Correlation of splint therapy outcome with the electromyography of masticatory muscles in temporomandibular disorder with myofascial pain

Efficiency of occlusal splint therapy on orofacial muscle pain reduction: a systematic review

BACKGROUND

This systematic review aims to examine the existing original studies to determine the effectiveness of occlusal splints (OSs) in the management of orofacial myalgia and myofascial pain (MP) in comparison with no treatment or other interventions.

MATERIALS AND METHODS

Based on the inclusion and exclusion criteria of this systematic review, randomized controlled trials were qualified, in which the effectiveness of occlusal splint therapy in the management of muscle pain was examined in comparison with no treatment or other interventions. This systematic review was conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020. The authors searched three databases (PubMed, CINAHL (The Cumulative Index to Nursing and Allied Health Literature) and Scopus) for English publications published between January 1, 2010, and June 1, 2022. The last database search was carried out on June 4, 2022. Data were extracted from the included studies and assessed for risk of bias using the revised Cochrane risk-of-bias tool for randomized trials.

RESULTS

Thirteen studies were identified for inclusion in this review. In total, 589 patients were diagnosed with orofacial muscle pain who underwent education and various forms of therapy including different types of OSs, light emitting diode therapy, acupuncture, low-level laser therapy, device-supported sensorimotor training, Kinesio Taping, myofunctional therapy, and physical therapy. All studies included demonstrated a high risk of bias.

CONCLUSIONS

There is insufficient evidence regarding whether OS therapy in the treatment of orofacial myalgia and MP offers an advantage over other forms of interventions or no treatment. Further reliable clinical studies in this area are needed to improve the quality of research, which should be performed with larger groups of blinded respondents and controls.

CLINICAL RELEVANCE

Due to the large-scale nature of orofacial muscle pain, it is assumed that each dental clinician will meet patients with orofacial muscle pain repeatedly in daily practice; hence, the review of the effectiveness of OSs in the management of orofacial myalgia and MP is necessary.

Changes in Maximum Mandibular Mobility Due to Splint Therapy in Patients with Temporomandibular Disorders

Splint therapy is widely used in the treatment of myofascial pain, but valid studies on the efficacy of this therapy are rare. The purpose of the present study was to investigate which qualifiable and quantifiable effects of splint therapy are detectable. For this purpose, 29 patients (21 women, mean age 44.6 ± 16 years) diagnosed with myofascial pain (RDC/TMD) were investigated in this prospective clinical trial (10/6/14An). Patients were treated with Michigan splints applied overnight for three months. Before (T1) and after three months of treatment (T2), patients were registered with an electronic ultrasound device with qualitative and quantitative evaluation of the registrations and a qualitative assessment of pain symptoms using a verbal analog scale. Significant differences were found between maximum mouth opening (MMP) (p < 0.001) and right condylar movement (CM) at MMP (p = 0.045). Qualitative assessment revealed that 24 of 29 patients experienced an improvement in pain symptoms, 17 of whom experienced complete remission. The results of the qualitative and quantitative analysis provide indications of the effectiveness of the splint therapy. In addition to quantitative measurements, the ultrasound facebow technique was also able to provide qualitative information.

Monitoring of awake bruxism by intelligent app

Background. Bruxism is a topic of much controversy and is continually debated in the field of dentistry due to the multifaceted clinical relationship that results in painful conditions and consequences to patients. The aim of this review was to determine the effectiveness of a smartphones app in monitoring awake bruxism. Methods. PROSPERO (registration number: CRD42021271190). The eligibility criteria were as followed: observational studies, case-control studies, studies that reported odds ratios, and studies on awake bruxism. The following keywords were searched: [smartphones apps] AND [apps] AND [awake bruxism], OR [sleep bruxism], OR [sleep hygiene], OR [parasomnias], AND [habits]. Results. All the included studies found that the use of the smartphone app allows controlled awake bruxism monitoring. The results also show that the slepp bruxism and awake bruxism  are interactive, having negative synergism and substantially increasing the risks of temporomandibular joint pain and temporomandibular disorders. Discussion. In the awake bruxims it was possible to identify 70% symptoms through the different frequencies of behavior provided by the App, within the present technological tools have become daily in young and adult population. The app is effective and easy to use by patients, effectively limiting biases the time of evaluation.

Monitoring of awake bruxism by intelligent app

Background. Bruxism is a topic of much controversy and is continually debated in the field of dentistry due to the multifaceted clinical relationship that results in painful conditions and consequences to patients. The aim of this review was to determine the effectiveness of a smartphones app in monitoring awake bruxism. Methods. PROSPERO (registration number: CRD42021271190). The eligibility criteria were as followed: observational studies, case-control   studies, studies that reported odds ratios, and studies on awake bruxism. The following keywords were searched: [smartphones apps] AND [apps] AND [awake bruxism], OR [sleep bruxism], OR [sleep hygiene], OR [parasomnias], AND [habits]. Results. All the authors agree that the use of the smartphone app allows controlled awake bruxism monitoring. The results also show that                                     the two bruxism are interactive, having negative synergism and substantially increasing the risks of temporomandibular joint pain and temporomandibular disorders. Discussion. In the AB it was possible to identify 70% symptoms through the different frequencies of behavior provided by the App, within the present technological tools have become daily in young and adult population. The app is effective and easy to use by patients, effectively limiting biases the time of evaluation.

Occlusal splint therapy in patients with Ménière's disease and temporomandibular joint disorder

Objective

This retrospective study aimed to verify the outcomes of stabilising occlusal splint therapy prescribed to 22 patients with unilateral definite Ménière’s disease and comorbid temporomandibular joint disorder.

Methods

The results of a battery of audiometric and vestibular tests were recorded before and after 6 months of treatment, as well as the scores of disease-specific questionnaires.

Results

The average hearing threshold in the affected ear and the acoustic immittance were unchanged. No spontaneous and positional nystagmus were recorded. Caloric hypo-responsiveness and vestibular myogenic evoked responses did not vary. No changes of stabilometric body sway parameters in eyes opened condition and with optokinetic stimulation delivered to the unaffected labyrinth were observed. A significant reduction was recorded in eyes closed condition and with the optokinetic stimulation toward the affected ear. The Tinnitus Handicap Inventory, the Situational Vertigo Questionnaire and the Numeric Pain Rating Scale scores improved. The number of vertigo attacks was reduced.

Conclusions

Occlusal splint therapy is a favourable option to reduce aural symptoms of Ménière’s disease and comorbid temporomandibular joint disorder, even if its pathophysiological mechanism remains elusive.

Comparative evaluation of occlusal splint therapy and muscle energy technique in the management of temporomandibular disorders: A randomized controlled clinical trial

Background:

Contradicting evidence regarding the effects of occlusal splint therapy in the management of Temporomandibular disorder (TMD) and promising results shown by muscle energy technique.

Aim:

To determine and compare the effects of occlusal splint therapy, muscle energy technique, and combined treatment with education for self-management and counseling in the management of TMD.

Study Design and Settings:

Randomized clinical trial.

Methodology:

A total of 160 participants diagnosed with TMD according to Diagnostic Criteria/TMD axis I were randomly allocated into four treatment groups with equal allocation ratio using random numbers table. The main inclusion criteria were the presence of pain in the preauricular area, TMJ and/or muscles of mastication and maximum mouth opening <40 mm. Group A participants received muscle energy technique, Group B participants received occlusal splint therapy, Group C participants received combined treatment, and Group D participants received education for self-management and counseling (control). Control group treatment was provided to all the trial participants.

Statistical Analysis:

Intragroup comparison was made using Friedman test and Wilcoxon test while intergroup comparison was done using Kruskal–Wallis test and Mann–Whitney U test.

Results:

Intensity of pain on a visual analog scale and maximum mouth opening were measured at baseline, at 1 week, at 2 weeks, at 1 month, and after 3 months.

Conclusion:

Muscle energy technique, occlusal splint therapy and combined treatment significantly reduce pain compared to controls and muscle energy and combined treatment are superior to other groups for mouth opening improvements in patients with TMD.

The hierarchy of different treatments for myogenous temporomandibular disorders: a systematic review and network meta-analysis of randomized clinical trials

The best treatment modality for the management of painful temporomandibular disorders of muscular origin (M-TMD) with predictable outcomes based on solid evidence is still not well defined. Thus, the aim of this network meta-analysis (NMA) was to identify the best treatment for adult patients with M-TMD. An electronic search was undertaken from the inception of each database to August 2018, to identify randomized clinical trials (RCTs), which are comparing two or more of the following treatment modalities in patients with M-TMD: counseling therapy; occlusal appliances; manual therapy; laser therapy; dry needling; intramuscular injection of local anesthesia (LA) or botulinum toxin-A (BTX-A); muscle relaxants; hypnosis/relaxation therapy; oxidative ozone therapy; and placebo or no treatment. Primary outcome variables were the reduction of pain and mechanical sensitivity. The secondary outcome was the maximal mouth opening (MMO). The quality of evidence was rated according to Cochrane's tool for assessing risk of bias. Standardized mean difference was used to analyze via frequentist network meta-analysis (NMA), using STATA software. 52 RCTs were included in this NMA. At the most follow up moments, manual therapy, counseling therapy, occlusal splints therapy, and needling using BTX-A or LA as well as dry needling significantly decreased post-treatment pain intensity in M-TMDs, when compared to placebo.  At short term (≤5 months), the four highest-ranked treatments for post-treatment pain reduction were manual therapy (83.5%, low quality evidence), ozone therapy (75.7%, very low quality evidence),counseling  therapy (71.2%, moderate quality), and occlusal appliances  (71.7%,moderate quality evidence). When intermediate term (≥6 months)was considered, BTX-A (85.8%, very low quality evidence) , counseling therapy(80%, low quality evidence), occlusal appliances  (62.8%, low quality evidence) and hypnosis (50.6%, very low quality evidence) were the four highest-ranked treatments.  This NMA reveals that manual therapy can be considered the most effective treatment for M-TMD, followed by counseling treatment, intramuscular injection of LA, and occlusal appliances  . However, considering the limitations of the studies included, and the scarce of strong evidence, the present findings should be interpreted cautiously.

An Overview of Anterior Repositioning Splint Therapy for Disc Displacement-related Temporomandibular Disorders

Anterior repositioning splint (ARS) therapy is considered one of the most effective therapies for treating disc displacement-related temporomandibular disorders (TMDs), which account for a large proportion of TMD cases. Owing to the wide application of this therapy, the exact mechanism of remission has increasingly drawn attention. Given that practitioners have different views on ARS therapy, its indications are broadened, and operating methods diverged. This review attempts to provide an overview of ARS therapy and helps practitioners establish indications and suitable operating methods. Representative views in the past 10 years were summarised, and conclusions were drawn as follows: The mechanism of ARS therapy is mainly attributed to internal derangement correction, improvement of stress distribution and recently reported joint remodeling. It has an evident effect in the short term, and the most prevalent operating methods are protruding the mandible to the edge-to-edge position and wearing the ARS for 24 hours daily for 3-6 months. However, long-term stability is not optimal, and thus indications should be selected carefully. Notably, most of the clinical studies in this field are case analyses with low-quality evidence. Well-designed RCTs are required to further validate relevant theories.

Oral splints for temporomandibular disorder or bruxism: a systematic review

Objectives To evaluate the clinical-effectiveness of oral splints for patients with TMD or bruxism for the primary outcomes: pain (TMD) and tooth wear (bruxism).

Data sources Four databases including MEDLINE and EMBASE were searched from inception until 1 October 2018.

Data selection and extraction Randomised controlled trials comparing all types of splints versus no/minimal treatment for patients with TMD or bruxism were eligible. Standard Cochrane review methods were used. Standardised mean differences (SMD) were pooled for the primary outcome of pain, using random effects models in TMD patients.

Data synthesis Thirty-seven trials were included and the evidence identified was of very low certainty using GRADE assessments. When all subtypes of TMD were pooled into one global TMD group, there was no evidence that splints reduced pain: SMD (up to 3 months) -0.18 (95% CI -0.42 to 0.06); 13 trials, 1,076 participants. There was no evidence that any other outcomes improved when using splints. There was no evidence of adverse events associated with splints, but reporting was poor regarding this outcome. No trials measured tooth wear in patients with bruxism. There was a large variation in diagnostic criteria, splint types and outcome measures used and reported. Sensitivity analyses based on these factors did not indicate a reduction in pain.

Conclusions The very low-certainty evidence identified did not demonstrate that splints reduced pain in TMD as a group of conditions. There is insufficient evidence to determine whether splints reduce tooth wear in patients with bruxism.

Oral splints for patients with temporomandibular disorders or bruxism: a systematic review and economic evaluation

BACKGROUND

Splints are a non-invasive, reversible management option for temporomandibular disorders or bruxism. The clinical effectiveness and cost-effectiveness of splints remain uncertain.

OBJECTIVES

The objectives were to evaluate the clinical effectiveness and cost-effectiveness of splints for patients with temporomandibular disorders or bruxism. This evidence synthesis compared (1) all types of splint versus no/minimal treatment/control splints and (2) prefabricated versus custom-made splints, for the primary outcomes, which were pain (temporomandibular disorders) and tooth wear (bruxism).

REVIEW METHODS

Four databases, including MEDLINE and EMBASE, were searched from inception until 1 October 2018 for randomised clinical trials. The searches were conducted on 1 October 2018. Cochrane review methods (including risk of bias) were used for the systematic review. Standardised mean differences were pooled for the primary outcome of pain, using random-effects models in temporomandibular disorder patients. A Markov cohort, state-transition model, populated using current pain and Characteristic Pain Intensity data, was used to estimate the incremental cost-effectiveness ratio for splints compared with no splint, from an NHS perspective over a lifetime horizon. A value-of-information analysis identified future research priorities.

RESULTS

Fifty-two trials were included in the systematic review. The evidence identified was of very low quality with unclear reporting by temporomandibular disorder subtype. When all subtypes were pooled into one global temporomandibular disorder group, there was no evidence that splints reduced pain [standardised mean difference (at up to 3 months) -0.18, 95% confidence interval -0.42 to 0.06; substantial heterogeneity] when compared with no splints or a minimal intervention. There was no evidence that other outcomes, including temporomandibular joint noises, decreased mouth-opening, and quality of life, improved when using splints. Adverse events were generally not reported, but seemed infrequent when reported. The most plausible base-case incremental cost-effectiveness ratio was uncertain and driven by the lack of clinical effectiveness evidence. The cost-effectiveness acceptability curve showed splints becoming more cost-effective at a willingness-to-pay threshold of ≈£6000, but the probability never exceeded 60% at higher levels of willingness to pay. Results were sensitive to longer-term extrapolation assumptions. A value-of-information analysis indicated that further research is required. There were no studies measuring tooth wear in patients with bruxism. One small study looked at pain and found a reduction in the splint group [mean difference (0-10 scale) -2.01, 95% CI -1.40 to -2.62; very low-quality evidence]. As there was no evidence of a difference between splints and no splints, the second objective became irrelevant.

LIMITATIONS

There was a large variation in the diagnostic criteria, splint types and outcome measures used and reported. Sensitivity analyses based on these limitations did not indicate a reduction in pain.

CONCLUSIONS

The very low-quality evidence identified did not demonstrate that splints reduced pain in temporomandibular disorders as a group of conditions. There is insufficient evidence to determine whether or not splints reduce tooth wear in patients with bruxism. There remains substantial uncertainty surrounding the most plausible incremental cost-effectiveness ratio.

FUTURE WORK

There is a need for well-conducted trials to determine the clinical effectiveness and cost-effectiveness of splints in patients with carefully diagnosed and subtyped temporomandibular disorders, and patients with bruxism, using agreed measures of pain and tooth wear.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068512.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 7. See the NIHR Journals Library website for further project information.

The treatment modalities of masticatory muscle pain a network meta-analysis

BACKGROUND

Numerous treatment modalities have been attempted for masticatory muscle pain in patients with temporomandibular disorders (TMD). To compare the treatment efficacy of more than 2 competing treatments, a network meta-analysis (NMA) was conducted.

METHODS

This study was reported with reference to the extended Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting of systematic reviews incorporating network meta-analyses. Medline via Pubmed, Embase via OVID, and Cochrane Library Central were searched (up to February 11, 2019). Axis I protocol of Diagnostic Criteria or Research Diagnostic Criteria for Temporomandibular Disorders (DC/TMD, RDC/TMD) were chosen as diagnostic standards. The PICOS (Problem/patient, Intervention, Comparison, Outcome, Study design) method was used to screen trials under eligibility criteria. And the NMA was performed with mvmeta commands in Stata (StataCorp, Tex).

RESULTS

Of 766 studies searched, 12 randomized clinical trials (RCTs) were finally included. Nineteen different therapies were found and further categorized into 9 treatment modalities. The general heterogeneity was not found among included trials. But predictive intervals (PrIs) were conspicuously wider than confidential intervals (CIs) of all pairwise comparisons, indicating that heterogeneity may exist between studies. Complementary therapy showed the greatest probability (42.7%) to be the best intervention. It also had the highest mean rank (2.3) in the rankogram and the biggest value of surface under the cumulative ranking (SUCRA, 84.1%).

CONCLUSIONS

Based on the limited evidence of available trials, complementary therapy seemed to be slightly more effective than remaining treatment modalities for pain reduction in TMD patients with masticatory muscle pain. High-quality randomized controlled trials are expected to validate the findings.

Occlusal stabilization splint for patients with temporomandibular disorders: Meta-analysis of short and long term effects

Background

Psychological discomfort, physical disability and functional limitations of the orofacial system have a major impact on everyday life of patients with temporomandibular disorders (TMDs). In this study we sought to determine short and long term effects of stabilization splint (SS) in treatment of TMDs, and to identify factors influencing its efficacy.

Methods

MEDLINE, Web of Science and EMBASE were searched for randomized controlled trials (RCTs) comparing SS to: non-occluding splint, occlusal oral appliances, physiotherapy, behavioral therapy, counseling and no treatment. Random effects method was used to summarize outcomes. The effect estimates were expressed as odds ratio (OR) or standardized mean difference (SMD) with 95% confidence interval. Subgroup analyses were carried out according to the use of Research Diagnostic Criteria (RDC/TMD) and TMDs origin. Strength of evidence was assessed by GRADE. Meta-regression was applied.

Results

Thirty three eligible RCTs were included in meta-analysis. In short term, SS presented positive overall effect on pain reduction (OR 2.08; p = 0.01) and pain intensity (SMD -0.33; p = 0.02). Subgroup analyses confirmed SS effect in studies used RDC/TMD and revealed its effect in patients with TMDs of muscular origin. Important decrease of muscle tenderness (OR 1.97; p = 0.03) and improvement of mouth opening (SMD -0.30; p = 0.04) were found. SS in comparison to oral appliances showed no difference (OR 0.74; p = 0.24). Meta-regression identified continuous use of SS during the day as a factor influencing efficacy (p = 0.01). Long term results showed no difference in observed outcomes between groups. Low quality of evidence was found for primary outcomes.

Conclusion

SS presented short term benefit for patients with TMDs. In long term follow up, the effect is equalized with other therapeutic modalities. Further studies based on appropriate use of standardized criteria for patient recruitment and outcomes under assessment are needed to better define SS effect persistence in long term.

Assessment of functional improvement with temporalis myofascial flap after condylectomy in elderly patients with anterior disc displacement without reduction and an erosive condylar surface

Background

The purpose of this study was to investigate the functional effects of temporalis myofascial flap after condylectomy, with or without disc removal, in elderly patients with anterior disc displacement (ADD) without reduction and an erosive condylar surface of the temporomandibular joint (TMJ).

Methods

A total of 15 joints from 11 elderly patients (71–78 years old) were included. The patients had pain, mandibular dysfunction symptoms, and unilateral or bilateral ADD as well as an erosive condylar surface of the TMJ. All patients underwent temporalis myofascial flap reconstruction after condylectomy, with or without disc removal. If the maximal mouth opening (MMO) remained <35 mm after condylectomy, coronoidotomy was also performed. Self-assessed pain and mandibular function, including MMO and protrusive and lateral movements, were evaluated.

Results

No patient experienced serious complications. Most measurements improved significantly after surgery compared to preoperatively. Most patients achieved nearly-normal mouth opening at 4 weeks after surgery. Although most patients felt discomfort during active postoperative physiotherapy, no patient reported serious pain during the follow-up period.

Conclusion

Although nonsurgical therapy is often the first treatment choice for ADD without reduction of the TMJ, surgical intervention involving condylectomy and temporalis myofascial flap reconstruction may be a reasonable first option for elderly patients with an erosive condylar surface of the TMJ.

Soft versus hard occlusal splint therapy in the management of temporomandibular disorders (TMDs)

Aim

To compare between soft and hard occlusal splint therapy for the management of myofacial pain dysfunction (MPD) or internal derangement (ID) of the temporomandibular joint (TMJ) with reciprocal clicking.

Patients and methods

This study included 50 patients (age range: 24–47 years) who had been diagnosed with MPD or ID of the TMJ in the form of reciprocal clicking. Patients were divided into two groups. They were treated for 4 months with either a vacuum-formed soft occlusal splint constructed from 2-mm-thick elastic rubber sheets (soft splint group) or a hard flat occlusal splint fabricated from transparent acrylic resin (hard splint group). Monthly follow-up visits were performed during the treatment period. Before treatment and 1, 2, 3 and 4 months after treatment, the dentist measured all parameters of TMJ function (pain visual analog scores, tenderness of masticatory muscles, clicking and tenderness of the TMJ, and range of mouth opening).

Results

All parameters of TMJ function showed significant improvement in both groups during the follow-up period, with a statistically significant difference between the two groups at the 4-month follow-up visit.

Conclusions

Both forms of occlusal splints (soft and hard) improved TMJ symptoms in patients with MPD or ID of the TMJ. However, the soft occlusal splints exhibited superior results after 4 months of use.

Mandibular function after Myorelaxation Therapy in temporomandibular disorders

PURPOSE

The aim of this study was to analyze the efficacy of Myorelaxation Therapy in temporomandibular disorders on the basis of mandibular movement measurements, reported functional impairment and clinical findings.

MATERIAL/METHODS

To ascertain the mandibular movements 78 women were investigated. The first group consisted of 32 consecutive patients (23.3±4.8 years) suffering from muscle disorder and disk displacement with a reduction serving as a treated group. The second group was formed from 46 volunteers, as a healthy group (20.1±1.3 years). Jaw-tracking records (K7, Myotronics-Noromed Inc.) were performed including the measurements of opening, lateral and protrusive movement range, maximal and average velocity of opening/closing. Reported impairment and clinical data were collected. The treatment involved nocturnally applied a non-occluding sublingual relaxation splint combined with daily performed stretching exercises. Measurements were taken before treatment, after 4 weeks with no interventions (control period) and after 3 weeks, 3 and 6 months.

RESULTS

After the treatment mandibular opening range increased by 8mm (19%, p<0.05), lateral movement by 2.1mm (36%, p<0.05) while protrusive movement decreased by 0.5mm (p>0.05). Maximal and average velocity parameters significantly increased (p>0.05). These results were supported by the decrease in reported impairment and clinical pain occurrence (p<0.05). Only joint clicking change was non-significant (p>0.05).

CONCLUSIONS

Myorelaxation Therapy was effective in the treatment of our group of patients. A significant improvement in the opening and lateral movement range, as well as opening/closing velocity was obtained after 6 months of treatment. This method can be easily managed by general practitioner, especially in muscles-related TMD types.

Sleep bruxism: a comprehensive overview for the dental clinician interested in sleep medicine

Sleep bruxism (SB) is a common sleep-related motor disorder characterized by tooth grinding and clenching. SB diagnosis is made on history of tooth grinding and confirmed by polysomnographic recording of electromyographic (EMG) episodes in the masseter and temporalis muscles. The typical EMG activity pattern in patients with SB is known as rhythmic masticatory muscle activity (RMMA). The authors observed that most RMMA episodes occur in association with sleep arousal and are preceded by physiologic activation of the central nervous and sympathetic cardiac systems. This article provides a comprehensive review of the cause, pathophysiology, assessment, and management of SB.