Botulinum Toxin Type A Injection Research Articles

Evaluating the Efficacy and Safety of Botulinum Toxin in Treating Overactive Bladder in the Elderly: A Meta-Analysis with Trial Sequential Analysis of Randomized Controlled Trials.

Overactive bladder (OAB) significantly impairs quality of life in the elderly. Although the intradetrusor injection of botulinum toxin type A (BoNT-A) is a treatment option, its effects on older adults remain uncertain. This study aimed to evaluate the efficacy and safety of BoNT-A intradetrusor injections in elderly OAB patients through a systematic review and meta-analysis. A comprehensive literature search was conducted using the PubMed, Embase, Cochrane Library, Scopus, and CINAHL databases from inception to 30 May 2024. The primary outcomes were improvements in daily urinary incontinence (UI) episodes and patient-reported outcomes, while the secondary outcomes focused on potential adverse events. Four randomized controlled trials with 803 participants were included. BoNT-A injections significantly reduced daily UI episodes at 4-6 weeks (mean difference [MD]: -3.82; 95% confidence interval [CI]: -6.29 to -1.35) and at 12 weeks (MD: -2.17; 95% CI: -3.22 to -1.12). However, BoNT-A was associated with an increased risk of elevated post-void residual (Risk Difference [RD]: 0.154; 95% CI: 0.058 to 0.251) and urinary tract infection (RD: 0.111; 95% CI: 0.005 to 0.217), with no significant difference observed in the initiation of catheterization or hematuria. Trial sequential analysis confirmed a sufficient sample size and statistical power. In conclusion, while BoNT-A effectively manages OAB in the elderly, careful post-injection monitoring is warranted due to its potential risks.

Efficacy and Complications of Full Dose versus Half Dose of Botulinum Toxin Type A Injection in Benign Essential Blepharospasm

Objective: To compare the effectiveness, patient satisfaction, and complications associated with pretarsal botulinum toxin type A (BTX-A) injections using half versus full doses of benign essential blepharospasm (BEB). Materials and Methods: A prospective double-masked randomized control trial was conducted in 20 patients. Each patient was randomized to receive either 40 or 80 units of BTX-A injections at Thammasat Hospital between April 2022 and August 2023. The primary outcome measures were frequency and severity using the Jankovic Rating Scale (JRS), latency to response, self-response scale, and patient satisfaction scale at four weeks and 12 weeks post-injection. The secondary outcome measures were complications of injection in each visit. Results: There were no significant differences between the groups receiving half-dose and full-dose BTX-A injections in the self-response scale at 2.60±0.52 versus 2.00±1.15, (p=0.277), patient satisfaction scale at 8.30±1.57 versus 7.00±1.49, (p=0.063) at four weeks and JRS frequency at 1.00±0.82 versus 1.20±0.92, (p=0.687), JRS severity at 1.30±1.16 versus 1.40±0.97, (p=0.784), latency to response at 5.80±1.99 versus 6.80±1.93, (p=0.214), self-response scale at 2.70±0.48 versus 2.20±0.63, (p=0.067), and patient satisfaction scale at 8.10±1.60 versus 8.30±1.49, (p=0.776) at 12 weeks. Complications, including epiphora, dry eye, and lagophthalmos, were observed in both groups. Conclusion: The present study indicated no significant differences between half-dose and full-dose BTX-A injections. Either dose showed comparable efficacy and safety in treating BEB. Trial registration: The present study protocol was registered at the Thai Clinical Trials Registry (TCTR20240320002; date March 20, 2024).

Peculiarities of the botulinum toxin type A injection technique and its effectiveness in the surgical treatment of large ventral hernias

Ventral hernias (VH) continue to be one of the most common surgical pathologies in planned and emergency surgery. Surgical treatment of large VH (≥10 cm) requires the use of traumatic surgical techniques in order to align the edges of the hernia defect and restore the integrity of the anterior abdominal wall. Objective — to assess the effectiveness of the botulinum toxin type A (BTA) injections and to study the peculiarities of their administration into the muscles of the anterior abdominal wall in patients with large VH in the preoperative period. Materials and methods. A prospective cohort study included 66 patients with large VH, primary (PVH), and incisional (IH). From June 2017 to August 2024, all patients underwent treatment and received injections of 100 units of BTA into the anterior abdominal wall muscles in the preoperative period. The patients’ average age was 58.98±9.48. There were 23 men (34.8%) and 43 women (65.2%). Before BTA, the average width of the hernial defect in PVH patients was 12.29±1.93 cm, whereas IH was 13.46±2.06 cm. All patients underwent surgical intervention for their hernias 4—5 weeks after the injection of BTA. Results. No complications were detected throughout the BTA administration or the 4—5 weeks of observation before the surgical hernia repair. After injection, the length of the anterior abdominal wall muscles increased by an average of 1.7 cm (min 0.1 cm, max 4.01 cm) on each side. Patients with PVH had an average hernial defect width reduction of 4.17±0.68 cm, whereas those with IH had an average reduction of 5.14±0.75 cm (p <0.001). After BTA administration, the volume ratio of the hernia sac to the abdominal cavity decreased from 4.97±3.55% to 3.70±2.77% in patients with PVH (p=0.008) and from 5.59±3.71% to 4.21±2.88% in patients with IH (p=0.008). Conclusions. The administration of 100 units of botulinum toxin type A in the preoperative period consistenly increases the length of the abdominal wall muscles, reduces the width of the hernial defect, and enhances the possibilities of further surgical treatment of large VH using laparoscopic technologies.

Evaluating the Impact of BoNT-A Injections on Facial Expressions: A Deep Learning Analysis.

Botulinum Toxin Type A (BoNT-A) injections are widely used for facial rejuvenation, but their effects on facial expressions remain unclear. This study aims to objectively measure the impact of BoNT-A injections on facial expressions using deep learning techniques. 180 patients aged 25-60 years who underwent BoNT-A application to the upper face were included. Patients were photographed with neutral, happy, surprised, and angry expressions before and 14 days after the procedure. A Convolutional Neural Network (CNN)-based Facial Emotion Recognition (FER) system analyzed 1440 photographs using a hybrid dataset of clinical images and the Karolinska Directed Emotional Faces (KDEF) dataset. The CNN model accurately predicted 90.15% of the test images. Significant decreases in the recognition of angry and surprised expressions were observed post-injection (p<0.05), with no significant changes in happy and neutral expressions (p>0.05). Angry expressions were often misclassified as neutral or happy (p<0.05), and surprised expressions were more likely to be perceived as neutral (p<0.05). Deep learning can effectively assess the impact of BoNT-A injections on facial expressions, providing more standardized data than traditional surveys. BoNT-A may reduce the expression of anger and surprise, potentially leading to a more positive facial appearance and emotional state. Further studies are needed to understand the broader implications of these changes.

Immediately Injections of Botulinum Toxin A After Surgical Excision for Ear Keloids: A Retrospective Study.

Ear keloids are pathologic scar hyperplasia in the ear region. The most therapeutic approach was surgical shave excision with radiation therapy. However, radiation therapy is easily delivered to healthy surrounding tissues. In the last years, injections with botulinum toxin type A (BTX-A) have been proven to improve surgical scars effectively in clinical trials. This study aimed to evaluate the effect of immediate injections of BTX-A after surgical excision for ear keloids. From January 2020 to January 2023, 33 consecutive patients with ear keloids were enrolled. All patients underwent scar excision and revision at the same time when they needed BTX-A. It was injected into surgical wound closure immediately after surgery. The results of this study were evaluated at follow-up from 7 to 18 months using the Vancouver Scar Scale (VSS) and the Visual Analogue Scale (VAS). From January 2020 to January 2023, 33 patients received concomitant therapy of immediate injections of BTX-A after surgery for ear keloids. The patients were evaluated at follow-ups lasting 7 to 18 months. Only one case recurred within the follow-up period, and no adverse effects were reported. This study demonstrates that significant cosmetic outcomes in ear keloid treatment were achieved after early postsurgical BTX-A injections. The patients reported high satisfaction and few complications.

Transurethral Intraprostatic Injection of Botulinum Toxin Type A for the Treatment of Category III Chronic Prostatitis: A Randomized Sham Controlled Study

Abstract Background Chronic non-bacterial prostatitis (CNBP) is a common disease associated with pain, urinary and sexual symptoms. Diagnosis and treatment of CNBP is usually difficult and requires multiple approaches and usually with unsatisfactory outcomes. Aim and Objectives to assess the effectiveness of the intraprostatic Botulinum toxin type A (BONT-A) in the treatment of refractory CNBP in a randomized sham-controlled trial. Subject and Methods 70 patients with refractory CNBP were equally randomized into two groups. Patients in treatment group (group 1) received transurethral intraprostatic BONT-A injection, whereas patients in sham group (group 2) received transurethral intraprostatic saline injection. Baseline national institute of health chronic prostatitis symptom index (NIHCPSI) was evaluated before intervention and reassessed after 1, 3 and 6 months following treatment. Result Age, prostate size, duration of symptoms as well as baseline total NIHCPSI were not statistically significantly different between both groups before intervention (30.29 vs. 29.8 for group 1 vs. group 2 respectively, p = 0.583). We found statistically significantly reduction of NIHCPSI total score in group 1 compared to group 2 at all intervals of follow up (27.21 vs. 29.03, p = 0.037, 24.97 vs. 28.59, p &amp;lt; 0.001 and 21.76 vs. 27.27, p &amp;lt; 0.001, at 1, 3 and 6 months respectively). Mean pain subscale scores statistically significantly decreased in group 1 compared to group 2 from baseline (14.77 and 14.06 for group 1 and group 2 respectively, p = 0.127) to 12.52 and 13.79, p = 0.010, 11.53 and. 13.25 p &amp;lt; 0.001 and 10 and 13.33, p &amp;lt; 0.001 after 1, 3 and 6 months respectively. Similarly, mean quality of life score statistically significantly improved in group 1 compared to group 2 from baseline (7.74 and. 8.40 for group 1 and. group 2 respectively, p = 0.038), then after 1, 3 and 6 months (6.09 vs. 7.88, p &amp;lt; 0.001, 5.56 vs. 7.81, p &amp;lt; 0.001 and 4.74 vs. 7.39, p &amp;lt; 0.001 respectively). Mean urinary symptoms scores statistically significantly decreased in group 1 compared to group 2 at all follow up intervals from baseline (7.77 and. 7.34 for group 1 and group 2 respectively, p = 0.136), to 6.15 vs. 7.06, p &amp;lt; 0.001, 5.75 vs. 6.97, p &amp;lt; 0.001, 4.91 vs. 6.58 p &amp;lt; 0.001 after 1, 3 and 6 months respectively. Maximal effect of treatment with BONT-A was at 6 months. Mild dysuria and hematuria were the only two postoperative complications encountered after intervention in both groups. Conclusion Transurethral intraprostatic injection of BONT-A is a safe and effective treatment for refractory CNBP.

Ultrasound-Guided Botulinum Toxin-A Injections into the Masseter Muscle for Both Medical and Aesthetic Purposes.

With the increasing use of Botulinum toxin type A (BoNT-A) injections in the masseter muscles for both medical and aesthetic purposes, there is a constant need to continually enhance the efficacy of these treatments and reduce the risk of potential adverse events. This review provides an in-depth analysis of the masseter muscle's anatomical structure and essential landmarks and emphasizes the advantages of ultrasound (US) guidance in improving the precision of BoNT-A injections compared to conventional blind methods. The review is supplemented with comprehensive figures, including graphics, clinical images, and ultrasound visuals, to support the discussion. Potential complications such as paradoxical bulging, inadvertent injections into the risorius muscle or parotid gland, facial paralysis, and the risk of bone resorption are examined. Future research should aim at refining injection techniques and assessing the long-term effects of repeated treatments to ensure optimal patient care and safety.

An Ultrasonographic Analysis of the Deep Inferior Tendon in the Masseter Muscle: Implications for Botulinum Toxin Injections.

(1) Background: With the increasing aesthetic pursuit of facial features, the clinical use of Botulinum Toxin Type A (BoNT-A) injections for masseter hypertrophy has been on the rise. However, due to variations in masseter muscle structure and differences in clinicians' injection techniques, blind injections may lack precision, potentially compromising treatment accuracy and increasing the risk of complications. (2) Objectives: The study aims to use ultrasonography to detail the deep inferior tendon (DIT) within the masseter muscle in a young Chinese cohort, refine its classification, analyze muscle belly thickness and variations across groups, and propose a customized ultrasound-guided BoNT-A injection protocol. (3) Methods: Ultrasound imaging was used to observe the bilateral masseter muscles at rest and during clenching. The features of the DIT were classified from these images, and the thickness of the masseter's distinct bellies associated with the DIT types was measured in both states. (4) Results: The study cohort included 103 participants (27 male, 76 female), with 30 muscles in the normal masseter group and 176 muscles in the hypertrophy group. The DIT was categorized as Type A, B (subtypes B1, B2), and C. The distribution of these types was consistent across normal, hypertrophic, and gender groups, all following the same trend (B > A > C). In hypertrophy, Type B1 showed uniform thickness across masseter bellies, B2 presented with a thinner intermediate belly, and Type C had mainly superficial muscle enlargement. Changes in muscle thickness during clenching were noted but not statistically significant among different bellies. (5) Conclusions: The study evidences individual variation in the DIT, highlighting the importance of precise DIT classification for effective BoNT-A injections. A tailored ultrasound-guided BoNT-A injection strategy based on this classification may enhance safety and efficacy of the therapy.

Prospective Analysis of the Effectiveness of Targeted Botulinum Toxin Type A Injection Using an Ultrasound-Guided Single-Point Injection Technique for Lower Face Contouring.

Background: Botulinum toxin type A (BoNT-A) injection is widely used for masseter hypertrophy. Traditional BoNT-A injection methods often incorporate landmark-guided blind injections, which approximate the shape of the masseter muscle inject across various points. Conversely, ultrasound (US)-guided injection techniques offer real-time visualization and dynamic monitoring, enhancing accuracy. Patients and Methods: 50 patients who underwent BoNT-A injections were included in this trial. One on the face side received a landmark-guided injection, and the other side was treated with a US-guided injection. Initial and post-procedure measurements of muscle thickness at the upper, middle, and lower regions were collected using ultrasound. Results: Both methods led to a significant reduction in muscle thickness one month after injection. In the upper area, the absolute difference in muscle thickness between the two methods was observed as a mean ± standard deviation (SD) value of 0.37 ± 0.0314 (p < 0.0001), indicating a superior effect with US-guided injection. Similarly, in the middle area, the mean ± SD difference was 0.41 ± 0.0608 (p < 0.0001) and in the lower area, the mean ± SD difference was 0.24 ± 0.0134 (p = 0.0004). Conclusions: This study demonstrated that the US-guided single-point injection technique is a more effective and accurate method for BoNT-A injection compared to the conventional method.

Dose-Dependent Effects of Botulinum Toxin Type A on Prevention of Postoperative Scars in Various Regions in the Body: A Prospective, Double-Blind Randomized Controlled Trial.

Botulinum toxin type A (BTXA) can improve wound healing and reduce scar formation; however, the exact dose required to prevent postoperative scarring across various anatomical sites remains unclear. This study aimed to investigate the effectiveness and optimal concentrations of BTXA for preventing postoperative scarring across various common surgical sites throughout the body. In this prospective randomized controlled trial, 46 patients with benign skin tumors received injections of 1, 2.5, or 5U/0.1mL of BTXA or 0.9% saline immediately following surgical tumor excision on both sides of the incisions. Follow-ups were conducted at 7days, 15days, and 1, 3, and 6months postoperatively. Patient-reported adverse events and standardized digital photographs were collected. Scar formation was assessed using the modified Stony Brook Scar Evaluation Scale (mSBSES). All 46 patients completed the trial without severe complications. The mSBSES scores were higher in the experimental groups at all follow-ups. The 5U/0.1mL BTXA dose group demonstrated optimal scar prevention at all high-risk sites for scar hyperplasia. No significant difference was observed between the 2.5U/0.1mL and 5U/0.1mL doses for intermediate-risk sites, while 1U/0.1mL dose was sufficient for low-risk sites. Overall, 86.5% of patients were satisfied with their treatments, with 16.3% being very satisfied. Early postoperative BTXA injection can reduce or prevent hypertrophic scarring, with optimal doses ranging from 1 to 5U/0.1mL depending on the surgical site, supporting broader clinical application of BTXA. The effectiveness of different concentrations of botulinum toxin type A (BTXA) in preventing postoperative scarring was compared, expanding the scope of previous research, which focused only on the head, face, and neck regions, to include the trunk and extremity areas. Different optimal injection strategies were determined based on different surgical sites and their risks of developing hypertrophic scars. The study demonstrates that BTXA not only reduces scar formation but also enhances patient satisfaction and reduces postoperative itching and pain, contributing to overall better postoperative outcomes. By establishing the efficacy and optimal dosing of BTXA for various surgical sites, this research supports the potential for broader clinical application of BTXA in aesthetic and reconstructive surgeries. 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 .

Assessing the efficacy and quality of Life improvements of botulinum toxin type a with topical minoxidil versus topical minoxidil in male androgenetic alopecia: a randomized controlled trial.

Androgenetic alopecia (AGA) is a common type of hair loss in men and efficacy and safety of current medical treatment remain limited. Therefore, the present study aimed to investigate the efficacy and safety of botulinum toxin type A (BTA) combined with Minoxidil in patients with AGA. 60 male patients were included in this study and control group received topical 5% Minoxidil and the treatment group received BTA combined with topical 5% Minoxidil. BTA injections (60-70 U) were administered at 30-35 scalp sites. Head photographs were taken at baseline, 2nd, 4th, and 6th months. Clinical descriptions recorded scalp conditions, and patient satisfaction along with Dermatology Life Quality Index scores were documented. The treatment group (TG) showed significant hair growth differences compared to the control group (CG) at the 4th month (P < 0.001) and 6th month (P = 0.0046) post-treatment. TG had improved Investigator Global Assessment (IGA) scores in the 4th month (P = 0.0001) and 6th month (P = 0.0259) compared to CG. Patient satisfaction in TG for hair growth and scalp improvement was higher than CG (all P < 0.05). TG exhibited substantial quality of life improvement at the 4-month (P = 0.0009) and 6-month (P = 0.0099). No adverse reactions were observed post-botulinum toxin injection. BTA combined with Minoxidil effectively promotes hair growth, enhances the quality of life, and alleviates scalp symptoms in male AGA patients at 4th and 6th months, with no adverse effects compared to Minoxidil alone.Trial registration number: Ethics Committee of Shanghai Tongji Hospital (ID: K-2018-026).

Botulinum Toxin Type A (BoNT-A) Use for Post-Stroke Spasticity: A Multicenter Study Using Natural Language Processing and Machine Learning.

We conducted a multicenter and retrospective study to describe the use of botulinum toxin type A (BoNT-A) to treat post-stroke spasticity (PSS). Data were extracted from free-text in electronic health records (EHRs) in five Spanish hospitals. We included adults diagnosed with PSS between January 2015 and December 2019, stratified into BoNT-A-treated and untreated groups. We used EHRead® technology, which incorporates natural language processing and machine learning, as well as SNOMED CT terminology. We analyzed demographic data, stroke characteristics, BoNT-A use patterns, and other treatments. We reviewed the EHRs of 1,233,929 patients and identified 2190 people with PSS with a median age of 69 years; in total, 52.1% were men, 70.7% had cardiovascular risk factors, and 63.2% had suffered an ischemic stroke. Among the PSS patients, 25.5% received BoNT-A at least once. The median time from stroke to spasticity onset was 205 days, and the time from stroke to the first BoNT-A injection was 364 days. The primary goal of BoNT-A treatment was pain control. Among the study cohort, rehabilitation was the most common non-pharmacological treatment (95.5%). Only 3.3% had recorded monitoring scales. In conclusion, a quarter of patients with PSS received BoNT-A mainly for pain relief, typically one year after the stroke. Early treatment, disease monitoring, and better data documentation in EHRs are crucial to improve PSS patients' care.

Temporary Delayed Hypersensitivity Reaction to Botulinum Toxin-A After COVID-19 Vaccination: A Case Series.

The occurrence of a hypersensitivity reaction with the injection of botulinum toxin type A (BTX-A) in cosmetic use is a rare complication. We report the largest case series of temporary delayed hypersensitivity reaction (DHR) with BTX-A following COVID-19 vaccination and the first cases to incobotulinum toxin A (incoBTX-A). A retrospective multicentric case series of patients who developed a DHR to BTX-A after COVID-19 vaccination. Twelve patients were treated with BTX-A injections for the management of facial rhytids. The age range was between 29 and 45years. Ten (83.3%) were female. Ten (83.3%) patients received incoBTX-A, and two received onabotulinum toxin A (onaBTX-A). All patients had COVID-19 vaccination (mRNA vaccine) between 1 and 7months before. Within an average time of 24h after BTX-A injection, all patients developed progressive facial swelling and erythema that were more prominent at the injection points. Intradermal allergic tests to BTX-A were performed in six (50%) patients, and the results were all negative. Adequate clinical control was achieved with systemic corticosteroids and antihistamines. After 1year with no further vaccination, a new BTX-A treatment (provocation test) was performed in all patients with no secondary effects. Previous COVID-19 vaccination and the absence of new adverse events with further BTX-A injections suggest a temporary DHR. Clinicians should be aware of the importance of immunization history and its potential post-vaccine immunogenic effects with BTX-A. 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 .

Response to Botulinum Toxin Type-A in Patients with Refractory Chronic Migraine

Background: Due to its debilitating nature, refractory chronic migraine (RCM) is primarily associated with a poor quality of life. However, controversy remains regarding the efficacy and safety of botulinum toxin for treating RCM. Objectives: The aim of this study was to investigate the efficacy of botulinum toxin type A (BTX-A) in patients with RCM. Methods: In this retrospective cross-sectional study conducted between April 2016 and March 2021, RCM patients who were resistant to conventional therapies and received BTX-A injections were followed for 7 and 14 days after the injection. The outcome variables included the frequency, duration, and severity of migraine episodes, the need for painkillers, adverse events, and the patient's perceived improvement. Data were analyzed using SPSS. Results: In total, 52 RCM patients with a mean age of 31.84 years participated, of whom 69.2% were female. The frequency of migraine episodes decreased from a baseline of 9.84 to 3.94 and 1.25 at 7 and 14 days after injection, respectively (P &lt; 0.001). The duration of migraine episodes dropped from 3 hours at baseline to 1.74 and 1.17 hours at 7 and 14 days post-BTX-A injection, respectively (P &lt; 0.001). The severity of migraines alleviated from 8.07 at baseline to 6.48 and 3.38 at the respective follow-up times (P &lt; 0.001). The need for painkillers also decreased at follow-ups (P &lt; 0.001). Males achieved better treatment outcomes regarding the frequency of migraine episodes and the need for medications compared to females following BTX-A treatment (P &lt; 0.05). Frontotemporal and frontotemporal-occipital headache distributions showed fewer migraine episodes, shorter duration, less severity, and lower need for painkiller consumption compared to other migraine types (P &lt; 0.05). The most common adverse event was localized pain (42.3%), followed by itching (25.0%). A considerable number of patients felt improvement. Conclusions: According to our findings, BTX-A is a safe and well-tolerated treatment for patients with RCM. Validation of these results requires adequately precise studies investigating the effect of BTX-A in detail.

Treatment of masseter muscle hypertrophy with botulinum toxin type A injection: A review of adverse events.

The popularity of noninvasive botulinum toxin type A (BTX-A) injections for masseter muscle hypertrophy is increasing among Asian individuals with a square-shaped lower face. This study aimed to analyze the adverse events (AEs) caused by BTX-A injections into the masseter muscle. This observational study retrospectively evaluated 46 250 patients who underwent BTX-A injections into the masseter muscle in 2022. The inclusion criteria were the diagnosis of an AE by the physician at the return visit and subsequent follow-up of progress (n = 223). The patients who were lost to follow-up (n = 40) were excluded from the study. Among the 223 patients with AEs, the most common AE was paradoxical bulging (88.3%, n = 197/223). The average period from treatment until confirmation of improvement was 159.6 ± 113.6 days (range 13-667 days) for all AEs, all of which were temporary. The period until improvement was 166.1 days in the intervention group (n = 122) and 151.9 days in the observation group (n = 101) (p = 0.24). As the period until improvement of AEs included the period until the patients visited the clinics and the improvements were confirmed by physicians, the actual period was likely to have been shorter. (1) All AEs were temporary. (2) All AEs improved within 22.2 months (within 5.3 ± 3.8 months on average). (3) There was no significant difference between the intervention and observation groups in the period until the improvement of AEs.

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

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. 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. 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. 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.

Noninvasive analysis of overactive muscle structure and elasticity after botulinum toxin type A injection: a systematic review and meta-analysis.

Injections of botulinum toxin type A (BoNT-A) are the first-line treatment for spastic muscle overactivity (MO). Some authors observed that BoNT-A injections lead to changes in muscle structure and muscle elasticity that are probably not completely reversible. This possible effect is critical, as it could lead to negative impacts on the effectiveness of BoNT-A interventions. Our study aimed to evaluate the current literature regarding changes in muscle elasticity and structure after BoNT-A injection, by diagnostic imaging, in neurological populations with MO. Our second objective was to pool all articles published on this topic in order to provide a quantitative synthesis of the data. A systematic search was conducted between October 2021 and April 2023 using different databases in accordance with PRISMA guidelines. Two independent reviewers screened articles for inclusion, extracted data, and evaluated methodological quality of the studies. A meta-analysis was performed to compare muscle elasticity and structure before and after BoNT-A injections. A sample of 34 studies was selected for qualitative review and 19 studies for quantitative review. Meta-analysis of pre-post studies demonstrated significant improvement with a medium effect size (standardized mean difference=0.74; 95% CI 0.46-1.02; P<0.001) of muscle elasticity assessed by ultrasound elastography (USE) 4 weeks after BoNT-A injection. No statistically significant difference was found for muscle thickness, pennation angle, and muscle echo-intensity assessed by magnetic resonance imaging and/or ultrasonography at short-term. On the other hand, normalized muscle volume decreased with a small effect size (standardized mean difference = -0.17; 95% CI -0.25 - -0.09; P<0.001) 6 months after BoNT-A injection. Muscle elasticity measured by USE improves with a temporary effect at short-term following BoNT-A injections. Synthesis of studies that assesses muscle structure is hindered by methodological differences between studies. However, based on a small amount of data, normalized muscle volume seems to decrease at long-term after BoNT-A injections in children with CP suggesting that the timing of re-injection should be considered with caution in this population. Further work should focus on the long-term effect of repeated injections on muscle structure and elasticity in neurological populations.

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

To assess the therapeutic efficacy of botulinum toxin type A (BTX-A) for managing myofascial pain related to temporomandibular disorders (TMDs). 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. 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. 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 of augmented-dosed surgery versus botulinum toxin A injection for acute acquired concomitant esotropia: a 2-year follow-up

Background/aimsThis study aims to evaluate the clinical efficacy of botulinum toxin type A (BTXA) injection and augmented-dosed surgery in the treatment of acute acquired concomitant esotropia (AACE), and explore potential...

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.