RESUMEN
PURPOSE: To analyze the functions of the stomatognathic system in children with or without molar-incisor hypomineralization (MIH). METHODS: For this cross-sectional study, 72 children aged 6-12 years were recruited and divided in two groups: with MIH (G1) and without MIH (G2). T-SCAN was used to verify the distribution of occlusal contacts, gnathodynamometer to measure maximum molar bite force, and Iowa Oral Pressure Instrument (IOPI) to assess the strength of facial expression muscles. The t test and paired t test (p ≤ 0.05) were used for statistical comparisons. RESULTS: The molars affected by MIH exhibited lower distribution of occlusal forces (p < 0.001) and lower maximum molar bite force (p < 0.05) compared to the molars in the control group. However, there was no difference between the MIH-affected sides compared to the unaffected side, nor between the molars affected by MIH and their antagonists (p > 0.05). There were no differences in the forces of the facial expression muscles between the groups. CONCLUSIONS: These findings suggest that MIH significantly impacts occlusal force distribution and bite force, but not facial expression musculature.
Asunto(s)
Fuerza de la Mordida , Músculos Masticadores , Diente Molar , Humanos , Niño , Estudios Transversales , Masculino , Femenino , Diente Molar/fisiopatología , Músculos Masticadores/fisiopatología , Hipoplasia del Esmalte Dental/fisiopatología , Sistema Estomatognático/fisiopatología , Hipomineralización MolarRESUMEN
BACKGROUND: The literature does not report any association between habitual snoring and sleep bruxism, but these situations can be a reason for frequent complaints of individuals, impairing the quality of life. This study was performed to investigate the sleep period and amount of habitual snoring in individuals with sleep bruxism observing expiratory, inspiratory, and mixed snoring. MATERIAL AND METHODS: A total of 90 individuals were screened and divided into the following groups: with sleep bruxism (n=45) and those without sleep bruxism (n=45). Single night sleep polysomnography was performed to diagnose sleep bruxism, quantify habitual snoring and sleep period. The results were tabulated and submitted to a Multivariate analysis of variance (MANOVA) to compare the means of the two independent groups, considering the affected diagnosis of sleep bruxism, snoring (independent variables) and age as covariate. For the post hoc, was used correcting for multiple comparisons (Bonferroni test, P<.05). RESULTS: There was statistically significant difference among the groups ( p=.001) in the sleep period, in that individuals with sleep bruxism slept for a longer duration (with sleep bruxism group: 460 minutes and without sleep bruxism group: 401 minutes). There were no statistically significant differences among the groups for the number of inspiratory, expiratory and mixed snores, but was observed greater amount of snoring in the with sleep bruxism group. CONCLUSIONS: The main finding of this study is that individuals with sleep bruxism slept longer than the control group. It may also be suggested that individuals with sleep bruxism tended to increase the amount of habitual snoring during sleep.
Asunto(s)
Bruxismo del Sueño , Ronquido , Humanos , Polisomnografía , Calidad de Vida , Factores de TiempoRESUMEN
BACKGROUND: Neurodegenerative diseases that affect the cerebellum, especially in elderly individuals, cause impairment of motor coordination and quality of life. The presente study evaluated the electromyographic activity and thickness of the right and left masseter and temporal muscles, and the maximum molar bite force of individuals with spinocerebellar ataxia. MATERIAL AND METHODS: Twenty-eight individuals were divided into two groups: those with (n=14) and without (n=14) spinocerebellar ataxia. Data on the masticatory muscles obtained from the electromyographic activity (resting, right and left laterality and protrusion), muscle thickness (maximal voluntary contraction and tensile strength) and maximum bite force (right and left) were tabulated and descriptive analysis using Student's t-test (P ≤ 0.05). RESULTS: In the comparison between groups, greater electromyographic activity was demonstrated for individuals with spinocerebellar ataxia, with a statistically significant difference in protrusion and laterality for the temporal muscles (P = 0.05). There was no statistically significant difference between the groups for masticatory muscles thickness in the conditions evaluated. For maximum molar bite force, the group with spinocerebellar ataxia showed lower bite force (P ≤ 0.05). CONCLUSIONS: The data obtained suggest that spinocerebellar ataxia promotes functional reduction in the stomatognathic system, mainly affecting the electromyographic activity and bite force, hindering chewing, with a resultant alteration of nutritional intake and a decrease of quality of life.
Asunto(s)
Fuerza de la Mordida , Ataxias Espinocerebelosas/fisiopatología , Sistema Estomatognático/fisiopatología , Adulto , Brasil , Estudios de Casos y Controles , Oclusión Dental , Electromiografía , Femenino , Lateralidad Funcional , Humanos , Masculino , Mandíbula , Músculo Masetero/fisiopatología , Masticación , Músculos Masticadores/fisiopatología , Persona de Mediana Edad , Diente Molar , Estudios Prospectivos , Calidad de Vida , Músculo Temporal/fisiopatología , Trastornos de la Articulación Temporomandibular/fisiopatologíaRESUMEN
Neck pain is the most common musculoskeletal complaint among computer office workers. There are several reports about the coexistence of neck pain and temporomandibular disorders (TMD). However, there are no studies investigating this association in the context of work involving computers. The purpose of this study was to verify the association between TMD and neck pain in computer office workers. Fifty-two female computer workers who were divided into two groups: (i) those with self-reported chronic neck pain and disability (WNP) (n = 26) and (ii) those without self-reported neck pain (WONP) (n = 26), and a control group (CG) consisting of 26 women who did not work with computers participated in this study. Clinical assessments were performed to establish a diagnosis of TMD, and craniocervical mechanical pain was assessed using manual palpation and pressure pain threshold (PPT). The results of this study showed that the WNP group had a higher percentage of participants with TMD than the WONP group (42·30% vs. 23·07%, χ(2) = 5·70, P = 0·02). PPTs in all cervical sites were significantly lower in the groups WNP and WONP compared to the CG. Regression analysis revealed TMD, neck pain and work-related factors to be good predictors of disability (R(2) = 0·93, P < 0·001). These results highlighted the importance of considering the work conditions of patients with TMD, as neck disability in computer workers is explained by the association among neck pain, TMD and unfavourable workplace conditions. Consequently, this study attempted to emphasise the importance of considering work activity for minimising neck pain-related disability.
Asunto(s)
Dolor Crónico/fisiopatología , Músculos del Cuello/fisiopatología , Dolor de Cuello/fisiopatología , Enfermedades Profesionales/fisiopatología , Exposición Profesional/prevención & control , Trastornos de la Articulación Temporomandibular/fisiopatología , Lugar de Trabajo , Adulto , Dolor Crónico/diagnóstico , Dolor Crónico/etiología , Computadores/estadística & datos numéricos , Estudios Transversales , Evaluación de la Discapacidad , Ergonomía , Femenino , Humanos , Dolor de Cuello/etiología , Enfermedades Profesionales/diagnóstico , Enfermedades Profesionales/etiología , Dimensión del Dolor , Proyectos Piloto , Rango del Movimiento Articular , Conducta Sedentaria , Autoinforme , Trastornos de la Articulación Temporomandibular/diagnóstico , Trastornos de la Articulación Temporomandibular/etiología , Interfaz Usuario-ComputadorRESUMEN
This study aimed to comparatively analyse the electromyographic activity of the masseter and temporal muscles at rest and during mandible postural clinical conditions (right and left laterality, protrusion and maximum voluntary contraction), right and left maximum molar bite forces and the masticatory efficiency of individuals with schizophrenia or mood disorders - all medicated (medicated groups) compared with control group (healthy volunteers) via electromyography. Individuals were distributed into three groups: Group I (Schizophrenia - 20 individuals), Group II (mood disorders - 20 individuals) and Group III (Control - 40 individuals). Basically, the results were only statistically significant for the clinical mandible conditions and bite force. The most unsatisfactory results were observed in the medicated groups in relation to the control group. The group with mood disorders obtained the most unsatisfactory results compared with the group with schizophrenia. It was suggested by these observations that the association of mood disorders and schizophrenia with medication has negatively affected the stomatognathic system in relation to controls when the electromyography and bite force were used for the analysis.
Asunto(s)
Fuerza de la Mordida , Músculo Masetero/fisiopatología , Masticación/fisiología , Trastornos del Humor/fisiopatología , Esquizofrenia/fisiopatología , Músculo Temporal/fisiopatología , Adulto , Estudios de Casos y Controles , Electromiografía/métodos , Femenino , Humanos , Masculino , Músculo Masetero/efectos de los fármacos , Persona de Mediana Edad , Trastornos del Humor/tratamiento farmacológico , Esquizofrenia/tratamiento farmacológico , Músculo Temporal/efectos de los fármacos , Adulto JovenRESUMEN
The objective of this study was to determine whether dentofacial deformities (class II and class III) influence maximum isometric tongue strength compared with a group without deformities. A total of 126 adult patients participated in the study. Of these, 45 had a class II diagnosis (14 men and 31 women) and 81 a class III diagnosis (35 men and 46 women), all of them with indication of orthognathic surgery. Fifty adult volunteers (17 men and 33 women) with no changes in dental occlusion (class I) and with no clinical signs of dysfunction of the temporomandibular joint represented the control group. Tongue strength (in N) was measured with a dynamometer. The maximum strength of the anterior portion was determined with the instrument positioned on the retroincisor region and the maximum strength of the dorsum with the instrument positioned in the region of the hard palate. Data were analysed statistically by analysis of variance (anova) and by the Pearson correlation test. No significant difference (P > 0·05) in tongue strength in the anterior or dorsal region was observed between the groups with dentofacial deformities or between these groups and the control. The tongue strength of the anterior and dorsal regions was not influenced by the dentofacial deformity.
Asunto(s)
Contracción Isométrica/fisiología , Maloclusión de Angle Clase III/fisiopatología , Maloclusión Clase II de Angle/fisiopatología , Fuerza Muscular/fisiología , Lengua/fisiopatología , Adolescente , Adulto , Fenómenos Biomecánicos , Diseño de Equipo , Femenino , Humanos , Masculino , Dinamómetro de Fuerza Muscular , Paladar Duro/anatomía & histología , Adulto JovenRESUMEN
OBJECTIVE: To determine whether dentofacial deformities influence maximal isometric bite force in affected individuals compared to a control group. DESIGN: A total of 125 volunteer adult patients attended at a hospital participated in the study. Of these, 44 had a confirmed diagnosis of class II deformity (GII: 13 men and 31 women; mean age: 27 years) and 81 had class III deformity (GIII: 35 men and 46 women; mean age 25 years), all of them with indication of orthognathic surgery and under orthodontic treatment. Fifty adult volunteers (CG: 17 men and 33 women; mean age: 22 years) with no alterations of dental occlusion or clinical signs of temporomandibular joint dysfunction participated as controls. Maximal isometric bite force was measured with an electronic gnathodynamometer alternately positioned on each side of the dental arch in the region of the molar teeth and the subjects were instructed to bite it as strongly as possible, with the value being recorded in Newtons. Individuals with good understanding of oral language and with no cognitive or neuromuscular deficits were selected. Data were analysed statistically by the mixed effects model. RESULTS: There was no statistically significant difference (P>.05) in maximal isometric bite force between subjects with class II and class III dentofacial deformities, although the values for both groups were lower than those of control individuals. CONCLUSION: Dentofacial deformity affected maximal isometric bite force regardless of its pattern.
Asunto(s)
Fuerza de la Mordida , Maloclusión de Angle Clase III/terapia , Maloclusión Clase II de Angle/terapia , Ortodoncia Correctiva , Adolescente , Adulto , Femenino , Humanos , Contracción Isométrica/fisiología , Masculino , Maloclusión Clase II de Angle/fisiopatología , Maloclusión de Angle Clase III/fisiopatología , Diente Molar/fisiopatología , Prognatismo/fisiopatología , Prognatismo/terapia , Retrognatismo/fisiopatología , Retrognatismo/terapia , Adulto JovenRESUMEN
This research evaluated the effects of Brånemark protocol on electromyography of the masseter and temporal muscles. The patients were divided into two groups: Group I: patients who wore an implant-supported prosthesis in the mandibular arch following Brånemark protocol, and maxillary removable complete dentures; Group II: dentate individuals (control). Electromyography was carried out at rest, right (RL) and left (LL) laterality, protrusion and maximum voluntary contraction (MVC). Data were compared by t-test. At rest, a higher electromyographic (EMG) activity was observed in Group I, and the values were significant in the right masseter and left temporal muscles. In RL, there were statistically significant differences for right masseter (P < 0·01), left masseter and temporal muscles and for the left temporal muscle in LL (P < 0·05). In protrusion, Group I presented a higher EMG activity, and there was a statistically significant difference for the right masseter muscle (RM) (P < 0·05). In MVC, the EMG values were higher in Group II (control), but significant just for the right temporal muscle (P < 0·05). In conclusion, individuals with mandibular fixed dentures supported according to the Brånemark protocol and maxillary removable complete dentures showed a higher activity of masticatory muscles during the mandibular postural clinical conditions examined; however, in the MVC, Group I presented lower values when compared to dentate group. Despite presenting different EMG values in all of the clinical conditions, both groups showed similar EMG patterns of muscle activation which demonstrates that the proposed treatment can be considered as a good option for oral rehabilitation.
Asunto(s)
Prótesis Dental de Soporte Implantado , Dentadura Completa Superior , Músculo Masetero/fisiología , Músculo Temporal/fisiología , Anciano , Anciano de 80 o más Años , Brasil , Estudios de Casos y Controles , Electromiografía/métodos , Femenino , Humanos , Registro de la Relación Maxilomandibular , Masculino , Masticación/fisiología , Persona de Mediana Edad , Contracción Muscular/fisiología , Guías de Práctica Clínica como AsuntoRESUMEN
The purpose of this study was to evaluate the influence of age on the electromyographic activity of masticatory muscles. All volunteers were Brazilian, fully dentate (except for Group I - mixed dentition), Caucasian, aged 7-80, and divided into five groups: I (7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years) and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided with respect to gender (20 M/20 F). Surface electromyographic records of masticatory muscles were obtained at rest and during maximal voluntary contraction, right and left laterality, maximal jaw protrusion and maximal clenching in the intercuspal position. Statistically significant differences (P < 0.05) were found in all clinical conditions among the different age groups. Considerably different patterns of muscle activation were found across ages, with greater electromyographic activity in children and youth, and decreasing from adults to aged people.
Asunto(s)
Envejecimiento/fisiología , Fuerza de la Mordida , Masticación/fisiología , Músculos Masticadores/fisiología , Contracción Muscular/fisiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Electromiografía , Femenino , Humanos , Masculino , Desarrollo Maxilofacial , Persona de Mediana Edad , Estándares de Referencia , Adulto JovenRESUMEN
Dental absence interferes in the physiological functioning of the masticatory system, promoting occlusal and functional alterations. The purpose of this study was to verify maximal bite force and maximal bite force correlated with electromyographic activity in 14 partially edentulous and 14 dentate individuals. Bite force in right and left molar and incisor regions were registered using a dynamometer with capacity of up to 1000N, adapted for oral conditions and at the same time electromyography was performed using Myosystem-Br1 with electrodes positioned on right and left masseter and temporalis muscles, and one reference electrode on the frontal bone. The highest value out of three recordings was considered the individual's maximal bite force. Statistical analysis of the bite force data was performed by means of t-test and Pearson's bivariate correlation test was used for the analysis between bite and electromyographic activity using SPSS 12.0 software. Dentate individuals showed greater maximal bite force in the three regions. Correlations between electromyographic activity and bite force in the dentate group obtained positive coefficients for every muscle in the right molar region, for the left temporalis in the left molar region, and for every muscle in the incisive region. For the partially edentulous group, only the left temporalis muscle presented a positive correlation in the right molar region, there was positive correlation for the right masseter and right and left temporalis in the left molar region, and, in the incisive region, every muscle presented negative correlation. These data evidence the strong influence of dental loss over the maximal bite force and small correlation between bite force and electromyographic activity.
Asunto(s)
Fuerza de la Mordida , Electromiografía/instrumentación , Arcada Parcialmente Edéntula/fisiopatología , Músculo Masetero/fisiopatología , Diente Molar/fisiopatología , Músculo Temporal/fisiopatología , Adulto , Femenino , Humanos , Masculino , Programas InformáticosRESUMEN
AIM: The mandibular division of the trigeminal nerve is the largest of the three major divisions of the trigeminal nerve (fifth cranial nerve). In this way, many health professionals belonged to different fields are commonly evaluating patients suffering with orofacial pain and stomatognatic dysfunction associated to this structure. But, in the most cases, it is difficult to establish a correct diagnosis due to the anatomical complexity of the head and neck surfaces, especially when the focus is the trigeminal nerve. Thus, the objective of this research was to present the anatomical variations of the mandibular nerve and its branches correlated to more common clinical situations. METHODS: For this purpose, 20 human heads were anatomically dissected, so to study their structures, an external, medial and endocranial view. RESULTS: No significant variations related to ophthalmic and maxillary nerves were observed. Anatomical variations were observed in 20% of the total human heads dissected, all related to mandibular nerve and its branches: masseter, temporal, auriculotemporal and lingual. Variations in three to seven, on the number of the following nerves ramus, masseter and temporal were described. CONCLUSIONS: According to the present data using the described methodology, it was possible to conclude that anatomical variations are present in many subjects and they can explain many clinical situations that involve the stomatognathic structures.
Asunto(s)
Variación Genética , Nervio Mandibular/anatomía & histología , Adulto , Nervio de la Cuerda del Tímpano/anatomía & histología , Dolor Facial/etiología , Humanos , Complicaciones Intraoperatorias/prevención & control , Nervio Lingual/anatomía & histología , Traumatismos del Nervio Lingual , Masculino , Mandíbula/anatomía & histología , Persona de Mediana Edad , Traumatismos del Nervio TrigéminoRESUMEN
UNLABELLED: The masseter and temporal muscles of patients with maxillary and mandibular osteoporosis were submitted to electromyographic analysis and compared with a control group. In conclusion, individuals with osteoporosis did not show significantly lower masticatory cycle performance and efficiency compared to the control group during the proposal mastications. INTRODUCTION: This study aimed to examine electromyographically the masseter and temporal muscles of patients with maxillary and mandibular osteoporosis and compare these patients with control patients. METHODS: Sixty individuals of both genders with an average age of 53.0 +/- 5 years took part in the study, distributed in two groups with 30 individuals each: (1) individuals with osteoporosis; (2) control patients during the habitual and non-habitual mastication. The electromyographic apparel used was a Myosystem-BR1-DataHomins Technology Ltda., with five channels of acquisition and electrodes active differentials. Statistical analysis of the results was performed using SPSS version 15.0 (Chicago, IL, USA). RESULTS: The result of the Student's t test indicated no significant differences (p > 0.05) between the normalized values of the ensemble average obtained in masticatory cycles in both groups. CONCLUSION: Based on the results of this study, it was concluded that individuals with osteoporosis did not show significantly lower masticatory cycle performance and efficiency compared to control subjects during the habitual and non-habitual mastications. This result is very important because it demonstrates the functionality of the complex physiological process of mastication in individuals with osteoporosis at the bones that compose the face.
Asunto(s)
Mandíbula/fisiopatología , Masticación/fisiología , Maxilar/fisiopatología , Osteoporosis/fisiopatología , Anciano , Estudios de Casos y Controles , Electromiografía , Femenino , Humanos , Masculino , Músculo Masetero/fisiopatología , Persona de Mediana Edad , Músculo Temporal/fisiopatologíaRESUMEN
OBJECTIVE: The purpose of this study was to investigate correlations between masseter muscle activity and cephalometric measures in Angle's class III dental malocclusion under the clinical rest position. METHODS: Eight volunteers, both sex, age 7-12, were submitted to an electromyographic analysis of the masseter muscle, subdivided in the upper, medium and lower regions, and to a cephalometric analysis of 15 angle and linear measurements. After normalization, the data was subjected to a statistical, non-parametric Spearman correlation test, by means of the SPSS 12.0 program. RESULTS: Statistically significant correlations were observed between the clinical rest condition before and after the execution of exercises (a serie of mandibular movements), and the cephalometric measurements angle SN GoGn, angle SNA, angle SNB, angle SND, upper incisive. NA angle, upper incisive-NA distance, lower incisive. NB angle, lower incisive-NB distance and angle IMPA, and the different regions of the masseter muscle. CONCLUSIONS: The significant statistical correlation found between the cephalometric analysis and the function of the masseter muscle indicate a strong influence of the musculature under a clinical rest condition over the cranial-facial development in the Angle's class III dental malocclusion. There is a selective activity of the different regions of the masseter muscle under the clinical rest condition in the Angle's class III dental malocclusion. There is a demand for research to complement these findings in other classes of dental malocclusion.
Asunto(s)
Cefalometría/métodos , Electromiografía/métodos , Maloclusión de Angle Clase III/patología , Maloclusión de Angle Clase III/fisiopatología , Músculo Masetero/patología , Músculo Masetero/fisiología , Niño , Electrodos , Femenino , Humanos , Masculino , Mandíbula/fisiología , Descanso , Cráneo/crecimiento & desarrolloRESUMEN
The aim of this work was to analyze electromyographically the facial muscles: orbicularis oris (upper and lower fascicles), orbicularis oculi (right and left lateral portions) and frontal, in blind and clinically normal (control) individuals, in various clinical conditions. Electromyographic averages of all data collected were normalized by maximal voluntary contraction of the studied muscles and statistical analysis was performed by Student's t test, using "Statistical Package for the Social Sciences" software--SPSS 12.0 (Chicago, IL). It was found that electromyographic alterations occur in the facial musculature that influences facial expressions of individuals. Results for the orbicularis oris muscle demonstrated that myoelectric activity among blind and control subjects was greater for the control group at muscular rest, blowing, and in labial projection. Electromyographic analysis of the orbicularis oculi among blind and control subjects in three clinical conditions studied demonstrated that activity was greater for the control group at muscular rest, blinking, and forced blinking. For the frontal muscles were demonstrated that electromyographic activity was greater for blind individuals. These data suggest the influence of congenital blindness on muscular development, including alterations in electromyographic activity of skin musculature in individuals with visual impairment.
Asunto(s)
Ceguera/fisiopatología , Parpadeo/fisiología , Electromiografía , Expresión Facial , Músculos Faciales/fisiopatología , Adolescente , Adulto , Ceguera/congénito , Electrodos , HumanosRESUMEN
AIM: The success of ceramic restorations is influenced by biocompatibility and resistance provided after bonding with an adhesive system. The aim of this in vitro study was to evaluate the adhesive bond strength between ceramic (IPS Classic V, Ivoclar Vivadent) and composite resin (Z-250, 3M), submitted or not to thermocycling treatment. METHODS: Forty ceramic cylinders were obtained with the following dimensions: 2 mm diameter and 3 mm high. The bond surface was polished with polishing paper (#600), conditioned with 10% hydrofluoric acid and silanized, according to manufacturer's recommendations. Later, the ceramic cylinders were bonded, with resinous cement (Rely X, 3M) to composite resin cylinders (Z-250, 3M) with the same dimensions, under 1 kg load. The assemblies were divided into two groups submitted to the following treatments: Group 1 (control): immersed in distilled water at 37 degrees C for 3 days, and Group 2: thermocycled (500 cycles) into two baths (5 degrees C and 55 degrees C), with 1 min of storing time each. In order to evaluate the adhesive resistance, the assemblies were tractioned in a universal testing machine (EMIC MEM 2000) with a crosshead speed of 0.5 mm/min. Obtained data were submitted to statistical analysis (ANOVA and Tukey's test). RESULTS: The means (MPa) and standard deviation obtained for Groups 1 and 2 were, respectively, 29.64+/-9.48 and 17.55+/-4.78. Group 1 presented significantly higher values than Group 2 (P<0.05). CONCLUSION: The results obtained in this study showed that the thermocycling procedure decreased the adhesive resistance between the materials studied.
Asunto(s)
Cerámica , Resinas Compuestas , Cementos de Resina , Ensayo de Materiales , Mecánica , TemperaturaRESUMEN
This study verified the effect of unilateral teeth extraction on the periodontal ligament in gerbils (Meriones unguiculatus). Ten adult male gerbils weighing about 50 g had induced occlusal alterations by upper left molar extractions while the other ten animals, only submitted to surgical stress, were considered as controls. The periodontal ligament was characterized by qualitative and quantitative analysis, histological description and histomorphometric quantification. Significant alterations were observed on the left side of the experimental group (P < 0.05), the hypofunctional region, when it was compared with the contralateral side and the corresponding region of the control group. Two months after occlusal alterations induced by unilateral teeth extraction, atrophic histological alterations and a decrease in the periodontal space on the ipsilateral side characterized the periodontal ligament. In this study it was possible to conclude that the gerbil can be used in experimental models attempting to correlate the periodontium's biological response to various mechanical stresses, as the periodontal ligament was shown to be highly sensitive to occlusal alterations.
Asunto(s)
Análisis del Estrés Dental/veterinaria , Gerbillinae , Ligamento Periodontal/patología , Extracción Dental/veterinaria , Animales , Modelos Animales de Enfermedad , Masculino , Distribución Aleatoria , Extracción Dental/efectos adversosRESUMEN
AIM: To assess the effect of acupuncture on the temporal and masseter muscles activity employing surface electromyography. METHODS: Thirty volunteers were evaluated according to three groups of acupuncture application: selected local points, selected points at distance and association of local and distant points. Bipolar surface electrodes were positioned bilaterally on the anterior portion of temporal muscle, as well as in the median region of masseter muscle. An electromyograph connected to a computer and a specific software registered the muscular activity before and after acupuncture, in the following experimental conditions: 1- Rest Position (RP); 2- Maximum Intercuspation Clenching (MIC); 3- Bilateral Molar Clenching with Cotton Rolls (BMCCR). The mean values obtained for the activities of the studied muscles were submitted to Analysis of Variance and Tukey complementary test. RESULTS: The electromyographic activity of the studied muscles was lower after the application of the methods of acupuncture in the Rest, and higher after the application of the acupuncture in the Maximum Intercuspation Clenching; the electromyographic activity of the temporal muscle was higher than the masseter muscle in the Rest and lower in the Bilateral molar clenching with cotton rolls; the electromyographic activity showed to be modified after the three used methods of acupuncture in the Maximum Intercuspation Clenching. In this clinical condition, the method of long-distance acupuncture was higher than the application of local needles and the associated method. CONCLUSION: Acupuncture provided alterations in the activity of the studied muscles, favoring conditions of rest and muscular tightness.
Asunto(s)
Acupuntura , Electromiografía , Músculo Masetero/fisiología , Músculo Temporal/fisiología , Puntos de Acupuntura , Adulto , Fuerza de la Mordida , Femenino , Humanos , Contracción Isométrica/fisiología , MasculinoRESUMEN
This study had the goal of determining if the amplitude of the surface electromyograph signals changes in terms of time of analysis and subjects, deaf or normal listeners, when estimated in a 250 ms of length window, visually determined, considering the most stable signal period from the center of the chewing cycle. In order to do this, groups with control subjects, listeners and deaf individuals, who made use of the Brazilian sign language (LIBRAS), were studied. All participants performed continuous 5 s of chewing for the electromyographic recording of the temporalis and masseter muscles. The normalized RMS values of three chewing cycles were compared between and among groups. The results from the Kruskall-Wallis test did not show any statistically significant differences (p > 0.05) between the normalized RMS values obtained in the three individual chewing cycles, for each of the two completed and evaluated cycles, in both groups studied. The Mann-Whitney test showed that the mean normalized RMS values obtained in the first chewing cycle were higher for the control group when compared to the mean amplitude values of the first chewing cycle of the group of deaf volunteers. It can be concluded that, in these experimental conditions, the RMS values obtained from the select windows of 250 ms length duration, in relatively stable periods of the electromyographic signal of chewing cycles did not suffer any changes in terms of EMG register duration, in both studied groups, but does give evidence of the differences among the groups.
Asunto(s)
Sordera/fisiopatología , Músculo Masetero/fisiopatología , Masticación/fisiología , Músculo Temporal/fisiopatología , Adolescente , Adulto , Estudios de Casos y Controles , Electromiografía , Humanos , Lengua de Signos , Factores de TiempoRESUMEN
This study had as objective to analyze with computerized electromyography the masseter muscles bilaterally in twenty individuals with temporomandibular joint dysfunction (DTM), being: the group I consisting of ten individuals with complete dentition and group II constituted by ten individuals with posterior dental absences; comparing nine clinical activities: rest before and after exercises, maximum habitual intercuspation (MIH), right and left laterality, forced centric occlusion, protrusion, bilateral molar bite and chewing. It was utilized the Electromyography K6I-Myotronics, with eight canals and surface silver electrodes. By means of the results analysis, we verified significant differences between the groups (p < 0.01), being group I, presented greater electromyographic activity (32.98 microvolts), than the group II (22.31 microvolts), suggesting that this individuals presented low muscular activity. The interaction between the groups and the clinical activities was significant (p < 0.01), as well as between the groups, clinical activities and muscles (p < 0.05). To clarify which amongst the relative averages the clinical activities were different, calculated the critical value of Tukey, being that rest before and after exercises, MIH, right and left laterality, presented averages with similar distributions, with values below of the values of Tukey, as well as forced centric occlusion, protrusion, bilateral molar bite and chewing presented higher values than Tukey. Based on this research's data, we concluded that the electromyographical analysis of the masseter muscles in Individuals with TMD, dentulous and with dental absence showed that individuals with TMD, dentulous or not, presented elevated muscular activity in rest position and individuals with TMD, dentulous, presented higher electromyographical activity than the individuals with TMD and lacking posterior teeth.
Asunto(s)
Arcada Parcialmente Edéntula/complicaciones , Arcada Parcialmente Edéntula/fisiopatología , Músculo Masetero/fisiopatología , Trastornos de la Articulación Temporomandibular/complicaciones , Trastornos de la Articulación Temporomandibular/fisiopatología , Adulto , Estudios de Casos y Controles , Oclusión Dental , Electromiografía , Femenino , Humanos , Masculino , Masticación/fisiología , Descanso/fisiologíaRESUMEN
OBJECTIVE: The purpose of this study was to investigate the levels of upper member muscles' activation of deaf individuals, who use the Brazilian sign language - LIBRAS, comparing these findings to volunteers with no postural deviations and normal hearing METHODS: Forty eight volunteers divided into two groups comprising healthy and deaf subjects (24 volunteers for each group). The signs of rest were obtained with the volunteer maintaining the upper member in an anatomical position, but with the forearm flexed and sustained by the lower member. Maximum voluntary isometric contractions (MVIC) of the biceps, triceps, deltoid, and trapezius muscles were performed in the position of muscular function testing. Statistical analysis was performed using the SPSS-10.0. Continuous data with normal distribution were analyzed by ANOVA with the significance level of p < 0.01. RESULTS: The normalized electromyographic muscle data obtained in muscular rest do not show statistically significant differences among the studies muscles, in both groups. In the comparison of normalized RMS values obtained in MVIC, the mean values for the trapezius muscle of deaf group were statistically lower than control group. CONCLUSIONS: This study's results indicate there are no differences between the levels of muscular activation for arm biceps, arm triceps, and the anterior portion of the deltoid muscle between the mean normalized RMS values of deaf and healthy individuals.