The amplitude distribution of electromyographic activity in painful masseter muscles during unilateral chewing

The relation between integrated electromyographic activity and computed biting force during voluntary isometric contraction was evaluated in the masticatory muscles of healthy subjects. The slopes of the curves relating integrated electromyographic activity to computed biting force in masseter muscles were steeper on the non-preferred chewing side than on the preferred chewing side, and they progressively became steeper during the course of continuous isometric contraction of a given biting force.

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Relation between Headache and Mastication Muscle Tone in Adolescents

Pain Research and Management ◽

10.1155/2018/7381973 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7

Author(s):

Ewa Wozniak ◽

Jolanta E. Loster ◽

Aneta Wieczorek

Keyword(s):

Temporomandibular Disorders ◽

Muscle Tone ◽

Activity Index ◽

Contractile Activity ◽

Electromyographic Activity ◽

Everyday Functioning ◽

Language Version ◽

Group I ◽

Axis I ◽

Masseter Muscles

Headache is a common problem in the population, which decreases the quality of life and makes everyday functioning difficult. It often coexists with typical symptoms of temporomandibular disorders. The objective of the study was to clarify whether there is a relationship between the presence of headache in young volunteers and the mastication muscle tone. Material and Method. Volunteers aged 18 years who underwent general dental examination, clinical evaluation, and examination using the dual-axis diagnostic system Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) form in the Polish language version participated in the study. On the basis of the examination results, these individuals were divided into three groups according to RDC results. A group of healthy individuals (axis I value 0), a group of sick individuals (axis I diagnosis Ia, IIa, or IIIa), and a group of individuals suffering from depression (axis II values 1–3) were singled out. Then, volunteers were divided into two groups: group I reporting headache and group II without any pain. In each of these individuals, the contractile activity of the masseter muscles and anterior temporal muscles was recorded bilaterally as the surface electromyographic activity (sEMG) at rest, during swallowing, and maximum clenching. The activity index ranging between +100 (activity of the masseter muscles only) and −100 (activity of the anterior temporal muscles only) was used to indicate the predominance of activity of the study muscles. Results. The statistical analysis of data showed that there was a significant relationship between the presence of headache and a change in the mastication muscle tone, expressed as the predominant activity of the temporal muscles, only in the group of sick individuals during maximum clenching. Summary. The diversity of sEMG results implies that a change in the mastication muscle tone is not a direct consequence of headache, but it has to be modified by other factors.

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Simultaneous Noxious Stimulation of the Human Anterior Temporalis and Masseter Muscles. Part II: Effects on Jaw Muscle Electromyographic Activity

Journal of Oral & Facial Pain and Headache ◽

10.11607/ofph.2300 ◽

2019 ◽

Vol 39 (4) ◽

pp. 426-239

Author(s):

Magda Amhamed ◽

Terry Whittle ◽

John Gal ◽

Greg Murray

Keyword(s):

Noxious Stimulation ◽

Electromyographic Activity ◽

Jaw Muscle ◽

Masseter Muscles ◽

Stimulation Of ◽

Anterior Temporalis

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

Journal of Dental Research Dental Clinics Dental Prospects ◽

10.34172/joddd.2021.038 ◽

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 ◽

...

Keyword(s):

Clinical Evidence ◽

Masticatory Muscles ◽

Emg Activity ◽

Electromyographic Activity ◽

Group Function ◽

Canine Guidance ◽

Student’S T ◽

The Right ◽

Masseter Muscles ◽

Student’S T Test

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.

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Electromyographic Investigation of Masticatory Muscles in Unilateral Cleft Lip and Palate Patients with Anterior Crossbite

The Cleft Palate-Craniofacial Journal ◽

10.1597/1545-1569_1998_035_0415_eiommi_2.3.co_2 ◽

1998 ◽

Vol 35 (5) ◽

pp. 415-418 ◽

Cited By ~ 2

Author(s):

Weiran Li ◽

Jiuxiang Lin ◽

Minkui Fu

Keyword(s):

Cleft Lip ◽

Cleft Lip And Palate ◽

Masticatory Muscles ◽

Asymmetry Index ◽

Chinese Patients ◽

Control Group ◽

Electromyographic Activity ◽

Normal Individuals ◽

Masseter Muscles ◽

Electromyographic Investigation

Objective To evaluate the characteristics of masticatory muscle activity in operated unilateral cleft lip and palate (UCLP) patients with anterior crossbite compared with normal individuals. Subjects Sixteen male and 13 female Chinese patients with UCLP and anterior crossbite. Fifteen male and 13 female Chinese individuals without cleft abnormalities served as a control group. Design Electromyographic activity of the masseter muscles and anterior temporalis muscles was recorded bilaterally in different mandibular positions using bipolar surface electrodes. Results Compared to noncleft controls, patients with UCLP demonstrated (1) higher activation levels of masseter and temporalis muscles in the rest position, (2) lower potential function of masseter and temporalis, (3) inharmonious activity of the masticatory muscles during mandibular border movement, (4) a higher asymmetry index of the masseter and temporalis muscles, and (5) longer silent periods of the two muscles. Conclusions The function of masticatory muscles is different in patients with UCLP with anterior crossbite. Muscle function should be considered when evaluating cleft patients for orthodontic treatment and orthognathic surgery.

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Severity of TMD Related to Age, Sex and Electromyographic Analysis

Brazilian Dental Journal ◽

10.1590/0103-6440201302310 ◽

2014 ◽

Vol 25 (1) ◽

pp. 54-58 ◽

Cited By ~ 12

Author(s):

Marcelo Oliveira Mazzetto ◽

Carolina Almeida Rodrigues ◽

Laís Valencise Magri ◽

Melissa Oliveira Melchior ◽

Guiovaldo Paiva

Keyword(s):

Signs And Symptoms ◽

Cross Sectional Study ◽

Masticatory Muscles ◽

Emg Activity ◽

Electromyographic Activity ◽

Sectional Study ◽

Clinical Expression ◽

Cross Sectional ◽

Electromyographic Analysis ◽

Masseter Muscles

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.

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