Can the severity of orofacial myofunctional conditions interfere with the response of analgesia promoted by active or placebo low-level laser therapy?

Effect of low-level gallium aluminum arsenide laser therapy on the chewing performance and pain perception of patients with systemic lupus erythematosus: A randomized controlled clinical trial

OBJECTIVE

To evaluate the effect of low-level laser therapy (LLLT) on pain intensity (PI) and chewing performance (CP) in systemic lupus erythematosus (SLE) patients with myogenic temporomandibular disorder (TMD).

METHODS

Ninety-one patients were randomly allocated to three groups: Group L (intervention), Group P (placebo), and Group C (control). Outcomes were PI (assessed with visual analog scale (VAS)) and CP (assessed with the geometric mean diameter (GMD) of crushed test food). Measurements were performed at T0 (before the LLLT), T1 (immediately after the LLLT), and T2 (1-month follow-up). Data were analyzed using Generalized Linear Models, Kruskal-Wallis, and Friedman tests.

RESULTS

For T1 and T2, Group L demonstrated the lowest values for both GMD (6283.7 ± 257.2 µm; 6382.7 ± 303.7 µm) and VAS (5;6) (p < 0.001).

CONCLUSION

LLLT was an effective therapeutic approach in reducing pain and improving CP for one month in SLE patients with myogenic TMD.

Analysis of the Use of Sample Size and Effect Size Calculations in a Temporomandibular Disorders Randomised Controlled Trial-Short Narrative Review

BACKGROUND/OBJECTIVES

Temporomandibular disorder (TMD) is the term used to describe a pathology (dysfunction and pain) in the masticatory muscles and temporomandibular joint (TMJ). There is an apparent upward trend in the publication of dental research and a need to continually improve the quality of research. Therefore, this study was conducted to analyse the use of sample size and effect size calculations in a TMD randomised controlled trial.

METHODS

The period was restricted to the full 5 years, i.e., papers published in 2019, 2020, 2021, 2022, and 2023. The filter article type-"Randomized Controlled Trial" was used. The studies were graded on a two-level scale: 0-1. In the case of 1, sample size (SS) and effect size (ES) were calculated.

RESULTS

In the entire study sample, SS was used in 58% of studies, while ES was used in 15% of studies.

CONCLUSIONS

Quality should improve as research increases. One factor that influences quality is the level of statistics. SS and ES calculations provide a basis for understanding the results obtained by the authors. Access to formulas, online calculators and software facilitates these analyses. High-quality trials provide a solid foundation for medical progress, fostering the development of personalized therapies that provide more precise and effective treatment and increase patients' chances of recovery. Improving the quality of TMD research, and medical research in general, helps to increase public confidence in medical advances and raises the standard of patient care.

Role of Photobiomodulation Therapy in Modulating Oxidative Stress in Temporomandibular Disorders. A Systematic Review and Meta-Analysis of Human Randomised Controlled Trials

This systematic review and meta-analysis (PROSPERO registration; ref CRD 42020198921) aimed to govern photobiomodulation therapy (PBMT) efficacy in temporomandibular disorder (TMD). PRISMA guidelines and Cochrane Collaboration recommendations were followed. Differences in pain reduction assessment by qualitative measurement with visual analogue scale pain (VAS), pressure threshold (PPT) and maximum mouth opening (MMO) were calculated with 95% confidence intervals and pooled in a random effects model with a subgroup analysis, evaluating the role of follow-up duration. Heterogeneity was analysed using Q and I² tests. Publication bias was assessed by visual examination of funnel plot symmetry. Qualitative analysis revealed 46% of the 44 included studies showed a high risk of bias. Meta-analysis on 32 out of 44 studies revealed statistically significant intergroup differences (SSID) for VAS (SMD = -0.55; 95% CI = -0.82 to -0.27; Z = 3.90 (p < 0.001)), PPT (SMD = -0.45; 95% CI = -0.89 to 0.00; Z = 1.97 (p = 0.05)) and MMO (SMD = -0.45; 95% CI = -0.89 to 0.00; Z = 1.97 (p = 0.05)), favouring PBMT compared to control treatment strategies. Sensitivity analysis revealed SSID (SMD = -0.53; 95% CI = -0.73 to -0.32; Z = 5.02 (p < 0.0001)) with low heterogeneity (Τ² = 0.02; χ² = 16.03 (p = 0.31); I² = 13%). Hence, this review, for first time, proposed suggested recommendations for PBMT protocols and methodology for future extensive TMD research.

Effect of Low Level Laser Therapy (LLLT) on muscle pain in temporomandibular disorders – an update of literature

Introduction: Temporomandibular disorders are complex pathologies with multifactorial aetiology. Due to this matter, different therapeutic approaches have been developed, one of them being physical therapy (also known as physiotherapy). Low-level laser therapy is often used in treating musculoskeletal diseases, TMJ pain and, although the exact mechanism of LLLT has not yet been completely elucidated, it seems that this kind of therapy induces analgesic, anti-inflammatory and bio-stimulating effects. The aim of this study was to create an update of scientific literature regarding the clinical use of LLLT in patients with temporomandibular disorders, and to identify the impact of this therapy on reducing pain in the masticatory muscles. Methods: A research of literature was performed - articles published over the last 10 years (January 2009 until December 2019) were searched for by introducing a combination of different keywords on the PubMed and ScienceDirect databases. Results: A total number of 294 articles were found. After applying inclusion and exclusion criteria, 28 articles were taken into consideration for our study, and among them, 9 were systematic meta-analyses or literature reviews and 19 were clinical studies. Conclusion: Low level laser therapy may effectively reduce pain in patients suffering from muscular- and/or joint-specific TMDs, but the effect appears to last only for a short period of time, and can be achieved only in less complex cases. LLLT may also improve oro-facial functions by reducing muscular activity. This research also reveals the need for better-designed clinical trials with larger sample sizes, in order to evaluate the efficacy of LLLT on improving the signs and symptoms of TMDs. Key words: Low-level laser therapy, temporomandibular disorders, muscle pain,

Influence of tongue exercise and orofacial myofunctional status on the electromyographic activity and pain of chronic painful TMD

Objective: To analyze the influence of tongue exercise and myofunctional status on the electromyographic activity (EMG) and pain perception in individuals with chronic painful TMDs.Methods: Twenty-four subjects diagnosed according to the DC/TMD (18-52 years old) were assessed: EMG on the masseter and anterior temporalis; myofunctional orofacial conditions underwent clinical assessment (OMES); and questionnaire for self-perception of TMD signs and symptoms (ProTMDMulti). The 50th percentile was calculated to establish a cutoff value based on OMES scores related to the functional variables of the tongue.Results: The compared groups showed no differences (p > 0.05) in self-perception of their TMD signs and symptoms or in the EMG activity during tongue exercises.Discussion: The myofunctional status of the tongue showed no impact on the painful TMD or on the activity of the masticatory muscles (captured during tongue exercise). The indication of tongue exercises in TMD cases is a safe and adequate possibility.

Placebo and nocebo response magnitude on temporomandibular disorder-related pain: A systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review (SR) was to answer the following question: "In adult patients with temporomandibular disorder (TMD)-related pain, what is the placebo or nocebo effect of different therapies?"

METHODS

A SR was performed with randomised clinical placebo-controlled trials on diagnosed painful TMD studies from five main databases and from three grey literature. Studies included must have sample older than 18 years, with painful TMD, which diagnosis was done by Research Diagnostic Criteria (RDC/TMD) or Diagnostic Criteria (DC/TMD).

RESULTS

Out of 770 articles obtained, 42 met the inclusion criteria for qualitative and 26 for quantitative analysis. Meta-analysis indicated mean variation on pain intensity for placebo therapy was higher on laser acupuncture with 45.5 mm point reduction, followed by avocado soya bean extract with 36 mm and amitriptyline 25 mg with 25.2 mm. Laser showed a 29% of placebo effect, as well medicine with 19% and other therapies with 26%. Possible nocebo effect of 8% pain increase was found for intra-articular injection of Ultracain.

CONCLUSIONS

Based on the available data, the placebo response could play a major effect on TMD pain management and may be responsible from 10% to 75% of pain relief. Laser acupuncture, avocado soya bean and amitriptyline promoted the higher placebo effect. Possible nocebo effect was found only for Ultracain injection with 8%.

CLINICAL RELEVANCE

Clinicians could apply such evidence to optimise pain management and judgement about treatment efficacy, and researches may find it useful when designing their investigations.