a significant part of the population and fractures are the most common complications associated with this disease, leading to high public health costs. Thus, the prevention of fractures is relevant to individuals with signs and symptoms as well as to the health system. Postmenopausal osteoporosis has been associated with oxidative stress, emphasizing the importance of an efficient defense system to maintain bone health. Lycopene is a carotenoid with antioxidant properties that may stimulate osteoblastogenesis and inhibit osteoclastogenesis. The purpose of this investigation was to analyze the influence of lycopene in the bone neoformation of calvaria defects in ovariectomized rats utilizing the concentration of 45 mg/kg. Wistar Hannover female rats were divided into ovariectomized and sham groups. The ovariectomized animals received 45 mg/kg lycopene (OvxL) or water (Ovx) by daily gavage the day after ovariectomy/sham surgery for 16 weeks. Twelve weeks after ovariectomy, there were performed 5-mm calvaria defects followed by euthanasia after 4 weeks. Samples of bone tissue were collected to perform morphological and morphometrical analysis of the neoformed bone area, and percentage with Software Image J. Morphological evaluation showed mature bone with more osteocytes in the group OVxL when compared to the other groups. The morphometrical analysis demonstrated a significant increase of bone neoformation in the group OvxL (p<0.05). The data obtained suggest that lycopene benefits bone repair in the absence of estrogenic hormones.

Resumo A osteoporose afeta grande parte da população e as fraturas são as complicações mais importantes relacionadas a essa doença, gerando altos gastos para o poder público. Dessa forma, a prevenção de fraturas decorrentes da osteoporose torna-se relevante tendo em vista que gera benefícios tanto para o indivíduo acometido pela doença quanto para o sistema de saúde. A osteoporose pós menoupasa tem sido associada ao estresse oxidativo, portanto, um eficiente sistema de defesa antioxidante é primordial para a manutenção da saúde óssea. O licopeno é um carotenoide antioxidante que aparentemente estimula a osteoblastogênese e inibe a osteoclastogênese. O objetivo deste estudo foi analisar a influência do licopeno na neoformação óssea em defeitos de calvária em ratas ovariectomizadas utilizando a concentração de 45 mg/kg. Foram utilizados 15 ratas Wistar Hannover pesando aproximadamente 200g, sendo que 10 animais foram submetidos à ovariectomia bilateral e 5 (Grupo Sham) foram submetidos à simulação da cirurgia de ovariectomia bilateral. Os animais ovariectomizados foram divididos aleatoriamente em 2 grupos: Ovariectomizado (Ovx) e Ovariectomizado Licopeno (OvxL) que receberam água e licopeno respectivamente, por sonda gástrica, diariamente. As administrações iniciaram-se no dia seguinte à cirurgia de ovariectomia e/ou da exposição dos ovários e foram mantidas por 120 dias, data de realização da eutanásia. O grupo Sham recebeu água diariamente. Noventa dias após a ovariectomia bilateral foram confecionados defeitos ósseos nas calvárias de todos os animais e após trinta dias as ratas foram eutanasiadas. As amostras de tecido ósseo foram coletadas e foi realizado o processamento para a obtenção das lâminas histológicas. Foram realizadas as análises morfológicas e morfométrica, onde foi estimada a área (mm2) e porcentagem (%) relativa de osso neoformado utilizando o Software Image J. A avaliação morfológica evidenciou a ação benéfica do licopeno pois os animais que receberam esse antioxidante apresentaram um tecido ósseo mais maduro, com maior presença de osteócitos quando comparados aos demais grupos. Por meio das análises morfométricas verificou-se maior neoformação óssea para os animais que receberam o licopeno (p<0,05). Diante dos resultados obtidos, concluiu-se que o licopeno na concentração de 45 mg/Kg teve efeito benéfico no processo de reparação, promovendo significante formação óssea frente à ausência de hormônios estrogênicos.

Ferrans and Powers Quality of Life Index Applied to Nursing Students during the COVID-19 Pandemic / Índice de Qualidade de Vida de Ferrans e Powers Aplicado a Estudantes de Enfermagem Durante a Pandemia de COVID-19

COVID-19 pandemic can have a significant impact on an individual's physical and emotional well-being. However, it is important to note that not all experiences of the pandemic are negative. This study aims to evaluate the perception of quality of life of students enrolled in a nursing course during the COVID-19 pandemic by administering a global questionnaire. A quantitative, exploratory, cross-sectional, and descriptive study to investigate perception of quality of life of students during the COVID-19 pandemic. Participants comprised 80 students graduating with a nursing qualification between 2020 and 2021. The Ferrans and Powers Quality of Life Index was used in the study. The mean scores are reported as follows: health/functioning domain (22.06), socioeconomic domain (21.40), psychological/spiritual domain (23.34), and family domain (23.06), with an average general quality of life index of 22.46. After evaluating the domains, it was found that there was a higher perception of the psychological/spiritual domain and lower perception of the socioeconomic domain. The results supported the internal consistency reliability of the entire Quality of Life (QLI; alpha=0.95) and the four subscales (alpha=0.88, 0.71, 0.92, and 0.80). The study suggests that the COVID-19 pandemic did not have an impact on the perceived quality of life among students.(AU)

Pandemia de COVID-19 pode ter um impacto significativo no bem-estar físico e emocional de um sujeito. No entanto, é importante notar que nem todas as experiências da pandemia são negativas. Este estudo teve como objetivo avaliar a percepção da qualidade de vida de estudantes matriculados em um curso de enfermagem durante a pandemia de COVID-19 por meio da aplicação de um questionário global. Estudo quantitativo, exploratório, transversal e descritivo para investigar a percepção da qualidade de vida de escolares durante a pandemia de COVID-19. Participaram 80 estudantes concluintes do curso de enfermagem entre 2020 e 2021. O Índice de Qualidade de Vida de Ferrans e Powers foi utilizado no estudo. Os escores médios foram relatados da seguinte forma: domínio saúde/funcionamento (22,06), domínio socioeconômico (21,40), domínio psicológico/espiritual (23,34) e domínio família (23,06), com média geral do índice de qualidade de vida de 22,46. Após a avaliação dos domínios, constatou-se maior percepção do domínio psicológico/espiritual e menor percepção do domínio socioeconômico. Os resultados apoiaram a confiabilidade da consistência interna de toda a Qualidade de Vida (QLI; alfa=0,95) e as quatro subescalas (alfa=0,88, 0,71, 0,92 e 0,80). O estudo sugere que a pandemia de COVID-19 não teve impacto na qualidade de vida percebida entre os estudantes.(AU)

Effect of dry needling and instrumental myofascial release on masticatory, facial, and cervical muscles of patients with temporomandibular disorders of muscular origin.

Background: To evaluate the effectiveness of dry needling (DN) and instrumental myofascial release (IMR) therapies in the cervico-cranio-mandibular system through pain, bite force, and distribution of occlusal contacts in patients with muscular temporomandibular disorders. Material and Methods: Thirty patients were divided into treatment groups: DN (n=15) and IMR (n=15). Therapeutic efficacy regarding pain perception and tolerance of masticatory, facial, and cervical muscles, bite force, and distribution of occlusal contacts were analyzed in this observational longitudinal clinical study pre/post-intervention and pre/post one month of therapeutic intervention. The data were tabulated and statistically analyzed (repeated measures and Bonferroni post-hoc test, p<0.05). Results: There was a statistically significant difference in pain between the groups in the comparison of pre- and post-intervention with effect on time versus intervention in the head and neck. Pain perception and tolerance showed a statistical effect of time on the temporal, suboccipital, sternocleidomastoid, mental (right and left), right masseter, and left trapezius muscles. There was a statistically significant effect of the intervention on the mentalis, supraorbital, and infraorbital (right and left) muscles. There was a statistically significant effect of the interaction on the upper masseter (right and left), anterior temporal (left), suboccipital, sternocleidomastoid, and mentalis (left) muscles. There was an increase in post-intervention molar bite force in the groups, with a statistical effect on time versus intervention in the right and left regions. Contact of occlusal forces at the maxilla/mandible interface showed a difference between the mean times on teeth 26-36 after versus 1 month after the intervention. Conclusions: The two therapeutic techniques are viable for the treatment of muscular temporomandibular disorders; however, IMR proved to be more effective immediately after the intervention and after one month. Key words:Temporomandibular disorders, pain, masticatory muscles, facial muscles, cervical muscles, dry needling, instrumental myofascial release.

Orthodontic treatment of children with anterior open bite and posterior crossbite: An analysis of the stomatognathic system.

Dental malocclusions are deviations from normalities due to the inadequate growth and development of the dental arch which provides functional changes to the stomatognathic system. The aim of this longitudinal study was to evaluate the electromyographic activity (EMG) the masseter and temporalis muscles, strength of the orofacial tissues and occlusal force of children with anterior open bite (n = 15) and posterior crossbite (n = 20), 7 days after the removal of the orthodontic apparatus. A fixed horizontal palatal crib was used in the treatment of anterior open bite and the fixed appliances Hyrax or MacNamara was used in the treatment of posterior crossbite. EMG of the masticatory muscles was recorded using an electromyograph with wireless sensors during mandibular tasks. Habitual chewing was assessed using the integral of the linear envelope of the electromyographic signal in the masticatory cycles. The strength of the tongue and facial muscles was measured using the Iowa Oral Pressure Instrument. T-Scan was used to analyze the force of occlusal contact. Molar bite force was measured by digital dynamometer. Significant differences (p < 0.05) were found in the EMG data of the masseter and temporalis muscles in the static and dynamic mandibular tasks. There were no significant difference in strength of orofacial tissues, occlusal contact force and molar bite force 7 days after the removal of the orthodontic apparatus. The results of this study suggest that the orthodontic treatment of anterior open bite and posterior crossbite in children promoted functional alteration in the electromyographic activity of masseter and temporalis muscles.

Effect of acupuncture on the molar bite force in women with chronic neck pain / Efecto de la acupuntura sobre la fuerza de mordida en mujeres con cervicalgia crónico

Objetive: To investigate the maximum molar bite force in women with chronic neck pain after treatment with acupuncture. Materials and Methods: Twenty-three women with chronic neck pain participated. Dynamometer was used to measure the right and left maximum molar bite force. Dong Bang acupuncture needles - 0.25 mm x 30 mm was inserted into the integumentary tissue. Treatment was 10 sessions, each 30 minutes long and twice a week. Results: The right (p = 0.01) and left (p = 0.004) molar bite force was assessed after treatment with acupuncture, and showed increased occlusal strength. Conclusions: This study suggests a functional improvement in the stomatognathic system in women with chronic cervical pain after treatment with acupuncture. However, it is important to note that further research is needed to fully elucidate the long-term effects and potential clinical implications of these findings in the field of pain management and rehabilitation.

Objetivo: Investigar la fuerza masticatoria máxima en mujeres con dolor crónico de cuello después del tratamiento con acupuntura. Materiales y Métodos: Participaron veintitrés mujeres con dolor crónico de cuello. Se utilizó un dinamómetro para medir la fuerza máxima de mordida del molar derecho e izquierdo. Agujas de acupuntura Dong Bang se insertaron 0,25 mm x 30 mm en el tejido tegumentario. El tratamiento fue de 10 sesiones, cada una de 30 minutos de duración, dos veces por semana. Resultados: Se observó la fuerza de mordida del molar derecho (p=0.01) e izquierdo (p=0.004) después del tratamiento con acupuntura, que mostró un aumento de la fuerza oclusal. Conclusión: Este estudio sugiere una mejora funcional en el sistema estomatognático en mujeres con dolor cervical crónico después del tratamiento con acupuntura. Sin embargo, es importante señalar que se necesita más investigación para dilucidar por completo los efectos a largo plazo y las posibles implicaciones clínicas de estos hallazgos en el campo del tratamiento y la rehabilitación del dolor.

Stroke: An electromyographic approach to the masseter and temporal muscles, orofacial soft tissue pressure, and occlusal force.

Stroke is a cerebrovascular disease that triggers changes in the central and peripheral nervous systems, and can compromise human body function. This cross-sectional observational study aimed to analyze the electromyographic (EMG) activity of the masseter and temporal muscles, orofacial soft tissue pressure, and strength of occlusal contacts in patients who had suffered a stroke. Twenty-four patients were divided into two groups: stroke (n = 12) and control (n = 12). The EMG of the masseter and temporal muscles was evaluated during mandibular rest, protrusion, right laterality, left laterality, and maximal voluntary contraction. The Iowa Oral Pressure Instrument (IOPI) was used to measure pressure from the tongue, lips, and buccinator muscles. A computerized system for occlusal analysis (T-Scan III) was used to measure the occlusal contact points of the right and left hemiarches (upper and lower) and the upper and lower first molars. Data were subjected to Student's t-test (p < 0.05). The stroke group had lower normalized electromyographic activity, with a significant difference in the left temporal muscle during rest (p = 0.03) when compared to the control group. There was a significant difference between the groups in tongue pressure (p = 0.004) with a lower mean value in the stroke group. There was a significant difference between the groups in the evaluation of the occlusal contact points of the first permanent molars, with a lower mean percentage in the stroke group. The results indicate that stroke negatively affects functional performance of the stomatognathic system.

Functional assessment of respiratory muscles and lung capacity of CrossFit athletes.

CrossFit is a high-intensity training related to physical fitness and respiratory capacity that can promote changes in lung function. This cross-sectional study was aimed at evaluating respiratory muscle strength, electromyographic (EMG) activity, and lung capacity in CrossFit athletes. Thirty subjects aged between 25 and 35 years were divided into groups: CrossFit athletes (n=15) and sedentary individuals without comorbidities (n=15). Respiratory muscle strength was evaluated using maximal inspiratory and expiratory pressures, lung capacity, and EMG of the sternocleidomastoid, serratus anterior, external intercostal, and diaphragm muscles at respiratory rest, maximal inspiration and expiration, and respiratory cycle. Data were tabulated and subjected to statistical analyses (t-test and Spearman test, P<0.05). Respiratory muscle strength on EMG of the sternocleidomastoid, serratus, external intercostal, and diaphragm muscles at the respiratory cycle and maximal forced inspiration and expiration were higher in the CrossFit athletes group than in the sedentary group without comorbidities. CrossFit athlete group showed significantly strong positive correlation between maximal inspiratory and expiratory muscle strengths (Spearman rho= 0.903, P=0.000), with increasing muscle strength during inspiration favoring an increase in strength during expiration. The forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) also showed a significantly high positive correlation (Spearman rho=0.912, P=0.000) in the CrossFit athletes group, showing that higher FVC favors higher FEV1. The results of this study suggest that improved fitness is based on increased respiratory muscle strength on EMG in CrossFit athletes.

Electromyographic analysis of the stomatognathic system of children with Molar-incisor hypomineralization.

INTRODUCTION: Molar-incisor hypomineralization (MIH) is a qualitative defect of dental enamel that affects one or more permanent first molars, with or without involvement of the incisor teeth. This condition leads to challenges to dental care and treatment planning. AIM: Based on the hypothesis that children who have MIH possibly present alterations in postural and masticatory activities and considering the absence of studies investigating these parameters, the present study evaluated the functionality of the stomatognathic system considering the mentioned aspects. MATERIALS: The comparison of individuals with (MIHG; n = 32) and without MIH (CG; n = 32) was evaluated by electromyographic activity of the masseter and temporal muscles (right and left), as well as evaluation of the masticatory cycles during habitual mastication. RESULTS: MIHG showed muscle hyperactivity in postural and dynamic conditions compared to the CG; higher electromyographic values for MIHG when compared to CG in the following postural conditions: at rest for the right temporal (p = 0.00) and left temporal muscles (p = 0.03); in the protrusion to the right temporal muscle (p = 0.02); in the right laterality for the right masseter (p = 0.00) and left temporal muscles (p = 0.01); in the left laterality for the right masseter (p = 0.03) and left temporal (p = 0.04) muscles. In dynamic conditions with consistent food, significance was observed for the left temporal (p = 0.01); and with soft food for the right (p = 0.01) and left temporal muscles (p = 0.04). CONCLUSIONS: Children with MIH seem to have impaired functionality of the stomatognathic system. Children with MIH have alterations in the stomatognathic system.

Prevalence of chewing difficulty in older people in long-term care: A systematic review and meta-analysis.

BACKGROUND: Many factors can influence chewing, including age. The ageing process causes morphophysiological changes in the body, including in the performance of the stomatognathic system, which directly affect chewing and swallowing. OBJECTIVE: To determine the prevalence of chewing difficulty in older people in long-term care. METHODS: We searched six electronic databases and the grey literature. Qualitative and quantitative analyses, including risk of bias, were performed on studies that met the inclusion criteria. The meta-analysis of proportions with a random effects model was performed, and heterogeneity was explored by meta-regression. Risk of bias was determined using the Joanna Briggs Institute's Critical Appraisal Checklist. The certainty of evidence was verified using the GRADE tool. RESULTS: Twelve articles were included in the meta-analysis. The pooled prevalence estimate was 35% (95% confidence interval, 0.19-0.54). As heterogeneity still persisted even after sensitivity analysis, the predictors of mean sample age and sample size were meta-regressed to assess whether these covariates explained the variance between effect sizes. The covariable sample size of the study included in the analysis explained 84.3% of the heterogeneity existing in the analysis (R2  = 84.3%; P = .0008). The risk of bias was low in three studies, eight studies had a moderate risk of bias and one study had a high risk of bias. As for the prevalence of chewing difficulty, the GRADE criteria were considered very low. CONCLUSION: About one in three older people in long-term care have difficulty in chewing.

Amyotrophic Lateral Sclerosis: An Analysis of the Electromyographic Fatigue of the Masticatory Muscles.

Amyotrophic lateral sclerosis is a chronic degenerative disease that affects motor neurons, thereby promoting functional changes in the human body. The study evaluated the electromyographic fatigue threshold of the masseter and temporal muscles of subjects with amyotrophic lateral sclerosis. A total of eighteen subjects were divided into two groups: amyotrophic lateral sclerosis (n=9) and disease-free control (n=9). The groups were equally divided according to gender (7 males, 2 females). The fatigue threshold was analysed using median frequencies obtained during the 5-second window (initial [IP], mid [MP], and final [FP] periods) of electromyographic signalling of the masseter and temporal muscles bilaterally, with reduction in muscle force during maximal voluntary dental clenching. Significant difference (p<0.05) in the left temporal muscle: IP (p=0.05) and MP (p=0.05) periods was demonstrated. The amyotrophic lateral sclerosis group showed a decrease in median frequency of the electromyographic signal of the masseter and temporal muscles compared to the control group. Amyotrophic lateral sclerosis promotes functional impairment of the stomatognathic system, especially at the electromyographic fatigue threshold of the masticatory muscles.

Effect of intervertebral disc degeneration on the stomatognathic system function in adults.

OBJECTIVE: To analyze the electromyographic activity (EMG) and thermographic patterns of the masseter and temporalis muscles and pressure of the orofacial tissues in individuals with intervertebral disc degeneration (IDD). METHODS: This study had two distinct groups: with IDD (n = 16) and controls (n = 16). EMG at rest, protrusion, right and left laterality, and maximum voluntary contraction were evaluated. Tongue, orbicularis oris, and buccinator muscles pressures were measured by Iowa Oral Performance Instrument. The thermographic patterns were analyzed using infrared thermography. RESULTS: Comparisons between groups showed significant differences regarding at rest [right (p = 0.05) and left (p = 0.05) masseter and right temporal (p = 0.05)], orofacial tissue pressure [tongue (p = 0.001), orbicularis oris (p = 0.01), and buccinator (p = 0.0001)], but no significant differences for the thermographic patterns. CONCLUSION: IDD modifies the functionality of the craniomandibular complex, influencing the performance of the stomatognathic system.

Impact of Hemorrhagic Stroke on Molar Bite Force: A Prospective Study.

Stroke is a neurological deficit of cerebrovascular origin that promotes physical impairments of adult individuals. The present study is aimed to demonstrate whether hemorrhagic stroke affects the maximum molar bite force. The prospective study carried in Centro Universitario Claretiano de Batatais, Brazil, determined the distribution of the sample into two groups: hemorrhagic stroke group (n=18, median age, 62.5 years) and disease-free group (n=18, median age, 62.0 years), with 10 men and 8 women in each group. Subjects were paired one-to-one (age and body mass index). The dynamometer was used to measure the maximum molar bite force (right and left). All analyses were performed with a significance level of 5% (Student's t-test). Differences were found on the right (p=0.048) and left (p=0.042) molar bite force, with lower bite force (both sides) in hemorrhagic stroke group. The study suggests that hemorrhagic stroke negatively affects the maximum molar bite force and necessitates changes in food intake to nutritious and softer consistency foods.

Análise dos efeitos da marcha suspensa na atividade eletromiográfica dos membros inferiores e irradiação motora aos membros superiores em lesados medulares / Analysis of the effects of body weight-supported gait training on the electromyographic activity of the lower limbs and motor irradiation to the upper limbs in spinal cord injured patients

A reabilitação na esteira com suporte parcial de peso (ESPP) nos indivíduos lesados medulares pode reproduzir de modo passivo a marcha, proporcionando-lhes a descarga de peso em membros inferiores (MMII) e a manutenção da postura ortostática. O objetivo do estudo foi analisar se, durante a marcha passiva na ESPP, existe irradiação motora de MMII aos membros superiores. Foram selecionados três indivíduos do gênero masculino, com diagnóstico de Traumatismo Raquimedular baixo (T10 e L1), classificados como ASIA A com preservação parcial de raízes nervosas. Os indivíduos foram submetidos a uma avaliação passiva da marcha na ESSP, utilizando a avaliação eletromiográfica dos músculos: bíceps braquial (BB), reto femoral (RF) e gastrocnêmio lateral (GL) bilateralmente e a uma análise estatística, incluindo testes de Shapiro-Wilk e de Levene, One way ANOVA, post-hoc Tukey HSD. Na condição clínica de repouso, observou-se menor ativação dos músculos BB bilateralmente, quando comparado aos músculos RF e GL, fato justificado pelos comprometimentos secundários advindos da lesão dos indivíduos. As condições clínicas do ciclo da marcha (CM) repetiram-se três vezes; no CM1 observou-se uma maior ativação eletromiográfica do músculo GL direito e uma menor ativação do músculo BB direito, e estatisticamente, GL direito e BB esquerdo demonstraram maior atividade média (resultados estatisticamente significantes). No CM2 o mesmo padrão de ativação do CM1 foi observado, no entanto o músculo RF direito reduziu seu limiar de ativação. No CM3 os níveis de ativação das condições anteriores mantiveram-se, no entanto, o músculo RF esquerdo apresentou aumento nos limiares de ativação eletromiográfica, quando comparado aos demais músculos. Com base nestes resultados, o músculo BB apresentou variações quantitativas na ativação eletromiográfica, determinando a presença de irradiação motora de MMII para superiores durante o CM. Em uma análise qualitativa, foi observado que durante as fases de apoio da marcha houve "picos" de ativação deste músculo. [au]

Rehabilitation on the treadmill with partial body weight support (PBWS) in individuals with spinal cord injuries can passively reproduce gait, helping them with weight bearing on the lower limbs (LL) and orthostatic posture. The objective of the study was to assess motor irradiation from the lower limbs to the upper limbs during gait training with PBWS. The participants were three male individuals diagnosed with low spinal cord injury (T10 and L1), classified as ASIA A, with partial preservation of nerve roots. Subjects were submitted to gait training with PBWS and electromyographic assessment of the muscles Biceps brachii (BB), Rectus femoris (RF) and Lateral Gastrocnemius (LG) on both sides. Statistical analysis included Shapiro-Wilk and de Levene tests, One way ANOVA test and Tukey's HSD post-hoc test. In the resting state, there was less activity of BB muscles on both sides when compared to the RF and LG, which can be explained by the secondary impairments arising from the individuals' injury. The gait cycle (GC) was repeated three times; in GC1 there was greater electromyographic activity in the right LG muscle and lower activity of the right BB muscle and, statistically, right LG and left BB showed higher mean activity (statistically significant results). In GC2, the same pattern of activity of GC1 was observed, but the right RF muscle reduced its activation threshold. In GC3, the activity levels of the previous cycles were maintained, but the left RF muscle showed an increase in the thresholds of electromyographic activation when compared to the other muscles. Based on these results, the BB muscle presented quantitative variations in electromyographic activation, demonstrating the presence of motor irradiation from LL to upper limbs during the GC. The qualitative analysis showed "peaks" of activity in this muscle mainly during the support phases of the gait training. [au]

Intervertebral Disc Degeneration: Functional Analysis of Bite Force and Masseter and Temporal Muscles Thickness.

Intervertebral disc degeneration is a pathological condition associated with the intervertebral disc and is related to functional alterations in the human body. This study aimed to evaluate the maximum molar bite force and masseter and temporal muscles thickness in individuals with intervertebral disc degeneration. Thirty-two individuals were divided into two groups: those with degeneration of intervertebral discs (n=16) and those without degeneration (n=16). The maximum molar bite force (on the right and left sides) was measured using a dynamometer. Masseter and temporal muscle thickness during mandibular task rest and dental clenching in maximum voluntary contraction were analysed using ultrasound. Significant differences in the left molar bite force (p=0.04) were observed between the groups (Student's t-test, p<0.05). The intervertebral disc degeneration group had a lower maximum molar bite force. No significant differences in muscle thickness were observed between the masseter and temporal muscles in either group. However, based on clinical observations, the group with intervertebral disc degeneration presented less masseter muscle thickness and greater temporal muscle thickness in both mandibular tasks. Degenerative disease of the intervertebral discs promoted morphofunctional changes in the stomatognathic system, especially in maximum molar bite force and masticatory muscle thickness. This study provides insight into the interaction between spinal pathology and the stomatognathic system, which is important for healthcare professionals who treat patients with functional degeneration.