Electromyographic activity assessment of individuals with and without temporomandibular disorder symptoms

Temporomandibular disorder in individuals with spinal cord injuries

OBJECTIVE

This study evaluated Temporomandibular Disorder (TMD) in individuals with Spinal Cord Injuries (SCI) compared to individuals without physical disabilities.

DESIGN

Cross-sectional.

SETTING

International Fair of Technologies in Rehabilitation and Accessibility (REATECH) and School of Dentistry at the University of São Paulo (USP), Brazil.

PARTICIPANTS

In total, 19 patients with SCI and 19 patients without SCI (36.9 ± 11.4 years old) were examined by a calibrated examiner.

METHODS

using the following parameters: cervical spine mobility, palpation of muscle groups of the head and neck, functional manipulation of the lateral and medial pterygoids, and joint palpation (Diagnostic Criteria). The pattern and amplitude of mandibular movements were determined during screening using the Helkimo index.

STATISTICAL ANALYSES

Student's t-test, chi-square, Fisher's exact and Shapiro-Wilk test were used.

RESULTS

The groups did not differ in the presence of noise, pain, temporomandibular joint palpation, locking, dislocation, jaw pain, muscle sensitivity, or in pain, mobility of the cervical spine and functional manipulation. With respect to the jaw mobility index, the groups differed in range of movement (P = 0.020) and maximum right lateral movement (P = 0.007), with the worst values in the SCI group. The groups also differed in relation to lateral flexion in cervical mobility, in which the group without SCI presented better results (P = 0.046).

CONCLUSION

The Spinal Cord Injuries group showed higher levels of TMD in terms of range of movement, lateral flexion, and maximum right lateral movement, than the individuals without physical disabilities, demonstrating a clinical significance between cervical and mandibular disability in this group.

Masticatory Function in Individuals with Temporomandibular Disorders: A Systematic Review and Meta-Analysis

The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol in the PubMed, Cochrane Library, LILACS, EBSCO, Scielo, between 2012 and 2022. The methodological quality was assessed by using the Newcastle-Ottawa Study Quality Assessment Scale. Mean differences and 95% confidence intervals were calculated and combined in meta-analyses. A total of 1202 participants were included in this systematic review (690 with TMD; 512 without TMD), with 22 articles being included in the qualitative analysis. Only three studies enabled the comparative analysis of the results. Ten articles showed a high methodological quality and a low risk of bias, and twelve had a low methodological quality and an increased risk of bias. The meta-analysis showed that the differences between the intervention and control groups were not statistically significant for the percentage overlapping coefficient of the anterior temporal muscle, for the masseter, and for the torque coefficient. The parameters analyzed with the compound technique for chewing showed altered mandibular functions in individuals with TMD. With the EMG method, it was possible to suggest that TMD in adult individuals causes compensatory muscle behaviors, and several changes in the masticatory function were found.

Is jaw muscle activity impaired in adults with persistent temporomandibular disorders? A systematic review and meta-analysis

Understanding jaw muscle activity changes in temporomandibular disorders (TMD) is crucial to guide clinical management. The nature of these changes is currently unclear. Explore changes in jaw muscle activity in TMD. Electronic databases (PubMed, EMBASE, CINAHL, Scopus, Web of Science, Cochrane) and bibliographies were searched from inception to 9 July 2020 for eligible studies, including grey literature. Case-control and interventional studies reporting time-domain and frequency-domain electromyographic measures of jaw muscle activity in TMD and control groups were included. SIGN checklist for case-control studies was used to evaluate risk of bias. Results were pooled for meta-analysis using random-effects model. Confidence in cumulative evidence was established using American Academy of Neurology guidelines. Forty-five studies were included. Most were rated moderate risk of bias. Activity of four muscles (masseter, temporalis, lateral pterygoid, suprahyoids) was assessed across six domains (resting, clenching, chewing, swallowing, concentrating, resisted mandibular movements), with partial meta-analysis scope. Masseter and temporalis activity were significantly higher at rest (P = .05, P < .0001), but lower during brief maximal clenching (P = .005, P = .04) in TMD vs controls. Insufficient data precluded meta-analysis of remaining outcomes and subgroup analysis. Confidence in cumulative evidence ranged from moderate to very low. Changes in jaw muscle activity exist in TMD, which are both task-specific and muscle-specific. It remains unclear whether jaw muscle activity changes vary between TMD subgroups. Muscle function should be considered in clinical management of TMD. Insufficient subgroup data highlight future direction for research.

Analysis of Masticatory Muscle Activity Based on Presence of Temporomandibular Joint Disorders

Background

This study was conducted to analyze the activity of masticatory muscles depending on the presence of temporomandibular joint disorders (TMD) when foods of various hardness are masticated.

Material/Methods

We enrolled 20 subjects (13 men and 7 women) who met our selection criteria, and they were divided into 3 groups (the Disorder Group, the Malalignment Group, and the Control Group) based on surveys and screening inspection. The average of reference voluntary contraction (RVC) was used to measure masticatory muscle activity. Using surface electromyography (SEMG) for each group during masticatory activity, the activities of the masseter muscle and temporalis muscle were measured based on the hardness of 3 different foods (soft, sticky, and hard).

Results

Characteristics of these 3 groups prior to the experiment were identical, and subsequent findings were as follows: First, when masticating sticky food, the Disorder Group and Malalignment Group showed significant differences from the Control Group in activities of the masseter muscle and temporalis muscle (p<0.05). Second, when masticating hard food, the Malalignment Group and Control Group showed significant differences from the Disorder Group in the masseter muscle and temporalis muscle activities (p<0.05). Based on these findings, the study showed that malalignment affects movement of the temporomandibular joint during mastication of sticky food, and the temporomandibular joint movement was affected by the presence of pain during mastication of hard food.

Conclusions

Our results provide basic data useful in the diagnosis of temporomandibular joint disorder, as well as guiding future studies on this topic.

Association between severity of the temporomandibular disorder, neck pain, and mandibular function impairment

ABSTRACT Purpose: to investigate the possible association between the severity of the temporomandibular disorder, cervical pain, and mandibular function impairment. Methods: is a cross-sectional, descriptive study, conducted with 32 individuals with temporomandibular disorder, categorized by degree of severity, according to the Fonseca Index. Using the diagnosis criteria for temporomandibular disorder, the likely etiological factors for the disorder were established, as well as the intensity of the functional disability, resulting from cervical pain and of the mandibular impairment. The data obtained were statistically treated, adopting the significance level of 5%. Results: the mean age was 33.8 years, 90.6% being females. As for the degree of disorder, 56.3% presented severe TMD, followed by 28.1% showing a moderate one. The myogenic etiology was present in 93.7% of the patients. Cervical pain was present in 90.6% of them, of which, 59.4% presented a mild disability, and 25%, a moderate one. Considering the mandibular function, 46.9% of the patients presented a low, 40.6%, a moderate, and 12.5%, a severe impairment. There was a statistically significant association between cervical pain and mandibular function (p = 0.011). However, although there was an increase in cervical disability and in mandibular impairment as the severity of the TMD also increased, these associations were not statistically significant (p = 0.178 and p = 0.102, respectively). Conclusion: it can be stated that there is a higher prevalence of severe TMD and of myogenic origin, and that cervical pain influences, directly, the mandibular function, which is not necessarily related to the severity of the temporomandibular alteration. Likewise, such severity does not present a relationship to mandibular function impairment either.

An assessment of the usefulness of Kinesiograph as an aid in the diagnosis of TMD: a review of Manfredini et al.'s studies

AIM

Performing a literature review of publications by Dr. Manfredini et al. related to their temporomandibular joint (TMJ) injection therapy outcome with conclusions on the clinical utility of computerized measurement devices used in the management of temporomandibular disorders (TMDs). In addition, reviewing their published opinion on an occlusion: TMD versus a biopsychosocial paradigm for TMD. Manfredini et al. authored an article published in the Journal of the American Dental Association (JADA) 2013, "An Assessment of the usefulness of jaw kinesiography in monitoring temporomandibular disorders," the most recent of 12 articles. In all studies, subjects received TMJ injections with an objective measurement outcome criterion; increased maximum mouth opening (MMO) and subjective symptom improvement of pain and chewing function. In the 2013 JADA article, the Mandibular Kinesiograph, referred to as KG, measured MMO before and after therapy. In 11 prior articles, all subject groups with limited mouth opening exhibited very significant increased MMO post-treatment, documenting treatment success using the same 2013 protocol. The 2013 study showed a 1·1 mm improved MMO, described as insignificant. The authors did not critique or explain the aberrant, skewed 2013 outcome data contrasted with their prior studies, which showed overwhelmingly significant increased MMO. Instead, they concluded that the MMO recording device was clinically useless. This motivated a literature review of the authors' TMD publications.

CONCLUSION

The publications by Manfredini et al. recognized proponents of the psychosocial model of TMD, including the 2013 article, appear to be part of a campaign denying an occlusion: TMD relationship and disparaging the specific computerized measurement devices and the dentists using them in the management of their TMD patients using neuromuscular occlusion dental treatment.

Temporomandibular disorders: A position paper of the International College of Cranio-Mandibular Orthopedics (ICCMO)

PURPOSE

Two principal schools of thought regarding the etiology and optimal treatment of temporomandibular disorders exist; one physical/functional, the other biopsychosocial. This position paper establishes the scientific basis for the physical/functional. THE ICCMO POSITION: Temporomandibular disorders (TMD) comprise a group of musculoskeletal disorders, affecting alterations in the structure and/or function of the temporomandibular joints (TMJ), masticatory muscles, dentition and supporting structures. The initial TMD diagnosis is based on history, clinical examination and imaging, if indicated. Diagnosis is greatly enhanced with physiologic measurement devices, providing objective measurements of the functional status of the masticatory system: TMJs, muscles and dental occlusion. The American Alliance of TMD organizations represent thousands of clinicians involved in the treatment of TMD. The ten basic principles of the Alliance include the following statement: Dental occlusion may have a significant role in TMD; as a cause, precipitant and/or perpetuating factor. Therefore, it can be stated that the overwhelming majority of dentists treating TMD believe dental occlusion plays a major role in predisposition, precipitation and perpetuation. While our membership believes that occlusal treatments most frequently resolve TMD, it is recognized that TMD can be multi faceted and may exist with co-morbid physical or emotional factors that may require therapy by appropriate providers. The International College of Cranio-Mandibular Orthopedics (ICCMO), composed of academic and clinical dentists, believes that TMD has a primary physical/functional basis. Initial conservative and reversible TMD treatment employing a therapeutic neuromuscular orthosis that incorporates relaxed, healthy masticatory muscle function and a stable occlusion is most often successful. This is accomplished using objective measurement technologies and ultra low frequency transcutaneous electrical neural stimulation (TENS).

CONCLUSION

Extensive literature substantiates the scientific validity of the physical/functional basis of TMD, efficacy of measurement devices and TENS and their use as aids in diagnosis and in establishing a therapeutic neuromuscular dental occlusion.

CLINICAL IMPLICATIONS

A scientifically valid basis for TMD diagnosis and treatment is presented aiding in therapy.

Validation of the multimedia version of the RDC/TMD axis II questionnaire in Portuguese

OBJECTIVE

The aim of the study was to validate the multimedia version of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II Questionnaire in Portuguese language.

MATERIAL AND METHODS

The sample comprised 30 patients with signs and symptoms of temporomandibular disorders (TMD), evaluated at the Orofacial Pain Control Center of the Dental School of the University of Pernambuco, Brazil, between April and June 2006. Data collection was performed using the following instruments: Simplified Anamnestic Index (SAI) and RDC/TMD Axis II written version and multimedia version. The validation process consisted of analyzing the internal consistency of the scales. Concurrent and convergent validity were evaluated by the Spearman's rank correlation. In addition, test and analysis of reproducibility by the Kappa weighted statistical test and Spearman's rank correlation test were performed.

RESULTS

The multimedia version of the RDC/TMD Axis II questionnaire in Portuguese was considered consistent (Crombrach alpha = 0.94), reproducible (Spearman 0.670 to 0.913, p<0.01) and valid (p<0.01).

CONCLUSION

The questionnaire showed valid and reproducible results, and represents an instrument of practical application in epidemiological studies of TMD in the Brazilian population.