Correlation Among Pain Intensity, Catastrophizing, and Falls in Older Individuals With Unilateral Knee Osteoarthritis: A Cross-Sectional Study.

OBJECTIVE: The purpose of this study was to investigate whether pain intensity and catastrophizing are associated with fear of falls and the number of falls in older persons with knee osteoarthritis (OA). METHODS: A cross-sectional study was conducted involving 100 volunteers (male and female participants), 60 to 80 years old, with a diagnosis of knee OA. Patients were recruited from a physical therapy clinic in the city of São Paulo, Brazil, from March 2019 to November 2019. The following measures were used for the evaluations: Numerical Rating Pain Scale (NRPS), Pain-Related Self-Statement Scale (PRSS), and Falls Efficacy Scale. In statistical analysis, histograms were created to determine the distribution of data. Spearman's correlation coefficients (rs) were then calculated to determine the strength of the associations among the variables. The receiver operating characteristic curve was used to identify the accuracy of PRSS and NRPS in differentiating participants with a history of falls from those without. RESULTS: No significant correlation was found among the pain intensity, pain catastrophizing, fear of falling, and number of falls (rs value ranging from -0.033 to -0.167; P value ranging from .096-.743). The accuracy of PRSS and NRPS in differentiating participants with falls from those without was insufficient, with area under the curve values of 0.46 and 0.42, respectively. CONCLUSION: Pain catastrophizing and intensity were not significantly associated with fear of falling and numbers of falls in older individuals with unilateral knee OA.

Photobiomodulation on trigeminal neuralgia: systematic review.

Trigeminal neuralgia is a recurrent episode of facial pain, that may be associated with other conditions such as multiple sclerosis, neoplasms, and nerve compromises or may occur due to an unknown cause. The available treatments are pharmacotherapy or surgery; however, both are susceptible to develop side effects. Photobiomodulation could be a promising alternative therapy for trigeminal neuralgia. A systematic review of literature was carried out using the PRISMA protocol, in the PubMed/MEDLINE, Embase, and Web of Science databases. Risk of bias by ROB 2.0 protocol was performed in included studies. Initially, 20 identified articles were collected varying between the years of 1983-2018, from which 6 were included. A total of 193 patients were evaluated; photobiomodulation was compared to conventional therapies, TENS, and therapy combinations with pharmacotherapy. The overall risk of bias was low, with some concerns in the randomization and double-blinding process; moreover, there are few reports in the literature. Photobiomodulation appears to be as effective as conventional therapies, being a coadjutant therapeutic opportunity for the treatment of trigeminal neuralgia.

Association between convergence insufficiency and temporomandibular disorder cross-sectional study.

OBJECTIVES: Evaluate whether there is an association between convergence insufficiency and temporomandibular disorder (TMD) and whether there is an association between pain and range of motion in different degrees of TMD. METHODS: We evaluated 138 individuals with TMD and 46 without TMD using the Research Diagnostic Criteria for temporomandibular disorders, the Fonseca Anamnestic Index (FAI), Numeric Pain Rating Scale, and the measurement of mandibular range of motion (ROM). Convergence insufficiency was diagnosed using the convergence test and Convergence Insufficiency Symptom Survey. Analysis of variance was used to compare age and mandibular ROM. The Kruskal-Wallis was used to compare mandibular ROM and pain between groups. The chi-square test was used to evaluate associations between TMD subgroups and the FAI, sex, and ocular convergence. RESULTS: The majority of individuals without TMD did not exhibit convergence insufficiency. The frequency convergence insufficiency was significantly higher among individuals with severe TMD (p < 0.003). Mean pain severity differed between individuals with and without TMD. Mandibular ROM diminished with the increase in TMD severity. CONCLUSIONS: Convergence insufficiency, age, the increase in pain, and the reduction in mandibular range of motion were associated with the degrees of TMD severity. Despite the significant associations between convergence insufficiency and both pain and TMD severity, these variables cannot be indicated as predictive factors due to the low variability in the linear regression analysis. CLINICAL RELEVANCE: The present findings can assist in decision making regarding the treatment of severe TMD and the evaluation of ocular convergence.

Exercise program combined with electrophysical modalities in subjects with knee osteoarthritis: a randomised, placebo-controlled clinical trial.

BACKGROUND: It is not yet clear which of the various electrophysical modalities used in clinical practice is the one that contributes most positively when added to an exercise program in patients with knee osteoarthritis (OA). The aim of the present study was to analyze the clinical effects of the inclusion of interferential current therapy (ICT), shortwave diathermy therapy (SDT) and photobiomodulation (PHOTO) into an exercise program in patients with knee OA. METHODS: This prospective, five-arm, randomised, placebo-controlled trial was carried out with blinded participants and examiners. We recruited 100 volunteers aged 40 to 80 years with knee OA. Participants were allocated into five groups: exercise, exercise + placebo, exercise + ICT, exercise + SDT, and exercise + PHOTO. The outcome measures included Western Ontario and McMaster Universities (WOMAC), numerical rating pain scale (NRPS), pressure pain threshold (PPT), self-perceived fatigue and sit-to-stand test (STST), which were evaluated before and after 24 treatment sessions at a frequency of three sessions per week. RESULTS: In all groups, there was a significant improvement (p < 0.05) in all variables over time, except pressure pain threshold. We observed significant differences (p < 0.05) between the groups for WOMAC function (exercise vs. exercise + placebo, mean difference [MD] = 5.55, 95% confidence interval [CI] = 3.63 to 7.46; exercise vs. exercise + ICT, MD = 3.40, 95% CI = 1.46 to 5.33; exercise vs. exercise + SDT, MD = 4.75, 95% CI = 1.85 to 7.64; exercise vs. exercise + PHOTO, MD = 5.45, 95% CI = 3.12 to 7.77) and WOMAC pain, with better scores achieved by the exercise group. However, these differences were not clinically relevant when considering the minimum clinically important difference. CONCLUSION: The addition of ICT, SDT or PHOTO into an exercise program for individuals with knee OA is not superior to exercise performed in isolation in terms of clinical benefit. clinicaltrials.gov: NCT02636764, registered on March 29, 2014.

Intraoral photobiomodulation diminishes pain and improves functioning in women with temporomandibular disorder: a randomized, sham-controlled, double-blind clinical trial : Intraoral photobiomodulation diminishes pain in women with temporomandibular disorder.

The aim of the present study was to evaluate the effect of intraoral photobiomodulation involving super-pulsed laser (905 nm) combined with red (640 nm) and infrared (875 nm) light-emitting diodes on pain, mandibular range of motion, and functioning in women with myogenous temporomandibular disorder. A randomized, sham-controlled, double-blind clinical trial was conducted involving 30 women with myogenous temporomandibular disorder diagnosed using the Research Diagnostic Criteria for Temporomandibular Disorders. The participants were randomly allocated to two groups (active and sham photobiomodulation). The evaluations involved this use of the visual analog scale, digital calipers, and a functional scale. Photobiomodulation was administered intraorally in the region of the pterygoid muscles, bilaterally, in all participants for a total of six sessions. Evaluations were performed on five occasions: prior to the intervention, immediately after the first session, 24 h and 48 h after the first session, and after the six sessions. Significant differences between groups were found regarding pain (p ≤ 0.01) and functioning (p ≤ 0.04). However, no statistically significant difference was found regarding range of mandibular motion. The findings demonstrate that intraoral photobiomodulation involving super-pulsed laser (905 nm) combined with red (640 nm) and infrared (875 nm) light-emitting diodes diminishes pain and improves functioning but does not exert an influence on mandibular range of motion in women with temporomandibular disorder.Trial registration: NCT02839967.

Is there a difference in the electromyographic activity of the masticatory muscles between individuals with temporomandibular disorder and healthy controls? A systematic review with meta-analysis.

The diagnosis of temporomandibular disorders (TMD) is complex, and it is not yet clear in the literature whether the clinical changes associated with these disorders are also reflected in the electromyographic (EMG) activity of the muscles of mastication. To determine whether there is a difference in the electromyographic activity of the masticatory muscles between individuals with TMD and healthy controls. ScienceDirect, EMBASE, MEDLINE, PEDro, SciELO, CINAHL and LILACS databases from January 2000 to February 2019. Cross-sectional studies, crossover studies and randomised controlled trials evaluating EMG activity of right and left masseter and anterior temporal muscles in patients with TMD and healthy controls. Two independent assessors extracted data from the selected articles. The risk of bias was determined using a checklist for assessing methodological quality created based on the guidelines of the Strengthening the Reporting of Observational Studies in Epidemiology and International Society of Electrophysiology and Kinesiology. Mean differences and 95% confidence intervals were calculated and combined in meta-analyses. A total of 51 267 studies were retrieved, and 12 were included in this review. Only two studies enabled the comparative analysis of the results. The different EMG signal capturing, processing and analysis methods used constitute an important limitation to the comparative analyses of the results reported in the studies selected for the present review. This systematic review did not demonstrate evidence of significant differences in the EMG activity of the masticatory muscles between individuals with TMD and healthy controls.

Muscle fiber conduction velocity and EMG amplitude of the upper trapezius muscle in healthy subjects after low-level laser irradiation: a randomized, double-blind, placebo-controlled, crossover study.

Although low-level laser therapy (LLLT) is an important resource for the treatment of non-specific neck pain patients, the dose which presents the greatest therapeutic potential for the treatment of this pathology is still unclear. The present study aimed to evaluate the immediate effect of LLLT on the muscle fiber conduction velocity (MFCV) and electromyographic activity (EMG) of the upper trapezius (UT) muscle in healthy individuals. A total of 20 healthy subjects were enrolled in a randomized, double-blind, crossover study. Active LLLT (820 nm wavelength, 30 mW, energy total 18 J) or placebo LLLT (pLLLT) was delivered on the UT muscle. Each subject was subjected to a single session of active LLLT and pLLLT. Surface electromyography (sEMG) signal of the UT muscle was recorded during five different step contractions of shoulder elevation force (10-30% maximal voluntary contraction) pre- and post-LLLT irradiation. The values of MFCV and sEMG global amplitude (RMSG) were used to calculate the effects of LLLT. The results showed no difference in the MFCV comparing the LLLT and pLLLT groups (F = 0.72 p = 0.39, η p2 = 0.004). However, a significant difference was observed in the RMSG between the LLLT and pLLLT (F 1,2 = 16.66; P < 0.0001, η p2 = 0.09). Individuals who received active LLLT presented a significant decrease in RMSG after laser application (F = 61.28; p < 0.0001, η p2 = 0.43). In conclusion, the 820 nm LLLT, with energy total of 18 J, did not alter the MFCV but significantly reduced the sEMG signal amplitude of the upper trapezius muscle in healthy subjects to a level of up to 30% of maximal voluntary contraction.

Combined Use of Diadynamic Currents and Manual Therapy on Myofascial Trigger Points in Patients With Shoulder Impingement Syndrome: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to evaluate the effect of combined manual therapy (MT) and diadynamic (DD) currents on myofascial trigger points of the upper trapezius muscle in individuals with a diagnosis of unilateral shoulder impingement syndrome. METHODS: A randomized clinical trial was conducted involving 60 individuals with shoulder impingement syndrome who were allocated to the following 3 groups: (1) MT and DD currents (MTDD), (2) MT alone, and (3) DD currents alone. The participants were submitted to 16 treatment sessions over an 8-week period and were evaluated using the Numerical Rating Pain Scale as well as the pain and disability subscales of the Shoulder Pain and Disability Index. RESULTS: Differences in Numerical Rating Pain Scale scores (secondary outcome) between MTDD and MT groups (mean difference 2.25 points, 95% confidence interval 1.07-3.42) and between MTDD and DD groups (mean difference 2.30 points, 95% confidence interval 1.42-3.17) were clinically relevant. No clinical gains were observed in the comparisons between groups of Shoulder Pain and Disability Index scores. CONCLUSION: The combination of MT and DD currents on myofascial trigger points was more effective at reducing pain intensity but not disability than each therapy performed individually for patients with unilateral shoulder impingement syndrome.

Correlation Between Severity of Temporomandibular Disorder, Pain Intensity, and Pressure Pain Threshold.

OBJECTIVE: The aim of the present study was to correlate the severity of temporomandibular disorder (TMD) with the pressure pain threshold over the temporomandibular joint and masticatory muscles. METHODS: A blind, cross-sectional study was conducted involving 60 women ages 18 to 40 years with a diagnosis of myogenous TMD. Evaluations were performed using the Fonseca Anamnestic Index (FAI), the visual analogue scale, and algometry over the temporomandibular joint and masticatory muscles. Spearman's correlation coefficients (rs) were calculated to measure the association between TMD severity, pain intensity, and the pressure pain threshold. RESULTS: A moderate, significant, and negative correlation was found between TMD severity and the pressure pain threshold over the left masseter muscle (rs = -0.276; P = .034). No significant correlations were found for the other variables analyzed (P = .124-.985). CONCLUSIONS: Temporomandibular disorder measured using the FAI was associated to the pressure pain threshold over the masseter muscle. The significant and negative association found between the score of the FAI and the pressure pain threshold over the masseter muscle demonstrated that patients with more severe signs and symptoms of TMD had a lower pressure pain threshold.

Association of Pain Catastrophizing With Static Balance, Mobility, or Functional Capacity in Patients With Knee Osteoarthritis: A Blind Cross-sectional Study.

OBJECTIVE: The aim of this study was to investigate whether catastrophizing is associated with static balance, mobility, and functional capacity in patients with knee osteoarthritis. METHODS: A blind, cross-sectional study was conducted involving 60 volunteers (males and females), ages 40 to 80 years, with a diagnosis of knee osteoarthritis. Patients were recruited from a physical therapy clinic in the city of São Paulo, Brazil. The following measures were used for the evaluations: Pain-Related Self-Statement Scale, Functional Reach Test, Timed Up and Go Test, Lower Extremity Functional Scale, and Western Ontario and McMaster University Osteoarthritis Index. In statistical analysis, histograms were created to determine distribution of data. Spearman's correlation coefficients (rs) were then calculated to determine the strength of the associations among the variables. RESULTS: No significant correlation was found between the Pain-Related Self-Statement Scale score and the other clinical measures employed in the present study: Functional Reach Test (rs = 0.151; P = .249), Timed Up and Go Test (rs = -0.147; P =.264), Lower Extremity Functional Scale (rs = 0.023; P = .860), and Western Ontario and McMaster University Osteoarthritis (rs = -0.222; P = .088). CONCLUSIONS: In this study, catastrophizing was not associated with static balance, mobility, or functional capacity in patients with knee osteoarthritis.

Immediate Effect of Acupuncture on Electromyographic Activity of the Upper Trapezius Muscle and Pain in Patients With Nonspecific Neck Pain: A Randomized, Single-Blinded, Sham-Controlled, Crossover Study.

OBJECTIVE: The objective of this study was to assess changes in upper trapezius myoelectric activity and pain in patients with nonspecific neck pain after a single session of acupuncture (ACP). METHODS: A blinded randomized clinical trial was conducted. Fifteen patients with nonspecific neck pain and 15 healthy participants were enrolled in a randomized, single-blinded, crossover study. Each participant was subjected to a single session of ACP and sham acupuncture (SACP). The electromyography (EMG) signal of the upper trapezius muscle was recorded during different step contractions of shoulder elevation force (15%-30% maximal voluntary contraction) before and after ACP treatment. RESULTS: Significant effects were confirmed after the treatment (ACP and SACP) for Numeric Rating Scale scores (F1,28 = 51.61; P < .0001) and pain area (F1,2 = 32.03; P < .0001). Significant decreases in the EMG amplitude were identified for the nonspecific neck pain group (NPG) (F1,112 = 26.82; P < .0001) and the healthy participant group (HPG) (F1,112 = 21.69; P < .0001) after ACP treatment. No differences were identified between the ACP and SACP treatment protocols for Numeric Rating Scale score (NPG: F1,28 = 0.95; P = .33), pain area (NPG: F1,28 = 1.97; P = .17), or EMG amplitude (NPG: F1,112 = 0.47; P = .49; HPG: F1,112 = 0.75; P = .38). CONCLUSION: The effect of ACP at acupoints triple energizer 5 and large intestine 11 triple energizer 5, or in close proximity, contributes to pain relief among patients with nonspecific neck pain. The electromyographic analysis indicated a greater resistance to muscle fatigue and decrease of activity of the upper trapezius muscle among healthy participants and patients with nonspecific neck pain.

Evaluation of pain, jaw movements, and psychosocial factors in elderly individuals with temporomandibular disorder under laser phototherapy.

Few studies have been carried out on the application of laser phototherapy (LPT) for treating painful temporomandibular disorder (TMD) in elderly population that is growing worldwide. The aim of the present study was to evaluate the pain, jaw movements, and psychosocial factors in ten elderly patients with painful TMD before and after LPT. All patients were evaluated before and after LPT by using the Research Diagnostic Criteria for temporomandibular disorders (RDC/TMD) axes I and II. For pain assessment, a visual analogue scale (VAS) was used. The LPT was carried out with an GaAlAs diode laser (780 nm; spot size 0.04 cm(2)) in punctual and contact mode. Two settings of irradiations were applied as follows: in patients presenting myofascial pain, 10 mW, 5 J/cm(2), 20 s, 0.2 J per application point; and in patients with joint TMD, 70 mW, 105 J/cm(2), 60 s on five points, 4.2 J per point. Two sessions of LPT were carried out per week over four consecutive weeks, in the total of eight sessions. Data was statistically analyzed (p < 0.05). Significant pain reduction was found in all patients. There were increase in maximum mouth opening without pain and reduction in muscle pain during right and left lateral excursion. A significant reduction in chronic pain severity (p = 0.02) and significant improvements in depression (p = 0.038) and nonspecific physical symptoms with pain (p = 0.0167) were observed. The present findings indicate that LPT is able to promote pain relief and improvement of jaw movements in elderly patients with TMD, with a positive effect on psychosocial aspects.

Impact in oral health and the prevalence of temporomandibular disorder in individuals with Parkinson's disease.

The aims of the present study were to investigate the prevalence of temporomandibular disorder (TMD) in a group of patients with Parkinson's disease (PD), and to analyze oral health according to the severity of the disease. [Methods] Signs and symptoms of TMD were evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders, and oral health impact was measured using the Oral Health Impact Profile. The unpaired Student's t-test was used to compare groups with and without TMD. Pearson's correlation coefficients were calculated to determine correlations between the level of functional independence and oral health impact. Fisher's exact test was used to test the association between TMD and the severity of symptoms of PD. [Results] Fifty-nine individuals with PD were analyzed. The prevalence of TMD was 20.33%. No statistically significant associations were found between TMD and the severity of PD. Oral health impact was considered weak, but a statistically significant difference between groups with and without TMD was found for psychological disability (p = 0.003). No significant correlation was found between the level of functional independence and oral health impact. [Conclusion] The prevalence of TMD among patients with Parkinson's disease was 20.33%. A statistically significant difference between groups with and without TMD was found regarding the psychological disability domain.

Correlation of stress and muscle activity of patients with different degrees of temporomandibular disorder.

[Purpose] Temporomandibular disorder is one of the many different adverse health conditions that can be triggered by stress. Therefore, a biopsychosocial model has been proposed to characterize the multifactorial nature of temporomandibular disorder. The aim of the present study was investigate the correlation of salivary cortisol levels with the activities of the masseter and anterior temporal muscles of patients with different degrees of temporomandibular disorder. [Subjects and Methods] Forty-nine women between 18 and 40 years of age with a diagnosis of myogenous temporomandibular disorder based on the Research Diagnostic Criteria for temporomandibular disorders were evaluated using the Fonseca Index to determine the degree of the disorder. Salivary cortisol levels were determined and surface electromyography was used to evaluate electrical activity in the masticatory muscles. [Results] Positive correlations were found among the degree of temporomandibular disorder, electromyographic activity and salivary cortisol: as women with more severe temporomandibular disorder had greater electrical activity in the muscles analyzed, especially the anterior temporal muscle, and higher levels of cortisol. [Conclusion] Muscle activity was greater among individuals with severe temporomandibular disorder and positive correlations were found among electromyographic activity, salivary cortisol and the degree of temporomandibular disorder severity.

Analysis of laser therapy and assessment methods in the rehabilitation of temporomandibular disorder: a systematic review of the literature.

The aim of the present study was to perform a systematic review of the literature on the effects of low-level laser therapy in the treatment of TMD, and to analyze the use of different assessment tools. [Subjects and Methods] Searches were carried out of the BIREME, MEDLINE, PubMed and SciELO electronic databases by two independent researchers for papers published in English and Portuguese using the terms: "temporomandibular joint laser therapy" and "TMJ laser treatment". [Results] Following the application of the eligibility criteria, 11 papers were selected for in-depth analysis. The papers analyzed exhibited considerable methodological differences, especially with regard to the number of sessions, anatomic site and duration of low-level laser therapy irradiation, as well as irradiation parameters, diagnostic criteria and assessment tools. [Conclusion] Further studies are needed, especially randomized clinical trials, to establish the exact dose and ideal parameters for low-level laser therapy and define the best assessment tools in this promising field of research that may benefit individuals with signs and symptoms of TMD.

Influence of temporomandibular disorder on temporal and masseter muscles and occlusal contacts in adolescents: an electromyographic study.

BACKGROUND: The aim of the present study was to analyse the influence of temporomandibular disorder (TMD) on electromyographic activity in the masseter and temporal muscles of adolescents and investigate a possible association with the number of occlusal contacts. METHODS: The Helkimo Index was administered for the diagnosis of TMD and classification of the adolescents into three groups: without TMD; with mild TMD; and with moderate/severe TMD. Carbon paper was used for the determination of occlusal contact points. A standardised electromyographic evaluation was performed on the masticatory muscles at rest, during habitual chewing and during maximum voluntary clenching. The readings were normalised to maximum voluntary clenching. Statistical analysis involved the chi-squared test and Fisher's exact test. The Kruskal-Wallis test and one-way analysis of variance with Dunn's post hoc test were used to compare differences between groups. Pearson's correlation coefficients (r) were calculated for the determination of correlations between the number of occlusal contacts and RMS values. RESULTS: Electromyography revealed significant differences in the right and left masseter and temporal muscles at rest and during chewing among the three groups. These differences were not observed during maximum voluntary clenching. No statistically significant differences were found between the groups with and without TMD regarding the number of occlusal contacts. CONCLUSION: Electromyographic activity in the masseter and temporal muscles was greater among adolescents with moderate to severe TMD.

Effects of massage therapy and occlusal splint therapy on mandibular range of motion in individuals with temporomandibular disorder: a randomized clinical trial.

OBJECTIVE: The purpose of this study was to investigate the effects of massage therapy compared with occlusal splint therapy on mandibular range of motion (ROM) in individuals with temporomandibular disorder (TMD) and compare the results with ROM obtained in a group of individuals without this disorder. METHODS: A blinded randomized clinical trial was conducted. Twenty-eight volunteers with TMD were randomly distributed into either a massage therapy group or an occlusal splint group. Both treatments were provided for 4 weeks. Fourteen individuals without TMD were consecutively allocated to a comparison group. Fonseca anamnestic index was used to characterize TMD and allocate the volunteers to either of the intervention groups or asymptomatic comparison group. Mandibular ROM was evaluated before and after treatment using a digital caliper. Two-way repeated-measures analysis of variance with a post hoc Bonferroni testing was used for intergroup and intragroup comparisons (level of significance was set to 5%). Cohen d was used to calculate the effect size. RESULTS: In the intragroup analysis, significant increases in ROM were found for all measures in both the massage and occlusal splint groups (P < .05). A small to moderate clinical effect of treatment with the occlusal splint was found regarding right and left lateral excursion in comparison with the massage therapy and asymptomatic comparison groups (0.2

Effect of botulinum toxin type a combined with physical therapy on functional capacity in children with spastic cerebral palsy: a randomized controlled clinical trial.

OBJECTIVE: Investigate the effects of botulinum toxin type A (BoNT-A) combined with physical therapy on functional capacity in children with spastic cerebral palsy (CP). METHODS: Twenty-four children with spastic CP were treated with either BoNT-A and physical therapy or physical therapy alone. RESULTS: Significant differences (p < 0.05) were found after 30 days of treatment for the Berg Scale, Timed Up and Go (TUG) test, Ashworth Scale and Pediatric Evaluation of Disability Inventory (PEDI) and after three months for the Berg Scale, TUG test and PEDI. No significant differences (p > 0.05) were found in the control group. DISCUSSION: BoNT-A combined with physical therapy leads to significant improvements in spasticity and functionality in children with CP within a period of three months from the onset of treatment.

Pattern of electromyographic activity in mastication muscles of adolescents with temporomandibular disorder.

UNLABELLED: [Purpose] The aim of the present study was to assess the behavior of the mean and median frequencies of the electromyography signal of the mastication muscles of adolescents with different degrees of TMD severity. [Subjects] Forty-two adolescents aged 14 to 18 years. [Methods] The adolescents were classified according to severity using the Helkimo Index. The control group consisted of 14 subjects with no signs or symptoms of TMD. Three readings were taken in during maximum intercuspation and mandibular rest, with each reading lasting 10 seconds. [Results] Significant differences (p=0.0001) were found in the mean frequency (Hz) between the control group (CG), mild TMD group (MG) and moderate/severe TMD group (MSG), especially during mandibular rest, for all muscles evaluated: right temporal: CG (137.5), MG (194.2), MSG (291.7); left temporal: CG (106.9), MG (200.6), MSG (294.2); right masseter: CG (155.7), MG (242.8), MSG (278.3); left masseter: CG (125.0), MG (214.6), MSG (316.7). Greater differences among groups were found under the condition of mandibular rest. CONCLUSIONS: Adolescents with TMD especially those with more severe symptoms exhibit hyperactivity of the mastication muscles.