Low-level laser therapy in temporomandibular joint disorders: a systematic review

Photobiomodulation inhibits neuronal firing in the superficial but not deep layer of a rat spinal dorsal horn

Photobiomodulation (PBM) has attracted attention as a treatment for chronic pain. Previous studies have reported that PBM of the sciatic nerve inhibits neuronal firing in the superficial layers (lamina I-II) of the spinal dorsal horn of rats, which is evoked by mechanical stimulation that corresponds to noxious stimuli. However, the effects of PBM on the deep layers (lamina III-IV) of the spinal dorsal horn, which receive inputs from innocuous stimuli, remain poorly understood. In this study, we examined the effect of PBM of the sciatic nerve on firing in the deep layers of the spinal dorsal horn evoked by mechanical stimulation. Before and after PBM, mechanical stimulation was administered to the cutaneous receptive field using 0.6-26.0 g von Frey filaments (vFFs), and vFF-evoked firing in the deep layers of the spinal dorsal horn was recorded. The vFF-evoked firing frequencies were not altered after the PBM for any of the vFFs. The inhibition rate for 26.0 g vFF-evoked firing was approximately 13 % in the deep layers and 70 % in the superficial layers. This suggests that PBM selectively inhibits the transmission of pain information without affecting the sense of touch. PBM has the potential to alleviate pain while preserving the sense of touch.

Temporomandibular Disorders Management-What's New? A Scoping Review

Temporomandibular disorders include various conditions that impact the masticatory system, affecting its structure, function, or physiology. Clinicians face a complex array of therapeutic options when treating this group of diseases, emphasizing the importance of evaluating the current evidence to guide decisions in patient care. The main objective of this article is to conduct a scoping review on the available treatment approaches to manage temporomandibular disorders (TMDs). An extensive search of the literature was performed on Scopus, Pubmed, Embase, and Web of Science. Systematic reviews published in the last 5 years were considered. Out of the 2183 publications identified, 109 studies were included in this review. Among them, 39 articles focused on the non-invasive approach, while 120 delved into the minimally invasive approach, and 15 explored the surgical approach. Non-invasive or conservative approaches like cognitive-behavioral therapy, physical therapy, and acupuncture offer effective pain management and functional improvements in TMDs. Emerging treatments offer promising alternatives for treating these disorders. Surgery should be reserved for severe cases, with conservative therapies used in conjunction with invasive procedures for optimal patient outcomes.

Evaluating the Impact of Various Treatment Modalities on the Chewing Efficiency of Anterior Disc Displacements of Temporomandibular Joint Disorder Cases: A Comparative Study

Aim

Internal disc displacement of the temporomandibular joint (TMJ) is identified by an anomaly between the condylar-disc assembly, which, in many cases, may lead to discomfort and malfunction of the chewing function. The study's objective was to assess the effects of four distinct treatment approaches on temporomandibular disorder cases with anterior disc displacements focusing on their chewing efficiency.

Materials and Methods

One hundred participants suffering from reducible TMJ disc displacement were selected for enrollment in the study. Subjects were divided equally into four groups: group I patients were treated with behavioral therapy; group II patients were treated with low-level laser therapy (LLLT); group III patients were treated with anterior repositioning splints; and group IV patients were treated with flat plane splints. Chewing efficiency was assessed utilizing the fractional sieving method and a synthetic food substitute was created using silicon impression material. The statistical analysis encompassed comparisons of chewing efficiency between groups and between baseline and posttreatment within each group, employing analysis of variance (ANOVA) and paired t tests, respectively.

Results

Using the paired t test, a significant difference in chewing efficiency values as expressed by the median particle size was observed between the baseline and 6-month values in all groups (P < 0.05), except for group I where no significant change was noted over the 6 months (P > 0.05). The one-way ANOVA test revealed a statistically significant difference among groups following therapies (P ˂ 0.05). The post hoc Tukey test was employed for pairwise comparisons and revealed statistically significant variances in the main values of chewing efficiency among all groups at a 95% confidence level (P ˂ 0.05).

Conclusion

The study's results suggest that occlusal splints and LLLT are more effective in improving chewing efficiency than behavioral interventions.

Treatments for painful temporomandibular disc displacement with reduction: a network meta-analysis of randomized clinical trials

There is currently no consensus on the best treatment for painful temporomandibular disc displacement with reduction (DDwR), and no network meta-analysis of randomized clinical trials (RCTs) comparing all types of treatment for this condition has been conducted. The objective of this study was to compare and rank all treatments for DDwR, including conservative treatments, occlusal splints, low-level laser therapy (LLLT), manual therapy, no treatment (control), arthrocentesis (Arthro) alone, Arthro plus intra-articular injection of platelet-rich plasma (Arthro-PRP) or hyaluronic acid (Arthro-HA), and Arthro plus occlusal splint. Predictor variables were pain intensity and maximum mouth opening (MMO). The mean difference with 95% confidence interval was estimated using Stata software. The GRADE system was used to assess the certainty of the evidence. Twenty RCTs reporting 1107 patients were identified in the literature search; 980 of these patients were included in the network meta-analysis. Direct meta-analysis showed that Arthro-PRP significantly reduced pain intensity compared to Arthro alone, while occlusal splint and manual therapy were superior to conservative treatment (all very low quality evidence). Arthro with intra-articular injection of PRP/HA ranked as the most effective treatment in terms of pain reduction, whereas LLLT ranked the best choice for increasing MMO for patients with DDwR. However, it is important to note that the evidence for the superiority of these treatments is generally of very low quality. Therefore, further high-quality research is needed to confirm these findings and provide more reliable recommendations for the treatment of DDwR.

The Effect of Photobiomodulation on Temporomandibular Pain and Functions in Patients With Temporomandibular Disorders: An Updated Systematic Review of the Current Randomized Controlled Trials

Introduction: Temporomandibular disorders (TMDs) are the most prevalent non-dental origin orofacial pain conditions affecting the temporomandibular joints (TMJs) and/or orofacial muscles. Photobiomodulation therapy (PBMT) is a conservative way to improve function and reduce symptoms in TMD patients. This systematic review was conducted to update evidence about the effects of PBMT on pain intensity, TMJ movements, electromyography (EMG) activity, pressure pain threshold (PPT), and TMJ sound in patients with TMDs. Methods: A systematic literature search was conducted in Web of Science, PubMed/Medline, and Scopus databases using appropriate keywords and specific strategies from January 2000 to September 2022. Data extraction was done based on the inclusion/exclusion criteria. Results: A total of 40 studies were included. All included studies except one provided information on pain intensity; 27 studies showed a reduction in pain intensity in PBMT groups compared to control groups. Seven out of 15 studies, which reported maximum mouth opening (MMO), showed a greater MMO in PBMT groups than in placebo groups. In addition, the figures for passive maximum mouth opening (PMMO) and active maximum mouth opening (AMMO) in all the studies reporting PMMO and AMMO were higher in PBMT groups. In eight out of ten studies, lateral movement (LM) was greater in PBMT groups. Moreover, in three studies out of four, protrusive movement (PM) was reported to be greater in the PBMT group. Four out of nine studies showed a greater PPT in the PBMT group. Reduced TMJ sounds in the PBMT group were reported in two out of five studies. In addition, in most studies, no difference in EMG activity was detected between the two groups. Conclusion: This updated systematic review showed the promising effects of PBMT on the alleviation of pain and improvement in MMO. Using the infrared diode laser with a wavelength ranging between 780-980 nm, an energy density of<100 J/ cm2, and an output power of≤500 mW for at least six sessions of treatment seems to be a promising option for treating mentioned TMDs signs and symptoms based on the previously reported findings.

Efficacy of laser therapy for temporomandibular disorders: A systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review was to evaluate the efficacy of laser therapy in temporomandibular disorders (TMD).

METHODS

Randomized controlled trials (RCTs) in regard to this issue were searched in electronic databases. Three investigators independently screened the eligible studies, and the quality of the included studies was assessed according to the risk of bias tool recommended by the Cochrane handbook. The primary outcome measure was the degree of pain, reported on a visual analog scale (VAS), and the secondary outcome measures were TMJ function, including maximum active vertical opening (MAVO), maximum passive vertical opening (MPVO), left and right lateral movement (LLE, RLE). Pooled effect sizes were calculated using random effects models and 95% confidence interval (95% CI).

RESULTS

A total of 28 randomized controlled trials were included. Laser therapy had a more significant effect in terms of VAS (SMD=﹣1.88; 95% CI=﹣2.46 to﹣1.30; P<0.00001; I² =93%), MAVO (MD = 4.90; 95% CI= 3.29 to 6.50; P < 0.00001; I² =72%), MPVO (MD=5.8²; 95% CI= 4.62 to 7.01; P<0.00001; I² =40%) and RLE (MD = 0.73; 95% CI= 0.23 to 1.22; P = 0.004; I² = 0%) as compared to placebo group. However, there was no significant difference in LLE between two groups (MD= 0.35; 95% CI=﹣0.31 to 1.01; P=0.30; I² =0%).

CONCLUSIONS

Laser therapy can effectively reduce pain but have small effect on improving mandibular movement of TMD patients. More well-designed RCTs with large sample sizes are needed for further validation. And these studies should report detailed laser parameters and provide complete outcome measure data.

PROSPERO

CRD42022349719.

Near-Infrared Light-Activated Mesoporous Polydopamine for Temporomandibular Joint Osteoarthritis Combined Photothermal-Chemo Therapy

The treatments generally employed for temporomandibular joint osteoarthritis (TMJOA) involve physical therapy and chemotherapy, etc., whose therapeutic efficacies are impaired by the side effects and suboptimal stimulus responsiveness. Although the intra-articular drug delivery system (DDS) has shown effectiveness in addressing osteoarthritis, there is currently little reported research regarding the use of stimuli-responsive DDS in managing TMJOA. Herein, we prepared a novel near-infrared (NIR) light-sensitive DDS (DS-TD/MPDA) by using mesoporous polydopamine nanospheres (MPDA) as NIR responders and drug carriers; diclofenac sodium (DS) as the anti-inflammatory medication; and 1-tetradecanol (TD) with a phase-inversion temperature of 39 °C as the drug administrator. Upon exposure to 808 nm NIR laser, DS-TD/MPDA could raise the temperature up to the melting point of TD through photothermal conversion, and intelligently trigger DS release. The resultant nanospheres exhibited an excellent photothermal effect and effectively controlled the release of DS through laser irradiation to accommodate the multifunctional therapeutic effect. More importantly, the biological evaluation of DS-TD/MPDA for TMJOA treatment was also performed for the first time. The experiments' results demonstrated that DS-TD/MPDA displayed a good biocompatibility in vitro and in vivo during metabolism. After injection into the TMJ of rats afflicted with TMJOA induced by unilateral anterior crossbite for 14 days, DS-TD/MPDA could alleviate the deterioration of TMJ cartilage, thus ameliorating osteoarthritis. Therefore, DS-TD/MPDA could be a promising candidate for photothermal-chemotherapy for TMJOA.

Efficacy of stabilisation splint and low-level laser therapy for patients with chronic closed lock from non-reducible displaced temporo-mandibular joint discs: A parallel randomised clinical trial

BACKGROUND

Stabilisation splint therapy (SST) and low-level laser therapy (LLLT) are effective-invasive treatment for temporo-mandibular disorder (TMD) patients. However, the specific efficacy of each therapy in patients with chronic closed lock (CCL) from temporo-mandibular joints (TMJ) disc displacement without reduction (DDwoR) remains unknown.

OBJECTIVES

The aim of this study was to assess and compare the efficacy of SST and LLLT alone or in combination in patients with CCL from TMJ DDwoR.

METHODS

This parallel randomised clinical trial included 42 patients who were diagnosed with CCL from TMJ DDwoR. Patients were allocated equally and randomly into three treatment groups: group I received combined SST and LLLT, group II received LLLT and group III received SST. Maximum mouth opening (MMO), visual analogue scale (VAS), muscle and joint palpation scores and time required to achieve normal state were evaluated at baseline, 1, 2, 4 weeks, 3 and 6 months after the intervention. Data were collected and analysed using SPSS software.

RESULTS

Regarding MMO and VAS, a statistically significant improvement was found between group I versus group II and versus group III at all evaluation times. Regarding muscle and joint palpation scores, a statistically significant difference was found between group I versus group III, while non-significant difference was found between group I and group II. A statistically significant faster improvement was found in group I versus group III and versus group II.

CONCLUSION

All treatment modalities can be effective in management of CCL from a TMJ DDwoR cases, but the combined SST and LLLT group seems to provide the best and quickest improvement.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05548894.

Application of photobiomodulation for chronic pain-related TMD on pain points versus pre-established points: Randomized clinical trial

Photobiomodulation therapy (PTB) is a therapeutic possibility for temporomandibular disorders (TMD), but its effectiveness and protocols for use remain controversial. This study is a RCT that compared the effectiveness of PTB on pain points of the masticatory muscles and TMJs, located through palpation versus application of pre-established points in women with painful TMD, diagnosis by DC/TMD (Diagnostic Criteria for Temporomandibular Disorders - Brazilian Portuguese version). Therefore, a total sample of 54 women, aged between 18 and 60 years, was investigated. Volunteers were randomly randomized and PTB was applied in four different groups with a dose of 4 J and 6 J divided into pre-established application points (PE - G1) and pain points (PD - G2) - Groups 4PE, 4PD, 6PE and 6PD. Four laser applications were performed with a wavelength of 780 nm, one session per week, totaling one month of therapy. The following assessments were performed: DC/TMD, Brief Pain Inventory (BPI), McGill Questionnaire - Short Version (SF-MPQ) and Pain Intensity, Visual Analogue Scale (VAS). Friedman's test was used for within-group comparisons, while the Mann-Whitney test was used for between-group comparisons (p < 0.05). According to the results, laser application on pain points (G2) was more effective. McGill's results showed that regardless of dose, the pain point application group had better outcomes (p = 0.004). Pain intensity evaluation (last days) also showed that application at the pain points was more effective regardless of dose (p = 0.0002). Medians and interquartile deviations showed overall that PTB was more effective at pain points, with a trend towards better outcomes at the 6 J dose. Therefore, it can be concluded that in women with chronic painful TMD, the application of PTB at pain points is more effective than the application at pre-established points. Therefore, individualized PTB protocols are proposed, based on examination palpation of the masticatory structures.

A Scoping Review of the Use of Pioglitazone in the Treatment of Temporo-Mandibular Joint Arthritis

Thiazolidinediones (TZDs) are a group of diabetes medications currently being investigated for anti-arthritis effectiveness, one of which is pioglitazone. The purpose of this scoping review is to evaluate the potential use of pioglitazone in the treatment of temporomandibular joint (TMJ) arthritis. The criteria of eligibility were studies with the diagnosis of arthritis and pioglitazone treatment with a change in any inflammation index as an outcome. Of the 1169 records initially identified following the selection process, two animal studies and four clinical studies were included in the review. Improvements from the baseline were observed in each treatment group for each inflammation indicator. The results of the animal studies on the temporomandibular joints and on patients with rheumatoid and psoriatic arthritis indicate that the drug in question may have potential to treat arthritis, including within the temporomandibular joint.

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.

Prognostic criteria for the management of temporomandibular disorders using arthrocentesis with normal saline and arthrocentesis with normal saline and platelet-rich plasma

Temporomandibular joint disorders (TMDs) are ailments affecting the jaws and allied structures, resulting in many pathologies (TMJ hypermobility, internal disc derangement, bone changes, degenerative disorders, and ankylosis). Pain, clicking or crepitus, restricted range of motion, deranged jaw function, and deflected or deviated mouth opening and closing are the commonly observed manifestations in TMDs. Internal derangement refers to an aberrant relation of the articular disc to the condyle and fossa, respectively. Conventional therapies highlight the role of non-invasive conservative treatment strategies, namely joint unloading, anti-inflammatory drugs, and physiotherapy. Current literature has emphasized the use of corticosteroids and platelet-rich plasma (PRP) as treatment strategies in TMDs. This study aimed to evaluate whether intra-articular injection of PRP after normal saline lavage in TMJ minimizes the symptoms of TMDs, as compared to injection of normal saline. Thirty patients with TMD according to research diagnostic criteria (RDC) were selected. One group received arthrocentesis with normal saline, and the other group received arthrocentesis with PRP injection. The patients were assessed for pain, maximum inter-incisal mouth opening, bite force, and TMJ sounds. TMDs treated by PRP injection had slightly better results. More studies are required to substantiate the outcome. Injections of PRP were more effective in reducing the symptoms than arthrocentesis with normal saline.

Nonpharmacological Interventions for Pain in Patients with Temporomandibular Joint Disorders: A Systematic Review

This systematic review aimed to compare the efficacy of nonpharmacological therapies for painful temporomandibular joint disorders. The protocol was registered on International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020171364). The search was performed on the electronic databases PubMed, Google Scholar, Clinical Trials, and Web of Science. The eligibility criteria were randomized controlled trials in patients diagnosed with painful temporomandibular joint disorders comparing the pain relief between conventional treatment and nonpharmacological therapies such as acupuncture, physiotherapy, low-level laser, and massage. Fourteen articles were included in this review. At the overall bias of the studies included, 71.42% exhibited some concerns and 28.57% had high risk. The efficacy of nonpharmacological interventions was found to be moderate in the short term and variable in the long term for pain reduction in patients with temporomandibular joint disorders. The evidence pointed out that acupuncture, laser therapy, and physiotherapy are potentially useful interventions for pain relief in patients with temporomandibular joint disorders. However, there is a lack of consistency and short-term follow-up in the studies to determine the lasting of such effect.