Pain Management and Rehabilitation for Central Sensitization in Temporomandibular Disorders: A Comprehensive Review

Temporomandibular Joint Disorder: An integrated study of the pathophysiology, neural mechanisms, and therapeutic strategies

OBJECTIVE

The study aims to investigate Temporomandibular Joint Disorder (TMJD) through a interdisciplinary lens, integrating insights from neuroscience, dentistry, and psychology to dissect its complex pathophysiology and neural mechanisms. It focuses on exploring the neurobiological underpinnings of TMJD, emphasizing the role of pain perception, modulation, and the impact of neurophysiological changes on the disorder.

DESIGN

This is a comprehensive narrative review of the literature.

RESULTS

Research findings pinpoint altered pain perception and modulation processes as central neural mechanisms contributing to TMJD, highlighting the importance of personalized treatment approaches due to the disorder's complexity and patient variability. The study recognizes advances in neuroscience offering new treatment avenues, such as neuromodulation and biofeedback, which provide non-invasive and personalized options. However, it also addresses the challenges in TMJD research, such as the multifaceted nature of the disorder and the need for more comprehensive, interdisciplinary strategies in research and clinical practice.

CONCLUSIONS

TMJD is a multifaceted disorder requiring an interdisciplinary approach for effective management. The study stresses the crucial role of neuroscience in understanding and treating TMJD, facilitating the development of innovative treatment strategies. It emphasizes the need for further research, advocating an integrated approach that combines neuroscience, dentistry, and psychology to address TMJD's complexities comprehensively and improve patient care, thereby enhancing the quality of life for affected individuals.

Quality of life and level of physical activity of individuals with temporomandibular disorders with and without otological symptoms: Secondary analysis of a cross-sectional study

BACKGROUND AND PURPOSE

Otological symptoms (OS) are highly prevalent in individuals with temporomandibular disorders (TMD). Individuals with TMD and OS have more neck disability and decreased deep neck muscles endurance when compared to individuals without OS. However, no studies have evaluated whether OS is associated with lower Quality of Life (QoL) and worse levels of physical activity. This study aimed to evaluate the QoL and level of physical activity of individuals with TMD with and without OS.

METHODS

In this cross-sectional study, 62 individuals with TMD were allocated into 2 groups: TMD with OS (n = 36) or TMD without OS (n = 26). Self-reported complaints of dizziness, vertigo, tinnitus, earache, ear fullness, or hypoacusis were considered as OS. QoL was assessed with the WHOQOL-Bref and physical activity with the IPAQ-SF. Independent t-test and chi-squared test were used for analysis between-groups. Effect sizes were reported using Cohen's d. A Pearson correlation was used to compare the number of OS and QoL scores. A significance level of p < 0.05% and 95% confidence intervals were considered statistically significant.

RESULTS

The total generic scores for QoL were not different between-groups (p = 0.076), but individuals with TMD with OS had lower satisfaction (p = 0.015; d: 0.63) and physical domain (p = 0.015; d: 0.64) scores with a moderate effect size. In TMD with OS, 69.4% of individuals were irregularly active and 50% for the TMD without OS, with no statistical significance (p > 0.05). The number of OSs was inversely and weakly associated with the QoL total score.

CONCLUSION

Individuals with TMD and OS are associated with worsened QoL (physical domain and satisfaction) when compared to individuals with TMD without OS. The higher the number of OS, the worse the QoL score. Individuals with TMD with and without OS had similar levels of physical activity, but a high prevalence of irregularly active and sedentary individuals within TMD diagnosed population was found.

Efficacy of rehabilitation treatments in improving functioning in patients with fibromyalgia: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Fibromyalgia is a debilitating condition marked by persistent pain and reduced functionality. Various therapeutic methods have been suggested to alleviate symptoms in individuals with fibromyalgia, yet the impact of diverse rehabilitation strategies remains unclear.

OBJECTIVE

This systematic review and meta-analysis aimed at assessing the efficacy of rehabilitation interventions in improving functioning in fibromyalgia patients.

METHODS

We conducted a comprehensive literature search of multiple international databases (PubMed, Scopus, and Web of Science) from their inception until November 22nd, 2023. We identified 23 randomized controlled trials (RCTs) assessing multiple rehabilitation strategies. The primary outcome was the Fibromyalgia Impact Questionnaire (FIQ). Study quality was assessed using the Cochrane Risk-of-Bias Tool for Randomized Trials (RoB 2). The study protocol was registered in PROSPERO (CRD42020197666).

RESULTS

Our meta-analysis rehabilitation interventions significantly reduce FIQ scores (MD =-11.74, 95% CI: -16.88 to -6.59, p< 0.0001). Notably, the subgroup analysis showed that different rehabilitation modalities seem to induce different therapeutic responses.

CONCLUSIONS

Rehabilitation strategies hold promise in addressing the functional impairments and improving the overall well-being of individuals with fibromyalgia. The study underscores the need for further research to determine the optimal rehabilitation approach and its potential impact on the multilevel disability characterizing patients with fibromyalgia.

Sleeping and waking-state oral behaviors in TMD patients: their correlates with jaw functional limitation and psychological distress

OBJECTIVES

This study investigated oral behaviors in various temporomandibular disorder (TMD) subtypes, assessing their frequency, extent, and associations with both jaw functional status and psychological distress.

MATERIALS AND METHODS

Anonymized data from consecutive "initial-visit" TMD patients at a university-affiliated oral medicine clinic were obtained. Alongside demographic information, patients completed various questionnaires including the Diagnostic Criteria for TMD (DC/TMD) Symptom Questionnaire, Oral Behavior Checklist (OBC), Jaw Functional Limitation Scale-20 (JFLS-20), Patient Health Questionnaire-9 (PHQ-9), and General Anxiety Disorder Scale-7 (GAD-7). Patients underwent a protocolized clinical examination and received diagnoses of pain-related (PT), intra-articular (IT), or combined (CT) TMD using the DC/TMD diagnostic algorithms. Data were evaluated with Chi-square/non-parametric tests and logistic regression analyses (α = 0.05).

RESULTS

The study comprised 700 patients (mean age 37.4 ± 15.7 years), with 12.6%, 15.1%, and 72.3% diagnosed with PT, IT, and CT, respectively. For all TMD subtypes, oral activities during sleep were more prevalent than those during wakefulness. While variations in total/subscale OBC scores were insignificant, substantial differences were observed in global/subscale JFLS (PT, CT > IT), depression (PT, CT > IT), and anxiety (CT > IT) scores. Near-moderate correlations (rs = 0,36-0.39) were discerned between overall/waking-state non-functional oral behaviors and depression/anxiety. Multivariate analysis indicated that the odds of different TMD subtypes were influenced by sex, age, and jaw functional status.

CONCLUSIONS

For all TMD patients, sleep-related oral activities were more commonly reported than waking-state activities. Factors such as sex, age, and jaw functional limitation are associated with the likelihood of different TMD subtypes.

STATEMENT OF CLINICAL RELEVANCE

Oral behaviors, in themselves, do not predict distinct TMD subtypes, in contrast to factors such as sex, age, and jaw functional status.

Conceptualising TMD symptom burden in youths: Symptom duration, frequency, intensity and interference

OBJECTIVE

This study aimed to conceptualise Temporomandibular disorder (TMD) symptom burden and severity and explored their interrelationships with somatic symptoms and psychological distress.

METHODS

Participants were recruited from a local polytechnic. The quintessential five TMD symptoms (5Ts) of the Diagnostic Criteria for TMDs (DC/TMD) were appraised and extended to evaluate the duration, frequency, intensity and interference of discrete TMD symptoms. Global TMD severity (GS) was computed by totaling the points for all TMD symptoms and dimensions. TMD (TS) and somatic symptom (SS) burden were assessed based on the Somatic Symptoms Scale-8, while psychological distress was measured with the Depression, Anxiety and Stress Scales-21. Statistical analyses were performed using Kruskal-Wallis/Dunn tests and Spearman's correlation (α = .05).

RESULT

Of the 366 eligible participants (mean age 19.1 ± 2.3 years), 51.4% were 5Ts-negative and 48.6% were 5Ts-positive. Among the 5Ts-positive individuals, 25.3%/64.0% were 'bothered a little' whereas 4.5%/10.7% were 'bothered a lot' by TMD pain/headache. Correspondingly, 32.6%/12.4%/5.1% were 'bothered a little' while 2.8%/2.8%/1.1% were 'bothered a lot' by TMJ sounds/closed/open locking. TS burden was moderate-to-strongly correlated to aggregate symptom duration, frequency, intensity, interference, GS and SS burden (rs = .50-.88). While TS burden and GS were weakly associated with psychological distress (rs = .18-.36), SS burden was moderately related to depression, anxiety and stress (rs = .47-.53).

CONCLUSIONS

TS burden can serve as a proxy for global TMD severity and may be more meaningful than the mere presence of TMD symptoms in clinical and research settings.

Comorbidities between temporomandibular disorders and somatization in young adults: exploring links with personality, emotional, and sleep disturbances

OBJECTIVE

The comorbidities between temporomandibular disorders (TMDs) and somatization and their associations with personality traits, emotional disorders, and sleep disturbances were investigated.

STUDY DESIGN

Adults aged 18 to 24 years completed an electronic survey encompassing TMD symptoms (5Ts), Patient Health Questionnaire-15, Big Five Personality Inventory-10, Depression Anxiety Stress Scales-21, and Pittsburgh Sleep Quality Index. Data were assessed using non-parametric tests/correlation analysis and logistic regression analysis (α = 0.05).

RESULTS

The sample comprised 365 participants, of whom 22.2% and 19.5% were 5Ts-negative without and with somatization, respectively, and 18.1% and 40.3% were 5Ts-positive without and with somatization, respectively. Significant differences in neuroticism, distress, depression, anxiety, stress, and sleep quality were observed between 5Ts-negative participants with somatization and 5Ts-positive participants with somatization compared with 5Ts-negative participants without somatization and 5Ts-positive participants without somatization. Distress, anxiety, stress, and sleep were moderately correlated with somatic but not TMD symptoms (rs = 0.45-0.52).

CONCLUSIONS

Irrespective of whether they had TMDs, participants with somatization exhibited heightened levels of neuroticism and emotional and sleep disturbances.

Aesthetic Rehabilitation Medicine: Enhancing Wellbeing beyond Functional Recovery

Although rehabilitation medicine emphasizes a holistic health approach, there is still a large gap of knowledge about potential interventions aimed at improving overall wellbeing through cosmetic interventions. Therefore, this narrative review investigates the role of different rehabilitative techniques in enhancing aesthetics, quality of life, and psychosocial wellbeing for patients with disabilities. The study follows the SANRA framework quality criteria for a narrative review. Literature searches across PubMed/Medline, Web of Science, and Scopus identified articles focusing on rehabilitation strategies within the aesthetic rehabilitation domain. The review identified evidence supporting injection procedures, such as Botulinum Toxin, Platelet-Rich Plasma, Hyaluronic Acid, Ozone, and Carboxytherapy, and assessing their applications in several disabling disorders. Additionally, physical therapies like Extracorporeal Shock Wave Therapy, Laser Therapy, Microcurrent Therapy, Tecar Therapy, and physical exercises were explored for their impact on cutaneous microcirculation, cellulite treatment, wound healing, and scar appearance improvement. Lastly, the manuscript underlines the role of manual therapy techniques in addressing both physical discomfort and aesthetic concerns, discussing their effectiveness in adipose tissue therapy, scar tissue mobilization, and regional fat thickness reduction. Taken together, this review emphasizes the role of a multidisciplinary approach, aiming to provide valuable insights into potential benefits for both functional and aesthetic outcomes.

Exploring HD-tDCS Effect on μ-opioid Receptor and Pain Sensitivity in Temporomandibular Disorder: A Pilot Randomized Clinical Trial Study

This study explored the association between experimentally-induced pain sensitivity and µ-opioid receptor (μOR) availability in patients with temporomandibular disorder (TMD) and further investigated any changes in the pain and μOR availability following high-definition transcranial direct current stimulation (HD-tDCS) over the primary motor cortex (M1) with pilot randomized clinical trials. Seven patients with TMD completed either active (n = 3) or sham treatment (n = 4) for 10 daily sessions and underwent positron emission tomography (PET) scans with [11C]carfentanil, a selective μOR agonist, a week before and after treatment. PET imaging consisted of an early resting and late phase with the sustained masseteric pain challenge by computer-controlled injection of 5% hypertonic saline. We also included 12 patients with TMD, obtained from our previous study, for baseline PET analysis. We observed that patients with more sensitivity to pain, indicated by lower infusion rate, had less μOR availability in the right amygdala during the late phase. Moreover, active M1 HD-tDCS, compared to sham, increased μOR availability post-treatment in the thalamus during the early resting phase and the amygdala, hippocampus, and parahippocampal gyrus during the late pain challenge phase. Importantly, increased μOR availability post-treatment in limbic structures including the amygdala and hippocampus was associated with decreased pain sensitivity. The findings underscore the role of the μOR system in pain regulation and the therapeutic potential of HD-tDCS for TMD. Nonetheless, large-scale studies are necessary to establish the clinical significance of these results. TRIAL REGISTRATION: ClinicalTrial.gov (NCT03724032) PERSPECTIVE: This study links pain sensitivity and µ-opioid receptors in patients with TMD. HD-tDCS over M1 improved µOR availability, which was associated with reduced pain sensitivity. Implications for TMD pain management are promising, but larger clinical trials are essential for validation.

Efficacy of ultrasound-guided galvanic electrolysis technique and physical therapy in patients with Achilles' tendinopathy: A pilot randomised controlled trial

BACKGROUND

Ultrasound-guided galvanic electrolysis technique (USGET) is an innovative mini-invasive intervention with the potential to optimise outcomes in the treatment of Achille's tendinopathy (AT).

OBJECTIVE

The aim of this pilot study is to evaluate the efficacy of adding USGET to conventional eccentric exercise treatment in patients with chronic AT.

METHODS

Inclusion criteria were patients with unilateral non-insertional AT, pain lasting > 3 months, aged 25-60 years. Patients were randomised in two groups receiving the same physiotherapy treatment (2 sessions per week for 8 weeks). In addition, the experimental group received three USGET stimulations, one every 15 days. Outcome measures were assessment of Achilles tendinopathy severity using the Victorian Institute of Sport Assessment-Achilles (VISA-A) and pain intensity using the Visual Analogue Scale (VAS). Assessment points occurred at the onset of treatment (T0), its conclusion (T1), and subsequent follow-ups at one (T2) and two months (T3).

RESULTS

Out of the 52 patients who met the study inclusion criteria, two participants withdrew from the study, resulting in a total of 50 subjects who completed the research. None of the parameters showed a different distribution at T1 (p> 0.337). At T2, there was a statistical difference in VISA-A (p= 0.010) and its subscales and VAS (p= 0.002) in the USGET group. At T3, both groups improved with a statistical difference observed in VISA-A (p< 0.001) and its subscales Pain (p= 0.004), Function (p= 0.003) and Sport (p= 0.002), but the EG patients showed a greater improvement. No adverse events were reported.

CONCLUSION

The effect of USGET combined with eccentric exercise appears to be a safe and effective technique for achieving pain relief and functional recovery in the medium term, supporting the integrated use of USGET as a rehabilitative treatment option for patients with chronic AT.

Temporomandibular disorder pain in older adolescents-young adults: Interrelationship with somatic burden, mental ill-being, and well-being

OBJECTIVES

The associations of Temporomandibular disorder (TMD) pain with somatic symptoms, mental ill-being/distress, and well-being were explored, along with the mental correlates of TMD (TS) and somatic symptom (SS) burden in older adolescents-young adults.

METHODS

TMD/somatic symptoms were appraised with the five quintessential symptoms (5Ts) of the DC/TMD/Somatic Symptom Scale-8, whereas mental distress/well-being was assessed with the Depression, Anxiety, Stress Scales-21/Scales of Psychological Well-being-18. Data were examined using Chi-square/non-parametric tests and multivariate analyses (α = .05).

RESULTS

Among the 366 participants, 51.4%, 28.1%, 6.8%, and 13.7% had no TMD (NT), TMD pain (TP), TMD dysfunction (TD), and combined TMD (CT) respectively. Though mental distress varied substantially (CT, TP>NT, TD), no significant differences in well-being were discerned. SS burden, but not TS burden, was moderately correlated to distress.

CONCLUSIONS

The prospect of TMD pain was increased by being female, depressed, and anxious but reduced by "positive relations with others" and "self-acceptance".

Whole Body Cryostimulation: A New Adjuvant Treatment in Central Sensitization Syndromes? An Expert Opinion

Central sensitisation is defined as a multifactorial etiopathogenetic condition involving an increase in the reactivity of nociceptive neurons and alterations in pain transmission and perception in the central nervous system. Patients may present with widespread chronic pain, fatigue, sleep disturbance, dizziness, psychological (e.g., depression, anxiety, and anger) and social impairment. Pain can be spontaneous in onset and persistence, characterised by an exaggerated response and spread beyond the site of origin, and sometimes triggered by a non-painful stimulus. Whole-body cryostimulation (WBC) could be an adjuvant therapy in the management of this type of pain because of its global anti-inflammatory effect, changes in cytokines and hormone secretion, reduction in nerve conduction velocity, autonomic modulation, and release of neurotransmitters involved in the pain pathway. In several conditions (e.g., fibromyalgia, rheumatoid arthritis, and chronic musculoskeletal pain), WBC affects physical performance, pain perception, and psychological aspects. Given its multiple targets and effects at different organs and levels, WBC appears to be a versatile adjuvant treatment for a wide range of conditions of rehabilitation interest. Further research is needed to fully understand the mechanisms of analgesic effect and potential actions on pain pathways, as well as to study long-term effects and potential uses in other chronic pain conditions.

Correlates of jaw functional limitation, somatization and psychological distress among different temporomandibular disorder diagnostic subtypes

OBJECTIVES

This study investigated the jaw functional status and severity of somatic/psychological symptoms in different Diagnostic Criteria for temporomandibular disorders (DC/TMD) diagnostic subtypes and established the correlates between jaw functional limitation, somatization, depression and anxiety.

METHODS

Data were accrued from consecutive 'first-visit' patients seeking TMD treatment at a university-based oral medicine/diagnosis clinic. Axis I physical TMD diagnoses were derived using the DC/TMD methodology and patients were categorized into pain-related (PT), intra-articular (IT) and combined (CT) TMD groups. Axis II measures were also administered and included the Jaw Functional Limitation Scale-20 (JFLS-20), Patient Health Questionnaire-15 and 9 (PHQ-15 and PHQ-9) and General Anxiety Disorder Scale-7 (GAD-7). Chi-square/Kruskal-Wallis tests and Spearman's correlation were employed for statistical evaluations (α = .05).

RESULTS

The final dataset consisted of 772 TMD patients (mean age of 37.7 ± 15.9 years; 70.2% females). The prevalence of PT, IT and CT was 11.9%, 15.7% and 72.4%, respectively. Significant differences in functional jaw limitations, somatization, depression (CT, PT > IT) and anxiety (CT > PT, IT) were observed. Moderate-to-severe somatization, depression and anxiety were detected in 12.6%-15.7% of patients. For all three TMD groups, JFLS global scale/subscale scores were weakly associated with somatization, depression and anxiety scores (rs  < 0.4). Moderate-to-strong correlations were noted between somatization, depression and anxiety (rs  = 0.50-0.74).

CONCLUSIONS

Functional jaw limitations were associated with painful TMDs but appear to be unrelated to somatization and psychological distress. Somatization and depression/anxiety were moderately correlated, underscoring the importance of somatic symptom screening when managing TMD patients.

Causal effects of life course adiposity on temporomandibular disorders: A Mendelian randomization study

BACKGROUND

Previous studies investigated the associations between obesity and temporomandibular disorders (TMDs), but the evidence for the causal inferences was unclear.

OBJECTIVE

We aimed to investigate the causal link between life course adiposity and TMDs.

METHODS

Mendelian randomization (MR) studies were performed using genetic instruments for birth weight (BW) (N = 261 932), childhood body mass index (BMI) (N = 39 620), childhood body size (N = 454 718), adult BMI (N = 99 998), body fat percentage (N = 454 633) and TMDs (N = 211 023). We assessed the overall effect of each life course adiposity factor via inverse-variance weighted (IVW), weighted median, and MR-Egger methods and performed extensive sensitivity analyses. Additionally, multivariable MR was conducted to evaluate the direct and indirect effects of childhood BMI on TMDs while accounting for BW and adult BMI, and vice versa.

RESULTS

Univariable MR analyses revealed a causal effect of low childhood adiposity on an increased risk of TMDs (childhood BMI: IVW OR: 0.65, 95% CI: 0.54-0.78, p < .001; childhood body size: IVW OR: 0.56, 95% CI: 0.43-0.73, p < .001). No causal association existed between genetically predicted BW, adult BMI, or body fat percentage and TMDs. In the multivariable MR analyses, the effects of childhood BMI on TMDs occurrence remained significant and direct, even after adjusting for BW and adult BMI (multivariable IVW OR: 0.78, 95% CI: 0.61-0.99, p = .048). No pleiotropy and heterogeneity were detected (p > .05).

CONCLUSION

Low childhood BMI might causally increase the risk of TMDs through a direct pathway.

Conservative Management of Acute Sports-Related Concussions: A Narrative Review

This review explores the application of the conservative management model for pain to sports-related concussions (SRCs), framing concussions as a distinct form of pain syndrome with a pathophysiological foundation in central sensitization. Drawing parallels with proven pain management models, we underscore the significance of a proactive approach to concussion management. Recognizing concussions as a pain syndrome allows for the tailoring of interventions in alignment with conservative principles. This review first covers the epidemiology and controversies surrounding prolonged concussion recovery and persistent post-concussion symptoms (PPCS). Next, the pathophysiology of concussions is presented within the central sensitization framework, emphasizing the need for early intervention to mitigate the neuroplastic changes that lead to heightened pain sensitivity. Five components of the central sensitization process specific to concussion injuries are highlighted as targets for conservative interventions in the acute period: peripheral sensitization, cerebral metabolic dysfunction, neuroinflammation, glymphatic system dysfunction, and pain catastrophizing. These proactive interventions are emphasized as pivotal in accelerating concussion recovery and reducing the risk of prolonged symptoms and PPCS, in line with the philosophy of conservative management.

Age and sex differences in comorbidities in adult temporomandibular disorders: A cross-sectional study using Korea National Health and Nutrition Examination Survey (KNHANES)

OBJECTIVES

To investigate the relationship between Temporomandibular disorder (TMD) and associated comorbidities in groups matched according to age and sex.

METHODS

Using data from the cross-sectional fifth Korea National Health and Nutrition Examination Survey (KNHANES). Of the 25,534 eligible KNHANES, 17,762 adults aged ≥19 years who responded to survey questionnaire on TMD and comorbidities. Subjects were classified into eight groups according to age and sex. Logistic regression analyses were performed to evaluate the association between TMD and comorbidities according to age and sex.

RESULTS

Of the enrolled participants, 2,107 (11.86%) complained of ≥1 TMD symptoms. In all groups, odds ratios (ORs) for prevalence of TMD were >1 in those with tinnitus. Rhinitis was closely associated with TMD in 6 groups. ORs for TMD with comorbidities according to age and sex were as follows: hypertension, men aged 50-64 years (OR 0.62; CI 0.41-0.94); ischemic heart disease, men aged 35-49 years (4.38; 1.54-12.47); osteoarthritis, women aged 50-64 years (1.38; 1.03-1.86); diabetes mellitus, men aged 35-49 years (0.21; 0.05-0.88); depression, men aged 50-64 years (1.68; 1.00-2.83), women aged 35-49 years (1.39; 1.05-1.85) and women aged 65-80 years (2.01; 1.46-2.77); migraine, men aged 50-64 years (1.60; 1.14-2.25), women aged d35-49 years (1.44; 1.14-1.81) and women aged 35-49 years (1.43; 1.07-1.90); cold hypersensitivity in the hands and feet, men aged 19-34 years (1.64; 1.05-2.58), men aged 35-49 years (1.68; 1.04-2.70), men aged 65-80 years (1.74; 1.09-2.75) and women aged 35-49 years (1.45; 1.15-1.84); olfaction disorder, men aged 50-64 years (2.49; 1.39-4.43); voice disorder, men aged 50-64 years (2.25; 1.28-3.96) and women aged 65-80 years (1.69; 1.09-2.63).

CONCLUSIONS

This study confirmed that the types and effects of comorbidities related to prevalence of TMD may differ according to the patient's age and sex and this result will increase the predictability of the onset of TMD.

Role of non-invasive objective markers for the rehabilitative diagnosis of central sensitization in patients with fibromyalgia: A systematic review

BACKGROUND

Central sensitization cannot be demonstrated directly in humans. Therefore, studies used different proxy markers (signs, symptoms and tools) to identify factors assumed to relate to central sensitization in humans, that is, Human Assumed Central Sensitization (HACS). The aims of this systematic review were to identify non-invasive objective markers of HACS and the instruments to assess these markers in patients with fibromyalgia (FM).

METHODS

A systematic review was conducted with the following inclusion criteria: (1) adults, (2) diagnosed with FM, and (3) markers and instruments for HACS had to be non-invasive. Data were subsequently extracted, and studies were assessed for risk of bias using the quality assessment tools developed by the National Institute of Health.

RESULTS

78 studies (n= 5234 participants) were included and the findings were categorized in markers identified to assess peripheral and central manifestations of HACS. The identified markers for peripheral manifestations of HACS, with at least moderate evidence, were pain after-sensation decline rates, mechanical pain thresholds, pressure pain threshold, sound 'pressure' pain threshold, cutaneous silent period, slowly repeated evoked pain sensitization and nociceptive flexion reflex threshold. The identified markers for central manifestations of HACS were efficacy of conditioned pain modulation with pressure pain conditioning and brain perfusion analysis. Instruments to assess these markers are: pin-prick stimulators, cuff-algometry, repetitive pressure stimulation using a pressure algometer, sound, electrodes and neuroimaging techniques.

CONCLUSIONS

This review provides an overview of non-invasive markers and instruments for the assessment of HACS in patients with FM. Implementing these findings into clinical settings may help to identify HACS in patients with FM.

Involvement of the Transient Receptor Channels in Preclinical Models of Musculoskeletal Pain

BACKGROUND

Musculoskeletal pain is a condition that affects bones, muscles, and tendons and is present in various diseases and/or clinical conditions. This type of pain represents a growing problem with enormous socioeconomic impacts, highlighting the importance of developing treatments tailored to the patient's needs. TRP is a large family of non-selective cation channels involved in pain perception. Vanilloid (TRPV1 and TRPV4), ankyrin (TRPA1), and melastatin (TRPM8) are involved in physiological functions, including nociception, mediation of neuropeptide release, heat/cold sensing, and mechanical sensation.

OBJECTIVE

In this context, we provide an updated view of the most studied preclinical models of muscle hyperalgesia and the role of transient receptor potential (TRP) in these models.

METHODS

This review describes preclinical models of muscle hyperalgesia induced by intramuscular administration of algogenic substances and/or induction of muscle damage by physical exercise in the masseter, gastrocnemius, and tibial muscles.

RESULTS

The participation of TRPV1, TRPA1, and TRPV4 in different models of musculoskeletal pain was evaluated using pharmacological and genetic tools. All the studies detected the antinociceptive effect of respective antagonists or reduced nociception in knockout mice.

CONCLUSION

Hence, TRPV1, TRPV4, and TRPA1 blockers could potentially be utilized in the future for inducing analgesia in muscle hypersensitivity pathologies.

Pain alleviation improves balance control and muscular coordination of lower limbs in patients with chronic ankle instability during sinusoidal perturbations

BACKGROUND

It is well established that individuals with chronic ankle instability manifest deficits in balance control and muscle activation. Given the prevalence of pain as a prominent symptom in this population, there is a need for in-depth investigation of its role in contributing to these impairments.

METHODS

A Stewart platform was used to generate translational sinusoidal perturbations in the antero-posterior direction. Eighteen individuals with chronic ankle instability and concurrent ankle pain were recruited. They were instructed to assume a central stance on the support surface with open eyes both before and 30 min after local analgesia. Data of center of pressure and electromyography of the tibialis anterior and medial gastrocnemius were recorded. Statistical analysis was performed to make comparisons pre- and post-analgesia using two-tailed paired t-test for the continuous variables.

FINDINGS

Pain intensity was significantly decreased after local anesthetic injections. Antero-posterior center of pressure parameters significantly decreased following the injection. Also, there was an increase in the regularity of the center of pressure pattern. The electromyographic pattern of the tibialis anterior and medial gastrocnemius exhibited various activation patterns. After pain alleviation, the characteristic electromyographic response of the tibialis anterior and medial gastrocnemius was reciprocal contraction and relaxation that corresponded with the sinusoidal pattern of the perturbations.

INTERPRETATION

Individuals who had chronic ankle instability and ankle pain demonstrated impaired balance control during sinusoidal perturbations. Mitigating pain improved their balance performance, evident in the center of pressure pattern and the coordination of lower limb muscles.

Advancements in Understanding and Classifying Chronic Orofacial Pain: Key Insights from Biopsychosocial Models and International Classifications (ICHD-3, ICD-11, ICOP)

In exploring chronic orofacial pain (COFP), this review highlights its global impact on life quality and critiques current diagnostic systems, including the ICD-11, ICOP, and ICHD-3, for their limitations in addressing COFP's complexity. Firstly, this study outlines the global burden of chronic pain and the importance of distinguishing between different pain types for effective treatment. It then delves into the specific challenges of diagnosing COFP, emphasizing the need for a more nuanced approach that incorporates the biopsychosocial model. This review critically examines existing classification systems, highlighting their limitations in fully capturing COFP's multifaceted nature. It advocates for the integration of these systems with the DSM-5's Somatic Symptom Disorder code, proposing a unified, multidisciplinary diagnostic approach. This recommendation aims to improve chronic pain coding standardization and acknowledge the complex interplay of biological, psychological, and social factors in COFP. In conclusion, here, we highlight the need for a comprehensive, universally applicable classification system for COFP. Such a system would enable accurate diagnosis, streamline treatment strategies, and enhance communication among healthcare professionals. This advancement holds potential for significant contributions to research and patient care in this challenging field, offering a broader perspective for scientists across disciplines.

Hyaluronic acid injections for pain relief and functional improvement in patients with temporomandibular disorders: An umbrella review of systematic reviews

BACKGROUND

Temporomandibular disorders (TMD) are the main cause of chronic facial pain, and intra-articular (IA) injections of hyaluronic acid (HA) are commonly performed.

OBJECTIVES

This umbrella review of systematic reviews aimed at analysing the effectiveness of HA injections on pain and functional outcomes in patients affected by TMD.

METHODS

PubMed, Cochrane Library and PEDro were systematically searched from inception until 17 January 2023 to identify systematic reviews evaluating the effects on pain and functional outcomes of HA IA injections. PROSPERO registration number: CRD42022382586.

RESULTS

Out of 316 papers suitable for title/abstract screening, 18 articles were included in the umbrella review. Thirteen studies included only randomized controlled clinical trials (RCTs). The included systematic reviews reported no statistically significant differences between HA and corticosteroids, whereas platelet derivates seem to have good results in pain relief. The literature did not show severe adverse events, except for mild pain in the site of injection. Concerning the quality assessment of the 18 systematic reviews, 2 (11.11%) had a high quality, 3 (16.67%) a moderate quality, 7 (38.89%) a low quality and 6 (33.33%) a critically low quality.

CONCLUSIONS

Taken together, findings of this umbrella review showed intriguing effects of IA HA injections in terms of reduction of pain intensity and improvement of functioning in patients affected by TMD. Furthermore, there is no agreement on the effectiveness of a combination of arthrocentesis or arthroscopy with IA HA injections. Although the literature showed these positive results after IA HA injections, the overlapping of primary studies in the systematic reviews included might have affect our results, such as the very low quality of the papers. Thus, further RCTs are needed to confirm the efficacy of IA injections of HA on pain relief in patients with TMD.

DC/TMD axis I subtyping: generational and gender variations among East Asian TMD patients

OBJECTIVES

This study examined the generational-gender distinctions in Diagnostic Criteria for Temporomandibular disorders (DC/TMD) subtypes among East Asian patients.

METHODS

Consecutive "first-visit" TMD patients presenting at two university-based TMD/orofacial pain clinics in China and South Korea were enlisted. Demographic information along with symptom history was gathered and clinical examinations were performed according to the DC/TMD methodology. Axis I physical diagnoses were rendered with the DC/TMD algorithms and categorized into painful and non-painful TMDs. Patients were categorized into three birth cohorts, specifically Gen X, Y, and Z (born 1965-1980, 1981-1999, and 2000-2012 respectively) and the two genders. Data were evaluated using Chi-square/Kruskal-Wallis plus post-hoc tests and logistic regression analyses (α = 0.05).

RESULTS

Gen X, Y, and Z formed 17.2%, 62.1%, and 20.7% of the 1717 eligible patients examined (mean age 29.7 ± 10.6 years; 75.7% women). Significant differences in prevalences of arthralgia, myalgia, headache (Gen X ≥ Y > Z), and disc displacements (Gen Z > Y > X) were observed among the three generations. Gen Z had substantially fewer pain-related and more intra-articular conditions than the other generations. Women presented a significantly greater frequency of degenerative joint disease and number of intra-articular conditions than men. After controlling for generation-gender interactions, multivariate analyses showed that "being Gen X" and female increased the risk of painful TMDs (OR = 2.20) and reduced the odds of non-painful TMDs (OR = 0.46).

CONCLUSIONS

Generational-gender diversities in DC/TMD subtypes exist and are important for guiding TMD care and future research endeavors.

The continuous adverse impact of COVID-19 on temporomandibular disorders and bruxism: comparison of pre- during- and post-pandemic time periods

INTRODUCTION

Some of the conditions affected by the COVID-19 pandemic were Temporomandibular Disorders (TMD) and bruxism. The present study compares the effect of the pandemic on TMD and bruxism (sleep and awake) in three time periods: before the pandemic (pre-COV), during the pandemic (during-COV) and after the pandemic subsided (post-COVR).

MATERIAL AND METHODS

A total of 587 adult patients (108 in the pre-COV group, 180 in the during-COV group and 252 in the post-COVR group) who arrived for a routine dental treatment between October 2018 and January 2023 were evaluated according to Axis I diagnosis of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Each patient received a DC/TMD Axis I diagnosis as follows: (i) Painful TMD (defined by the presence of at least one of the following - local myalgia, myofascial pain with referral, arthralgia or headache attributed to TMD); (ii) Non painful TMD (defined by the presence of disc displacement with/without reduction, degenerative joint disorders and/or dislocation), (iii) Possible sleep bruxism (SB) and/or (iv) Possible awake bruxism (AB).

STATISTICAL METHODS

Logistic regression analyses were conducted to establish the impact of time and gender on the prospects of painful TMD, non-painful TMD, SB and AB.

RESULTS

The odds of subjects to be diagnosed with painful TMD at the post-COVR era were 3.3 times higher compared to the pre-pandemic time period (pre-COV, 95% C.I. 1.438-7.585). The odds of subjects to be diagnosed with non-painful TMD during-COV were 4 times higher compared to the pre-COV era (95% C.I. 1.332-12.542). The odds of subjects to present possible SB at post-COVR were 2.7 times higher compared to pre-pandemic (pre-COV, 95% C.I. 1.258-5.889, p < 0.05) and the odds to present possible AB after the pandemic subsided (post-COVR) were 3.2 times compared to the pre-pandemic period (95% C.I. 1.496-6.949). The odds of female subjects to be diagnosed with either painful or non-painful TMD were 3.7-4.4 times higher, compared to males.

CONCLUSIONS

Results indicate that with regard to TMD and bruxism the pandemic adverse effects persist also after COVID-19 subsides and the restrictions caused by it are abolished. Apparently, during the pandemic females were affected more seriously by painful and non-painful TMD than males.

Photobiomodulation Therapy on the Palliative Care of Temporomandibular Disorder and Orofacial/Cervical Skull Pain: Preliminary Results from a Randomized Controlled Clinical Trial

The main symptoms of temporomandibular disorders (TMDs) are pain from musculoskeletal and/or joint-in the head and neck region-and complaints of difficulty in mandibular movements. The photobiomodulation therapy (PBMT) has been reported as a promising treatment in the management of these symptoms. The objective of this research was to assess the effect of PBMT immediately after irradiation on TMDs symptoms under a prospective clinical trial, randomized, triple-blinded, placebo-controlled, and with two parallel arms. According to the RDC/TMD, maximum mouth opening (MMO) and pain in the orofacial/cervical muscles and temporomandibular joint (TMJ) were recorded. One hundred forty-five participants (71 placebo and 74 PBMT experimental) were analyzed after irradiation protocols (sham-PBMT or PBMT) at the orofacial/cervical skull musculature and at the TMJ. The results showed a reduction in the total pain score (p = 0.026), a reduction in the number of painful points (p = 0.013), and an increase in the MMO (p = 0.016) in the PBMT protocol group when compared to the placebo protocol (sham-PBMT). The PBMT was shown to be effective in reducing orofacial/cervical skull pain immediately after the irradiation. It is clinically relevant and should be taken into consideration by professionals who are dedicated to treating this pathology because, in addition to bringing comfort to patients who need dental treatment, it also consists of a low-cost and low technical complexity clinical approach.

Analysis of Mandibular Muscle Variations Following Condylar Fractures: A Systematic Review

This review analyzes muscle activity following mandibular condylar fracture (CF), with a focus on understanding the changes in masticatory muscles and temporomandibular joint (TMJ) functioning.

MATERIALS AND METHODS

The review was conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A search was performed on online databases using the keywords "masticatory muscles" AND ("mandibular fracture" OR "condylar fracture"). The eligibility criteria included clinical trials involving human intervention and focusing on muscle activity following a condylar fracture.

RESULTS

A total of 13 relevant studies were reviewed. Various studies evaluated muscle activity using clinical evaluation, bite force measurement, electromyography (EMG), magnetic sensors and radiological examinations to assess the impact of mandibular fractures on masticatory muscles.

CONCLUSIONS

Mandibular condylar fractures can lead to significant changes in muscle activity, affecting mastication and TMJ functioning. EMG and computed tomography (CT) imaging play crucial roles in assessing muscle changes and adaptations following fractures, providing valuable information for treatment planning and post-fracture management. Further research is required to explore long-term outcomes and functional performance after oral motor rehabilitation in patients with facial fractures. Standardized classifications and treatment approaches may help improve the comparability of future studies in this field.

Repeatability of Teethan® indexes analysis of the masseter and anterior temporalis muscles during maximum clenching: a pilot study

OBJECTIVES

The aim of this study is to assess the repeatability of a surface electromyographic (EMG) device (Teethan®, Teethan S.p.A., Milan, Italy), designed for the analysis of the masseter and anterior temporalis muscles.

MATERIALS AND METHODS

Tests were performed on a sample of 30 healthy fully dentate TMD-free individuals randomly selected. Each test consisted of two distinct recordings performed at 5-min intervals: (i) the patient is asked to clench with maximum voluntary contraction (MVC), with two cotton rolls interposed between the dental arches; (ii) the patient is asked to repeat the same clenching activity without the cotton rolls. The outcomes of the study were the EMG indices conceptualized by the manufacturing company, based on the differences between the two test conditions (i.e., clenching on cotton rolls and on dentition). Pairwise correlation analysis and ANOVA test were performed to assess the strength of correlation and the significance of differences between the results of the three trials.

RESULTS

Thirty TMD-free healthy individuals (20 females and 10 males; mean age 44 years, range 16-60 years) took part in the study. ANOVA test did not show any statistically significant difference between the three trials. The Global Index, which is the mean of the other EMG indices, showed the highest correlation values between the three trials, while some other indices showed a weak-to-medium correlation level. One out of five participants showed a coefficient of variation higher than 10%.

CONCLUSIONS

The statistical analysis showed that the indices provided by the device are quite repeatable. However, this does not necessarily imply a specific clinical application of the device, which was here used in fully controlled experimental conditions.

CLINICAL RELEVANCE

The clinical usefulness of the applied protocol remains questionable. Further studies should test the repeatability of EMG findings gathered with this device under various circumstances, in a more heterogeneous population.

Novel Diagnostic and Therapeutic Approaches to Temporomandibular Dysfunction: A Narrative Review

Temporomandibular dysfunction (TMD) is a burgeoning area of study within the dental field. TMD is caused by abnormalities in the temporomandibular joint or muscles of mastication and can lead to pain, loss of function, and other complications. As this area of patient care receives increased focus, the ability to accurately diagnose TMD becomes paramount. The aim of this review is to summarize novel diagnostic and therapeutic techniques that have been proposed within the last approximately 3 years in order to inform readers of the cutting-edge advances in the field of TMD diagnosis and management, while also analyzing the clinical relevance of each study. A PubMed search was completed on 1 March 2023, using MeSH terms related to TMD diagnosis and treatment. The search yielded seven articles that pertained to the aim of this review article. The main findings from each study are summarized in this review article. These novel methods of diagnosing and treating TMD may improve our ability to assess and treat patients suffering from TMD.

Age and Gender, but Not Pain are Associated with Pressure Pain Thresholds in Patients with Temporomandibular Disorders: A Cross-Sectional Study

Purpose

This study aims to explore the association of pressure pain thresholds (PPTs) with age, gender, and pain in patients with temporomandibular disorders (TMD).

Patients and Methods

A total of 301 TMD patients (248 female and 53 male) were recruited and classified into the high and low age groups according to their median age of 26 years. Patients' demographics, pain-related variables, TMD-related variables, and PPTs of both left and right temporomandibular joints (TMJs), masseter, and temporalis were collected.

Results

Pain duration and visual analog scale of pain (VAS) showed no significant correlations with PPTs (P>0.05). Multiple linear regression analysis revealed a significant positive association of PPTs of all six sites with males (β=0.41-0.72 kg·cm-2, 95% CI (0.19-0.38, 0.74-0.99), P<0.001), as well as with the high age group [β=0.28-0.36 kg·cm-2, 95% CI (0.07-0.20, 0.47-0.53), P<0.020]. Furthermore, PPTs of the left TMJ showed a significant negative association with left pain-related TMD (PT) [β=-0.21 kg·cm-2, 95% CI (-0.38, -0.04), P=0.026], but PPTs of the remaining sites did not show a significant association with PT (P>0.05). Stratified analysis showed that PPTs in females were associated with the high age group [β=0.25-0.37 kg·cm-2, 95% CI (0.04-0.20, 0.45-0.56), P<0.020] and that PPT of the left TMJ was associated with left PT [β=-0.21 kg·cm-2, 95% CI (-0.39, -0.03), P=0.043]. The remaining PPTs did not show a significant association with PT (P>0.05). In males, PPTs did not show significant correlations with age, PT and VAS (P>0.05).

Conclusion

PPTs in the orofacial region are associated with gender and age in TMD patients. Pain duration and intensity show no significant correlations with PPTs in TMD patients. Researchers and dentists should take age and gender into account when using PPTs as auxiliary diagnostic indicators for PT.

Association of Oxidative-Stress-Related Gene Polymorphisms with Pain-Related Temporomandibular Disorders and Oral Behavioural Habits

The frequency of selected polymorphisms, one in each gene coding for proteins with antioxidative properties (CAT(rs1001179), SOD2(rs4880), GPX1(rs1050450), and NQO1(rs689452)), was compared between patients suffering from pain-related temporomandibular disorders (TMDp; n = 85) and control subjects (CTR; n = 85). The same was evaluated when participants were divided with respect to oral behavioural habits frequency into high-frequency parafunction (HFP; n = 98) and low-frequency parafunction (LFP; n = 72) groups. Another aim was to investigate whether polymorphisms in these genes can be associated with participants' psychological and psychosomatic characteristics. Polymorphisms were genotyped using the genomic DNA extracted from buccal mucosa swabs and real-time TaqMan genotyping assays. No differences in genotype distribution between TMDp patients and control subjects were found. Still, TMDp patients who were homozygous for minor allele A, related to the GPX1 polymorphism rs1050450, reported significantly more waking-state oral behaviours than GA + GG genotype carriers (score: 30 vs. 23, p = 0.019). The frequency of genotype AA for rs1050450 polymorphism was higher in HFP than in LFP participants (14.3% vs. 4.2%, p  = 0.030). The most important predictors of waking-state oral behaviours were depression, anxiety, AA genotype (rs1050450), and female sex. The explored gene polymorphisms were not found to be significant risk factors for either TMDp or sleep-related oral behaviours. The association of waking-state oral behaviours with selected gene polymorphisms additionally supports previous assumptions that daytime bruxism is more closely linked to various stress manifestations, which might also be reflected through the variability related to the cellular antioxidative activity.

Cervical Range of Motion Analysis Performed with an Accelerometer: A Study of Intersession Reliability for Dental Practice

During the clinical examination of subjects with temporomandibular disorders (TMDs), the dentist sometimes must evaluate the cervical spine, due to the anatomical and functional connections between the cervical portion of the spine and the stomatognathic apparatus. The accelerometer is a device that evaluates the Range of Motion (ROM) of the main movements of the head on the neck. To date, only a few studies have investigated the repeatability of the use of the accelerometer in the assessment of cervical ROM. Therefore, the present longitudinal observational study analyzed the repeatability of acquired cervical movements on a sample of volunteer subjects who underwent accelerometer testing. A sample of 32 subjects was tested twice within 14 days to assess cervical ROM using a standardized protocol based on a review of existing literature. The results show that the examination is reliable for all the positions of the jaw, except for the parameters regarding the asymmetries of rotation and bending. In conclusion, the accelerometer can be considered a reliable tool for evaluating the active cervical ROM. However, further studies will be necessary to make better evaluations.

In silico approach towards neuro-occlusal rehabilitation for the early correction of asymmetrical development in a unilateral crossbite patient

Neuro-occlusal rehabilitation (N.O.R.) is a discipline of the stomatognathic medicine that defends early treatments of functional malocclusions, such as unilateral crossbite, for the correction of craniofacial development, avoiding surgical procedures later in life. Nevertheless, N.O.R.'s advances have not been proved analytically yet due to the difficulties of evaluate the mechanical response after the treatment. This study aims to evaluate computationally the effect of N.O.R.'s treatments during childhood. Therefore, bilateral chewing and maximum intercuspation occlusion were modelled through a detailed finite element model of a paediatric craniofacial complex, before and after different selective grinding-alternatives. This model was subjected to the muscular forces derived from a musculoskeletal model and was validated by the occlusal contacts recorded experimentally. This approach yielded errors below 2% and reproduced successfully the occlusal, muscular, functional and mechanical imbalance before the therapies. Treatment strategies balanced the occlusal plane and reduced the periodontal overpressure (>4.7 kPa) and the mandibular over deformation (>0.002 ε) on the crossed side. Based on the principles of the mechanostat theory of bone remodelling and the pressure-tension theory of tooth movement, these findings could also demonstrate how N.O.R.'s treatments correct the malocclusion and the asymmetrical development of the craniofacial complex. Besides, N.O.R.'s treatments slightly modified the stress state and functions of the temporomandibular joints, facilitating the chewing by the unaccustomed side. These findings provide important biomechanical insights into the use of N.O.R.'s treatments for the correction of unilateral crossbite, but also encourage the application of computing methods in biomedical research and clinical practise.

Effectiveness of manual therapy and cervical spine stretching exercises on pain and disability in myofascial temporomandibular disorders accompanied by headaches: a single-center cohort study

BACKGROUND

Previous studies have demonstrated a relationship between headaches and temporomandibular disorders (TMDs). Moreover, recent studies have shown functional, anatomical, and neurological associations between the temporomandibular joint (TMJ) and upper cervical spine. This study aimed to investigate the effectiveness of manual therapy and cervical spine stretching exercises for pain and disability in patients with myofascial TMDs accompanied by headaches.

METHODS

Thirty-four patients recruited from Gyeryong Hospital with headaches and diagnosed with TMDs were randomly assigned to the experimental (n = 17) and control (n = 17) groups. Headache impact was assessed using the Korean Headache Impact Test-6. Masseter myofascial pain was measured using the visual analog scale, and TMJ pressure pain threshold levels were evaluated using an algometer. Neck pain intensity was assessed using the numerical rating scale. Once per week for 10 weeks, the experimental group received cervical spine-focused manual therapy and stretching exercises alongside conservative physical therapy, and the control group received conservative physical therapy alone. Patients were evaluated at baseline and 5 and 10 weeks post-intervention.

RESULTS

After the intervention, the experimental group exhibited significant reductions in the cervical kyphotic angle, Korean Headache Impact Assessment score, neck pain intensity, TMJ pain pressure threshold, Neck Disability Index score, and Jaw Functional Limitation Scale level compared with the control group (p < 0.01).

CONCLUSION

Manual therapy and stretching exercises could help resolve TMDs accompanied by headaches through biomechanical changes in the cervical spine. These findings may guide protocols and clinical trials involving manual therapy that align morphological structures.

Stress Experience, Depression and Neck Disability in Patients with Temporomandibular Disorder-Myofascial Pain with Referral

The etiology of temporomandibular disorders (TMDs) is firmly anchored in the biopsychosocial model in which a special role is attributed to the stress, depression, somatic symptoms, and anxiety. The aim of the study was to assess the level of stress, depression and neck disability in patients with temporomandibular disorder-myofascial pain with referral. The study group enrolled 50 people (37 women and 13 men) with complete natural dentition. All the patients underwent a clinical examination according to the Diagnostic Criteria for Temporomandibular Disorders and were diagnosed as individuals with myofascial pain with referral. The questionnaires were associated with stress, depression, and neck disability; Perceived Stress Scale (PSS-10), Beck Depression Inventory(BDI), and Neck Disability Index (NDI) were evaluated. Of the individuals evaluated, 78% showed elevated levels of stress, and the average value of the PSS-10 in the study group was 18 points (Me = 17). Furthermore, 30% of the subjects presented depressive symptoms, with the average value of BDI was 8.94 points (Me = 8), and 82% of the subjects showed neck disability. The multiple linear regression model revealed that BDI and NDI allowed explanations for the 53% differentiation of PSS-10. In conclusion, stress, depression, and neck disability coexist with temporomandibular disorder-myofascial pain with referral.

Oral-Gut Microbiota, Periodontal Diseases, and Arthritis: Literature Overview on the Role of Probiotics

Periodontal diseases are oral inflammatory diseases affecting the tissues supporting and surrounding the teeth and include gingivitis and periodontitis. Oral pathogens may lead to microbial products spreading into the systemic circulation and reaching distant organs, while periodontal diseases have been related to low-grade systemic inflammation. Gut and oral microbiota alterations might play a role in the pathogenesis of several autoimmune and inflammatory diseases including arthritis, considering the role of the gut-joint axis in the regulation of molecular pathways involved in the pathogenesis of these conditions. In this scenario, it is hypothesized that probiotics might contribute to the oral and intestinal micro-ecological balance and could reduce low-grade inflammation typical of periodontal diseases and arthritis. This literature overview aims to summarize state-of-the-art ideas about linkages among oral-gut microbiota, periodontal diseases, and arthritis, while investigating the role of probiotics as a potential therapeutic intervention for the management of both oral diseases and musculoskeletal disorders.

Kinesio Taping as a Therapeutic Tool for Masticatory Myofascial Pain Syndrome-An Insight View

Myofascial pain syndrome (MPS) is thought to stem from masticatory muscle hypersensitivity. Masticatory myofascial pain syndrome (MMPS) is characterized by multiple trigger points (MTrPs), also known as hyperirritable points, in taut bands of affected muscles, regional muscle pain, or referred pain to nearby maxillofacial areas like teeth, masticatory muscles or the temporomandibular joint (TMJ). Muscle stiffness, reduced range of motion, muscle weakening without atrophy, and autonomic symptoms may accompany regional discomfort. Multiple treatments have been utilized to reduce trigger points and mandibular function restrictions. As a result of these incapacitating symptoms, MMPS can significantly impair many elements of quality of life. The application of Kinesio tape (KT) is a non-invasive method of treating dormant myofascial trigger points. Utilizing the body's innate capacity for self-repair, this technique entails taping specific regions of the skin. KT alleviates discomfort, decreases swelling and inflammation, enhances or suppresses motor function in the muscles, stimulates proprioception, promotes lymphatic drainage, stimulates blood flow, and expedites tissue recovery. However, studies conducted to assess its effects have frequently yielded contradictory results. To the best of our knowledge, just a few research has looked into the therapeutic effects of KT on MMPS. The purpose of this review is to determine the efficacy of KT as a therapeutic tool for regular treatment or as an adjunct to existing therapy for MMPS based on the evidence presented in this review. To establish KT as a reliable independent treatment option, additional research is necessary to confirm the efficacy of KT techniques and applications, specifically randomized clinical trials.

The reliability of using light therapy compared with LASER in pain reduction of temporomandibular disorders: a randomized controlled trial

BACKGROUND

Temporomandibular Disorders (TMD) refer to a group of symptoms where pain is the most leading cause to demand a treatment by the patient. Light therapies are of great importance at current times due to its biosafety and non-invasive quality when used for the management of TMD symptoms. This study aimed to evaluate the efficacy of red LED light with low-level LASER in treating TMD patients.

MATERIALS AND METHODS

A double-blind randomized clinical study was conducted and included 60 patients along 3 groups (20 for each group) presented with myofascial pain related to TMD. Patients were randomly divided into 3 groups. Group A were managed by applying the LED light device into the trigger points without switching the device on. A red LED light was given to group B for 5 min at the tender muscles. Group C were treated by using low-level LASER therapy for 30 s. Patients were evaluated for any improvements regarding the pain score, presence of trigger points, and trismus along 4 visits (1 week interval between each visit). Any side effects related to the 2 devices were also assessed.

RESULTS

Both group B and C patients showed a statistically significant improvement in the pain value (P < 0.05) at the 3rd and 4th visits when compared to group A. Regarding tenderness, there was a reduction in the number of trigger points in both study groups; however, the results were insignificant in group B. Statistics showed insignificant differences between group B & C patients regarding pain and number of trigger points at all visits (P > 0.05).

CONCLUSION

Both LED light and LASER therapies could effectively relieve pain associated with myogenic TMD as there were no important differences between their outcomes. However, the biosafety and lower cost of the LED light device compared to the LASER should also be considered. Trial Registration This clinical trial was prospectively registered (TCTR ID: TCTR20190507002) on 07/05/2019. URL: http://www.thaiclinicaltrials.org/show/TCTR20190507002.

How Confinement and Back to Normal Affected the Well-Being and Thus Sleep, Headaches and Temporomandibular Disorders

The COVID-19 pandemic is having negative consequences not only for people's general health but also for the masticatory system. This article aimed to assess confinement and its new normal impact on well-being, sleep, headaches, and temporomandibular disorders (TMD). An anonymous survey was distributed to a Spanish university community. Participants completed a well-being index (WHO-5), a questionnaire related to sleep quality (the BEARS test), a headache diagnostic test (the tension type headache (TTH) and migraine diagnosis test), and the DC-TMD questionnaire. Questions were addressed in three scenarios: before confinement, during confinement, and the new normal. A total of 436 responses were collected (70% women, 30% men). A reduction in well-being and sleep quality was recorded. Respondents reported more TTH and migraines during and after confinement. Overall, confinement and return to normal did not increase TMD symptoms, and only minor effects were observed, such as more intense joint pain and a higher incidence of muscle pain in women during confinement. Reduced well-being is correlated with sleep quality loss, headaches, and TMD symptoms. This study provides evidence that pandemics and confinement might have had a negative impact on population health. Well-being was strongly affected, as were sleep quality, depression risk, TTH, and migraine frequency. In contrast, the temporomandibular joint and muscles showed more resilience and were only slightly affected.

Temporomandibular Disorders: Current and Future Concepts in Diagnosis and Management

Temporomandibular disorders (TMD) are musculoskeletal and/or neuromuscular conditions relating to muscles, joints, and the associated structures of the stomatognathic system [...].

Diagnosis and Treatment of Myogenous Temporomandibular Disorders: A Clinical Update

Myogenous temporomandibular disorders (M-TMDs) are the most common chronic orofacial pain, affecting the masticatory muscles and, thus, jaw movement. While a concise diagnosis is crucial to formulate a rational treatment plan, the similarities in clinical presentations that M-TMDs share with other neuromuscular disorders affecting the temporomandibular joint (TMJ) could easily confuse physicians. In addition to the basics, such as thorough history taking and meticulous clinical examinations, different imaging techniques are useful adjuncts to facilitate the diagnostic process. This review presents an overview of the current understanding on a variety of diagnostic and treatment modalities for M-TMD patients. It is essential to highlight that there is not a single treatment for all, and the benefits of multidisciplinary strategies have been noted for the effective management of myogenous TMD pain. Treatment modalities ranging from conservative to minimally invasive options are discussed in this review.