Masticatory Muscles Activity in Sport Climbers

Surface Electromyography in Dentistry-Past, Present and Future

Surface electromyography (sEMG) is a technique for measuring and analyzing the electrical signals of muscle activity using electrodes placed on the skin's surface. The aim of this paper was to outline the history of the development and use of surface electromyography in dentistry, to show where research and technical solutions relating to surface electromyography currently lie, and to make recommendations for further research. sEMG is a diagnostic technique that has found significant application in dentistry. The historical section discusses the evolution of sEMG methods and equipment, highlighting how technological advances have influenced the accuracy and applicability of this method in dentistry. The need for standardization of musculoskeletal testing methodology is highlighted and the needed increased technical capabilities of sEMG equipment and the ability to specify parameters (e.g., sampling rates, bandwidth). A higher sampling rate (the recommended may be 2000 Hz or higher in masticatory muscles) allows more accurate recording of changes in the signal, which is essential for accurate analysis of muscle function. Bandwidth is one of the key parameters in sEMG research. Bandwidth determines the range of frequencies effectively recorded by the sEMG system (the recommended frequency limits are usually between 20 Hz and 500 Hz in masticatory muscles). In addition, the increased technical capabilities of sEMG equipment and the ability to specify electromyographic parameters demonstrate the need for a detailed description of selected parameters in the methodological section. This is necessary to maintain the reproducibility of sEMG testing. More high-quality clinical trials are needed in the future.

Brazilian special olympics athletes: Oral health problems

AIMS

The people with intellectual disabilities have been reported to be a vulnerable population in terms of oral health. This study was carried out to determine the oral health condition and treatment needs of Special Olympics athletes in Brazil.

METHODS

This study is a retrospective review of oral health data collected from athletes participating in Healthy Athletes Program Special Olympics in Brazil, between the years 2015 and 2019. About 1241 athletes from the Brazil Special Olympics program were screened in the cities of São Paulo, Jundiai and Belo Horizonte (located in southeastern Brazil) and Recife (in northeastern Brazil). At each of these events, volunteer dental professionals performed an oral health screening for each athlete, All oral health assessments were done visually; and extra lighting were available if needed. The examinations were performed with the aid of a wooden spatula of the tongue depressor type and under natural light. The following parameters were recorded: mouth pain, untreated tooth decay, missing teeth, gingival signs, urgency and mouth hygiene habits. Data was analyzed using the STATA 14.0 program. Frequency tables were used for descriptive analyses. Categorical variables were compared between the different years of the event using the Chi-Square or Fisher's Exact test. Continuous variables were compared between different event years using the Kruskal-Wallis test followed by Dunn's post-hoc analyses. Simple logistic regression was used to assess the effect of age on dental assessment results. For all tests, a p-value was considered significant when less than or equal to .05.

RESULTS

No statistically significant differences were observed in the frequencies of Mouth Pain and Missing Teeth over the years (p > .05). In relation to Untreated Tooth Decay, there is a higher frequency in the years 2016 and 2018 and a lower frequency in the year 2015 (p = .048). Regarding Gingival Signs of inflammation, there is a higher frequency in the years 2016 and 2018 and a lower frequency in the year 2017 (p < .001). In relation to cases of urgency (in need of treatment (Urgent treatment need, Non-Urgent or Maintenance)), there was a higher frequency (no urgency) in 2016 (p = .007). Finally, in relation to mouth hygiene habits, there is a higher frequency of participants with irregular habits in the years 2017 and 2019 (p < .001).

CONCLUSION

The dental condition of Brazilian athletes Special Olympycs Brazil reported in this study from 2015 to 2019 showed us that athletes have a high prevalence of dental diseases and these needs could contribute to health damage. The athletes have many unmet dental treatment needs and these needs are similar in different regions of the country and in the years reported.

Effects of Contact Sports on Temporomandibular Disorders: An Observational Study

The study investigated the prevalence of temporomandibular disorders in 100 competitive athletes in contact sports, equally grouped by the practiced game: Soccer (SoG), Rugby (RG), American Football (AFG), Boxing (BoG), Basketball (BaG), compared to a randomly control group of 20 non-athletes (CG). Symptoms and signs were examined according to the standardized Diagnostic Criteria for Temporomandibular Disorders through a questionnaire and clinical evaluation. Arthralgia showed significant differences between RG and CG and between AFG and CG (p < 0.05). Study groups reported masticatory muscle pain during function, neck and shoulder pain more frequently than CG, except for BoG. Closing click was significantly more present in study groups than CG, while crepitation was significantly higher only in RG and AFG. The deviation was wider in SoG, RG and AFG compared to CG (p < 0.05). Tukey’s multiple comparisons test showed a statistically significant reduction in right laterotrusion in RG vs. CG (p < 0.05); the comparison showed a decrease in right laterotrusion in RG vs. SoG and BoG (p < 0.05), a decrease in endfeel in RG vs. CG, BaG and AFG (p < 0.05). The data seem to support a relationship between the prevalence of TMD symptoms and signs in competitive athletes in contact sports, especially in RG and AFG compared to CG.

Ecological Study on the Oral Health of Romanian Intellectually Challenged Athletes

This study aimed to give an image of the oral health status and treatment needs of intellectually challenged athletes taking part in Special Olympics—Special Smiles (SO-SS) events organized in Romania during 2011–2019 and to find potential associations with socio-economic factors. An observational ecological retrospective study was conducted, and 1860 oral examinations were performed on participants aged 8 to 30 years in nine SS-SO events. Oral examination was performed under field conditions. Percentage of caries-free subjects, mean DMF-T index and its components (D = decayed; M = missing; F = filled; T = teeth), restoration index RI = [F/(F + D) × 100]%, and Plaque Index were calculated for each of the nine groups. Caries-free subjects ranged between 5.90% and 21.70%. DMF-T ranged from 4.27 to 7.71. Higher values for “F” component (range 0.66–1.69) and RI (range 13.02–27.74%) were found in events held in cities from regions with higher reported Gross Domestic Product. Sealants were present in 0 to 8.4% of the subjects. In areas with lower numbers of inhabitants per dentist, more sealants were found (p < 0.001). Romanian SO athletes exhibited relatively poor oral health, limited access to dental treatment, and low level of prevention. Targeted prevention and treatment programs adjusted to specific conditions in each geo-economic region are needed.

Masticatory efficiency, bite force and electrical activity of the masseter and temporalis muscles in bodybuilders

Background

This study aimed to compare the masticatory efficiency, the maximum voluntary occlusal bite force (MVOBF) and the electrical activity (EMG) of masticatory muscles of practitioners of upper limb bodybuilding before and after physical activity.

Material and Methods

Twenty healthy individuals (10 men and 10 women, age from 18 to 30 (mean of 24.7 years old) without masticatory system disorders, that regularly practice hypertrophic physical activity were submitted to the analyses of masticatory efficiency, MVOBF, and surface EMG of the temporalis and masseter muscles. The masticatory efficiency was analyzed by comminution of the artificial material (Optocal®) and a sieving method. The MVOBF was measured by a dynamometer, and EMG was evaluated during resting mandibular position, maximum voluntary clenching (MVC), and MVC with a Parafilm M tape between teeth, and free mastication of chewing gum. The analyses were made before (T0) and immediately after the performance of upper limb bodybuilding exercises (T1). The data of masticatory efficiency and MVOBF were submitted to the Student T-test, and their correlations were analyzed by the Pearson correlation test, and the EMG data were submitted to the 2-way repeated measures ANOVA, all tests with a 5% significance.

Results

There was a significant decrease of masticatory efficiency after the training. No statistical difference in the MVOBF and EMG was found, and there was a positive correlation between masticatory efficiency and MVOBF.

Conclusions

Therefore, changes were found for masticatory efficiency only, which decreased after hypertrophic exercise. There was a positive correlation between masticatory efficiency and MVOBF. Key words:Masticatory efficiency, bite force, physical activity, electromyography.

Novel Functional Indices of Masticatory Muscle Activity

The aim of the present study was to analyze novel functional indices of masticatory muscle activity and compare them to existing and commonly used indices in patients with temporomandibular disorders (TMDs) and healthy adults. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 78 adult women qualified for the study. Subjects were divided into two groups: diagnosed TMDs (n = 36; mean age: 23.4 ± 2.6 years) and healthy adults (n = 42; mean age: 22.4 ± 2.3 years). Measurements of the bioelectric activity of the temporalis anterior (TA), superficial masseter (MM), and anterior bellies of the digastric muscle (DA) were carried out using the BioEMG III ™. Functional Clenching (FCI) and Functional Opening (FOI) indices were obtained as the ratio of the difference between the mean muscle root mean square (RMS) potentials during functional activity, including clenching (CL) and opening (MMO), and mean muscle resting (REST) potentials. Next, based on FCI and FOI indices, the Functional Clenching Activity Index (FCAI), Functional Clenching Symmetry Index (FCSI), and Functional Opening Symmetry Index (FOSI) were obtained. The statistical analysis showed significant differences in activity index left-sided (AcI_L) and Activity index both-sided (AcI_tot) between TMDs and healthy women during rest measurements. The significant differences between both groups were noted in terms of all Functional Clenching Indices except Functional Clenching Index for MM right-sided (FCI_MM-R). In all analyzed FCI indices, the control group showed higher values compared to the TMDs. Moreover, a significant difference between TMDs and controls was observed within Functional Clenching Activity Index left-sided (FCAI_L) (14.56 vs. −0.45, p = 0.01). Both functional indices, and asymmetry (AsI) and activity (AcI) indices seem to be reliable in assessing symmetry and activity within masticatory muscles. Further studies should be performed to verify the effectiveness and suitability of the assessment of masticatory muscles using functional indices.

Editorial on the Special Issue on "Mountain Sports Activities: Injuries and Prevention"

Recreational outdoor activities like mountain sports are gaining large popularity all over the world and particularly in the Alpine regions [...].

Mouthguard-effect of high-intensity weight training on masticatory muscle tone and stiffness in taekwondo athletes

This study aimed to analyze the effect of wearing a mouthguard or not on masticatory muscle tone and stiffness of male taekwondo athletes during high-intensity weight training. The participants were male taekwondo athletes and aged 18 to 22 years. We randomly divided 24 men into the control group (CON; without a mouthguard; n=12) and the experimental group (MOG; with a mouthguard; n=12). Masticatory muscle tone and stiffness were measured after weight training at a level of 70% of one-repetition maximum. As a result of this study, masticatory muscle tone was no different in intragroup and intergroup after experiment. In addition, although the masticatory muscle stiffness was significantly higher in the dominant side of the MOG, there was no difference in intergroup, intragroup, and interaction. Through this study, it is necessary to consider the selective wearing of a mouthguard according to the training methods when partially analyzed from the physiological point of view of the masticatory muscle of taekwondo athletes.