scholarly journals Electromyographic activity of the masseter muscle in individuals with group function and canine guidance

2021 ◽  
Vol 15 (4) ◽  
pp. 232-238
Author(s):  
Nathália de Oliveira Domingos ◽  
Roberto Bernardino Júnior ◽  
Patrícia Teixeira de Carvalho Gaspar ◽  
Frederico Balbino Lizardo ◽  
César Ferreira Amorim ◽  
...  

Background. There is no general consensus in restorative dentistry about which lateral guidance should be established. Some studies have shown that canine guidance decreases the tension of masticatory muscles. Others have reported that group function might achieve a better physiologic distribution of occlusal forces. Also, some reports have shown that both guidances are equally acceptable. Despite all discussions, clinical evidence of one guidance being superior to another is limited. Thus, this study aimed to analyze the electromyographic (EMG) activity of masseter muscles in individuals with group function and canine guidance. Methods. Twenty volunteers of both genders, aged 20-25, were divided into two groups: GF (group function guidance, n=10) and CA (canine guidance, n=10). EMG activity of masseters was captured using surface electrodes during habitual maximum intercuspation (HMI) and right and left lateral jaw movements and recorded using EMG amplitude values (RMS – root means square). Student’s t-test was used to compare mean RMS values between the groups and lateral movements in each group. Results. During HMI, there was no difference in masseter EMG activity between the groups. Both masseters showed higher activity in group GF only on the right side during lateral movements, while the left masseter exhibited higher activity on the nonworking side in both groups. The activity of both masseters distributed by tooth was higher in group CA. Conclusion. During tooth restorative procedures, any guidance is acceptable considering HMI. However, group function guidance is more favorable during lateral movements due to greater dissipation of occlusal pressures.

Author(s):  
Priscila Bageston de Britto ◽  
Maurício André Bisi ◽  
William Dhein

Background: Temporomandibular disorders (TMD) are disorders of multifactorial origin that affect the temporomandibular joint and/or masticatory muscles. The TMD can generate compensations where physical therapy acts through myofascial releases and joint mobilizations to restore functionality. Objective: To verify the effects of manual therapy techniques on pain and electromyographic activity (EMG) of masticatory muscles in TMD patients. Methods: This is a quasi-experimental study composed of 10 subjects with TMD and 10 healthy subjects who underwent a session of myofascial release, joint mobilization and digit-pressure on the masticatory and cervical muscles. Pain levels and electromyographic activities of the temporal and masseter muscles were bilaterally assessed during the following situations: (1) Maximum Occlusion and (2) Chewing in the right and the left side with chewing gum. Data analysis was performed using BIOMEC-SAS software, in which the data were filtered with a 4th order Butterworth bandpass filter with 20-400hz and normalized as a percentage of maximum occlusion. Data were divided into homolateral and contralateral muscles alongside chewing. EMG variables were compared by factorial ANOVA, and pain by dependent t-test. Results: TMD patients had pain level reduction during maximum occlusion (Pre:4.55±2.2; Post:2.55±1.6; p=<0.001), right chewing (Pre:2.3±2.16; Post:0.4±0.69; p = 0.02) and left chewing (Pre: 1.0±1.15; Post:0.10±0.31; p = 0.05). There was no effect of manual therapy techniques on the EMG activity bilaterally of the temporal (p = 0.617) and masseter (p = 0.926) muscles during chewing. Patients with TMD had higher EMG activities during chewing on the homolateral temporal (p = 0.001) and masseter (0.004) muscles compared to subjects without injury. Conclusion: Manual therapy techniques reduced pain level in TMD patients. No changes in EMG activity were observed after manual therapy techniques. Finally, the study provides evidence of the influence of manual therapy techniques on short-term pain.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243495
Author(s):  
Carla Moreto Santos ◽  
Marcelo Palinkas ◽  
Wilson Mestriner-Júnior ◽  
Isabela Hallak Regalo ◽  
Paulo Batista de Vasconcelos ◽  
...  

The maintenance of postural balance can be influenced by the lifestyle of a population. This study aimed to determine the electromyographic activity of the masseter and temporalis muscles during mandibular tasks and habitual and non-habitual chewing in indigenous individuals to reveal the differences among white Brazilian individuals. Sixty Brazilians (18 and 28 years) were divided into two groups: 30 Xingu indigenous individuals and 30 white Brazilian individuals, with 20 men and 10 women in each group. The individuals were assessed using the normalized electromyographic activity of mandibular tasks (rest, protrusion, right and left laterality) and electromyographic activity of masticatory cycles in habitual (peanuts and raisins) and non-habitual (Parafilm M) chewing. Data were analyzed using Student’s t-test (p < .05). Comparisons between the groups demonstrated significant differences. Indigenous individuals group presented a decrease in the normalized electromyographic activity of the masticatory muscles during mandibular rest [right masseter (p = .002) and left masseter (p = .004) muscles]. There was increase in the normalized electromyographic activity during protrusion [left temporal (p = .03) muscle]. There was increase in the electromyographic activity during chewing: peanuts [right masseter (p = .001), left masseter (p = .001) and right temporal (p = .01) muscles], raisins [right masseter (p = .001), left masseter (p = .002), right temporal (p = .008), left temporal (p = .01) muscles] and Parafilm M [left masseter muscle (p = .05)]. From the findings of this study, we concluded that in the comparison between indigenous and white individuals, positive changes were observed in the electromyographic pattern of the masticatory muscles in the mandibular postural conditions, with greater masticatory efficiency in the indigenous group.


2021 ◽  
Vol 64 (3) ◽  
pp. 179-182
Author(s):  
Lyubov V. Smaglyuk ◽  
Anastasiia V. Liakhovska

Aim: The aim of our study was to investigate features related to EMG-activity of masticatory muscles in subjects with TMD. materials and methods: The study comprised 22 patients with clinical symptoms of TMD. The average age of the subjects was 29.3 ± 4.4 years. Malocclusion was evaluated according to Angle classification, TMD – according to the Research Diagnostic Criteria (RDC/TMD). Registration of EMG-activity of masseter and anterior temporalis muscles was performed during maximum voluntary clenching, clenching on the right and left sides. Results: Normal activity of the masticatory muscles is characterized by symmetrical and EMG-activity of the masticatory muscles on the left and right sides. EMG-activity of masticatory muscles in subjects with TMD are characterized by: 1) increased values of EMG-activity of temporal and masseter muscles; 2) disproportional and asymmetric muscle work of the masticatory muscles on the right and left sides. Conclusions: Features of masticatory muscles activity in individuals with Angle Class I malocclusion and TMD were found.


2014 ◽  
Vol 25 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Marcelo Oliveira Mazzetto ◽  
Carolina Almeida Rodrigues ◽  
Laís Valencise Magri ◽  
Melissa Oliveira Melchior ◽  
Guiovaldo Paiva

Temporomandibular disorders (TMD) are manifested as a group of signs and symptoms that affect a particular population profile. Some variables such as sex and age influence the clinical expression of this condition. This observational descriptive cross-sectional study aimed to correlate the severity of TMD established by the craniomandibular index (CMI) with the variables: age, sex and electromyographic activity of the masseter and anterior temporal muscles. Fifty-four subjects (15 males/39 females) aged between 16 to 65 years (mean age = 41 years) and diagnosed with TMD were evaluated. Severity was determined by the CMI. These subjects also underwent examination by surface electromyography of the masseter and anterior temporal muscles. No correlation was found between age and severity of TMD (p=0.19/r=0.16), however there was a trend of greater severity in young adults (25-50 years). The sex variable in the correlation was positive with the CMI (p=0.03/r=-0.96) and superior to women. A greater EMG activity of the anterior temporal in relation to masseter (p=0.01) was found and the left temporal activity had the highest average (161.5 ± 44.6 Hz). The electromyographic activity of the anterior temporal and right masseter muscles was positively correlated with the Dysfunction Index CMI (p=0.01). The use of CMI to quantify the severity of TMD and of EMG to assess the functionality of the masticatory muscles can be important allies to direct the treatment.


2022 ◽  
pp. 98-100
Author(s):  
A. A. Sultanov ◽  
Y. Y. Pervov ◽  
A. K. Yatsenko ◽  
M. A. Sultanova ◽  
D. O. Drozdova

The article presents a clinical case of the diagnostics and treatment of the temporomandibular joint dysfunction (TMJ) in patient after orthodontic treatment. The hypertonia of masticatory muscles, limit of mouth opening and deviation of the jawbone to the right were observed during physical examination. Adhesion of the disk to the articular tubercle of the right temporal bone was detected on MRI. Hyperrotation of the articular head and the deviation of the jawbone to the right were observed on the charts during axiography. Disappearing of the feeling of heaviness in the right TMJ, free mouth opening, absence of deviation symptom, and the reduction of the rigidity of the masseter muscles were observed on the basis of diagnostic examinations after treatment. Presented clinical experience lets us make a conclusion that it is necessary to prescribe taking axiography and MRI during diagnosing and treating temporomandibular joint dysfunction.


Author(s):  
Larissa Chaves Cardoso FERNANDES ◽  
Patrícia Moreira RABELLO ◽  
Bianca Marques SANTIAGO ◽  
Marcus Vitor Diniz de CARVALHO ◽  
Manoel Raimundo de SENA JÚNIOR ◽  
...  

ABSTRACT Objetive To determine the percentage of correctness of the Orbital Index (OI) for estimation of sex, ancestry and age in Brazilian skulls. Methods Cross-sectional study of 183 human dry skulls from the southeastern Brazil. A total of 100 skeletons were males and 83 females; of which 36 were aged up to 39 years, 60 aged between 40 and 59 years, and 87 aged 60 years or older. As for ancestry, 103 were from white, 51 mixed race, and 29 black individuals. The OI was calculate by the formula = height/width x 100. The data were submitted to Student’s t test, F (ANOVA), Tukey and Kruskal Wallis tests as well as to discriminant analysis, with a 5% significance level. Results The sample was characterized as mesoseme, with a mean age of 56.62 (±19.97) years. No significant difference was observed (p=0.511) between the OI in females (right: 86.43 ± 6.58 and left: 86.70 ± 5.93) and males (right: 85.78 ± 6.69 and left: 86.37 ± 6.20). There were no significant differences between age, ancestry and the variables analyzed (p>0.05). The right and left orbital widths were significantly dimorphic between sexes (p<0.001). The percentage of correctness of the method for estimation of sex, age and ancestry was found to be 65.6%, 43.7%, and 43.6%, respectively. Conclusions The OI is not an appropriate method for estimation of sex, ancestry and estimation of age in this Brazilian sample. The methodology should be expanded to other population groups so that it can be improved.


Cephalalgia ◽  
2017 ◽  
Vol 38 (4) ◽  
pp. 718-729 ◽  
Author(s):  
Martin Syvertsen Mykland ◽  
Marte Helene Bjørk ◽  
Marit Stjern ◽  
Trond Sand

Background The migraine brain is believed to have altered cortical excitability compared to controls and between migraine cycle phases. Our aim was to evaluate post-activation excitability through post-movement beta event related synchronization (PMBS) in sensorimotor cortices with and without sensory discrimination. Subjects and methods We recorded EEG of 41 migraine patients and 31 healthy controls on three different days with classification of days in relation to migraine phases. During each recording, subjects performed one motor and one sensorimotor task with the right wrist. Controls and migraine patients in the interictal phase were compared with repeated measures (R-) ANOVA and two sample Student’s t-test. Migraine phases were compared to the interictal phase with R-ANOVA and paired Student’s t-test. Results The difference between PMBS at the contralateral and ipsilateral sensorimotor cortex was altered throughout the migraine cycle. Compared to the interictal phase, we found decreased PMBS at the ipsilateral sensorimotor cortex in the ictal phase and increased PMBS in the preictal phase. Lower ictal PMBS was found in bilateral sensorimotor cortices in patients with right side headache predominance. Conclusion The cyclic changes of PMBS in migraine patients may indicate that a dysfunction in deactivation and interhemispheric inhibition of the sensorimotor cortex is involved in the migraine attack cascade.


2008 ◽  
Vol 45 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Sossani Sidiropoulou-Chatzigianni ◽  
Moschos A. Papadopoulos ◽  
George Kolokithas

Objective: To assess the prevalence of radiographically detectable destruction of the temporomandibular joints in children with juvenile idiopathic arthritis and to study the possible relationships between condylar destruction and type and duration of the disease, as well as the type of occlusion. Material And Method: The study group consisted of 66 children with juvenile idiopathic arthritis (27 boys, 39 girls; mean age, 11.9 years). The possible presence of condylar destruction was examined in panoramic radiographs. The medical history and the type of malocclusion were registered also. The statistical evaluation was performed by means of descriptive statistics, Student's t test, Pearson's chi-square, and an analysis of variance test. The whole procedure was repeated after a 4-week interval to estimate the error of the method. Results: Of the children with juvenile idiopathic arthritis, 50% showed some form of condylar destruction. Significant correlation was found between the type of the disease and the condyles affected. In the polyarticular type of juvenile idiopathic arthritis, 75% of the children presented affected condyles and 55.6% of them showed lesions bilaterally. The condylar affection was found to be independent of sex, although girls showed a tendency to bilateral lesions. In children with unilateral destruction, the right condyle was affected four times more frequently than the left. The duration of juvenile idiopathic arthritis seems to be significantly correlated to condylar destruction and especially to bilateral destruction. Conclusion: Children with juvenile idiopathic arthritis presented a remarkable prevalence of condylar destruction, which was correlated to the type and duration of the disease.


Author(s):  
D.I. Aksyonov ◽  
Yu.N. Mayboroda ◽  
E.A. Bragin ◽  
I.N. Aksyonov

The aim study was to construct artificial dentitions based on the method of mathematical modeling with the progenic and prognatic ratios of toothless frontal segments and to analyze the functional activity of the masticatory muscles in patients using dentures made in this way, compared with standard prosthetic structures. To compare and interpret the data obtained, electromyographic studies were performed in the control group (16 people), whose teeth were made using the traditional method, and the main group (22 people), whose artificial teeth were formed according to individual mathematical calculations, taking into account the size of the sagittal gap of the frontal segments of the progenic and prognatic ratio of toothless jaws. Statistical processing of the results of the electro-myographic study was carried out using the Statistica application software package. The digital data were processed by the method of variational statistics using the Student's t-test. The analysis of the obtained data showed the advantages of using individual mathematical calculations when solving the issue of tactics for constructing dentitions in the frontal segment of toothless jaws, taking into account the degree of the sagittal gap in the progenic and prognatic correlation of the jaws and their possible combinations.


1998 ◽  
Vol 116 (5) ◽  
pp. 1808-1814 ◽  
Author(s):  
Fausto Viterbo ◽  
Evandro Teixeira ◽  
Katsumae Hoshino ◽  
Carlos Roberto Padovani

OBJECTIVE: We compared end-to-side neurorraphy with and without the perineural sheath. METHOD: Twenty rats were used. The peroneal nerve was sectioned and the distal end was sutured to the lateral face of the tibial nerve. We removed the perineural sheath only on the right side, but not on the left side. The proximal end of the peroneal nerve was curved back approximately at a 100° angle and implanted into the adductor muscle. Six months later, the 14 surviving animals were submitted to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. RESULTS: On the right side, the muscles that had positive response needed an average of 258.89 mV (±92.31) of electric stimulus and on the left side 298.34 mV (±139.32). The average weight of the tibial cranial muscles of the right side was 0.47 g (0.18) and for the left side 0.45 g (0.15). The distal end of the peroneal nerve showed averages of 310.29 (±191.34) nerve fibers on the right side and 287.71 (±183.60) on the left side. The tibial nerve above the neurorraphy showed averages of 939.46 (±223.51) nerve fibers on the right side and 959.46 (±327.48) on the left side. The tibial nerve below the neurorraphy showed averages of 935.17 (±298.65) nerve fibers on the right side and 755.31 (±323.26) on the left side. The average areas of the right tibial cranial muscles were 0.0162 m2 (±0.008), after 230 magnification, and 0.0152 m2 (0.0064) for the left tibial cranial muscles. The histological features of the tibial cranial muscles, taking normal as 100%, were 78.21 (±20.75) on the right side and 82.14 (±15.89) on the left side. The statistical analysis (Student's t test) did not reveal any difference (p>0.05) among right and left sides for all variables. CONCLUSION: The authors concluded that the two neurorraphies (with and without perineurium) did not show any difference regarding morphological and electrophysiological features studied.


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