Prevalence and correlation between TMD based on RDC/TMD diagnoses, oral parafunctions and psychoemotional stress in Polish university students

Synovial tissue cytokine profile in disc displacement of the temporomandibular joint

BACKGROUND

Symptomatic disc displacement (DD) of the temporomandibular joint (TMJ) may cause pain and limited mouth opening. The aetiopathogenesis is obscure and probably complex, which makes the diagnostic classification crude and mainly based on clinical criteria rather than disease mechanisms, and tissue characteristics.

OBJECTIVES

The study aim was to characterise and quantify synovial tissue in DD, where specific cytokine patterns might serve as potential biomarkers.

METHODS

An observational cohort study was performed harvesting synovial tissue from 63 patients: 44 with DD without reduction (DDwoR) and 19 with DD with reduction (DDwR). DDwoR was subdivided depending on type of onset (sudden, n = 17; delayed, n = 27), and DDwR served as the control group. Proteins were extracted from tissue samples and investigated in a multi-analytic profiling system.

RESULTS

DDwoR patients had significantly higher concentrations in 12 out of 28 analysed cytokines compared to DDwR. In the same statistical model, significantly lower concentrations of interferon gamma-induced protein (IP) 10, osteoprotegerin (OPG) and RANTES were detected in DDwoR patients. Women showed significantly higher concentrations of epidermal growth factor and interleukin (IL) 1ra compared to men. DDwoR with sudden onset had significant higher concentrations of bone morphogenetic protein 4, eotaxin and IL-8 compared to DDwoR with delayed onset.

CONCLUSIONS

Characterising the biomarker panel for TMJ conditions may serve as suggestible targets for disease classification and novel treatment options. The significantly lower concentrations of IP-10, OPG and RANTES could be proposed as putative markers for the separation of the studied conditions to other TMJ diseases.

Influence of Psychosocial Factors and Parafunctional Habits in Temporomandibular Disorders: A Cross-Sectional Study

INTRODUCTION

Temporomandibular disorders (TMDs) are abnormalities affecting the temporomandibular joint, jaw muscles, or both. An intrinsic relationship reportedly exists between TMDs and psychosocial factors, including stress. Parafunctional habits such as bruxism and clenching are also known to be responsible for TMDs.

OBJECTIVE

To determine the association of anxiety, depression, and bruxism with TMD symptoms and their relationship with age and sex.

METHODS

Patients included in the study reported, as their chief concern, pain lasting for more than a week in the temporomandibular joint area and/or masticatory muscles. The patients were divided into age groups as follows: Younger than 20 years, 21 to 30 years, 31 to 40 years, 41 to 50 years, 51 to 60 years, and above 60 years. Patients were examined clinically and were asked to complete an anamnestic questionnaire (modified version of Helkimo Anamnestic Index) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

Seventy-five patients (55 women, 20 men) were included in the study. The prevalence of TMDs was higher in female patients, of whom 33 (60%) had moderate to severe TMDs. Of the 20 male patients, 12 (60%) had signs and symptoms of moderate TMDs. Anxiety and depression scores were higher in female patients. No significant correlation was found between degree of malocclusion and TMDs.

DISCUSSION

We found correlations between the degree of TMD with age, sex, parafunctional habits, and psychosocial factors. Symptoms of TMD seemed to increase in patients with parafunctional habits, from younger to older age groups, and with increased anxiety and depression scores.

CONCLUSION

The degree of TMDs is higher in women, and TMDs are associated with higher anxiety and depression scores. Correlation between these factors paves the way for preventive actions aimed at those with moderate and severe signs of TMDs.

Great potential of ultrasound elastography for the assessment of the masseter muscle in patients with temporomandibular disorders. A systematic review

Objective:

To summarize the available evidence on the use of elastography in the assessment of the masseter muscle in healthy individuals and patients with masseter muscle disorders.

Methods:

Systematic literature review has been performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

Results:

16 of 142 studies identified were analyzed. Elastography was used in seven studies. Heterogeneity was observed in terms of study protocols, devices, patients, units of measure, and results. Elasticity values showed a correlation between the left and right masseter muscle side in healthy people, but not in patients with temporomandibular disorders (TMDs). Elasticity values increased in TMD and were correlated with the severity of TMD symptoms. Phantom studies proved the high reliability of elastography.

Conclusion:

Elastography is a promising tool for the assessment of the masseter muscle elasticity, but the evidence is insufficient. Studies on larger groups are needed to determine the accuracy of elastography to characterize masticatory muscle disorders.

The effects of estrogen on temporomandibular joint pain as influenced by trigeminal caudalis neurons

The signs and symptoms of persistent temporomandibular joint (TMJ)/muscle disorder (TMJD) pain suggest the existence of a central neural dysfunction or a problem of pain amplification. The etiology of chronic TMJD is not known; however, female sex hormones have been identified as significant risk factors. Converging lines of evidence indicate that the junctional region between the trigeminal subnucleus caudalis (Vc) and the upper cervical spinal cord, termed the Vc/C1-2 region, is the primary site for the synaptic integration of sensory input from TMJ nociceptors. In this paper, the mechanisms behind the estrogen effects on the processing of nociceptive inputs by neurons in the Vc/C1-2 region reported by human and animal studies are reviewed. The Vc/C1-2 region has direct connections to endogenous pain and autonomic control pathways, which are modified by estrogen status and are suggested to be critical for somatomotor and autonomic reflex responses of TMJ-related sensory signals.

Masticatory Muscles Activity in Sport Climbers

Masticatory muscle activity during teeth clenching is associated with changes in many physiological parameters throughout the body. Clenching can improve muscle activity, force production, rate of force development, and joint fixation. Hence, teeth clenching and masticatory muscle activity can be important in competitive sports activities. Sport climbing is becoming increasingly popular and will be included for the first time in the Summer Olympic Games, Tokyo, 2020. However, masticatory muscle activity in sport climbers has not yet been studied. The aim of the presented study is to compare the bioelectrical activity of the masticatory muscles in sport climbers and non-climbers in order to determine the relationship between these muscles and climbing activity. 44 subjects without masticatory system disorders (16 women and 28 men, average age 26.3) were divided into two groups of 22 sport climbers (8 women, 14 men, climbing experience >4 years), while 22 people (8 women, 14 men, with no regular sports activity) were assigned to the control group. Electromyographic examination of temporalis anterior (TA) and masseter muscle (MM) was evaluated in three conditions: during resting mandibular position, during maximum intercuspation clenching, and during maximum voluntary clenching with cotton rolls between teeth. For statistical analysis, the W Shapiro-Wilk test and the Mann-Whitney U test were used. Sport climbers showed significantly higher bioelectrical activities of MM during maximum intercuspation clenching (238.45 μV vs. 83.87 μV, p = 0.002), and during maximum voluntary clenching with cotton rolls between teeth (300.01 μV vs. 101.38 μV, p = 0.001) compared to controls. The differences between groups in relation to the resting bioelectrical activity of the MM muscles, and TA muscles in all conditions were not statistically significant (p > 0.05). Higher bioelectrical activity of masseter muscles during clenching in climbers can be associated with this sports activity. However, the mechanism remains unknown and requires future research.

Evaluation of the psychoemotional status of young adults with symptoms of temporomandibular disorders

BACKGROUND AND PURPOSE

Temporomandibular disorders (TMD) are among the most frequent pathologies of the stomatognathic system. One problem often associated with TMD is the psychoemotional status. The aim of study was to evaluate the psychoemotional status of young adults with pain symptoms associated with TMD.

MATERIAL AND METHODS

We analyzed the data of 260 volunteers. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) form was used to diagnose TMD. The relationships between TMD/RDC clinical diagnoses and psychoemotional status, as described by the Beck's Depression Inventory (BDI) and Perceived Stress Scale (PSS-10), were analyzed. We divide the group into four on the basis of RDC/TMD Axis I diagnosis. Group 0 included 30 students lacking TMD symptoms. Group I consisted of 30 people with myofascial pain (group IA in RDC/TMD). Group II contained 23 people with disk displacement with reduction (group IIA in RDC/TMD). Group III contained ten people (Group III diagnosis, often associated with pain).

RESULTS

We did not find statistically significant differences between the study groups. In subjects with pain (Groups I and III), we found the mean value on the BDI and PSS-10 scales to be higher than among the pain-free subjects (Groups 0 and II).

CONCLUSION

In young adults with TMD accompanied by pain, psychoemotional status should also be evaluated.

Association between bruxism and temporomandibular disorders in children: A systematic review and meta-analysis

BACKGROUND

Bruxism in children and its relation to the development of temporomandibular disorders (TMD) has not been clearly determined yet.

AIM

The objective of this systematic review was to evaluate the possible association between bruxism and TMD in children.

DESIGN

Seven databases were searched, and 497 articles were assessed. Methodological quality was assessed through Newcastle-Ottawa Scale. The meta-analysis was performed with the articles in which extraction of data was possible and the summary effect measure through odds ratio (OR) and respective 95% confidence intervals (CIs). Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence.

RESULTS

Ten cross-sectional studies were included in the systematic review. Of these, 8 showed a statistically significant association between bruxism and TMD. Seven studies however presented a high risk of bias. The meta-analysis was performed with 3 articles and obtained an OR of 2.97 (95% CI ranging from 1.72-5.15), indicating that children with bruxism are 2.97 times more likely to present TMD, with very low level of certainty defined by GRADE.

CONCLUSIONS

Although the studies showed high risk of bias, the qualitative analysis of individual studies showed that the children with bruxism have greater chance of developing TMD.

Prevalence of Temporomandibular Disorder in Turkish University Students: a Questionnaire Study

Background/Aim: Temporomandibular dysfunction (TMD) might influence any individual with different signs and symptoms irrespective of gender or age. The aim of this study is to assess the prevalence of TMD in Oral and Dental Health Program students of İstanbul University-Cerrahpaşa.

Material and Methods: This study include a sample of 486 students with age ranging from18 to 24 years. The presence and severity of TMD was evaluated using the Fonseca’s Anamnestic Index (FAI) and its questionnaire. The data were analysed using SPSS Version 22. The chisquare test was used to compare the data from different groups and to determine whether the differences were statistically significant.

Results: The results showed that a total of 47,53% of students had some degree of TMD and females were generally more affected than males. These degrees were as follows: 33,95 % were classified as mild, 11,52 % moderate and 2,05 % severe signs and symptoms. The women exhibited some degree of TMD (51,8%) at a higher frequency than men (40,33%). No significant differences were observed between gender for a same TMD severity degree (p>0.05).

Conclusions: A high prevalence of mild TMD was found in this study population. In addition, tense personalities, headaches, and temporomandibular joint (TMJ) sounds were the most prevalent findings of TMD. The present study suggests that Fonseca’s Anamnestic Index (FAI) has been used in screening for TMD for prevention and management of TMD in a non-patient young population.

The Diagnostic Value of Electromyography in Identifying Patients With Pain-Related Temporomandibular Disorders

Introduction: Orofacial pain disorders can be divided into several subgroups. One of them is temporomandibular disorders (TMD) with recognizable signs such as joint noises, limitations in the range of motion, or mandibular deviation during function and symptoms-pain in the muscles or joint. Surface electromyography (sEMG) is a diagnostic tool that ensures reliable and valid evaluation of muscle activity. sEMG detects electrical potentials and on this account may conceivably be employed in the TMD recognition. The aim of this study was to assess the sensitivity, specificity, and accuracy of electromyography in diagnosing subjects with temporomandibular disorders, including pain-free TMD and pain-related TMD. Methods: The sample comprised 88 patients with cleft lip and palate and mixed dentition. TMD has been recognized on the grounds of Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD). To evaluate the electrical activity of the temporal and masseter muscles in the rest position and during maximum voluntary contraction, a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) was used. The analysis of the receiver operating characteristic (ROC) curve gave information about accuracy, cut-off point value, sensitivity and specificity of the normalized sEMG data. Results: The highest diagnostic efficiency of sEMG in terms of identifying subjects with TMD and pain-related TMD was observed for the mean values of temporal and masseter muscle activity as well as the Asymmetry Index of the masseter muscles in a rest position. A moderate degree of EMG accuracy in differentiating between pain-related TMD and non-TMD children was observed for the mean values of masseter muscle activity and the Asymmetry Index of the masseter muscles at rest. Conclusion: An evaluation of electromyography exhibits its diagnostic usability in recognition of patients with pain-related TMD and it could be used as an adjunctive tool in the identification of this disorder. Clinical Trial Registration: This clinical research was registered in the ClinicalTrials.gov database under the number NCT03308266.

Oral parafunctions, personality traits, anxiety and their association with signs and symptoms of temporomandibular disorders in the adolescents

OBJECTIVES

To investigate the association between oral parafunctions, personality traits, anxiety and signs and symptoms of temporomandibular disorders in the adolescents.

METHODS

Two hundred and seventy adolescents were examined clinically for the signs and symptoms of temporomandibular disorders. Participants completed questionnaires about demographic variables, medical history, symptoms of temporomandibular disorders, parafunctional oral habits, Minnesota Multibasic Personality Inventory, and Spielberger State-Trait Anxiety Inventory.

RESULTS

Logistic regression analyses revealed that bruxism was associated with joint tenderness (Odds ratio (OR)=6.38, p < 0.01), joint noises (OR=6.02, p < 0.01) and masticatory muscle tenderness (OR=4.19, p < 0.05) to palpation. State anxiety showed increased risk of joint tenderness (OR=2.47, p < 0.05) and muscle tenderness (OR=3.25, p < 0.05) to palpation.

CONCLUSION

Within the limitations of this study, it was concluded that oral parafunctions, especially bruxism, state anxiety, depression and hysteria were associated with signs and symptoms of temporomandibular disorders in adolescents.

Prevalence of temporomandibular disorders and oral parafunctions in adolescents from public schools in Southern Italy

Objective: The aim of this cross-sectional epidemiologic study was to estimate the prevalence of temporomandibular disorders (TMDs) and oral parafunctions in Italian adolescents and to assess the associations between age, gender, oral habits, and TMD. Methods: Three hundred sixty-one adolescents, aged 14-18 years, were examined for TMDs according to the Research Diagnostic Criteria for TMD. Furthermore, oral habits were explored by means of a written questionnaire. Results: Almost one-third of the sample (27.4%) showed at least one TMD diagnosis, with myofascial pain being the most prevalent. Gum chewing was the most prevalent oral habit. The female gender and oral habits were significantly associated with TMD. Conclusion: TMD in adolescents, although lower than in adults, are significantly prevalent. General practitioners should include TMD screening methods in their routine dental examinations of adolescent patients. Adolescents should be instructed on how to avoid incorrect oral behaviors that might predispose them to the onset of TMD.

A high prevalence of TMD is related to somatic awareness and pain intensity among healthy dental students

OBJECTIVE

Dental students have been identified as a group with high risks of developing both temporomandibular disorders (TMD) and psychosocial conditions. Our primary aim was to evaluate the cross-sectional prevalence of TMD diagnoses, as defined in the Diagnostic Criteria (DC)/TMD, among dental students. The secondary aim was to evaluate the prevalence and association of behavioural and psychosocial factors in relation to DC/TMD diagnoses.

MATERIALS AND METHODS

The study was conducted among undergraduate dental students during the second semester of their third year at the Department of Odontology, Medical Faculty, Umeå University, Sweden. Three consecutive cohorts were recruited during August in 2013, 2014, 2015. In total, 54 students were included and examined according the DC/TMD procedure.

RESULTS AND CONCLUSIONS

The prevalence of any DC/TMD diagnosis was 30%. The most prevalent TMD diagnosis was myalgia. Individuals with a TMD-pain diagnosis (i.e. myalgia or arthralgia) reported significantly higher pain intensity levels according to the Graded Chronic Pain Scale (GCPS) as compared to individuals without TMD-pain (Fisher's exact test p < .001, two-sided). In addition, individuals with any TMD scored significantly higher jaw functional limitations according to the Jaw Functional Limitation Scale 20 (JFLS-20, p < .001) and oral parafunctions according to the Oral Behavior Checklist (OBC, p = .005) as compared to individuals without TMD. The psychosocial factors evaluated did not differ between individual with or without a TMD diagnosis. The majority of the dental students reported symptoms that are already identified as risk factors for developing TMD and pain conditions. However, longitudinal data are needed to evaluate how this evolves over time.

Anxiety and malocclusion are associated with temporomandibular disorders in adolescents diagnosed by RDC/TMD. A cross-sectional study

BACKGROUND

Temporomandibular Disorders (TMD) is a multifactorial condition, which could be associated to occlusal and psychological factors, such as anxiety.

OBJECTIVE

Investigate if anxiety and malocclusion are associated with the prevalence of TMD in adolescents.

METHODS

To ensure a population-based representative sample, 934 adolescents aged 10 to 14 years old from Curitiba-PR, Brazil were randomly selected and examined according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and malocclusion by a single-calibrated examiner (Kappa > 0.80). Anxiety was assessed according to trait anxiety (STAI-T), categorised as high, moderate and low levels. For occlusal exam, it was considered: Angel's molar relationship, anterior and posterior crossbite, excessive overjet, open and deep bite. The associations were analysed by the crude and adjusted prevalence ration (RP_a ) of TMJ, calculated by a Poisson multivariate regression with robust variance (α = 0.05).

RESULTS

The prevalence of at least one type of malocclusion was found in 52.3%. Anxiety was found in high level (12.2%), moderate (70.4%) and low (17.5%). Presence of high anxiety was significantly associated with the prevalence of TMD symptoms (RP_a  = 4.06, P < 0.001), as well as the prevalence of myofascial pain (RP_a  = 24.78; P < 0.001) and prevalence of disc displacement with reduction (RP_a  = 11.08, P < 0.001). Adolescents Class II had higher prevalence of myofascial pain (Class II RP_a  = 1.73; P < 0.015) than adolescents Class I. Adolescents Class III presented higher prevalence of myofascial pain (PR_a 2.53; P = 0.004) than adolescents Class I.

CONCLUSION

Anxiety is strongly associated with TMD in adolescents. Presence of Class II or III is associated with higher prevalence of myofascial pain in adolescentsPLESAE check and approve the edit made in the article title.

Association of temporomandibular disorder and high frequency of suicide ideation in Korean adolescents: a cross-sectional survey

BACKGROUND

This study investigated the association between psychological factors and temporomandibular disorder (TMD) in a representative sample using data from the Korean nationwide survey.

METHODS

The study included 1337 adolescents. Participants provided demographic, socio-economic and behavioural information, and responses to questionnaires assessing their mental health status including perceived stress, depressed mood and suicidal ideation in the presence of TMD. In univariate analysis, t-test was used to test the association between TMD and risk factors by gender in a complex sampling design. Multivariate logistic regression analyses were used to examine the association between TMD and psychological factors.

RESULTS

Male adolescents with TMD were highly engaged with depressed mood and suicidal ideation (p = .0006, p = .0223), however, no psychological factors were significant in female adolescents (p < .05). Male adolescents with both depressed mood and suicidal ideation had significantly high rates of TMD (p = .0024). The risks for experiencing depressed mood (OR: 3.07) and suicidal ideation (OR: 2.564) were significantly associated with TMD in male adolescents after adjusting confounders.

CONCLUSIONS

The results provide evidence that the depressed mood and suicidal ideation were associated with TMD in male adolescents. This study has important implications for enhanced screening and evaluation of mental health among patients with TMD according to gender.

A Self-Reported Association between Temporomandibular Joint Disorders, Headaches, and Stress

AIMS AND OBJECTIVES

Temporomandibular joint disorder (TMD) is an umbrella term for a number of conditions in the area of the joint, temple, and masticatory system. Many of those with TMD also suffer from headaches and anxiety. The aims and objectives of this study were to determine if there exists an association between the Diagnostic Criteria of TMD (DC/TMD) symptom questionnaire and report of headaches as well as stress.

MATERIALS AND METHODS

A cross-sectional study was implemented via the use of the DC/TMD symptom questionnaire and the perceived stress scale (PSS). This was distributed conveniently among dental students in a multi-dental school setting in Riyadh, Saudi Arabia, and was completed by 152 dental students. Odds ratios, Chi-square, and their corresponding 95% confidence intervals are reported. Statistical significance was set at P ≤ 0.05.

RESULTS

Those who ticked yes for pain on the TMD pain screener for pain with chewing hard or tough food, pain on mouth opening and lateral excursion, and pain with jaw habits as parafunction were at an odds risk from twice to thrice as likely to experience headaches. Similarly, those with poor coping skills on the PSS were more likely to have headaches (P = 0.002). Likewise, positive answers on the screener and symptom questionnaire were relevant with higher stress scores on the PSS.

CONCLUSION

This study clarifies and reiterates the intertwined power of both stress and headaches; the former being a role player in TMD progression and the latter its product. TMD is unfortunately on the rise; it should not be brushed off as a nuisance. A multidisciplinary approach in diagnosis and treatment of both TMD and headaches by a team of orofacial pain specialist, neurologist, psychiatrist and/or psychologist, and physical therapists to untangle the deceiving presentation of both conditions would not only provide a more favorable prognosis but also improve cost and time expenditures.

Comparison between Collagen and Lidocaine Intramuscular Injections in Terms of Their Efficiency in Decreasing Myofascial Pain within Masseter Muscles: A Randomized, Single-Blind Controlled Trial

Background and Objective

A novel option for myofascial pain (MFP) management and muscle regeneration is intramuscular collagen injections. The aim of the study was to evaluate the efficiency of intramuscular injections of collagen and lidocaine in decreasing MFP within masseter muscles.

Methods

Myofascial pain within masseter muscles was diagnosed on the basis of the Diagnostic Criteria for Temporomandibular Disorders (II.1.A. 2 and 3). A total of 43 patients with diagnosed MFP within masseter muscles were enrolled to the study (17 male and 26 female, 40 ± 3.8 years old) and randomly divided into three groups. The first group received injections using 2 ml of collagen MD Muscle (Guna), the second group received 2 ml of 2% lidocaine without a vasoconstrictor, and the third group 2 ml of saline as a control (0.9% NaCl). All patients received repeated injections at one-week intervals (days 0 and 7). The visual analogue scale was used to determine pain intensity changes during each follow-up visit (days 0, 7, and 14) in each group. The masseter muscle activity was measured on each visit (days 0, 7, and 14) with surface electromyography (sEMG) (Neurobit Optima 4, Neurobit Systems).

Results

We found that sEMG masseter muscle activity was significantly decreased in Group I (59.2%), less in Group II (39.3%), and least in Group III (14%). Pain intensity reduction was 53.75% in Group I, 25% in Group II, and 20.1% in Group III.

Conclusions

The study confirmed that intramuscular injection of collagen is a more efficient method for reducing myofascial pain within masseter muscles than intramuscular injection of lidocaine.

Electromyographic Analysis of Masticatory Muscles in Cleft Lip and Palate Children with Pain-Related Temporomandibular Disorders

Aim

The aim of this study was to assess the electrical activity of temporalis and masseter muscles in children with cleft lip and palate (CLP) and pain-related temporomandibular disorders (TMD-P).

Methods

The sample consisted of 31 CLP patients with a TMD-P (mean age 9.5 ± 1.8 years) and 32 CLP subjects with no TMD (mean age 9.2 ± 1.7 years). The children were assessed for the presence of temporomandibular disorders (TMD) using Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD). Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) in the mandibular rest position and during maximum voluntary contraction (MVC).

Results

The rest activity of the temporalis and masseter muscles was significantly higher in TMD-P group compared with non-TMD children. A significant decrease in temporalis muscle activity during MVC was observed in TMD-P patients. There was a significant increase in the Asymmetry Index for temporalis and masseter muscle rest activity in the TMD-P group.

Conclusion

Cleft children diagnosed with TMD-P have altered masticatory muscle activity, and this can affect their muscle function.

Assessment of the Short-Term Effectiveness of Kinesiotaping and Trigger Points Release Used in Functional Disorders of the Masticatory Muscles

Chronic face pain syndrome is a diagnostic and therapeutic problem for many specialists, and this proves the interdisciplinary and complex nature of this ailment. Physiotherapy is of particular importance in the treatment of pain syndrome in the course of temporomandibular joint functional disorders. In patients with long-term dysfunction of masticatory muscles, the palpation examination can localize trigger points, that is, thickening in the form of nodules in the size of rice grains or peas. Latent trigger points located in the muscles can interfere with muscular movement patterns, cause cramps, and reduce muscle strength. Because hidden trigger points can spontaneously activate, they should be found and released to prevent further escalation of the discomfort. Kinesiotaping (KT) is considered as an intervention that can be used to release latent myofascial trigger points. It is a method that involves applying specific tapes to the patient's skin in order to take advantage of the natural self-healing processes of the body. The aim of the study was to evaluate the effect of the kinesiotaping method and trigger points inactivation on the nonpharmacological elimination of pain in patients with temporomandibular disorders. The study was conducted in 60 patients (18 to 35 years old). The subjects were randomly divided into two subgroups of 30 people each. Group KT (15 women and 15 men) were subjected to active kinesiotaping application. Group TrP, composed of 16 women and 14 men, was subjected to physiotherapy with the release of trigger points by the ischemic compression method. The results show that the KT method and TrP inactivation brought significant therapeutic analgesic effects in the course of pain-related functional disorders of the muscles of mastication. The more beneficial outcomes of the therapy were observed after using the KT method, which increased the analgesic effect in dysfunctional patients.

Activation of β-catenin signaling in aggrecan-expressing cells in temporomandibular joint causes osteoarthritis-like defects

β-Catenin plays a critical role in cartilage formation and development. To further understand the role of β-catenin in osteoarthritis (OA) development in temporomandibular joint (TMJ), we have generated β-catenin conditional activation mice (β-cat(ex3)^Agc1CreER) by breeding Agc1-CreER mice with β-catenin^flox(ex3)/+ mice. Results of histologic analysis showed the progressive TMJ defects in 3- and 6-month-old β-cat(ex3)^Agc1CreER mice (tamoxifen induction was performed at 2 weeks of age), including decreased chondrocyte numbers in the superficial layer associated with less Alcian blue staining, increased numbers of hypertrophic chondrocytes in deep layers, and rough articular surface. Compared to the TMJ phenotype of β-cat(ex3)^Col2CreER mice, β-cat(ex3)^Agc1CreER mice showed much severe morphological defects in the superficial layer of TMJ. This may reflect that Agc1-CreER mice could efficiently target cells in the superficial layer of TMJ. Results of immunostaining showed significantly increased expression of MMP13, Col-X, Adamts4, and Adamts5 in TMJ of β-cat(ex3)^Agc1CreER mice. Results of proliferating cell nuclear antigen (PCNA), Ki67, and terminal deoxinucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) staining further demonstrated that cell proliferation was decreased and cell apoptosis was increased in condylar cartilage of β-cat(ex3)^Agc1CreER mice. Our findings indicate that abnormal upregulation of β-catenin in TMJ leads to defects assembling to OA-like phenotype, further demonstrating that β-catenin plays a critical role in TMJ pathogenesis.

Therapies targeting a cartilage-regulating signaling protein could mitigate painful damage inflicted on the jaw by age-related osteoarthritis. Many older individuals experience degeneration of the temporomandibular joint (TMJ), where the upper and lower jaw connect. Researchers led by Di Chen of Rush University Medical School in Chicago, USA, have developed a genetically-modified mouse model that reveals a likely molecular driver for TMJ osteoarthritis. Previous studies have implicated a protein called β-catenin in this process, and Chen’s team generated mice in which β-catenin levels can be selectively boosted in cartilage-forming cells at skeletal joints. This increased β-catenin markedly altered the organization of TMJ cartilage, with decreased cell proliferation and increased cell death. The effects were strikingly similar to human osteoarthritis, and the researchers hypothesize that compounds that counter β-catenin could offer useful treatments for this condition.

Functional Assessment of the Stomatognathic System, after the Treatment of Edentulous Patients, with Different Methods of Establishing the Centric Relation

The study compares subjective experiences of patients, wearing complete dentures. Two different methods of determining a centric relation were performed: the traditional method using wax occlusal rims and the Gerber method, based on gothic arch tracings. The success rate of establishing a centric relation in both methods was evaluated (rentgenodiagnostics). The influence of the method used to obtain the centric relation on patients' stomatognathic system (condyle centralization, pain) was also evaluated. Better results were achieved in gothic arch tracing method. Before every prosthetic treatment of edentulous patients, a functional analysis of the TMJ is necessary. The lack of centric relation, in a long term adaptation patients, does not lead to TMD symptoms. This trial is registered with NCT03343015.

Prevalence of temporomandibular disorders among a cohort of university undergraduates in Australia

AIM

The aim of the present study was to determine the prevalence of temporomandibular disorder (TMD) symptoms among dentistry students at James Cook University in Australia, and to determine the associations of TMD symptoms with demographic parameters and compare the prevalence to that of the Australian general population.

METHODS

The study was conducted at the School of Dentistry, James Cook University. Axis I symptom questionnaire of diagnostic criteria for TMD was used to assess the prevalence of TMD symptoms. Additional questions were included to gather demographic information on the participants. Data were collected anonymously via the online survey tool, SurveyMonkey.

RESULTS

The overall prevalence of TMD symptoms in this cohort was 77.2%. The most common TMD symptoms were pain (48.5%) and joint noises (48.5%). Females reported a significantly higher prevalence of TMD symptoms than males, with 73 of 88 female respondents (83%) and 32 of 48 male respondents (66.7%) reporting at least one symptom of TMD (P = .030).

CONCLUSIONS

The overall prevalence of TMD symptoms in the population studied was 77.2%, with female preponderance of TMD symptoms (83%). This is higher than the estimated prevalence (23%) in the Australian general population.

The Efficiency of Anterior Repositioning Splints in the Management of Pain Related to Temporomandibular Joint Disc Displacement with Reduction

Background and Objective

Intra-articular temporomandibular disorders are often related to pain in the area of the temporomandibular joint, ear, and temple. The aim of the study was to investigate the efficiency of anterior repositioning splints in decreasing pain related to temporomandibular joint disc displacement with reduction.

Methods

The research material consisted of 112 patients, aged 24 to 45 years, of both genders, who reported for treatment at the Consulting Room of Temporomandibular Joint Dysfunctions at the Jagiellonian University in Cracow between 2014 and 2016 due to pain in the area of the temporomandibular joint(s) and noise(s) of temporomandibular joint(s) present during jaw movements with comorbid contracture of masticatory muscles. Subjects were examined according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) protocol and, after diagnosis of painful disc displacement with reduction and masticatory muscle contracture, they were assigned randomly to either the study or control groups (56 patients in each). In the study group, we used an anterior repositioning splint on the full lower arch for about 20 hours usage over a 4-month period. In the control group, a noninvasive therapy was applied using a biostimulation laser over 12 sessions performed every second day on the area of both temporomandibular joints with mouth open and while performing muscle self-exercises with a dominant protrusive position of the mandible. Pain intensity was evaluated using the Verbal Numerical Rating Scale (VNRS) immediately before the treatment and then after 4 and 16 weeks. The obtained data were analyzed using the Mann–Whitney U test (p ≤ 0.005).

Results

The VNRS values reported during the final examination for the study group were significantly lower than for the control group (p=0.0004).

Conclusions

The anterior repositioning splint is an efficient tool in decreasing pain related to disc displacement with reduction. This trial is registered with Clinicaltrials.gov NCT03057262.

Prevalence of diagnosed temporomandibular disorders: A cross-sectional study in Brazilian adolescents

Background

The prevalence of signs and symptoms of temporomandibular disorders (TMD) increases during adolescence and adulthood. Few studies have examined TMD prevalence in Brazilian adolescents.

Aim

To investigate the prevalence of TMD in Brazilian adolescents.

Methods

A representative population-based sample of 934 adolescents (10–14-years-old) was examined. TMD screening was performed using a questionnaire by the American Academy of Orofacial Pain. TMD diagnoses used research diagnostic criteria for temporomandibular disorders (RDC/TMD—Axis-I). Examinations were performed by a single calibrated examiner (kappa > 0.80).

Results

The prevalence of TMD symptoms was 34.9%; the most frequently reported symptoms were headache and neck ache (20.9%), followed by joint sounds (18.5%). Myofascial pain was the most prevalent type (10.3%), followed by disc displacement with reduction (8.0%) and arthralgia (3.5%). There was a significant association between sex and TMD symptoms; prevalence was significantly higher in girls (RP = 1.37; 95% CI = 1.14–1.65; p = 0.001). Myofascial pain of TMD and displacement with reduction were more prevalent in girls (RP = 1.76; p = 0.007 and RP = 2.06; p = 0.004, respectively).

Conclusion

TMD symptoms were present in 34.9% of adolescents, with myofascial pain being the most prevalent type (10.3%). TMD was significantly more common in girls. Routine pediatric dental care should include a TMD screening.

Temporomandibular Disorder Diagnostic Groups Affect Outcomes Independently of Treatment in Patients at Risk for Developing Chronicity: A 2-Year Follow-Up Study

AIMS

To evaluate whether a biobehavioral intervention would be more effective than a self-care intervention or no intervention in reducing psychosocial distress, reducing pain, and improving functioning in patients with an acute myofascial temporomandibular disorder (m-TMD).

METHODS

Participants (n = 435) were from community dental clinics in the Dallas-Fort Worth Metroplex who were seeking treatment for their acute TMD symptoms and were recruited between 2008 and 2013. The participants were diagnosed using the Research Diagnostic Criteria for TMD (RDC/TMD) and assigned to a biobehavioral intervention, self-care intervention, or no intervention. Three outcomes were assessed: psychosocial distress, pain, and functioning; and treatment effectiveness was assessed according to TMD diagnosis. Outcome evaluations were conducted immediately postintervention as well as at 1 and 2 years postintervention. Analyses were conducted using two-level hierarchical multilevel linear models (MLMs).

RESULTS

Contrary to expectations, patients did not respond differently to the intervention based on their TMD diagnosis. Acute m-TMD patients, especially those with other comorbid TMD diagnoses, reported the highest levels of pain and pain-related symptoms and disability. They also exhibited poorer jaw functioning, especially if they were at high risk for chronic TMD.

CONCLUSION

This study indicates that acute m-TMD tends to result in more severe symptom presentations, particularly if diagnosed in combination with other TMD comorbidities. Additionally, patients do not appear to respond better to biobehavioral or self-care intervention on the basis of their TMD diagnosis.

Vertical Craniofacial Morphology and its Relation to Temporomandibular Disorders

Objectives

This study investigated the association between craniofacial morphology and temporomandibular disorders in adults. The influence of different craniofacial morphologies on painful temporomandibular disorders was also evaluated.

Material and Methods

A total of 200 subjects were selected, including 100 with temporomandibular disorders (TMD) and 100 without TMD (control), diagnosed by research diagnostic criteria for temporomandibular disorders. All subjects were submitted to lateral cephalometric radiographs, and classified as brachyfacial, mesofacial, or dolichofacial by Ricketts’ analysis. Data were analysed by Tukey-Kramer and Chi-square tests.

Results

No association between craniofacial morphology and TMD was found (P = 0.6622). However, brachyfacial morphology influences the presence of painful TMD (P = 0.0077).

Conclusions

Craniofacial morphology is not related to temporomandibular disorders in general.

Prevalence of diagnosed temporomandibular disorders among Saudi Arabian children and adolescents

Background

Studies have indicated that the prevalence of symptoms and signs of temporomandibular disorders (TMD) are rare early in childhood, but become more prevalent in adolescents and adulthood. To our knowledge, no study has investigated the prevalence of TMD-diagnoses in children in the general population. The aim was thus to investigate the prevalence of TMD-diagnoses among children and adolescents in the general population using the Research Diagnostic Criteria for TMD (RDC/TMD).

Methods

The current cross-sectional study consisted of 456 children and adolescents, aged between 10 and 18, randomly enrolled from 10 boy’s- and 10 girl’s- schools in Jeddah. The participants first answered two validated questions about TMD-pain, followed by a clinical examination according to RDC/TMD.

Results

One hundred twenty-four participants (27.2 %) were diagnosed with at least one TMD-diagnosis. Myofascial pain was the most common diagnosis (15 %) followed by disc displacement with reduction, arthralgia, myofascial pain with limited mouth opening and osteoarthrosis. Children diagnosed with myofascial pain more often reported orofacial pain, headache and tooth clenching (p < 0.05), whereas children with arthralgia more often reported orofacial pain and tooth grinding than those without a TMD-diagnosis (p < 0.05). Only 18 % of the subjects in the TMD group had sought a dentist or physician for their pain.

Conclusion

TMD was common among children and adolescents in Saudi Arabia. Self-reported orofacial pain and headache as well as bruxism were associated with a TMD-pain diagnosis and disc displacement. A surprisingly low percentage of children and adolescents sought treatment by a dentist or physician for their pains.

Muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction

The aim of this study is to evaluate muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction (TMD). Two hundred volunteers aged 19.3 to 27.8 years (mean 21.50, SD 0.97) participated in this study. Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany). Muscle fatigue was evaluated on the basis of a maximum effort test. The test was performed during a 10-second maximum isometric contraction (MVC) of the jaws. An analysis of changes in the mean power frequency of the two pairs of temporal and masseter muscles (MPF%) revealed significant differences in the groups of patients with varying degrees of temporomandibular disorders according to Di (P < 0.0000). The study showed an increase in the muscle fatigue of the temporal and masseter muscles correlated with the intensity of temporomandibular dysfunction symptoms in patients. The use of surface electromyography in assessing muscle fatigue is an excellent diagnostic tool for identifying patients with temporomandibular dysfunction.

Identification of mastication organ muscle forces in the biocybernetic perspective

Purpose of the Paper. This paper is an attempt to mathematically describe the mastication organ muscle functioning, taking into consideration the impact of the central nervous system. Material. To conduct model tests, three types of craniums were prepared: short, normal, and long. The necessary numeric data, required to prepare the final calculation models of different craniofacial types, were used to identify muscle and occlusion forces generated by muscles in the area of incisors and molars. The mandible in model tests was treated as a nondeformable stiff form. Methods. The formal basis for the formulated research problem was reached using the laws and principles of mechanics and control theory. The proposed method treats muscles as “black boxes,” whose properties automatically adapt to the nature of the occlusion load. The identified values of occlusion forces referred to measurements made in clinical conditions. Results. The conducted verification demonstrated a very good consistency of model and clinical tests' results. The proposed method is an alternative approach to the so far applied methods of muscle force identification. Identification of muscle forces without taking into account the impact of the nervous system does not fully reflect the conditions of mastication organ muscle functioning.

Impact of functional appliances on muscle activity: a surface electromyography study in children

Background

Electromyography (EMG) is the most objective tool for assessing changes in the electrical activity of the masticatory muscles.

The purpose of the study was to evaluate the tone of the masseter and anterior temporalis muscles in growing children before and after 6 months of treatment with functional removable orthodontic appliances.

Material/Methods

The sample conisted of 51 patients with a mean age 10.7 years with Class II malocclusion. EMG recordings were performed by using a DAB-Bluetooth instrument (Zebris Medical GmbH, Germany). Recordings were performed in mandibular rest position, during maximum voluntary contraction (MVC), and during maximum effort.

Results

The results of the study indicated that the electrical activity of the muscles in each of the clinical situations was the same in the group of girls and boys. The factor that determined the activity of the muscles was their type. In mandibular rest position and in MVC, the activity of the temporalis muscles was significantly higher that that of the masseter muscels. The maximum effort test indicated a higher fatigue in masseter than in temporalis muscles.

Conclusions

Surface electromyography is a useful tool for monitoring muscle activity. A 6-month period of functional therapy resulted in changes in the activity of the masticatory muscles.