Botulinum Toxin Type A for Painful Temporomandibular Disorders: Systematic Review and Meta-Analysis

Botulinum Toxin-A for the Treatment of Myogenous Temporomandibular Disorders: An Umbrella Review of Systematic Reviews

OBJECTIVE

Temporomandibular disorders (TMDs) encompass several conditions that cause pain and impair function of the masticatory muscles (M-TMDs) and temporomandibular joints. There is a large interest among clinicians and researchers in the use of botulinum toxin-A (BoNT-A) as a treatment for M-TMD. However, due to the lack of consistent evidence regarding the efficacy as well as adverse events of BoNT-A, clinical decision making is challenging. Therefore, this umbrella review aimed to systematically assess systematic reviews (SRs) evaluating BoNT-A treatment effects on pain intensity, mandibular movements, and adverse events in patients with M-TMDs.

METHOD

An electronic search was undertaken in the databases MEDLINE, EMBASE, CINAHL, Cochrane Central Registry of Controlled Trials (CENTRAL), Web of Science, Epistemonikos, ClinicalTrials.gov, and ICTRP to identify SRs investigating BoNT-A effects on M-TMDs, published from the inception of each database until 6 December 2023. The quality of evidence was rated according to the critical appraisal checklist developed by the umbrella review methodology working group. Only high-quality SRs were included.

RESULTS

In total, 18 SRs were included. BoNT-A was shown to be more effective than placebo to reduce pain intensity, but not compared to standard treatments. Additionally, BoNT-A was not superior to placebo or standard treatments regarding improvement of mandibular movements. BoNT-A was considered to have a higher risk for adverse events on muscle and bony tissue compared with other treatments.

CONCLUSION

The synthesis in this umbrella review provides the highest level of evidence present. Taken together, there are indications of effectiveness of BoNT-A for treatment of M-TMDs, supported by moderate evidence. However, considering the risk of causing serious adverse events, treatment with BoNT-A is recommended to be the last treatment alternative.

Effect of botulinum toxin type A on muscular temporomandibular disorder: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Botulinum toxin type A (BTX-A) is increasingly used to manage painful temporomandibular disorders (TMD). However, the effect of BTX-A on muscular TMD remains unclear.

OBJECTIVE

To assess the efficacy, safety and optimal dose of BTX-A for treating TMD.

METHODS

We conducted systematic literature searches in MEDLINE, Embase, Web of Science, ClinicalTrials.gov and Cochrane Library until March 2023. We extracted data from randomized controlled trials (RCTs) that evaluated the efficacy and safety of BTX-A in treating muscular TMD. We performed a meta-analysis using a random-effects model.

RESULTS

Fifteen RCTs involving 504 participants met the inclusion criteria. BTX-A was significantly more effective than placebo in reducing pain intensity, as measured on a 0-10 scale, at 1 month (MD [95% CI] = -1.92 [-2.87, -0.98], p < .0001) and 6 months (MD [95% CI] -2.08, [-3.19 to -0.98]; p = .0002). A higher dosage of BTX-A (60-100 U bilaterally) was associated with a greater reduction in pain at 6 months (MD [95% CI] = -2.98 [-3.52, -2.44]; p < .001). BTX-A also resulted in decreased masseter muscle intensity (μV) (MD [95% CI] = -44.43 [-71.33, -17.53]; p = .001) at 1 month and occlusal force (kg) at 3 months (MD [95% CI] = -30.29 [-48.22 to -12.37]; p = .0009). There was no significant difference in adverse events between BTX-A and placebo.

CONCLUSIONS

BTX-A is a safe and effective treatment for reducing pain and improving temporomandibular muscle and joint function in muscular TMD patients. A bilateral dose of 60-100 U might be an optimal choice for treating muscular TMD pain.

IncobotulinumtoxinA in refractory temporomandibular disorder due to disk dislocation: A prospective study

INTRODUCTION

Temporomandibular disorders (TMD) may include conditions involving the temporomandibular joint and/or masticatory muscles. Approximately 20 % of patients are refractory to first-line therapies. This study aims to evaluate the effects and safety of incobotulinumtoxinA in the treatment of refractory TMD due to disk dislocation.

MATERIAL AND METHODS

A quasi-experimental one-arm prospective study was conducted. Target population included individuals with a diagnosis of TMD due to disk dislocation. Patients were treated with electromyography or ultrasound guided injection of incobotulinumtoxinA in the masticatory muscles (20 U into each masseter and pterygoideus lateralis). Pain was assessed using the pain numerical rating scale, maximum unassisted mouth opening was measured in mm, and adverse events were registered at baseline, week 4, week 12 and week 24 post-treatment. Statistical analysis used the Wilcoxon test for the comparison of paired samples and the Mann-Whitney U test for independent samples, considering a p-value ≤ 0.05 as significant.

RESULTS

51 patients with 75 painful temporomandibular joints due to disk dislocation (38 with reduction and 37 without) were included. A significant reduction in pain from a pre-treatment mean of 6.08/10 to a post-treatment mean of 2.04/10 (week 4), 3.18/10 (week 12), and 3.65/10 (week 24) was observed (p < 0.001). A significant decrease in maximum unassisted mouth opening from a pre-treatment mean of 36.45 mm to a post-treatment mean of 32.29 mm at week 4 was observed (p < 0.001).

DISCUSSION

Botulinum toxin injection of the masticatory muscles is safe and seems equally effective in reducing pain in patients with refractory TMD due to disk dislocation.

Clinical aspects of mastication myalgia-an overview

Mastication myalgia is the most common cause of non-odontogenic pain in the orofacial region and is often associated with a reduced quality of life. The purpose of this review is to provide an overview of the clinical aspects of myalgia based on available research. The review includes epidemiological, diagnostic, and etiological aspects. In addition, the potential risk factors related to the transition from acute to chronic myalgia are explored and treatment strategies are presented for its management. As a result, this review may increase clinical knowledge about mastication myalgia and clarify strategies regarding prevention, diagnostics, and management to improve prognosis and reduce patient suffering.

Comparative analysis of different types of occlusal splints for the management of sleep bruxism: a systematic review

BACKGROUND

Sleep bruxism is a prevalent condition in dentistry practice, characterized by involuntary grinding or clenching of the teeth during sleep. Several therapies, including occlusal splints, have been used to manage sleep bruxism and temporomandibular disorders, including occlusal splints. This study aimed to compare the effectiveness of different occlusal splints in managing sleep bruxism.

METHODS

The PICO framework encompasses the characterization of the population, intervention, comparison, and pertinent outcomes. A comprehensive and systematic literature review was conducted on PubMed, Scopus, and Google Scholar to identify grey literature. The search specifically targeted scientific studies published before September 20, 2023. The Cochrane Collaboration Risk of Bias Tool assessed the accuracy of the included Randomized Control Trials (RCTs). The modified Newcastle-Ottawa Scale assessed non-randomized studies. Data were systematically extracted, synthesized, and reported thematically.

RESULTS

Out of the total of 808 articles that were evaluated, only 15 articles were found to meet the specified inclusion criteria. Adjustable splints, such as full-occlusion biofeedback splints, were more effective in reducing sleep bruxism episodes, improving patient-reported symptoms, and enhancing overall well-being. The impact of different occlusal sprints on electromyographic activity varies, and potential adverse effects should be considered individually.

CONCLUSIONS

This review provides valuable insights into the effectiveness of occlusal splints in managing sleep bruxism. The results of this study indicate that occlusal splint therapy is a viable treatment approach for sleep bruxism.

Temporomandibular disorders-review of evidence-based management and a proposed multidisciplinary care pathway

Temporomandibular disorders (TMDs) are a prevalent but complex group of conditions that cause orofacial pain. Temporomandibular disorders are recognized as one of the most common chronic pain conditions, alongside back pain and headache disorders. Given the competing theories surrounding what causes TMDs and limited high-equality evidence on optimally treating TMDs, clinicians often encounter challenges in developing an effective management plan for patients. Furthermore, patients will often seek advice from multiple health care providers from varying specialties, seeking curative management, often resulting in inappropriate treatments and no improvement in pain symptoms. Throughout this review, we explore the existing evidence base surrounding the pathophysiology, diagnosis, and management of TMDs. An existing United Kingdom-based multidisciplinary care pathway for the management of TMDs is described herein, highlighting the benefits of a multidisciplinary approach to patient care for TMDs.

Lateral pterygoid muscle ultrasound-guided injection: A technical note

BACKGROUND

Temporomandibular disorders (TMDs) are a frequent cause of orofacial pain, causing functional disability and a negative impact on quality of life. Botulinum toxin (BTX-A) injection in lateral pterygoid muscle (LPM) is one of the treatment modalities proposed, but the blind puncture guided by EMG carries a risk of vascular puncture or diffusion of the toxin to nearby muscles. We describe an ultrasound-guided approach and evaluate the spread of the injection in a fresh human cadaver.

METHODS

A fresh human cadaver was injected. An out-of-plane approach was performed using a convex probe, injecting 1.0 ml of 0.25% methylene blue dye into the LPM. After, a dissection was performed to isolate the lateral pterygoid muscle and assess the spread of the dye.

RESULTS

Ultrasound-guided injection allowed to visualize in real-time the spread of the dye within the LPM. The deep and superficial muscles nearby to LPM were not stained by the dye, but upper and lower head of LPM was heavily stained.

CONCLUSION

Ultrasound-guided approach for the injection of BTX-A into the LPM could be considered a successful and safe treatment for myofascial pain related to TMD. Therefore, further clinical studies are needed to study the reproducibility of ultrasound guided LPM injection and to evaluate the clinical results.

Outcomes of IncobotulinumtoxinA Injection on Myalgia and Arthralgia in Patients Undergoing Temporomandibular Joint Arthroscopy: A Randomized Controlled Trial

BACKGROUND

Several studies have considered Botulinum Neurotoxin Type A injections effective in treating temporomandibular joint disorder (TMD) symptoms. A double-blind, randomized, controlled clinical trial investigated the benefit of complementary incobotulinumtoxinA (inco-BoNT/A) injections in the masticatory muscles of patients submitted to bilateral temporomandibular joint (TMJ) arthroscopy.

METHODS

Fifteen patients with TMD and an indication for bilateral TMJ arthroscopy were randomized into inco-BoNT/A (Xeomin, 100 U) or placebo groups (saline solution). Injections were carried out five days before TMJ arthroscopy. The primary outcome variable was a Visual Analogue Scale for TMJ arthralgia, and secondary outcomes were the myalgia degree, maximum mouth opening, and joint clicks. All outcome variables were assessed preoperatively (T0) and postoperatively (T1-week 5; T2-6-month follow-up).

RESULTS

At T1, the outcomes in the inco-BoNT/A group were improved, but not significantly more than in the placebo group. At T2, significant improvements in the TMJ arthralgia and myalgia scores were observed in the inco-BoNT/A group compared to the placebo. A higher number of postoperative reinterventions with further TMJ treatments were observed in the placebo group compared to inco-BoNT/A (63% vs. 14%).

CONCLUSIONS

In patients submitted to TMJ arthroscopy, statistically significant long-term differences were observed between the placebo and inco-BoNT/A groups.

Short term effects of a novel combined approach compared with physical therapy alone among older patients with temporomandibular degenerative joint disease: a prospective cohort study

BACKGROUND

There is a lack of consensus regarding the best treatment option, including physical exercise, available for temporomandibular degenerative joint disease (DJD) that affect the older patients. Herein, we aimed to study and compare the efficacy of a combined approach using injection and home physical exercise with physical therapy alone as well as explored an optimal treatment strategy for older patients with DJD.

METHODS

We included 213 older patients with DJD treated at our medical centre from June 2020 to June 2021, 64 of whom were selected for analysis. Of these 64 patients, 32 received injections combined with home physical exercise, and the other 32 received physical therapy alone. Propensity score matching was used to ensure that the two groups did not differ significantly in categorical and continuous variables. Measurements included pain intensity, maximum mouth opening, joint crepitus, jaw functional limitation scale (JFLS) scores, treatment times, and treatment durations. Improvement in each measurement was compared between the two groups 2, 4, and 12 weeks after the treatment commenced, as were the final treatment times and durations.

RESULTS

Pain intensity, maximum mouth opening, and JFLS scores in the two groups improved 2, 4, and 12 weeks after treatment (all p < 0.05). The crepitus ratio improved significantly only in the combined treatment group after 12 weeks. Compared with the physical therapy group, pain while opening the mouth improved after 2, 4, and 12 weeks in the combined treatment group. Furthermore, 2 weeks after treatment, the physical therapy group showed significant improvement in maximal mouth opening compared with the combined treatment group. No significant between-group differences were observed regarding improvement in joint crepitus and JFLS scores at each observation point. The combined treatment group had a significantly lower number of visits than the physical therapy group; however, the treatment duration was longer.

CONCLUSION

Compared with physical therapy, pain while opening the mouth is significantly improved by the combined treatment within 12 weeks, and the number of required visits is fewer. Physical therapy improves the patients' mouth-opening capabilities in a short time (2 weeks), and the treatment cycle is short.

Preliminary Findings of the Efficacy of Botulinum Toxin in Temporomandibular Disorders: Uncontrolled Pilot Study

Temporomandibular disorders are a common pathology affecting up to 70% of the population, with a maximum incidence in young patients. We used a sample of twenty patients recruited in the Maxillofacial Surgery Service of the University Hospital of Salamanca (Spain), who met the inclusion criteria, with unilateral painful symptomatology of more than three months' duration. All patients were randomly treated by intramuscular and intra-articular injections of botulinum toxin (100 U) in eight predetermined points. Pain symptomatology was assessed by the visual analog scale (VAS) at the different locations, together with joint symptomatology, at baseline and six weeks after treatment. Adverse effects were also evaluated. In 85% of the patients, pain upon oral opening improved and 90% showed improvement in pain upon mastication. A total of 75% of the patients reported improvement in joint clicking/noise. Headaches improved or disappeared in 70% of the patients treated. Despite the limitations of the study and the preliminary results, intramuscular and intra-articular infiltrations with botulinum toxin were effective in the treatment of symptoms associated with temporomandibular disorders (TMDs), with minimal adverse effects.

Association between depression and temporomandibular dysfunction in adults - a systematic review

OBJECTIVE

To critically evaluate the literature and answer the question: "Is there an association between depression and temporomandibular disorder (TMD) in adults?"

METHODS

The personalized search strategy was applied to PubMed, Embase, Web of Science, and Scopus databases. Articles were selected in two stages according to the eligibility criteria. The Joanna Briggs Institute (JBI) tool was used to analyze the risk of bias according to the type of study.

RESULTS

The included articles presented a moderate risk of bias. Based on the studies, individuals with TMD have higher levels of depression compared to the control group. There is also a direct association in that individuals with depression are more susceptible to developing TMD.

CONCLUSION

There is a probable association between depression and TMD in adults. However, more studies with high methodological quality are needed to confirm this finding.

Patient experience and satisfaction with different temporomandibular joint treatments: A retrospective study

This retrospective study aimed to evaluate patient satisfaction with different temporomandibular joint (TMJ) treatments. Patients were included in the study according to the following inclusion criteria: 1) arthrogenous and/or myogenous temporomandibular disorders (TMD); 2) Dimitroulis classification category between 1-4; 3) conservative treatment without any improvement at least for 3 months; 4) indication for one of the following TMD treatments: injection of botulinum toxin; arthrocentesis; arthroscopy, and open surgery without alloplastic material; and 5) age ≥16 years. An independent satisfaction questionnaire with 11 queries was applied via phone call to all patients, which included 6 questions using a 10-point Likert scale and 5 yes-or-no questions. The principal outcome was the overall satisfaction with the clinical result of the treatment, and the secondary outcomes were specific satisfaction with the following: 1) pain reduction; 2) range of mouth opening; 3) chewing ability; 4) postoperative recovery; 5) the fulfillment of expectations; 6) treatment choice; 7) treatment recommendation to a friend; and 8) the need for another intervention. Anxiety and depression were also included as variables. Data were analyzed using descriptive statistics, non-parametric Kruskal-Wallis and Spearman rank correlation coefficient tests. A total of 120 patients (mean age 41.20 ± 17.78 years) were enrolled, comprising 109 women (90%) and 11 men (10%). The overall clinical satisfaction of all patients was 8.24 ± 2.23 (mean ± SD), and 97 patients (80.8%) stated that they would repeat the treatment. Patients submitted to TMJ arthrocentesis and arthroscopy had higher overall clinical satisfaction (9.09 ± 0.971 and 9.03 ± 1.13, p = 0.021) followed by open surgery (8.38 ± 1.84). The authors observed three statistically significant correlations: 1) overall clinical satisfaction and patient expectations (r = 0.803; p < 0.0001); 2) overall clinical satisfaction and post-treatment pain (r = -0.299; p = 0.003); and (3) the presence of depression and the need for further TMJ treatment (r = 0.186; p = 0.043). Within the limitations of the study it seems that patient expectations should be addressed ad initium, and the presence of a diagnosis of depression with concomitant TMD must alert the clinical team and patient for the possible need of additional treatment.

Botulinum Toxin, a Drug with Potential Interest for Dentists—An Introduction

The review is an introduction to medical, non-cosmetic treatments with botulinum neurotoxin (BoNT) in the orofacial region. It focuses on the current most common, best-documented and safest indications of interest for dentists in terms of dystonia and sialorrhea. These conditions are recommended to start with and suitable to gain better skill and experience with BoNT. The introduction also stresses the importance of correct diagnostics based on interdisciplinary cooperation, precise targeting of the injections, measurements of treatment effect, and control of the oral health with regard to side effects.

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.

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 1: therapeutic applications

Objective An evidence-based review on the safety and efficacy of botulinum toxin type-A (BoNTA) in orofacial conditions, focusing on the therapeutic applications and role of BoNTA as an adjuvant treatment.Data source and selection Data was collected using PubMed (Medline), Cochrane Library of Systematic Reviews and Cochrane Central Register of Controlled Trials electronic databases. Having satisfied the search parameters, 32 studies for therapeutic applications and 26 for BoNTA as an adjunctive treatment were included. The quality of relevant studies was assessed using the Best Evidence Topics (BETs) Critical Appraisal Tool.Data extraction The highest level of evidence (LOE) behind BoNTA safety and efficacy was for wound healing and scar management in the orofacial surgery context, where BoNTA was presented as an adjunctive modality. Level-I evidence was controversial for temporomandibular disorders and bruxism. However, it showed promising results for painful temporomandibular disorders of myogenic origin refractory to conservative therapies, and to decrease muscle contraction intensity in sleeping bruxism. There was only one level-II study for persistent recurrent aphthous stomatitis. Data showed limited level-III evidence for orofacial pain conditions (temporomandibular joint recurrent dislocation and pain, burning mouth syndrome or atypical odontalgia), oral cancer complications, or as an adjuvant to maxillofacial and orthognathic surgeries. Benefits of BoNTA in prosthodontics had weak level-IV evidence. No evidence was found among the periodontology field.Conclusion There is growing evidence to support the safety and efficacy of BoNTA in the investigated orofacial pathological conditions, with high levels of satisfaction from the patient and clinician perspective. However, there are some inconsistencies and limited high-quality evidence available. Well-designed controlled clinical trials are necessary to evaluate long-term safety, efficacy and cost-effectiveness before BoNTA is widely adopted with irrefutable evidence-based clinical guidelines.

Meta-Analysis of Shrinkage Mode After Neoadjuvant Chemotherapy for Breast Cancers: Association With Hormonal Receptor

Background

Patients with concentric shrinkage mode after neoadjuvant chemotherapy (NAC) is considered to be ideal candidates for breast conserving treatment (BCT). While, what proportion of patients would represent CSM have not been well defined. This study was conducted to pool the rates of concentric shrinkage mode (CSM) in patients undergoing NAC, determine the impact of hormonal receptor on the shrinkage mode after NAC and estimate the rates of the CSM in various subgroups.

Methods

We conducted a systematic review following the guidelines for Meta-Analyses and Systematic reviews for the PRISMA guidelines. We systematically searched the literature about shrinkage mode after NAC from PubMed, Web of Science, Embase, The Cochrane Library, CNKI, Wanfang database published from January 2002 to June 2020 on breast cancer shrinkage mode after NAC and carefully screened the literature by using eligibility criteria: (1) patients with primary breast cancer treated with NAC; (2) publications with available data of shrinkage mode measured by magnetic resonance imaging (MRI), or data of pathology and hormonal receptor. The association between shrinkage mode and hormonal receptor was estimated using Stata 15.1 software.

Results

This analysis included a total of 2434 tumors from 23 papers. The included studies were heterogeneous (I2 = 89.4%, P<0.01). Random effects model was used to estimate the overall rates of CSM: 56.6% [95%CI (50.5%, 62.7%)]. According to the analysis of hormonal receptor, 10 of the paper was included for HR+ (hormone receptor positive) type analysis and the rate of CSM for HR+ type was 45.7% [95%CI (36.4%, 55.0%)]; 9 of the paper was used for HR- type (hormone receptor negative) analysis and the incidence of HR-CSM is 63.1% [95%CI (50.0%, 76.1%)]; with HR+ type as the control, the OR of the HR- CSM rate is 2.32 (1.32, 4.08) folds of HR+ type. From subgroup analyses, the CSM% of luminal A, luminal B, Her2+, and triple negative were 29.7% (16.5%, 42.8%); 47.2% (19.1%, 75.3%); 59.0% (39.7%, 78.3%); 66.2% (52.8%, 79.6%), respectively.

Conclusions

Breast cancer patients undergoing NAC did not get an ideal odds ratio of CSM. The incidence of CSM in breast cancer after NAC is associated with hormonal receptor. Patients with triple-negative breast cancers have the highest rates of CSM after NAC. More care should be taken to select patients with the luminal subtypes for BCT throughout NAC.

Temporomandibular disorder treatment algorithm for otolaryngologists

OBJECTIVE

To review current literature describing the management of temporomandibular disorder (TMD) and to propose an evidence-based algorithm for otolaryngologists.

DATA SOURCES

A literature review using PubMed and Scopus was conducted to identify manuscripts that describe TMJ disorder etiology, diagnostic methods, and management across the fields of otolaryngology, general practice medicine, physical therapy, dentistry, and maxillofacial surgery.

REVIEW METHODS

Two reviewers subjectively evaluated the studies based on the inclusion criteria, incorporating them into a comprehensive algorithm.

CONCLUSIONS

TMD is one of the most common conditions presenting to otolaryngology outpatient clinics. Etiologies of TMD vary widely, including myofascial, intraarticular, neurologic, traumatic, or psychiatric in origin. When conservative measures fail to produce symptom relief, alternative treatments and referral to outside specialists including psychiatry, physical therapy, dentistry, and maxillofacial surgery may be indicated. Premature or inappropriate referrals may lead to patients suffering TMD for extended periods of time, with alternating referrals between various specialists. Thus, we present a TMD treatment algorithm for otolaryngologists to aid in the decision-making process in managing TMD.

IMPLICATIONS FOR PRACTICE

Patients frequently present to otolaryngology outpatient clinics for symptoms of TMD. Multidisciplinary practice may be necessary to effectively treat TMD of varying etiology and severity. Following conservative treatment, appropriate referrals and treatment plans will reduce ineffective use of resources, deferral of treatment, and patient suffering. For this reason, a comprehensive algorithm for otolaryngologists will improve resource utilization and efficiency of treatment to ultimately provide improved treatment outcomes for patients.

Masticatory Myofascial Pain Syndrome: Implications for Endodontists

INTRODUCTION

Masticatory myofascial pain syndrome can present similarly to other dental conditions in odontogenetic structures. Endodontists should be familiar with the symptomology and pathophysiology of masticatory myofascial pain syndrome to avoid misdiagnosis, incorrect treatment, and medicolegal repercussions. The aim of this review was to provide a foundational summary for endodontists to identify and correctly manage masticatory myofascial pain syndrome.

METHODS

A narrative review of the literature was performed through a MEDLINE search and a hand search of the major myofascial pain textbooks.

RESULTS

Masticatory myofascial pain syndrome is a musculoligamentous syndrome that can present similarly to odontogenic pain or refer pain to the eyebrows, ears, temporomandibular joints, maxillary sinus, tongue, and hard palate. Currently, the most comprehensive pathophysiology theory describing masticatory myofascial pain syndrome is the expanded integrated hypothesis. The most widely accepted diagnostic guidelines for masticatory myofascial pain syndrome are the Diagnostic Criteria for Temporomandibular Disorders; however, their diagnostic capability is limited. There is no hierarchy of treatment methods because each patient requires a tailored and multidisciplinary management aimed at regaining the muscle's range of motion, deactivating the myofascial trigger points, and maintaining pain relief.

CONCLUSIONS

The pain patterns for masticatory myofascial pain syndrome are well-known; however, there is a lack of consensus on the most proper method of trigger point diagnosis or pain quantification. The diagnostic strategies for masticatory myofascial pain syndrome vary, and the diagnostic aids are not well developed.

Assessment of anterior positioning splint in conjunction with lateral pterygoid BTX injection to treat TMJ disc displacement with reduction - a preliminary report

Objective

Treatment of temporomandibular disc displacement with reduction is controversial. This study assesses the use of an anterior positioning splint with botulinum toxin in the lateral pterygoid muscle (BTX) for such cases.

Methods

Twelve joints were included; groups I and II received BTX injection while group II also received an anterior positioning splint. Pain scores and clicking status were recorded at regular intervals then a postoperative MRI was done after 4 months.

Results

Clinical improvement was noted in both groups. Mean pain scores dropped significantly and clicks in the twelve joints disappeared in 83% of group I and 33% of group II. MRIs showed significant disc position improvement with the higher mean change (1.33 ± 0.76) in group I.

Group I showed better improvement of discal position and only one joint regained a click. Patients of group II reported discomfort from the splint which may have caused psychological distress and so worst pain scores.

Conclusions

Group I  showed slightly better results but the cost of BTX injections and the complications of the splint should be kept in mind and the decision of treatment selection made according to each condition.

Effect of botulinum toxin on quality of life of patients with chronic myofascial pain

Aim: This prospective controlled clinical study aimed to evaluate the effect of botulinum toxin Type A (BTX-A) on pain control and quality of life (QoL) in patients with chronic myofascial pain. Materials & methods: Patients with chronic myofascial pain were randomly divided into two groups (n = 20): counseling and self-care and Michigan-type occlusal splint (MOS) (CG-control group) or BTX-A injection (BTX-AG). The pain was evaluated with visual analogue scale and QoL with the oral health impact profile-14 (OHIP-14) questionnaire. Results: In both groups, the pain was reduced, and QoL improved after 30 days. The results of social disability and handicap were better for patients treated with counseling and self-care and MOS. Conclusion: Minimally invasive strategies and BTX-A application improved QoL and alleviated myofascial pain.

Are occlusal splints effective in reducing myofascial pain in patients with muscle-related temporomandibular disorders? A randomized-controlled trial

Objectives

This study aims to evaluate the effectiveness of upper Michigan occlusal splint (OS) compared to mandibular OS in terms of pain, range of motion (ROM), and muscle activity as assessed by surface electromyography (sEMG) in patients affected by muscle-related temporomandibular disorders (TMD).

Patients and methods

In this randomized-controlled trial, a total of 40 adult patients (13 males, 27 females; mean age: 47.2±12.8 years; range, 22 to 56 years) with a diagnosis of myofascial pain, lasting from at least three months on at least one masseter muscle. The patients were randomly allocated into two groups: Group 1 (n=20) using upper Michigan OS and Group 2 (n=20) using mandibular OS. At baseline (T0), at one (T1), three (T2), and six months (T3), the following outcomes were assessed: myofascial pain by Visual Analog Scale (VAS) and ROM of mandible movements, activity of the main masticatory muscles through sEMG.

Results

There were no significant intra-group differences in the outcome measures assessed in both groups. However, Group 2 had a significantly higher right lateral mandibular ROM at T2 (7.1±3.1 vs. 9.8±2.3, respectively; p<0.05) and a significantly higher left lateral mandibular ROM at T3 (7.6±3.5 vs. 10.5±2.1, respectively; p<0.05). We found no significant difference in none of the sEMG parameters.

Conclusion

Our study results suggest that OS, independently from being built on the upper or lower arch, seems to not have significant effects in reducing pain over a six-month period in TMD patients.