Efficacy of botulinum toxin in treating myofascial pain in bruxers: a controlled placebo pilot study

Efficacy of botulinum neurotoxin A in persistent idiopathic dentoalveolar pain: a case series

OBJECTIVES

Persistent idiopathic dentoalveolar pain (PIDP) is a challenging clinical entity associated with both physical and emotional consequences. Currently, the management is symptom-based and includes both topical and/or systemic treatments. More recently, botulinum neurotoxin-A (BONT-A) has been suggested as a treatment option.

MATERIALS AND METHODS

We present a case series of 9 patients (5 female) with mean age 56 ± 15 diagnosed with PIDP. All patients reported prior experience with systemic drugs without a sufficient pain-relieving effect. BONT-A (BOTOX, Allergan) 100 U diluted with saline solution was used and the dose ranged from 20U to 50U distributed in 3 sites (intraoral and/or extraoral) per session. Patients underwent further injections (50U) monthly if pain severity measured using a Numerical Rating Scale (NRS 0-10) was still > 3 for 3 months. Pain severity and characteristics were recorded at baseline (T0), after 1 month (T1), 2 months (T2) and 3 months (T3).

RESULTS

Mean pain intensity at baseline was NRS 6 (4-10). Latency before analgesic effect was at least 5-10 days after injection. Minor adverse effects were sickness and muscular hypotonia. Pain significantly reduced to NRS 4 (0-8) at T1, to NRS 2 (0-8) at T2 and to NRS 2 (NRS 0-8) at T3. Patients' functional variables (discomfort while chewing, talking, swallowing) were also recorded.

CONCLUSIONS

BONT-A is widely used and although the exact mechanism of action remains unclear, it can be used effectively in reducing pain for a variety of conditions including PIDP.

CLINICAL RELEVANCE

Our results suggest that BONT-A seems to be an alternative therapeutic approach for patients with PIDP.

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.

Comparison between botulinum toxin type A injection on masseter muscle only and additional injection on anterior belly of digastric muscle in sleep bruxism patients: A clinical trial

OBJECTIVE

This study aims to evaluate the effects on bite force and muscle thickness of the botulinum toxin (BoNT) injection for patients with sleep bruxism (SB) by comparing injections into the masseter muscle only and both the masseter and the anterior belly of the digastric muscle (ABDM) in a clinical trial.

METHODS

Twelve SB patients received BoNT-A injections using US-guided techniques into the masseter muscle only (Group A), while the remaining 12 SB patients received injections into both the masseter and ABDM (Group B). Bite force and muscle thickness were measured before injection, as well as 1 and 2 months after injection.

RESULTS

The bite force and masseter muscle thickness decreased in both Group A and Group B before injection, and at 1 and 2 months after injection. However, there was no significant difference (p > .05, repeated measures analysis of variance) between the two groups, and there was also no significant difference in ABDM thickness (p > .05, repeated measures analysis of variance).

CONCLUSION

This study is the first to assess the short-term effects of BoNT injected into ABDM for SB control. Results show no influence on SB reduction, suggesting the need for further research on BoNT's effectiveness in controlling intense ABDM contractions during sleep and assessing suprahyoid muscle potential impact on rhythmic masticatory muscle activity occurrence.

Clinical benefit of botulinum toxin for treatment of persistent TMD-related myofascial pain: A randomized, placebo-controlled, cross-over trial

BACKGROUND

Injections of botulinum toxin type A (BoNT-A) have been proposed as an additional treatment modality for patients suffering chronic temporomandibular disorder (TMD)-related myofascial pain (MFP). BoNT-A impairs muscle function, along with its analgesic effect, and a minimal effective dose should be used. The objective of this randomized placebo-controlled crossover study was to evaluate the clinical benefit of a moderate dose (50 U) of BoNT-A.

METHODS

Sixty-six subjects were randomized into two groups, one which received BoNT-A first and a second which received a saline solution (SS) first. Follow-ups were performed 2, 11, and 16 weeks after the injections. Diagnostic criteria for temporomandibular disorders (DC/TMD) diagnostic algorithms were used to evaluate characteristic pain intensity (CPI) and pain-related disability based on the Graded Chronic Pain Scale (GCPS). Electromyographic and bite force were also evaluated.

RESULTS

The within-group analysis showed a significant improvement in pain intensity and pain-related disability after BoNT-A (p < 0.001, p = 0.005, p = 0.011) and SS (p = 0.003, p = 0.005, p = 0.046) injections up to week 16. The between-group analysis of pain-related variables revealed no differences between groups at any time. Nonetheless, BoNT-A, but not SS, caused a significant decline in muscle performance. The number needed to treat (NNT) regarding a clinically significant pain reduction (≥30%) was 6.3, 57.0, and 19.0 at 2, 11, and 16-week follow-ups favoring BoNT-A.

CONCLUSIONS

Injections of 50 U of BoNT-A might improve MFP symptoms, but the specific effect of the drug on pain compared to the placebo is not obvious.

Is low dose of botulinum toxin effective in controlling chronic pain in sleep bruxism, awake bruxism, and temporomandibular disorder?

OBJECTIVE

To evaluate the effects of low doses of botulinum toxin type A (BoNT-A) to control pain in patients with sleep bruxism (SB), awake bruxism (AB), and temporomandibular disorder (TMD) during 180 days.

METHODS

Overall sample of thirty-five patients with chronic pain related to TMD, SB, and AB received a single dose of 20 U of BoNT-A in masseter and temporalis muscles. The pain was assessed with a visual analog scale (VAS) before and after 15, 30, 60, 90, and 180 days of the application.

RESULTS

The three clinical conditions experienced decrease in pain after 15 days of treatment (p < 0.0001); the maximum pain relief persisted for up to 90 days after BoNT-A application in patients with SB and AB and 15 days for patients with TMD.

CONCLUSION

A low dose of BoNT-A may be effective for controlling chronic pain related to SB and AB, but TMD pain reduction was short-lived.

Use of botulinum neurotoxin Type A in the management of primary bruxism in adults: An updated systematic review

STATEMENT OF PROBLEM

The psycho-emotional effects caused by the coronavirus pandemic have increased the intensity and number of cases of bruxism, for which no treatment has been considered fully effective. Botulinum neurotoxin Type A (BoNT-A) has shown positive results as an adjunct treatment of primary bruxism; however, this off-label use does not have an established protocol, and further studies are required.

PURPOSE

The purpose of this updated systematic review was to analyze the clinical outcomes of BoNT-A in the management of primary bruxism in adults.

MATERIAL AND METHODS

The review was registered under the International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42021287653, without funding. PubMed, Web of Science, Scopus, LILACS, Cochrane Library, and Open Grey Literature databases were searched by using the Mendeley Desktop software program without language restrictions up to June 6, 2021. The risk of bias of the selected randomized clinical trials was assessed by using RoB2, and the level of evidence was measured by 2 independent researchers using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool.

RESULTS

A total of 741 references were obtained from the 6 databases in this systematic review. The 11 randomized clinical trials selected achieved a reduction in bruxism symptoms by injecting BoNT-A into 211 participants with different protocols. The heterogeneity of the included studies did not permit a meta-analysis.

CONCLUSIONS

All the evaluated studies supported the effectiveness of BoNT-A injections in reducing bruxism symptoms. The reduction of symptoms can be obtained with doses lower than 25U applied exclusively in the masseter muscles.

Effects of botulinum toxin type A in patients with painful temporomandibular joint disorders: a systematic review and meta-analysis

Objective

To assess the therapeutic efficacy of botulinum toxin type A (BTX-A) for managing myofascial pain related to temporomandibular disorders (TMDs).

Methods

This study was conducted according to the PRISMA 2020 statement guidelines. The PubMed, Embase, and Cochrane Library databases were searched. Only randomized controlled trials were included. The primary outcome was a pain score on the visual analog scale, and the secondary outcomes were maximum mouth opening and adverse effects. The Cochrane risk of bias tool was used to assess risk bias. A meta-analysis of studies with the same interventions, controls, assessment methods, and follow-up durations was performed.

Results

A total of 519 studies were retrieved, of which 20 randomized controlled trials were included in the qualitative analysis and six were included in the meta-analysis. The results showed that, compared with placebo, BTX-A injection was more effective at relieving myofascial pain, and its effect was similar to that of conventional methods. However, there was no difference in maximum mouth opening between the two groups. After the study assessment with the RoB 2.0 tool, six studies showed a low risk of bias, 13 studies showed some concerns regarding the reported results, and only one study showed a high risk of bias. Adverse effects of BTX-A injection were observed in four studies.

Conclusions

In conclusion, BTX-A is effective at relieving pain in TMD patients but does not improve mouth opening. To minimize adverse effects, we recommend a low dose of BTX-A for TMD patients who do not experience complete pain relief from conservative treatments.

Efficacy and Safety of Botulinum Toxin in the Management of Temporomandibular Symptoms Associated with Sleep Bruxism: A Systematic Review

Sleep bruxism, characterized by involuntary grinding or clenching of teeth during sleep, poses significant challenges in management due to its potential to induce temporomandibular joint disorders (TMDs) and other related symptoms. The use of Botulinum toxin Type A (BoNT-A), also known as Botox®, has been proposed as a therapeutic intervention. This systematic review aims to evaluate the efficacy and safety of BoNT-A in the management of sleep bruxism, focusing on pain reduction, improvement in jaw function, reduction in bruxism episodes, and the incidence of adverse effects. An exhaustive search was conducted across PubMed, Scopus, and Embase databases up to January 2024, adhering to the PRISMA guidelines. Nine randomized clinical trials (RCTs) involving 137 participants were analyzed for efficacy and safety outcomes. The studies demonstrated a significant reduction in mean pain scores (from 7.1 to 0.2 at 6 months and 1 year post-treatment in one study) and a notable decrease in the number of bruxism events (from 4.97/h to 1.70/h in the BoNT-A group in another study). Additionally, improvements were observed in jaw stiffness and total sleep time. Adverse effects varied but were generally mild and transient, including injection site pain in 20% of participants in one study and cosmetic changes in smile in 15.4% of patients in another. These findings suggest that BoNT-A injections may provide some benefits for treating nocturnal bruxism, potentially reducing TMD symptoms like pain and improving jaw function. However, these findings are preliminary due to variability in study designs and the absence of detailed statistical analysis.

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.

The use of botulinum toxin for grinding in patients with Rett syndrome-Case report

AIMS

Rett syndrome (RTT) is a neurodevelopmental disorder caused by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene. It is characterized by profound and severe motor disability. Patients with RTT grind their teeth, causing damage to their permanent teeth. This article aims to describe the case of an 8-year-old child with RTT and the methods of botulinum toxin-based treatment for teeth grinding.

METHODS AND RESULTS

Surface electromyography (sEMG) was used to monitor the effects of treatment. The masseter and temporal muscles, responsible for the elevation of the mandible, were injected with botulinum toxin. The results of the sEMG examination performed 1 week, 1 month and 4 months after toxin administration were compared to the sEMG conducted before treatment. The research demonstrates a significant reduction in both grinding frequency and tension of the masseter and temporal muscles.

CONCLUSION

Possible adverse effects after chronic use of botulinum toxin were discussed. The article also emphasizes the need for masticatory muscle rehabilitation during botulinum toxin therapy. However, it is necessary to repeat this procedure on a larger group of children with RTT to establish our efforts' efficacy.

Can botulinum toxin injection alleviate the pain of bruxism? A Bayesian network analysis and a single-arm analysis

Background/purpose

There is inconsistent evidence regarding whether the botulinum toxin A (BTA) injection can relieve pain caused by bruxism. This study aimed to estimate the efficiency of BTA injection in relieving pain caused by bruxism at different follow-up periods.

Materials and methods

Five electronic databases were searched from 2005 to 2022 using search terms related to botulinum toxin and bruxism. Only controlled clinical trials were included. Two investigators reviewed each article and discussed any disagreements until a consensus was reached. Pain outcomes as evaluated by the visual analogue scale (VAS) were subjected to single-arm and Bayesian network meta-analyses. Pooling data were measured by a random-effects model.

Results

Eleven studies with a total of 365 bruxism patients were included. According to the single-arm analyses of the pooled data, the reduction in bruxism-related pain after BTA injection measured 4.06 points (95% CI = 3.37 to 4.75) on the VAS, and the pain relief was significant in the first 6 months after treatment (P < 0.01). According to the Bayesian analysis, BTA also resulted in significantly greater pain relief than oral splinting (mean difference (MD), -1.5; 95% credible interval (CrI) = -2.7 to -0.19) or saline injection (MD, -3.3; 95% CrI = -6.2 to -0.32).

Conclusion

BTA significantly relieves the pain of bruxism for 6 months after injection, and its therapeutic efficacy was higher than that of oral splinting. Nevertheless, further long-term follow-up randomized controlled trials comparing BTA with other management or drugs are warranted.

The effectiveness of botulinum toxin for temporomandibular disorders: A systematic review and meta-analysis

OBJECTIVE

The current body of research on utilizing botulinum toxin (BTX) to manage temporomandibular disorders (TMDs) has not yet yielded definitive conclusions. The primary objective of this study was to determine the effectiveness of BTX in pain reduction for TMDs compared to placebo and other treatments. The secondary outcomes evaluated were adverse events, maximum mouth opening, bruxism events, and maximum occlusal force.

MATERIALS AND METHODS

A literature search was performed on PubMed, Dimension Publication, Scopus, and Google Scholar. The RoB 2 tool was used for quality assessment. The mean differences in pain scores were estimated to measure the effect of BTX on pain reduction. For adverse events, the risk ratio for the incidence of side effects was calculated.

RESULTS

Two hundred and sixty non-duplicate articles were identified; however, only 14 RCTS were included in this review. The total study population included 395 patients. The overall risk of bias showed a low to moderate quality of evidence. Results from 6 studies were reported only narratively; four studies were used for meta-analysis on pain reduction, and five were used for meta-analysis on adverse events. The control used in the meta-analysis was placebo injections. Results of the meta-analysis for pain reduction were statistically insignificant for the BTX group with mean differences at MD = -1.71 (95% CI, -2.87 to -0.5) at one month, -1.53 (95% CI, -2.80 to -0.27) at three months, and -1.33 (95% CI, -2.74 to 0.77) at six months. This showed that BTX treatment was not significantly better than placebo for a reduction in pain scores at 1, 3, and 6 months. Regarding safety, the placebo group showed a relative risk of 1.34 (95%CI, 0.48-6.78) and 1.17 (95%CI, 0.54-3.88) at 1 and 3 months respectively. However, the risks were not statistically significant. There was also no difference in the effectiveness of BTX compared to placebo and other treatments for maximum mouth opening, bruxism events, and maximum occlusal force.

CONCLUSION

BTX was not associated with better outcomes in terms of pain reduction, adverse events, maximum mouth opening, bruxism events, and maximum occlusal force. More high-quality RCTs are needed to better understand this topic.

Does botulinum toxin have any role in the management of chronic pain associated with bruxism?

OBJECTIVE

To determine the efficacy of injectable botulinum toxin (BTA) in the management of pain associated with nocturnal bruxism.

METHODS

The study subjects consisted of 40 male and female volunteers who complained of chronic pain in the masseter muscles bilaterally due to bruxism. Twenty units of BTA were injected bilaterally into the masseter muscles. Clinical parameters of pain at rest and chewing were assessed at baseline, 2, 4, 8, 12, 16, 18, and 24 weeks using the visual pain scale (VPS).

RESULTS

The study included 24 females and 16 males aged 21 to 52 years (mean 33.9 ± 31.0). The mean VPS score on the first day was 5.75 (SD 1.9), significantly decreasing after two weeks to 0.44 (SD 0.727). The mean difference of VPS from 8 weeks up to 24 weeks gradually increase from 0.69 at 8 weeks to 2.00 at 24 weeks.

CONCLUSION

This study provides evidence that BTA could reduce the pain of nocturnal bruxism in affected patients.

Botulinum toxin-A effects on pain, somatosensory and psychosocial features of patients with refractory masticatory myofascial pain: a randomized double-blind clinical trial

The antinociceptive effect of BoNT-A have been well documented in animal studies; however, results of few but well-designed randomized placebo-controlled clinical trials about BoNT-A efficacy in masticatory myofascial pain (MFP) are inconsistent. Therefore, the present randomized, double-blind, placebo-controlled clinical trial evaluated the efficacy of BoNT-A in patients with refractory MFP. Twenty-eight patients with pain reduction of less than 30% despite conservative treatment and with an average pain intensity of > 50 mm on the visual analogue scale (VAS) participated. Patients were randomly assigned to receive a total of 80 U of BoNT-A or saline solution (SS) injected into the masseter and anterior temporalis muscles. Pain intensity (VAS), quantitative sensory testing (QST), conditioned pain modulation (CPM), and psychosocial status were examined. Follow-up was performed at 1 and 6 months. For repeated-measure comparisons between evaluation times, Friedman test with Bonferroni correction was used for pain and somatosensory variables and the Wilcoxon test for the psychosocial variables. The Mann-Whitney test was used for all comparisons between groups. The BoNT-A group had a significant decrease in pain intensity at follow-ups compared with the SS group (p < 0.001). QST assessment revealed higher pressure pain threshold values in the masseter muscle for BoNT-A group compared to SS (p < 0.03) at all follow-ups. No differences were found for mechanical pain threshold and wind-up ratio values (p > 0.05) in the entire study. The BoNT-A group presented the most efficient CPM effect (p < 0.03) only at the 1 month follow-up in the masseter muscle. There was a significant time effect for BoNT-A in all psychosocial variables (p < 0.05) and a drug effect in the Central Sensitization Inventory (p < 0.01), Pittsburgh Sleep Quality Index (p < 0.004), and Healthy Survey 36 (p < 0.05) at 6 months follow-up. The study demonstrates that a single injection-session of BoNT-A has positive effects on the hall pain spectrum of patients with refractory masticatory myofascial pain.

Effect of Botulinum Toxin on Masticatory Muscle Pain in Patients with Temporomandibular Disorders: A Randomized, Double-Blind, Placebo-Controlled Pilot Study

This study aimed to evaluate the efficacy of botulinum toxin type A (BoNT/A) in patients with temporomandibular disorders (TMDs) associated with masticatory muscle pain (MMP) and headaches. This randomized, double-blind, placebo-controlled pilot study is the first clinical trial to evaluate both disorders simultaneously. Twenty-one patients with myogenous TMD were randomly assigned to two groups. The experimental and control groups received injections of either BoNT/A or saline into the sites showing tenderness after palpation of a total of 16 muscle areas, including each masseter, a temporalis, splenius capitis, sternocleidomastoid, and trapezius muscle. During each visit, the clinical effects, based on the intensity of orofacial pain (OVAS), headache (HVAS), number of tender points (TPs), maximum mouth opening (MMO), and headache frequency (HF), were evaluated at four time points, namely, pre-injection and 4, 8, and 12 weeks after the injection, in both groups. Friedman and Mann-Whitney tests were used for the analyses. In the experimental group, the reductions in OVAS, TP, HVAS, and HF showed significant differences over time, excluding MMO, whereas there was no significant difference in any of the variables in the control group. In addition, the decline in TPs was significantly different between the experimental and control groups at all time points, especially after 4 and 12 weeks, compared to that during pre-injection. In conclusion, treatment with BoNT/A was relatively effective for masticatory muscle pain caused by TMDs and headache compared to the saline placebo.

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.

Quality of information on Instagram about masseter botox injection for bruxism

STATEMENT OF PROBLEM

Nowadays, masseter botulinum toxin injections are frequently used to treat bruxism. People first search for social media resources for their health-related problems. However, the quality of the information on Instagram about masseter botox injection for bruxism is unknown.

PURPOSE

The aim of this study was to evaluate the quality ant content of the Instagram posts shared publicly about masseter botox. The hashtag #masseterbotox was searched on Instagram.

MATERIALS AND METHODS

A total of 1000 posts were scanned. Unrelated posts were excluded from the study. The video posts were evaluated by using Global Quality Scale (GQS) and reliability of information toolkits.

RESULTS

One-hundred seventy-nine photograph and 65 video posts that met the criteria were analyzed. Most of the posts were posted by doctors and healthcare professionals (151 posts), followed by clinics (87 posts) and patients (6 posts). The information reliability scores of Instagram video posts about #masseterbotox were found to be very low (1.34±1.28). Number of views, reliability of information and GQS scores were not statistically significant between groups according to the source of the video posts (p>.05). GQS scores were higher in experience videos than information and advertisement videos (p<.05).

CONCLUSIONS

Clinicians should warn their patients about the reliability of information on Instagram and should guide them to the right social media resources.

CLINICAL IMPLICATIONS

Dental professionals should direct their patients about masseter botox injections to the right resources on social media platforms.

Effectiveness of Botulinum Toxin Injection on Bruxism: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The present study compiled evidence on the efficacy of botulinum toxin A (BTX) for management of bruxism.

METHODS

A literature review that included randomized control, cohort, as well as observational studies published between January 2000 and November 2022 was conducted. All studies related to BTX injections administered into the masseters of patients with bruxism were included. Primary outcomes were measured by performing a meta-analysis of changes in maximal biting forces and pain severity and meta-regression of the effects of the BTX dose.

RESULTS

Ten studies were included for quantitative analysis. The analysis of the maximal biting force after BTX injections demonstrated a significant reduction at 1 month or less compared with both oral splints (P < 0.000001) and saline injections (P = 0.01). BTX continued to outperform oral splinting (P = 0.001) and saline placebos (P = 0.03) at 3 months. Between 3 and 6 months, a significantly higher maximal biting strength was observed in the BTX group than the oral splinting group (P < 0.00001). No significant differences in the maximal biting force were observed between the BTX and saline placebo groups (P = 0.50). A similar trend was observed in the analysis of pain reduction after botulinum treatment. Additionally, for every unit increase in the BTX dose, pain severity decreased by 0.0831 points (P = 0.0011).

CONCLUSION

BTX is effective in reducing biting strength and pain severity. BTX effects are evident at less than 4 weeks, peak between 5 and 8 weeks, and last for up to 24 weeks. Higher BTX doses result in greater improvement in pain. Although BTX benefits manifest earlier, they gradually diminish, and oral splinting exerts a more enduring effect, especially after 9-12 weeks. BTX injections into masseters are recommended as management options for bruxers, especially for those having difficulties complying with wearing oral splints or those seeking earlier symptom relief. However, future studies should determine BTX effects beyond 24 weeks and after repetitive injections and how bruxers of different ages or genders respond to treatment.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Evaluation of the Relationship between Changes in Masseter Muscle Thickness and Tooth Clenching Habits of Bruxism Patients Treated with Botulinum Toxin A

Background

Bruxism is defined as recurrent masticatory muscle activity. Although there is not an agreed treatment method for bruxism, the application of botulinum toxin A (BT-A) has become a reliable lately. This study aimed to evaluate the correlation between the changes in masseter muscle thickness and clenching habits in bruxism patients treated with BT-A.

Methods

Twenty-five patients, 23 females and 2 males, diagnosed with possible sleep bruxism were included in the study. The Fonseca Anamnestic Index was applied to the patients to determine their clenching habits and depression levels both before the treatment, and 6 months after it. The masseter muscle thickness was measured using ultrasonography before the treatment and 3 months and 6 months after the treatment. All the patients were injected with a total of 50 U of BT-A, 25 U to each masseter.

Results

A statistically significant decrease in masseter muscle thickness was observed in the ultrasonography 3 and 6 months after the BT-A treatment. There was a statistically significant decrease in the Fonseca scores, in which the teeth clenching habits of the patients were evaluated 6 months after the treatment. Although there was a decrease in the depression levels of the patients 6 months after the treatment, this difference was not statistically significant.

Conclusion

When the results of this study were evaluated, it was seen that the BT-A injections are an effective, safe, and side effect-free method in the treatment of bruxism and masseter hypertrophy.

Effect of botulinum toxin A on pain, bite force, and satisfaction of patients with bruxism: A randomized single-blind clinical trial comparing two protocols

Purpose

The current study aims to evaluate bite force, perception of orofacial pain, and treatment satisfaction of patients with bruxism using two protocols of botulinum toxin A (BTX-A) injections.

Material and Methods

Two groups of patients seeking bruxism treatment and presenting bilateral orofacial pain of muscle origin were randomly created according to BTX-A injection sites: masseter muscle only, bilaterally (3 points in each muscle, 10 U per point), and masseter and temporal muscles (3 points in each masseter muscle and 2 points in each temporal muscle, 10 U per point). The patients were evaluated preoperatively and longitudinally at 15, 90, 120, and 180 days by the use of visual analog scales for pain and treatment satisfaction and a gnathodynamometer for bite force recording.

Results

The final sample included 10 participants in each group. Both groups presented mitigation of pain at 15, 90, 120, and 180 days in comparison with baseline; however, reduction in the posterior bite force was noted only at 15, 90, and 120 days. Quite high treatment satisfaction was reported from both groups at 15, 90, 120, and 180 days. No differences were observed between the groups in all evaluations and study periods.

Conclusion

In general, considering pain relief, reduction in bite force, and treatment satisfaction, both protocols of BTX-A seem to be somewhat equally effective in the short-term management (up to 120 days) of bruxism.

Botulinum toxin in the management of myalgia in temporomandibular disorders: are all injections equal?

Botulinum toxin (BTX) is becoming widely used as an adjunct to conservative management of myalgia-predominant temporomandibular disorders (TMDs) with reports of improved quality of life. There is, however, no consensus on the optimal dosage. Based on previous studies, dose regimens vary between clinicians, and we know of no standard dose protocol for the administration of BTX for the purpose of TMD management. A survey was sent to members of the British Association of Oral and Maxillofacial Surgeons (BAOMS) Temporomandibular Joint Sub-Specialty Interest Group (TMJ SSIG) and an international mailing list of high-volume TMJ surgeons (the TMJ Internetwork) to ascertain variations in dose regimens between different clinicians. The survey found that 41 respondents offered BTX to patients. The masseter muscle group was the most commonly injected site, and the majority of respondents (34/41) used Botox® (Allergan). Brands less commonly used included Dysport® (Ipsen), and Xeomin® (Merz Pharma). Botox® doses varied between 30 and 100 units, whilst Dysport® doses ranged from 50 - 300 units/muscle. The number of injection sites/muscle also varied. This survey demonstrates the wide variation in practice amongst clinicians with respect to BTX administration. To ensure optimal dose and response titration, further studies and evidence-based research are needed to standardise its use for the treatment of TMDs.

Promising minimally invasive treatment modalities for symptomatic temporomandibular joint disc displacement with reduction: a randomized controlled clinical trial

BACKGROUND

Pain and clicking are the primary complaints in patients suffering from temporomandibular joint disc displacement with reduction (DDwR), negatively affecting the patients' quality of life, making the treatment essential. This prospective randomized controlled trial (RCT) was conducted to evaluate the effectiveness of botulinum toxin type-A (BTX-A) and low level laser therapy (LLLT) in comparison to anterior repositioning appliance (ARA) for the treatment of DDwR.

METHODS

A total of 27 patients were randomly allocated to 3 groups; ARA (control group), BTX-A, and LLLT; with 9 patients each. All patients were evaluated before and 3 months after the treatment using a visual analogue scale (VAS) and magnetic resonance imaging (MRI).

RESULTS

At 3 months follow-up, all groups showed a significant reduction in pain assessed by VAS (P = 0.007). Measured on MRI, there was a significant improvement in disc position and joint space index (JSI) in BTX-A group (P < 0.001, P = 0.011) and LLLT group (P = 0.002, P = 0.017) in comparison to the control group (P = 0.087, P = 0.066) respectively. As for time of recovery, a statistically significant difference was observed in BTX-A group (P < 0.001) and LLLT (P < 0.001) group in comparison to ARA group, which showed the most prolonged duration for reduction of DDwR symptoms.

CONCLUSION

We concluded that BTX-A and LLLT could be considered effective alternative treatment modalities to ARA regarding reducing joint pain, clicking, and improving disc position in patients with symptomatic DDwR.

TRIAL REGISTRATION

This prospective double-blinded RCT has been registered at ClinicalTrials.gov with identification number: NCT05194488, 18/1/2022.

Are acupuncture and dry needling effective in the management of masticatory muscle pain: A network meta‐analysis of randomised clinical trials

BACKGROUND

Several studies have shown that both acupuncture and dry needling are effective in the treatment of musculoskeletal pains. Therefore, the aim of this network meta-analysis (NMA) was to investigate the treatment outcome of acupuncture and dry-needling for masticatory muscle pain (TMD-M) and to compare with active and inactive placebo.

MATERIAL AND METHOD

An electronic search was performed to identify randomised controlled trials (RCTs) published until September 2019, comparing dry-needling, acupuncture, and inactive as well as active placebo in patients with TMD-M. Outcome variables were post-treatment pain intensity, pressure pain threshold (PPT), and maximum mouth opening (MMO). The quality of evidence was rated according to Cochrane's tool for assessing the risk of bias. Mean difference was used to analyse via frequentist NMA using STATA-software.

RESULTS

Both NMA and direct pairwise meta-analysis have shown that there was no difference between active treatment with either acupuncture or dry-needling when compared to active and inactive placebo in patients with TMD-M with respect to pain intensity, and PPT (p > .05). However, there was a significant increase in MMO following dry-needling when compared to the placebo (very low-quality evidence).

CONCLUSION

Despite the short-term positive effect of MMO by dry-needling, this NMA could not show any pain-reducing effect in patients with TMD-M by acupuncture or dry-needling when compared to an active or inactive placebo. Taken together, this NMA indicates that it is the placebo effect that accounts for the majority of the treatment effect of TMD-M, rather than a real therapeutic effect of acupuncture/dry-needling.

Efficacy of botulinum toxin type a in the targeted treatment of sleep bruxism: a double-blind, randomised, placebo-controlled, cross-over study

Background

Intramuscular injections of botulinum toxin A (BTX-A) have been used in the treatment of sleep bruxism (SB) however controlled trials are limited and the optimal injection strategy and dose is not known.

Methods

This double-blind, randomised, placebo-controlled, cross-over study evaluated the efficacy and safety of BTX-A in participants with SB. Average bruxism events per hour of sleep (Bruxism Index, BI) was calculated using surface electromyography. Participants with BI >5 were included and randomised by order of injection (active or placebo with the opposite 20 weeks later) and into one of three differing treatment groups: bilateral masseter (60 units(U)), bilateral masseter and temporalis (90U) and bilateral masseter, temporalis and medial pterygoid muscles (120U). Change in BI and subjective measures of headache, pain, and bruxism at 4 and 12 weeks was calculated following intervention, and differences between treatment groups analysed.

Results

41 participants were recruited, 35 randomised and data from 22 participants (14 female) were analysed. BI was significantly lower at 4 weeks after active treatment when compared with placebo (mean=−1.66, p=0.003), not sustained at 12 weeks. The difference was greater with higher doses injected and among those with greater baseline BI. There was no difference in subjective measures at any time point. Five participants injected had mild, transient side effects.

Discussion

Targeted BTX-A injection is a safe and effective treatment for SB. A greater benefit may be achieved by administering BTX-A into more muscles and at higher total doses and among those with higher baseline BI.

Trial registration number

ACTRN12618001430224.

Efficacy of Botulinum Toxin Type-A I in the Improvement of Mandibular Motion and Muscle Sensibility in Myofascial Pain TMD Subjects: A Randomized Controlled Trial

This study assessed the effects of botulinum toxin type A (BoNT-A) in mandibular range of motion and muscle tenderness to palpation in persistent myofascial pain (MFP) patients (ReBEC RBR-2d4vvv). Eighty consecutive female subjects with persistent MFP, were randomly divided into four groups (n = 20): three BoNT-A groups with different doses and a saline solution group (placebo control group). Treatments were injected bilaterally in the masseter and anterior temporalis muscle in a single session. Clinical measurements of mandibular movements included: pain-free opening, maximum unassisted and assisted opening, and right and left lateral excursions. Palpation tests were performed bilaterally in the masseter and temporalis muscle. Follow-up occurred 28 and 180 days after treatment. For the statistical analysis the Mann–Whitney U-test with Bonferroni correction was used for groups comparisons. Regardless of dose, all parameters of mandibular range of motion significantly improved after 180 days in all BoNT-A groups, compared with the control group. Palpation pain over the masseter and temporalis muscles were significantly reduced in all BoNT-A groups regardless of dose, compared with the control group, after 28 and 180 days of treatment. Independent of doses, BoNT-A improved mandibular range of motion and muscle tenderness to palpation in persistent MFP patients.

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.

Botulinum Toxin Therapy for Oromandibular Dystonia and Other Movement Disorders in the Stomatognathic System

Various movement disorders, such as oromandibular dystonia, oral dyskinesia, bruxism, functional (psychogenic) movement disorder, and tremors, exist in the stomatognathic system. Most patients experiencing involuntary movements due to these disorders visit dentists or oral surgeons, who may be the first healthcare providers. However, differential diagnoses require neurological and dental knowledge. This study aimed to review scientific advances in botulinum toxin therapy for these conditions. The results indicated that botulinum toxin injection is effective and safe, with few side effects in most cases when properly administered by an experienced clinician. The diagnosis and treatment of movement disorders in the stomatognathic system require both neurological and dental or oral surgical knowledge and skills, and well-designed multicenter trials with a multidisciplinary team approach must be necessary to ensure accurate diagnosis and proper treatment.

Efficacy of botulinum-A for nocturnal bruxism pain and the occurrence of bruxism events: a meta-analysis and systematic review

The purpose of this study was to explore the treatment efficacy of botulinum-A (BTX-A) in nocturnal bruxism. Five electronic databases (PubMed, Web of Science, Cochrane, Embase and Clinical Trials) were searched to identify related randomised controlled trials up to September 1, 2020. Five evaluation indices were extracted, namely, the pain at rest and at chewing (PR and PC), the number of bruxism events (NBE) and the self-assessment by patients (SA), to assess the treatment efficacy of BTX-A in bruxism. All data analyses were conducted using Review Manager (Version 5.3; The Cochrane Collaboration, London, United Kingdom). Six studies were included in this review. The sample was composed of 148 participants. Compared with the placebo group, the BTX-A group showed the significantly improved the PR index scores (MD, 1.16 cm; 95%CI, 0.65 to 1.67 cm; p < 0.00001), slightly improved the PC index scores (SMD, 0.25; 95%CI -0.14 to 0.64; p = 0.21), and the NBEs were significantly decreased in the before-injection group compared with that in the after-injection group (MD, 1.72; 95%CI, 0.60 to 2.85; p = 0.003). The results of this study suggest that BTX-A possesses significant therapeutic efficiency for the relief of pain and events of bruxism. However, whether the events of bruxism would recur or rebound after botulinum toxin injection needs more follow-up clinical evidence.

Temporomandibular Disorder Patients Benefit From Intramuscular Botulinum Toxin Type a Injections

PURPOSE

The aim of this study was to analyze the clinical outcome of the use of botulinum toxin type A (BTX) intramuscular injections to the head and neck, particularly the masticatory muscles of patients with temporomandibular disorder (TMD).

METHODS

The medical records of all patients who had received intramuscular BTX injections between 2005 and 2018 at Päijät-Häme Central Hospital, Lahti, Finland were analyzed retrospectively. Gender, age, previous medical history, number of injections, injection areas, and therapeutic results were collected and analyzed. The outcome was divided into three categories based on the patients' subjective reports: not beneficial, beneficial, and highly beneficial.

RESULTS

A total of 68 patients had received intramuscular BTX injections in our unit for TMD symptoms. Clinical effectiveness could be analyzed from 63 patients. Overall, 87% of them reported favorable outcomes. 8 (13%) reported BTX injections as not beneficial, 15 (24%) as beneficial, and 40 patients (63%) as highly beneficial.Most patients had already received conventional treatment with an occlusal splint (93%) combined with pain medication (60%) in the primary care units before they were referred to our hospital.There were 59 (83%) female patients, and they responded better to BTX therapy than the male patients: 91% versus 57% (P value = 0.04). Average age at the first BTX injection visit was 44.6 years (range 17.8-77.2). Most commonly (65%), BTX was divided bilaterally to the masseter and temporalis muscles.

CONCLUSIONS

BTX injections had good therapeutic outcomes for our TMD patients. However, most patients require multiple injection visits.

A Novel Injection Technique to the Lateral Pterygoid Muscle for Temporomandibular Disorders: A Cadaveric Study

BACKGROUND

Lateral pterygoid muscle activity is associated with the pathological mechanisms of some temporomandibular disorders. The authors aimed to define and demonstrate a novel, practical, and safe technique for botulinum toxin type A injection to the lateral pterygoid muscle based on their findings. Their secondary aims were to standardize the injection pattern according to the variations of the lateral pterygoid muscle and its surrounding anatomical structures, and to establish its advantages over intraoral injection.

METHODS

Twenty cadaver heads were dissected. The lateral pterygoid muscle and its surrounding structures were investigated for anatomical variations. Based on these findings, a standardized extraoral injection protocol was defined and compared with the intraoral technique for accuracy and safety.

RESULTS

The average depth of the lateral pterygoid plate from the skin surface was 49.9 ± 2.2 mm, and the mean width of the lateral pterygoid plate was 10.5 ± 3.9 mm. The extraoral injection approach based on the location of the maxillary tuberosity, tragus, and lateral pterygoid plate was consistent in all dissections for the accuracy of the intramuscular injection. In the intraoral approach, standardization of the entry point of the needle through the oral mucosa is difficult, which makes adjustment of the depth of the injection challenging while increasing the risk of neurovascular injury.

CONCLUSIONS

The clinical significance of the lateral pterygoid muscle makes it worthwhile to implement minimally invasive treatments before considering more invasive options. The authors define a safe, accurate, and reliable approach with ease of administration in patients with temporomandibular disorders.

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.

Effects of Botulinum Toxin Type A on Pain among Trigeminal Neuralgia, Myofascial Temporomandibular Disorders, and Oromandibular Dystonia

The differences in analgesic effects of botulinum toxin type A were compared in 28 patients with trigeminal neuralgia, 53 patients with myofascial temporomandibular disorders, and 89 patients with the jaw closing oromandibular dystonia. The patients were treated by injection of botulinum toxin type A into the masseter, temporalis, medial pterygoid, and other muscles based on the symptoms of each patient. The pain severity was evaluated using the visual analog scale, pain frequency, and pain scale of the oromandibular dystonia rating scale. Botulinum toxin injection was performed 1068 times in all patients without significant adverse effects. The visual analog, pain frequency, and pain scales at baseline were reduced (p < 0.001) after two, four, eight, and 12 weeks after the first botulinum toxin therapy and at the endpoint. The effects differed significantly (p < 0.001) among the groups (repeated-measures analysis of variance). The mean improvement (0%, no effect; 100%, complete recovery) at the endpoint was 86.8% for trigeminal neuralgia, 80.8% for myofascial pain, and 75.4% for oromandibular dystonia. Injection of the botulinum toxin can be a highly effective and safe method to treat trigeminal neuralgia, myofascial pain, and oromandibular dystonia.

Identification of Type H Vessels in Mice Mandibular Condyle

Type H vessel is a specific vessel subtype that is strongly positive for CD31 and endomucin (CD31^hiEmcn^hi). It has already been identified that it can tightly regulate the coupling of angiogenesis and osteogenesis in the long bone of mice and human beings. The long bone is formed through endochondral ossification, which is the same type of process happening in mandibular condyle. Although the ossification of long bone and mandibular condyle has the same developmental process, the existence of type H vessels in the mouse condyle remains unclear. To address this, we identified that abundant type H vessels existed in the subchondral bone of the mouse condylar head and endosteum of the mouse condylar neck. Meanwhile, immunofluorescence imaging of the condyles in different ages of male C57BL/6J mice demonstrated that type H vessels decreased while aging. Furthermore, we validated a positive correlation between type H vessels and Osterix⁺ osteoprogenitors in the condyle induced by mandibular advancement. Mechanistically, we confirmed that deferoxamine mesylate, which promoted the proliferation of type H endothelial cells by activating hypoxia-inducible factor 1α (HIF-1α) signaling pathways, largely prevented the osteopenia in the condyle induced by botulinum toxin type A. Collectively, these results demonstrate that in the mouse condyle, type H vessels in areas of high function positively correlate with bone formation. In addition, we show a novel influence of HIF-1α signaling on osteogenesis via an increase in type H vessels. In conclusion, promoting angiogenesis of type H vessels is a promising strategy for the therapeutic improvement of osteogenesis in mandibular condyle.

Bruxism: Best Evidence Consensus Statement

PURPOSE

The purpose of this Best Evidence Consensus Statement is to report on the prevalence, potential causes or association, treatment and cure of bruxism.

MATERIALS AND METHODS

A literature search limited to Clinical Trials, Randomized Controlled Trials, Systematic Reviews and Meta Analyses, with the key words bruxism, and prevalence identified 22 references, bruxism and causation 21, bruxism, and treatment 117, and bruxism and cure none.

RESULTS

Prevalence received 5 references which were relevant to the question researched. Causation received 11 relevant references, treatment 34 relevant references and cure none. Eighteen additional references were culled from the reference lists in the aforementioned articles.

CONCLUSIONS

Due to variations in demographics and the dependence on anamnestic data, the true prevalence of bruxism in any specific population is unknown. There is moderate evidence that psychosocial factors such as stress, mood, distress, nervousness, and feeling blue are associated with sleep bruxism (SB) as well as caffeine, alcohol, and smoking. There is no consensus on what symptoms of SB or awake bruxism (AB) should be treated. There is some evidence that occlusal devices and bio feedback therapies can be utilized in SB treatment. There is conflicting evidence in the use of Botulinum toxin A and no compelling evidence for the use of drug therapy to treat SB. There is not an established cure for bruxism. The clinician is best served in using caution in the dental rehabilitation of patients with severe occlusal wear.

Alternative Clinical Indications of Botulinum Toxin

Botulinum toxin type A (BoNTA) is a powerful neurotoxin that inhibits acetylcholine release from presynaptic vesicles. The potency and safety profile of BoNTA grant the toxin vast therapeutic potential. It has been used off-label for a variety of dermatologic conditions. This review aims to analyze published literature regarding the benefits and risks of the off-label use of BoNTA beyond facial lines, including eccrine hidrocystomas, enlarged pores, keloids and hypertrophic scars, hidradenitis suppurativa, hyperhidrosis, masseter muscle hypertrophy, and salivary gland hypertrophy, among others. A MEDLINE search from January 2000 to December 2019 was conducted on the off-label uses of botulinum toxin in dermatology.

Efficacy of botulinum toxin in the management of temporomandibular myofascial pain and sleep bruxism

Objectives

This study sought to evaluate the efficacy of injecting botulinum toxin into the masseter and temporal muscles in patients with temporomandibular myofascial pain and sleep bruxism.

Materials and Methods

The study was conducted based on a clinical record review of 44 patients (36 females and eight males; mean age, 35.70±12.66 years). Patients who underwent the injection of botulinum toxin into the masseter and temporal muscles for the management of temporomandibular myofascial pain and sleep bruxism were included in the study. Patients were diagnosed based on the Diagnostic Criteria for Temporomandibular Disorders. Sleep bruxism was diagnosed according to the criteria defined by the American Academy of Sleep Medicine. The values of the visual analogue scale (VAS) and range of jaw motion, including unassisted maximum mouth opening (MMO), protrusion, and right and left laterotrusion, were observed preoperatively and postoperatively at one-, three-, and six-month follow-up visits.

Results

MMO, movements of the right and the left laterotrusion, and protrusion increased significantly (P<0.05), while VAS ratings decreased significantly at the three follow-up points relative to baseline values (P<0.05).

Conclusion

Botulinum toxin is an effective treatment for patients with temporomandibular myofascial pain and sleep bruxism.

The Current Trend in Management of Bruxism and Chronic Pain: An Overview of Systematic Reviews

Bruxism, specifically sleep bruxism (SB), is a worldwide discussed topic in the literature; however, there is insufficient evidence to define and support a standard approach for the treatment of SB. The purpose of this overview was to map the evidence from systematic reviews (SR), examining the effects of interventions to improve chronic pain related to bruxism. The methodological quality of SRs was assessed using the AMSTAR-2 tool. We conducted a comprehensive literature search in April 2020, in the following databases: Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, LILACS, BBO, and Epistemonikos. Nine SRs with critically low to high methodological quality were included. Considering the main findings, botulinum toxin type A (BTX-A) showed a significant pain and sleep bruxism frequency reduction when compared to placebo or conventional treatment (behavioral therapy, occlusal splints, and drugs), after 6 and 12 months. Occlusal splints combined to muscle massage showed some benefit in pain reduction. There was no difference in pain and bruxism frequency between biofeedback therapy and an inactive control group. Regarding drug therapy, there is no difference when amitriptyline, bromocriptine, clonidine, propranolol, and levodopa were compared to placebo. In conclusion, there is some evidence to support the use of occlusal splints plus massage, and BTX-A to reduce chronic pain related to SB. No evidence was provided to support the recommendation of biofeedback therapy and drug therapy. There is still a need for more methodologically rigorous randomized clinical trials (RCT) to be conducted on the efficacy and safety of different therapies for SB.

Ultrasound Imaging of Injections in Masseter Muscle without Contrast Agent Using Strain Elastography and a Novel B-Mode Spatiotemporal Filter

Botulinum toxin type A (BTX-A) injections in masseter muscle can alleviate muscle tightness and aching pain caused by idiopathic masticatory myalgia, a subform of the myofascial pain syndrome. Yet the injection procedure (number, amount) is currently empirical. In this ex vivo study, we determined the feasibility of using contrast-free ultrasound imaging to visualize the short-term injectate propagation. Ultrasound annotations of BTX-A injectate spread in N = 12 porcine masseter muscles were compared with the histopathology of the excised masseter. BTX-A presence was automatically detected in the ultrasound cine by: compensating tissue motion and deformation during injection with a novel spatiotemporal filtering (SF) algorithm, and by imaging tissue swelling strains with strain elastography (SE). BTX-A injectate introduced 6.5% (standard deviation = 5.0%) echogenicity contrast and 13.9% (standard deviation = 3.7%) tissue swelling strain. Muscle fasciae were a border for BTX-A distribution. The SF algorithm achieved significantly higher noise rejection (contrast-to-noise ratio = 4.63) than SE (2.56, p = 0.01), and state-of-the-art 2-D digital image correlation (1.81, p < 0.001) and direct image subtraction (1.29, p < 0.001) methods. Histopathology agreed well with ultrasound (Dice coefficient = 0.48), with deviations mainly explained by the three-dimensional inhomogeneous distribution of BTX-A. Preliminary in vivo patient results indicated that SF and SE discard artifactual BTX-A detection outside the injection region. The proposed methods contribute to objectivize ultrasound-guided injections, with additional applications, for instance, to monitor injectate spread of local anesthetics.

Effect of multiple injections of botulinum toxin into painful masticatory muscles on bone density in the temporomandibular complex

Background

Adverse effects of masticatory muscle injections of Botulinum Toxin (Btx) have been noted in animal and, less dramatically, human studies.

Objective

Among women treated in multiple community‐based private practices, to compare TMJ bone density and mandibular condylar volume between patients with myofascial TMJD receiving multiple masticatory muscle Btx treatments and similarly diagnosed women not receiving such treatment.

Methods

Cohorts consisted of women whose treatment charts indicated a diagnosis of myofascial TMJD: 35 received at least 2 Btx treatment cycles; 44 received none. Bone density at pre‐specified regions of interest (ROI) was defined by grey scale values from Cone Beam CT, adjusting for a fixed density phantom included in each scan. Mean bone density and mandibular condyle volume were compared between groups. Dose‐response effects were tested within the Btx‐exposed group.

Results

The mean density of primary and secondary ROIs was similar between exposure groups, as was condylar volume. Among Btx‐exposed women, increasing dose of Btx to the temporalis muscle was inversely proportional to the density of the trabecular area of the mandible body. Many Btx‐exposed women received smaller doses of Btx to the masseter muscles than in most TMJD Btx clinical trials.

Conclusion

Masticatory muscle injections of Btx failed to produce clinically significant TMJ bone‐related changes. Should Btx receive regulatory approval for treatment of myofascial TMJD, a phase IV study is recommended to evaluate potential adverse effects of Btx on bone and muscle when administered at higher doses and/or for more treatment cycles.

Clinical outcomes of botulinum toxin type A injections in the management of primary bruxism in adults: A systematic review

STATEMENT OF PROBLEM

Botulinum toxin has been used for various therapeutic and esthetic purposes for nearly 4 decades and has shown positive outcomes in patients with bruxism. However, the effectiveness of botulinum toxin injections as an alternative to traditional therapies in the management of primary bruxism is still unclear.

PURPOSE

The purpose of this systematic review was to analyze the clinical outcomes of the use of botulinum toxin type A injections in the management of primary bruxism in adults.

MATERIAL AND METHODS

Databases such as PubMed, Web of Science, Scopus, LILIACS, Cochrane Library, and Open Grey Literature were searched without language or date restrictions until October 6, 2019. Using Mendeley Desktop software to organize the references, 2 independent researchers selected the published clinical studies (Study type) on the improvement of symptoms (Outcome) in human adults with primary bruxism (Participants/Population) who received botulinum toxin type A injections (Intervention), placebo injections, saline injections, no injections, or other treatments (Comparator(s)/Control) for the management of bruxism.

RESULTS

A total of 601 references were initially obtained from the 6 databases. Six randomized clinical trials and 4 case series were selected and critically appraised according to the Fowkes and Fulton guidelines. Heterogeneity among the studies did not allow for a meta-analysis. All studies supported the efficacy and safety of botulinum toxin injections in reducing the symptoms of primary bruxism.

CONCLUSIONS

Botulinum toxin type A injections are effective in the treatment of the symptoms of primary bruxism in adults. Randomized clinical trials are still needed to establish a protocol for using botulinum toxin as an alternative to traditional therapies in the management of primary bruxism.

Efficacy and Safety of Botulinum Toxin Type A on Persistent Myofascial Pain: A Randomized Clinical Trial

This study assessed the safety and efficacy of three different doses of BoNT-A for persistent myofascial pain (MFP). One hundred female subjects were randomly assigned into five groups (n = 20): oral appliance (OA), saline solution (SS) and three BoNT-A groups with different doses. Pain intensity and pressure pain threshold were evaluated up to 24 weeks after treatment. Adverse effects related to muscle contraction, masticatory performance, muscle thickness and mandibular bone volume were also assessed. Changes over time were compared within and between groups. The “nparLD” package and Wilcoxon signed-rank test were used to analyze the data. BoNT-A reduced pain intensity (p < 0.0001) and increased pressure pain threshold (p < 0.0001) for up to 24 weeks compared to the placebo. No differences were found between BoNT-A and OA at the last follow-up. A transient decline in masticatory performance (p < 0.05) and muscle contraction (p < 0.0001), and a decrease in muscle thickness (p < 0.05) and coronoid and condylar process bone volume (p < 0.05) were found as dose-related adverse effects of BoNT-A. Regardless of the dose, BoNT-A was as effective as OA on MFP. Notwithstanding, due to BoNT-A dose-related adverse effects, we suggest the use of low doses of BoNT-A in MFP patients that do not benefit from conservative treatments.

Botulinum Toxin Therapy for Managing Sleep Bruxism: A Randomized and Placebo-Controlled Trial

The purpose of this study is to evaluate the effects of botulinum toxin type A (BoNT-A) for managing sleep bruxism (SB) in a randomized, placebo-controlled trial. Thirty SB subjects were randomly assigned into two groups evenly. The placebo group received saline injections into each masseter muscle, and the treatment group received BoNT-A injections into each masseter muscle. Audio-video-polysomnographic recordings in the sleep laboratory were made before, at four weeks after, and at 12 weeks after injection. Sleep and SB parameters were scored according to the diagnostic and coding manual of American Academy of Sleep Medicine. The change of sleep and SB parameters were investigated using repeated measures analysis of variance (RM-ANOVA). Twenty-three subjects completed the study (placebo group 10, treatment group 13). None of the SB episode variables showed a significant time and group interaction (p > 0.05) except for electromyography (EMG) variables. The peak amplitude of EMG bursts during SB showed a significant time and group interaction (p = 0.001). The injection decreased the peak amplitude of EMG bursts during SB only in the treatment group for 12 weeks (p < 0.0001). A single BoNT-A injection cannot reduce the genesis of SB. However, it can be an effective management option for SB by reducing the intensity of the masseter muscle.

Botulinum toxin in the management of temporomandibular disorders: a systematic review

The aim of this review was to critically investigate and assess the evidence relating to the use and efficacy of botulinum toxin (BTX) in the management of temporomandibular joint disorders (TMD) and masticatory myofascial pain. A comprehensive search was conducted of PubMed, Scopus, Embase, and Cochrane CENTRAL, to find relevant studies from the last 30 years up to the end of July 2018. Seven were identified. Three showed a significant reduction in pain between the BTX and placebo groups and one showed a clinical, but not a significant, difference. In one that compared BTX with another novel treatment, myofascial pain reduced equally in both groups, and in the remaining two there was no significant difference in pain reduction between the BTX and control groups. Of the four studies that assessed mouth opening, two reported that BTX had resulted in a slight improvement; one reported no improvement, and the other a worsening of the condition. A meta-analysis was not possible because of the considerable variation in the studies' designs, the heterogeneity between the groups, and the different assessment tools used. Despite showing benefits, consensus on the therapeutic benefit of BTX in the management of myofascial TMD is lacking. Further randomised controlled trials with larger sample sizes, minimal bias, and longer follow-up periods are now needed.

Decreased mandibular cortical bone quality after botulinum toxin injections in masticatory muscles in female adults

This study aimed to clarify how masticatory muscle atrophy induced by botulinum toxin (BTX) injection affects cortical bone quality of the mandible using 3D modeling technology. A total of 39 young (26.9 ± 6.0 years) and 38 post-menopausal (55.3 ± 6.3 years) females were included. Computed tomography (CT) images were obtained before and after 12 months of treatment. Predictor variables were application of a stabilization splint, and/or two times of BTX injection in the bilateral temporalis and masseter muscles within a six-month interval. Outcome variables were changes in average Hounsfield units (HU) and cortical thickness of region of interest (ROI). 3D mandibular models were reconstructed using CT images, and models were used to calculate average HU and cortical thickness of ROIs, including inferior half of the lateral surface of ascending ramus, coronoid process, and temporomandibular joint condyle. Cortical bone quality at muscle insertion site was influenced by decreased muscle thickness but seemed not to be affected by decreased functional loading. Reduced functional loading seemed to influence cortical bone quality of the condyles. These effects were more remarkable in post-menopausal females. Hence, decreased masticatory muscle thickness may lead to alterations of the mandibular cortical structures, especially in post-menopausal females.

Botulinum Toxin Type A in Dental Medicine

Botulinum toxins (BoNTs) are a product of the bacteria Clostridium botulinum. By entering nerve endings, they cleave and inactivate SNARE proteins, which are essential for neurotransmitter release. Prevention of acetylcholine release at the neuromuscular junction causes long-lasting and potentially fatal flaccid paralysis-a major feature of botulism. However, an intramuscular injection of minute amounts of BoNTs, primarily type A (BoNT-A), has useful long-lasting muscle relaxation effects on spastic motor disorders. This characteristic of BoNT-A is widely used in neurology and cosmetics. Over the last few decades, it has been demonstrated that the functions of BoNT-A are not limited to muscle-relaxing or autonomic cholinergic effects but that it can act as an analgesic agent as well. More recently, it was revealed that this antinociceptive effect starts after entering the sensory nerve endings, where these agents are axonally transported to the central nervous system, suggesting that at least part of their analgesic effect might be of central origin. Because of its antinociceptive effect, BoNT-A is currently approved for treatment of chronic migraine; nonetheless, case reports and preclinical and clinical experiments indicating its benefit in numerous potential painful conditions have increased. In the field of dentistry, the US Food and Drug Administration approved BoNT-A for the treatment of sialorrhea only. Legal status of the use of BoNT-A in other countries is less known. However, there are controlled clinical trials suggesting its efficacy in other conditions, such as bruxism, temporomandibular disorders, and trigeminal neuropathic pain. Thereby, using criteria of the American Academy of Neurology, we critically reviewed the uses of BoNTs in oral medicine and found it effective for trigeminal neuralgia (category A) and probably effective in temporomandibular disorders and bruxism.