What conservative interventions improve bite function in those with temporomandibular disorders? A systematic review using self-reported and physical measures

Long-Term Prognosis and Influencing Factors of Chinese Adolescents With Temporomandibular Disorder After Physical Therapy

BACKGROUND

Physical therapy is the preferred conservative treatment for patients with temporomandibular disorder (TMD). However, few studies have investigated the application of physical therapy in adolescents, especially follow-up studies on the long-term prognosis of these patients. This study investigated the short-term effects and long-term prognosis of physical therapy in adolescent patients with TMD and the factors influencing long-term symptoms.

METHODS

Information regarding baseline data, specific treatment methods, treatment times and evaluation results was collected retrospectively for adolescent patients with TMD who received physical therapy. Patients were followed up via telephone and online questionnaires, and the influence of age, sex, disease course, mouth opening, pain intensity, oral parafunctional habits and treatment methods on long-term symptoms was analysed.

RESULTS

Pain intensity, maximum mouth opening and the joint noise score improved significantly in 270/286 patients who received individualised comprehensive physical therapy. TMD-related symptoms improved with no noticeable impact on daily life in 187/199 patients who were followed up for an extended period (average, 30.71 ± 10.86 months) and were divided into asymptomatic or symptomatic groups according to the persistence of symptoms. Logistic regression analysis revealed that uncorrected oral parafunctional habits and fewer treatments were related to long-term symptoms.

CONCLUSION

The long-term prognosis of adolescent patients with TMD after physical therapy was satisfactory. However, 52.8% of the patients experienced persistent TMD-related symptoms for an extended period, possibly due to insufficient treatment times and parafunctional habits.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05781607.

Counselling for patients with a temporomandibular disorder: A scoping review and concept analysis

BACKGROUND

An integral component of comprehensive temporomandibular disorder (TMD) treatment involves what is commonly referred to in literature as patient counselling or patient education. Despite its importance, a clear definition of the concept is lacking.

OBJECTIVES

To describe the concept of counselling (i.e. what is it, what should it consist of, and when should it be given) through a concept analysis of the literature.

ELIGIBILITY CRITERIA

All papers that include a description of counselling or education for TMD are included.

SOURCES OF EVIDENCE

Literature searches were performed in the electronic databases PubMed, Cinahl, and PsycInfo.

CHARTING METHODS

A qualitative analysis was done using the principle-based concept analysis approach, where descriptions of counselling from the included papers were analysed by the researchers.

RESULTS

A total of 71 articles were included. Based on the qualitative analysis of the included articles and descriptions of counselling, the following content themes were identified: (1) general information on TMD; (2) overuse of the masticatory system; (3) posture education; (4) lifestyle and psychosocial factors; (5) exercise- and thermotherapy; and (6) additional information and therapies.

CONCLUSIONS

A definition and framework of counselling for TMD has been provided, which can be used in the clinic, research, and educational programs.

Pain-free bite force in a healthy population: Within-session test-retest reliability in different sitting positions

BACKGROUND

Pain-free bite force (PFBF) is a promising measure to evaluate bite function in temporomandibular disorders (TMDs), yet the reliability of the measure is unknown.

OBJECTIVES

Establish the (1) within-session test-retest reliability of PFBF in a healthy population for a single and mean of three trials in supported and unsupported sitting; (2) standard error of measurement (SEM) and minimal detectable change (MDC).

METHODS

Thirty healthy participants (n = 15 female, mean [SD] age = 34.4 [11.0] years) completed two sessions (30-60 min apart) comprising three PFBF trials on each side, in both supported and unsupported sitting, to provide data for 60 (30 participants × two sides) test-retest assessments. Test-retest reliability for the first trial and mean of three trials in each position were determined using intraclass correlation coefficients (ICCs), before calculating the corresponding SEM and MDC for males (M) and females (F) respectively.

RESULTS

Within-session reliability was considered excellent for a single trial in supported sitting (ICC = 0.85; SEM M/F = 99/84 N; MDC M/F = 275/232 N) and unsupported sitting (ICC = 0.91; SEM M/F = 72/59 N, MDC M/F = 200/163 N), and for a mean of three trials in supported sitting (ICC = 0.89; SEM M/F = 66/79 N, MDC M/F = 182/220 N) and unsupported sitting (ICC = 0.92; SEM M/F = 64/59 N, MDC M/F = 177/164 N).

CONCLUSION

Single and a mean of three trials in supported and unsupported sitting appear reliable methods to measure PFBF in a healthy population. Testing PFBF using a mean of three trials in unsupported sitting appears superior over other methods though due to higher test-retest reliability, and lower SEM and MDC. Future studies should examine the reliability of PFBF in TMD populations.

Literature Review of an Anterior Deprogrammer to Determine the Centric Relation and Presentation of Cases

The increasing demand for dental aesthetics, articulation corrections, and solutions for pain and frequent bruxism demands quick and effective restorative dental management. The biomedical research aimed to create a beneficial, ecological, and readily available anterior deprogrammer to determine the centric relation (CR) of cases. This medical device is additively manufactured from a biocompatible material. Size is customizable based on the width of the patient's anterior central incisors. This is a pilot study with two subjects. The task was to develop a complete data protocol for the production process, computer-aided design (CAD), and three-dimensional (3D) printing of the anterior deprogrammers. The research focused on creating simple and practically applicable tools for the dentist's prescription (anterior deprogrammer in three sizes), and secondly for the communication between the dentist and the patient (computer application). The tested hypothesis was whether, according to these novel tools, it is possible to produce functional occlusal splints, which could be manufactured using current technologies. This study compared a traditional splint with a digitally designed and 3D-printed one. The tested hypothesis was whether manufactured occlusal splints differ in patients' subjective perception of comfort. Each conservative treatment was monitored for ten weeks. Initial results are promising; no statistically significant difference was found between the productive technologies.

Do intra-articular temporomandibular disorders show an association between physical bite function, self-perceived bite limitation and kinesiophobia? A case-control study

BACKGROUND

Little is known about the impact of intra-articular temporomandibular disorders (TMDs) on bite function, or how bite impairments in this subgroup relate to self-perceived bite limitation or kinesiophobia. This presents a challenge to practitioners involved in delivering care.

OBJECTIVES

To determine what bite impairments are associated with intra-articular TMDs, and explore how these impairments relate to self-perceived bite limitations and kinesiophobia.

DESIGN

Observational, case-control study.

METHOD

Sixty participants (n = 30 intra-articular TMDs, n = 30 healthy controls) were recruited via convenience sampling. Bite function was explored using pain-free bite force and bite endurance/steadiness (submaximal bite hold) measures. Self-perceived bite function and kinesiophobia were evaluated via the Patient specific functional scale (PSFS) and the Tampa Scale for kinesiophobia of Temporomandibular disorders (TSK-TMD) respectively. Between-group data were compared and associations between physical bite impairments, self-perceived bite limitation and kinesiophobia were explored in the intra-articular TMD group.

RESULTS

Pain-free bite force was significantly impaired in the intra-articular TMD group (-108N, p < 0.01, d = 0.9), and this impairment demonstrated moderate association with degree of kinesiophobia (p < 0.01, r = -0.4). No significant between-group difference was observed for bite endurance or force steadiness (p > 0.05). No association was observed between pain-free bite force and self-perceived bite limitation, or self-perceived bite limitation and kinesiophobia (p > 0.05).

CONCLUSIONS

Impaired pain-free bite force appears to be an important feature of intra-articular TMDs which should be considered within management. Kinesiophobia may be important to consider when assessing bite function in this subgroup. Future research is needed to guide optimal interventions and inform subsequent management guidelines.

The Efficacy of Manual Therapy Approaches on Pain, Maximum Mouth Opening and Disability in Temporomandibular Disorders: A Systematic Review of Randomised Controlled Trials

Temporomandibular disorder (TMD) is a common condition disabling people and bringing up costs. The aim of this study was to investigate the effects of manual therapy on pain intensity, maximum mouth opening (MMO) and disability. Searches were conducted in six databases for randomised controlled trials (RCTs). Selection of trials, data extraction and methodological quality assessment were conducted by two reviewers with discrepancies resolved by a third reviewer. Estimates were presented as mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals (CIs). Quality of the evidence was assessed using the GRADE approach. Twenty trials met the eligibility criteria and were included. For pain intensity, high and moderate quality evidence demonstrated the additional effects of manual therapy at short- (95% CI -2.12 to -0.82 points) and long-term (95% CI -2.17 to -0.40 points) on the 0-10 points scale. For MMO, moderate to high quality evidence was found in favour of manual therapy alone (95% CI 0.01 to 7.30 mm) and its additional effects (95% CI 1.58 to 3.58 mm) at short- and long-term (95% CI 1.22 to 8.40 mm). Moderate quality evidence demonstrated an additional effect of manual therapy for disability (95% CI = -0.87 to -0.14). Evidence supports manual therapy as effective for TMD.

Silencing of TRPV4-expressing sensory neurons attenuates temporomandibular disorders pain

Identification of potential therapeutic targets is needed for temporomandibular disorders (TMD) pain, the most common form of orofacial pain, because current treatments lack efficacy. Considering TMD pain is critically mediated by the trigeminal ganglion (TG) sensory neurons, functional blockade of nociceptive neurons in the TG may provide an effective approach for mitigating pain associated with TMD. We have previously shown that TRPV4, a polymodally-activated ion channel, is expressed in TG nociceptive neurons. Yet, it remains unexplored whether functional silencing of TRPV4-expressing TG neurons attenuates TMD pain. In this study, we demonstrated that co-application of a positively charged, membrane-impermeable lidocaine derivative QX-314 with the TRPV4 selective agonist GSK101 suppressed the excitability of TG neurons. Moreover, co-administration of QX-314 and GSK101 into the TG significantly attenuated pain in mouse models of temporomandibular joint (TMJ) inflammation and masseter muscle injury. Collectively, these results suggest TRPV4-expressing TG neurons represent a potential target for TMD pain.

CMD und Kieferorthopädie

Die Craniomandibuläre Dysfunktion (CMD) ist mit einer Prävalenz von über 30% die häufigste chronische Schmerzerkrankung im Kiefer- Gesichtsbereich. Die Therapie erfordert einen interdisziplinären, individuell angepassten Behandlungsansatz. Diese Fallvorstellung soll einen Einblick über das Behandlungskonzept eines posterior-lateralen Zwangsbisses mit Oberkiefer- Okklusionsschiene und OK/UK Alignern (Invisalign) geben.

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.

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

Temporomandibular disorders (TMD) are a group of musculoskeletal diseases affecting masticatory muscles and temporomandibular joints (TMJ). In this context, the chronic TMD could be considered as a condition with chronic primary orofacial pain, presenting as myofascial TMD pain or TMJ arthralgia. In this context, myogenous TMD may present overlapping features with other disorders, such as fibromyalgia and primary headaches, characterized by chronic primary pain related to dysfunction of the central nervous system (CNS), probably through the central sensitization. This phenomenon could be defined as an amplified response of the CNS to sensory stimuli and peripheral nociceptive, characterized by hyperexcitability in the dorsal horn neurons in the spinal cord, which ascend through the spinothalamic tract. The main objectives of the management of TMD patients are: decreasing pain, increasing TMJ function, and reducing the reflex masticatory muscle spasm/pain. The first-line treatments are physical therapy, pharmacological drugs, occlusal splints, laser therapy, extracorporeal shockwave therapy, transcutaneous electrical nerve stimulation, and oxygen-ozone therapy. Although all these therapeutic approaches were shown to have a positive impact on the central sensitization of TMD pain, there is still no agreement on this topic in the scientific literature. Thus, in this comprehensive review, we aimed at evaluating the evidence on pain management and rehabilitation for the central sensitization in TMD patients.

Efficacy of conservative approaches on pain relief in patients with temporomandibular joint disorders: a systematic review with network meta-analysis

OBJECTIVE

The aim of this systematic review with meta-analysis was to evaluate the efficacy of conservative interventions in pain relief in patients with intracapsular temporomandibular disorders (TMD).

METHODS

PubMed, Scopus, and Web of Science were systematically searched until January 1st, 2022 to identify randomized controlled trials (RCTs) presenting patients with diagnosis of intracapsular TMD according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), conservative approaches as interventions, and pain intensity as outcome.

RESULTS

Out of 3372 papers, 13 RCTs were included, with 844 study participants. Most of them (n = 7) investigated the efficacy of splint appliance. Meta-analysis revealed that rehabilitative interventions had a significant overall effect size of 0.75 [0.17, 1.34], reporting splint appliance and laser therapy as significantly effective treatments.

CONCLUSION

Findings of this systematic review with network meta-analysis suggested that conservative approaches might be effective in pain relief of intracapsular TMD patients.

Biological and Molecular Docking Evaluation of a Benzylisothiocyanate Semisynthetic Derivative From Moringa oleifera in a Pre-clinical Study of Temporomandibular Joint Pain

Objective

Moringa oleifera possesses multiple biological effects and the 4-[(4′-O-acetyl-α-L- rhamnosyloxy) benzyl] isothiocyanate accounts for them. Based on the original isothiocyanate molecule we obtained a semisynthetic derivative, named 4-[(2′,3′,4′-O-triacetyl-α-L-rhamnosyloxy) N-benzyl] hydrazine carbothioamide (MC-H) which was safe and effective in a temporomandibular joint (TMJ) inflammatory hypernociception in rats. Therefore, considering that there is still a gap in the knowledge concerning the mechanisms of action through which the MC-H effects are mediated, this study aimed to investigate the involvement of the adhesion molecules (ICAM-1, CD55), the pathways heme oxygenase-1 (HO-1) and NO/cGMP/PKG/K⁺_ATP, and the central opioid receptors in the efficacy of the MC-H in a pre-clinical study of TMJ pain.

Methods

Molecular docking studies were performed to test the binding performance of MC-H against the ten targets of interest (ICAM-1, CD55, HO-1, iNOS, soluble cGMP, cGMP-dependent protein kinase (PKG), K⁺_ATP channel, mu (μ), kappa (κ), and delta (δ) opioid receptors). In in vivo studies, male Wistar rats were treated with MC-H 1 μg/kg before TMJ formalin injection and nociception was evaluated. Periarticular tissues were removed to assess ICAM-1 and CD55 protein levels by Western blotting. To investigate the role of HO-1 and NO/cGMP/PKG/K⁺_ATP pathways, the inhibitors ZnPP-IX, aminoguanidine, ODQ, KT5823, or glibenclamide were used. To study the involvement of opioid receptors, rats were pre-treated (15 min) with an intrathecal injection of non-selective inhibitor naloxone or with CTOP, naltrindole, or norbinaltorphimine.

Results

All interactions presented acceptable binding energy values (below −6.0 kcal/mol) which suggest MC-H might strongly bind to its molecular targets. MC-H reduced the protein levels of ICAM-1 and CD55 in periarticular tissues. ZnPP-IX, naloxone, CTOP, and naltrindole reversed the antinociceptive effect of MC-H.

Conclusion

MC-H demonstrated antinociceptive and anti-inflammatory effects peripherally by the activation of the HO-1 pathway, as well as through inhibition of the protein levels of adhesion molecules, and centrally by μ and δ opioid receptors.