Key Parameters for the Use of AbobotulinumtoxinA in Aesthetics: Onset and Duration

Efficacy and Safety of RelabotulinumtoxinA Liquid Botulinum Toxin in the Treatment of Lateral Canthal Lines: Results From the Phase 3 READY-2 Study

BACKGROUND

RelabotulinumtoxinA (RelaBoNT-A) is a complex-free, ready-to-use, liquid botulinum toxin A.

OBJECTIVE

Efficacy/safety of RelaBoNT-A treatment for lateral canthal lines (LCL).

METHODS

Randomized adults received RelaBoNT-A (30 U/side; n = 230) or placebo ( n = 73) during a 6-month, double-blind, Ph3 study (Relabotulinumtoxin Aesthetic Development Study-2 [READY-2]). Primary end points (Month 1, maximum smile) comprised: composite ≥2-grade responder rate using concurrent LCL severity investigator live assessment (LCL-ILA) and subject live assessment (LCL-SLA); LCL-ILA 0 (none)/1 (mild) responder rate. Subject satisfaction and adverse events were also reported.

RESULTS

Month 1 composite ≥2-grade responder rates were 51.8% (RelaBoNT-A) and 1.4% (placebo; ( p < .001). Month 1 none/mild LCL-ILA responder rates were 87.2% (RelaBoNT-A) and 11.9% (placebo; p < .001). Onset was reported Day 1 by 34%. At Month 6, LCL-ILA responder rates for RelaBoNT-A remained at 23.3% (none/mild) and 35.9% (≥1-grade improvement). Median return to baseline severity was 24.7 weeks; 64% (RelaBoNT-A group) had not returned to baseline at Month 6. RelaBoNT-A satisfaction was high through Month 6 (71%). Mild/moderate treatment-related adverse events occurred in 6.1% (RelaBoNT-A) and 5.5% (placebo).

CONCLUSION

RelaBoNT-A (60 U) treatment provided statistically significant improvement of moderate-to-severe LCL. One-third of subjects reported onset within 1 day and improvements were maintained through Month 6. Treatment satisfaction was high. RelaBoNT-A was well tolerated.

Botulinum Toxin in Aesthetic Medicine: A Bibliometric Analysis of Research Trends and Methodological Quality of the Top 100 Cited Publications

Background

Botulinum toxin is widely used in aesthetic medicine, with numerous studies examining its efficacy and safety.

Objectives

This bibliometric analysis aims to describe research trends and assess the methodological quality of the highest-impact botulinum toxin research in aesthetic applications.

Methods

The authors of this study identified the 100 most-cited publications on botulinum toxin in aesthetics using Web of Science, covering all available journal years (from inception to October 2024). The Oxford Centre for Evidence-Based Medicine Level of Evidence (LOE) was used to assess the methodological quality of each study.

Results

The authors identified 1728 articles on the aesthetic uses of botulinum toxin, with the top 100 most-cited articles spanning from 1994 to 2021. The United States dominated the research landscape with 50 articles, followed by Canada (15). The University of California (United States) and the University of British Columbia (Canada) emerged as the top contributing institutions. Among journals, Dermatologic Surgery led in publication count, followed by Plastic and Reconstructive Surgery and Aesthetics Surgery Journal. Notably, Professors Jean Carruthers and Alastair Carruthers from Canada were the leading researchers, topping both publication count and citation metrics. Notably, more than half of the studies were classified as LOE 5 (Expert Opinion/Narrative Review).

Conclusions

This bibliometric analysis reveals a paucity of high-quality studies in the field of botulinum toxin in aesthetic medicine, with research predominantly concentrated in western countries. These findings highlight the need for more rigorous, evidence-based studies and increased global collaboration to advance the understanding and application of botulinum toxin in aesthetics.

Level of Evidence 4 Therapeutic

Efficacy and Safety of RelabotulinumtoxinA, a New Ready-to-Use Liquid Formulation Botulinum Toxin: Results From the READY-1 Double-Blind, Randomized, Placebo-Controlled Phase 3 Trial in Glabellar Lines

BACKGROUND

RelabotulinumtoxinA (RelaBoNT-A, Galderma, Uppsala, Sweden) is an innovative, ready-to-use liquid botulinum toxin A, produced with PEARL (precipitation-free extraction and activity-preserving refined liquid) manufacturing technology, which yields a potent, complex-free formulation.

OBJECTIVES

In the READY-1 study, efficacy and safety outcomes following a single RelaBoNT-A treatment for glabellar line correction were examined.

METHODS

Adults with moderate to severe glabellar lines received RelaBoNT-A (50 U) or placebo in a 3:1 randomized, 6-month, phase 3, multicenter, double-blind study. Primary endpoints (examined at Month 1, maximum frown) comprised the composite ≥2-grade response, defined as ≥2-grades improvement from baseline on concurrent investigator (glabellar line investigator live assessment; GL-ILA) and participant (glabellar line subject live assessment; GL-SLA) severity scales (US endpoint), and the investigator-reported responder rate for participants scored as 0 (none) or 1 (mild) (GL-ILA scale only; EU endpoint). Participant satisfaction and treatment-emergent adverse events (TEAEs) were reported.

RESULTS

Overall, 297 adults were randomized and treated. Month 1 composite ≥2-grade responder rate was 82.9% (RelaBoNT-A, n = 199) vs 0% (placebo, n = 67; P < .001). Month 1 investigator-reported none or mild responder rate was 96.3% (RelaBoNT-A) vs 4.5% (placebo; P < .001). GL-ILA scores remained higher with RelaBoNT-A (23.6% [none or mild]; 58.1% [≥1-grade improvement]) vs placebo (1.5%; 10.4%, respectively) through Month 6 (P < .001). In the Kaplan-Meier analysis, 75% still showed GL-ILA and GL-SLA improvements from baseline at 169 days (end of study). Participants reported onset of effect from Day 1 (39%) and satisfaction with natural-looking results (96.8%; Month 1). RelaBoNT-A-related TEAEs were low (3.6%) and typically mild.

CONCLUSIONS

A single RelaBoNT-A treatment was effective and demonstrated a favorable safety profile. RelaBoNT-A provided significant improvements in glabellar line severity, high satisfaction, rapid onset, and enduring effectiveness throughout the 6-month study period.

LEVEL OF EVIDENCE: 1

Comparative study between the efficacy of prabotulinum toxin-A versus onabotulinum toxin-A for the treatment of upper facial expression lines

BACKGROUND

Botulinum Toxin (BoNTA) is the most used nonsurgical aesthetic procedure to treat facial expression lines.

AIMS

This study compared the efficacy of Prabotulinum toxin-A, a novel BoNTA that originates from Clostridium botulinum Hall-A, with onabotulinum toxin-A in treating facial expression lines using the Facial Wrinkle Scale (FWS) and FACE-Q questionnaires.

METHODS

This was an experimental, comparative, longitudinal, open-label, and prospective study. Patients aged between 25 and 40 years with upper-third facial expression lines were included. Follow-ups were made at three, seven, 30, and 120 days.

RESULTS

A total of 26 patients were included: 20 female, and six males, with a mean age of 28.26 years. An average of 31.00 IU and 31.38 IU were administered to the onabotulinum and prabotulinum groups, respectively. The prabotulinum group demonstrated superiority in FWS and Face-Q scores between the first and third days (p ≤ 0.001, p < 0.001, respectively), which continued on day 7. By day 30, there were no differences in the scores of the two questionnaires.

CONCLUSIONS

Prabotulinum toxin-A is a safe and effective treatment for upper-third facial wrinkles. On day three and seven, the results suggest that prabotulinum toxin-A has a quicker onset of action than onabotulinum toxin-A. On days 30 and 120, both groups showed similar FWS and Face-Q scores.

A Review of Current Data on Duration of Effect in Glabellar Lines After Treatment With AbobotulinumtoxinA 50 U

BACKGROUND

AbobotulinumtoxinA has become well established as a treatment option for moderate to severe glabellar lines since its first aesthetic approval in 2009.

OBJECTIVE

Pivotal trials leading to regulatory approval showed that abobotulinumtoxinA treatment was associated with high responder rates when defined as achievement of none or mild glabellar lines (0 or 1 on the glabellar line severity scale) and a duration of action of up to 5 months. More recently, the goals for treatment of glabellar lines have shifted toward not only achieving a decrease in glabellar line severity but also ensuring that patients are satisfied with their experience.

MATERIALS AND METHODS

Patients seek an improvement in the appearance of their glabellar lines while maintaining a "natural look," fast onset of effect, and long duration of response.

RESULTS

Trial designs have evolved to meet these new targets, including expanding the definition of responders to those having at least 1-grade improvement in the glabellar line severity scale score from baseline coupled with the use of subject satisfaction and psychological well-being questionnaires.

CONCLUSION

The findings demonstrate that abobotulinumtoxinA remains a well-tolerated and consistently effective treatment option associated with a rapid onset of effect, duration of efficacy lasting up to 6 months, and high, long-lasting levels of patient satisfaction.

Ready-to-use abobotulinumtoxinA solution versus powder botulinumtoxinA for treatment of glabellar lines: Investigators' and subjects' experience in a Phase IV study

BACKGROUND

Botulinum neurotoxin type A (BoNT-A) is well-established for treatment of glabellar lines (GLs), and mostly formulated as powders requiring reconstitution for injection. The approved liquid formulation, ready-to-use (RTU) abobotulinumtoxinA was developed to ease injection procedures and prevent reconstitution errors. This multicenter, open-label, Phase IV study evaluated GL treatment experience using RTU abobotulinumtoxinA versus powder BoNT-A (onabotulinumtoxinA).

METHODS

Females with experience of BoNT-A facial treatment were randomized 2:1 to GL treatment with 50 U RTU abobotulinumtoxinA (N = 99) or 20 U powder BoNT-A (N = 51) and followed-up for 6 months or 1 month, respectively. Assessments included: time to prepare each product for injection (primary endpoint); investigators' experience with product preparation/reconstitution; investigators' and subjects' treatment experience; safety; and for the RTU product: aesthetic improvement of GLs; subject satisfaction.

RESULTS

Compared with powder BoNT-A, RTU abobotulinumtoxinA required statistically significantly less preparation time (mean 0:33 vs. 1:34 min: s; p < 0.0001). Investigators preferred RTU abobotulinumtoxinA over powder BoNT-A (81% of treatment sessions) and found it allowed more time to communicate with subjects (97%). All investigators (100%) also found it easy-to-use, easy-to-learn, and that it fulfilled their expectations. Subjects found the RTU abobotulinumtoxinA treatment comfortable (91%), and through 6 months posttreatment, most reported satisfaction with their appearance (≥88%), looking natural (≥95%) and refreshed (≥80%). At Month 1, 99% of RTU-treated subjects had investigator-assessed improved aesthetic appearance in GLs, maintained in 76% at Month 6. No serious adverse events occurred.

CONCLUSION

RTU abobotulinumtoxinA for GL treatment is well-tolerated, efficacious, shows high levels of subject satisfaction throughout 6 months, saves time, and is preferred by clinicians over powder BoNT-A.

CLINICALTRIALS

GOV REGISTRY

NCT05277337.

Neuromodulators Raising Eyebrows: "Having Is Not so Pleasing, After All, as Wanting"

Level of Evidence IV 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 Effect of Climate on the Dose Requirements of Botulinum Toxin A in Cosmetic Interventions

BACKGROUND

Botulinum toxin A to the glabella is a popular cosmetic intervention. Functional musculature differences may arise from chronic behavioral adjustment to high sun exposure levels, requiring greater doses. This could affect clinical practice globally. This study investigated the effect of climate on real-world doses.

METHODS

The authors conducted a comparative cohort study using data from a registry from a single provider practicing across two centers: the United Kingdom and Malta. They classified one center as low sun exposure (United Kingdom winter month treatment) and the other as high sun exposure (Malta summer months). Patients were followed up once every 3 weeks and received top-up doses until full clinical paralysis was achieved. To standardize the comparison, the study included only women aged 35 to 60 years undergoing glabellar botulinum toxin treatment by experienced clinicians following standard procedures from 2012 to 2019. Smokers, those not seeking maximal paralysis, those documented as not compliant with posttreatment advice, those with colds or fevers, and those with broken cold supply chains were excluded. Univariable and multivariable analyses were undertaken.

RESULTS

A total of 523 patients were included: 292 "high-sun" patients and 231 "low-sun" patients. Mean total doses were significantly higher in the high-sun group (29.2 units versus 27.3 units; P = 0.0031). When correcting for age in multivariable analysis, the low-sun group still had lower total dose requirements ( P = 0.00574).

CONCLUSION

Patients injected with glabellar botulinum toxin in high-sun climates may have significantly increased dose requirements to achieve maximal paralysis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Aesthetic doctors' perception and attitudes toward tolerance in botulinum toxin

BACKGROUND

Botulinum toxin is a crucial therapeutic tool with broad indications in both cosmetic and medical fields. However, the expanding cosmetic use and increased dosages of botulinum toxin have raised concerns about resistance, making it essential to study the awareness and management practices among healthcare professionals.

METHODS

A survey was conducted among clinical physicians using botulinum toxin. The study investigated their experiences, awareness, and management practices related to toxin resistance. Real-time mobile app-based surveys were administered to clinicians attending the 45th International Academic Conference of the Korean Academy of Laser and Dermatology (KALDAT) on December 3, 2023.

RESULTS

Among 3140 participants, 673 clinical physicians completed the survey. Of these, 363 clinicians (53.9%) reported experiencing botulinum toxin resistance. Regarding the resistance rate, 59.4% indicated less than 1%, 36% reported approximately 1%-25%, and 95.4% reported less than 25%. Efforts to prevent resistance included maintaining intervals of over 3 months (54.8%), using products with lower resistance potential (47.0%), employing minimal effective doses (28.2%), and minimizing re-administration (14.9%).

CONCLUSION

In the South Korean aesthetic medicine community, a majority of clinical physician's report encountering botulinum toxin resistance. Given the potential loss of various benefits associated with resistance, there is a need to establish appropriate guidelines based on mechanistic studies and current status assessments. Educating clinicians on applicable guidelines is crucial.

The Patient Journey in Facial Aesthetics: Findings from a European Consensus Meeting on Improving the Quality of Life for Patients Receiving Botulinum Toxin Injections

Purpose

Successful treatment of facial lines with botulinum toxin is largely dependent on patient satisfaction; thus, a structured treatment journey that uses patient-reported outcomes (PROs) is helpful for maximizing botulinum toxin results. To develop a patient-centric approach for botulinum toxin injections in facial aesthetics, a group of clinicians met to provide opinions on an optimal treatment journey that uses PROs to quantify treatment benefits on patient quality of life.

Patients and Methods

A multidisciplinary panel of 9 clinicians with expertise in facial aesthetic procedures convened for an advisory board that was preceded by and followed up with a structured, multistep consensus discussion. Based on current literature, the panel's expertise, structured questions, and group discussion, panelists assessed, reconciled, and agreed upon on a patient journey for botulinum toxin treatment in facial aesthetics.

Results

Panelists agreed that an optimal patient journey includes screening, assessment, treatment, posttreatment, and follow-up visits. A compact, easy-to-complete, and digital PRO questionnaire should be provided before the visit. During screening, thorough assessments are integral for a successful patient journey because they provide an opportunity to understand treatment goals, address patient concerns, discuss risks and benefits, obtain medication lists/medical history, and take pretreatment photographs. Treatment strategies should include discussing and educating on the approach/choice of botulinum toxin and ensuring patients are comfortable. Posttreatment, clinicians should request intense muscle movements to enhance product uptake and be available to address patient concerns. Finally, during follow-up, PRO questionnaires can be provided to gauge patient satisfaction with treatment, and pretreatment photographs can be provided to allow patients to track their progression. Follow-ups should be scheduled with new patients or those reporting low satisfaction.

Conclusion

Establishing a relationship, being aware of the patient's goals, and developing an individualized care plan allows for a structured, patient-centered treatment journey that promotes positive aesthetic outcomes.

Efficacy and Safety of AbobotulinumtoxinA for the Treatment of Glabellar Lines in Chinese Patients: A Pivotal, Phase 3, Randomized, Double-Blind and Open-Label Phase Study

BACKGROUND

Various botulinumtoxinA formulations are approved for glabellar lines treatment worldwide, including abobotulinumtoxinA (Dysport^®).

OBJECTIVES

Assess abobotulinumtoxinA superiority versus placebo and non-inferiority versus active comparator (onabotulinumtoxinA; Botox^®), for the treatment of Chinese patients with moderate/severe glabellar lines.

METHODS

Phase 3, randomized study (NCT02450526) comprising a double-blind (cycle 1) phase and an open-label (cycles 2-5) phase. Patients received abobotulinumtoxinA 50 units or matching placebo (5:1), active comparator (onabotulinumtoxinA 20 units) or matching placebo (5:1). In cycles 2-5, eligible patients were retreated with abobotulinumtoxinA only. Responders had glabellar lines of none/mild severity.

PRIMARY ENDPOINT

responder rates at cycle 1, day 29 at maximum frown with abobotulinumtoxinA versus placebo (for superiority; by investigator's live assessment [ILA] and subject's self-assessment [SSA]), and versus active comparator (for non-inferiority; by ILA). Treatment-emergent adverse events were recorded.

RESULTS

Overall, 520 patients were randomized. Superiority and non-inferiority, respectively, were demonstrated for abobotulinumtoxinA versus placebo (ILA, SSA; both p < 0.0001) and abobotulinumtoxinA versus active comparator. AbobotulinumtoxinA efficacy was maintained over open-label cycles; median time to onset of efficacy was 2.0 days. After 6 months, 17% of patients treated with abobotulinumtoxinA remained responders. AbobotulinumtoxinA was well-tolerated. Safety results were in line with the known profile of abobotulinumtoxinA; adverse events rate decreased with repeated treatment.

CONCLUSIONS

After a single injection, abobotulinumtoxinA demonstrated superiority versus placebo and non-inferiority versus onabotulinumtoxinA for the treatment of moderate-to-severe glabellar lines in Chinese patients. Multiple injections of abobotulinumtoxinA demonstrated efficacy and safety in the treatment of glabellar lines in Chinese patients.

LEVEL OF EVIDENCE I

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 use of botulinum toxin in the acute management of symptomatic complex incisional hernia: a case series

PURPOSE

Complications of incisional hernia are amongst the commonest presentations to the emergency surgical take. Outcomes from emergency hernia repair are poor, particularly for those with complex defects and for the growing population of comorbid, high-risk patients. Attempts to avoid emergency surgery by improving success rates of non-operative management could prove hugely beneficial. Botulinum toxin A (Botox) is already used in the elective management of incisional hernia and this study evaluates if the relaxation produced could be used to augment the outcomes of conservative management of acutely presenting incisional hernia.

METHODS

Patients presenting between October 2020 and April 2022 without evidence of visceral ischaemia, who had been selected for a non-operative approach, were given 300 units of Botox under image guidance to the abdominal wall in addition to standard conservative measures.

RESULTS

Twelve patients were eligible for Botox administration. Median age was 75 years and median BMI was 36.45 kg/m². All patients were high risk; minimum ASA score was 3, and median frailty score was 5. In ten patients, symptoms resolved following Botox allowing for discharge without further complication. Seven subsequently referred on to the abdominal wall team. Symptoms did not settle in the two remaining patients; one required emergency laparotomy and the second was palliated.

CONCLUSION

Botox may be a useful adjunct to established non-operative measures in patients with acute presentations of incisional hernia. It may improve the acute symptoms, eliminate the need for high-risk emergency surgery, or provide a bridge to abdominal wall reconstruction.

Introducing a noninvasive, non-surgical, and reversible animal model for fecal incontinence using abobotulinumtoxinA in dogs

The aim of this study was to introduce a new animal model of fecal incontinence (FI) by injecting abobotulinumtoxinA in the external anal sphincter (EAS) muscle of dogs which replaces models based on anal sphincter destructions that are invasive, mostly require surgical procedures, expensive, permanent, and painful to the animals. 4 healthy mongrel dogs were used in this study. First, they were received NaCl 0.09% (as control) injections in EAS muscle and effects were assessed by means of Electromyography (EMG) and clinically evaluated by sphincter pinch test and presence of leakage of feces for 2 weeks. Then, they received abobotulinumtoxinA in EAS muscle and reevaluated for 6 weeks to see short-term and medium-term effects of abobotulinumtoxinA injection. Saline had no significant changes in results obtained from EMG, however, there were significant decreases in amplitudes of action potentials after receiving abobotulinumtoxinA in comparison with no injection or saline injection in EAS muscle. Pinch tests were normal after saline injection assessment period, however, then started to be negative, ranging from two days after abobotulinumtoxinA injection to seven days after receiving abobotulinumtoxinA. Animals also had significant presentations of fecal incontinence (leakage of feces and cage contamination with feces) from the 1^st week after receiving abobotulinumtoxinA until the 6^th week after receiving abobotulinumtoxinA. AbobotulinumtoxinA caused paralysis in the EAS and producd FI conditions in dogs. This animal model was an appropriate substitute to the various invasive, expensive and also complicated procedures with an easy, feasible, noninvasive and non-painful single-stage abobotulinumtoxinA injection.

Preclinical Evidence for the Role of Botulinum Neurotoxin A (BoNT/A) in the Treatment of Peripheral Nerve Injury

Traumatic peripheral nerve injuries tend to be more common in younger, working age populations and can lead to long-lasting disability. Peripheral nerves have an impressive capacity to regenerate; however, successful recovery after injury depends on a number of factors including the mechanism and severity of the trauma, the distance from injury to the reinnervation target, connective tissue sheath integrity, and delay between injury and treatment. Even though modern surgical procedures have greatly improved the success rate, many peripheral nerve injuries still culminate in persistent neuropathic pain and incomplete functional recovery. Recent studies in animals suggest that botulinum neurotoxin A (BoNT/A) can accelerate nerve regeneration and improve functional recovery after injury to peripheral nerves. Possible mechanisms of BoNT/A action include activation or proliferation of support cells (Schwann cells, mast cells, and macrophages), increased angiogenesis, and improvement of blood flow to regenerating nerves.

Evaluation of the Safety and Efficacy of a Biosimilar Abobotulinum Toxin Type A in Treating Moderate to Severe Glabellar Lines: A Non-Inferiority Double Blinded Randomized Controlled Trial

BACKGROUND

Injection of botulinum toxin for cosmetic purposes is a well-established practice.

OBJECTIVES

This study was conducted to compare the safety and efficacy of Dyston^® (investigational biosimilar abobotulinumtoxinA) with Dysport^® (abobotulinumtoxinA, Ipsen) in the treatment of moderate to severe glabellar lines.

METHODS

Out of 193 screened subjects, 126 volunteers with moderate to severe glabellar lines fulfilling eligibility criteria were randomized in a 1:1 ratio to receive either an intramuscular injection of 40-60 units of Dyston^® or Dysport^® . The primary objective was to test the non-inferiority of Dyston^® compared to Dysport^® as measured by the percentage of volunteers who achieved no or mild glabellar lines at maximum frown assessed by the physicians based on the Glabellar Line Severity Score (GLSS) at day 30. Secondary endpoints included the improvement in the glabellar lines at maximum frown and rest states at days 14, 60, 90 and 120 as well as the side effects of the treatment.

RESULTS

Response rates at maximum frown were 75.44% (43/57) in the Dyston^® group and 76.67% (46/60) in the Dysport^® group on day 30 (P value: 0.88, 95%CI: -14.24 to 16.70, diff: 1.23) as per-protocol set, and were 75.81% (47/62) and 76.19 (48/63) (P value: 0.96, 95%CI: -14.59 to 15.35, diff: 0.3) in the Dyston^® and the Dysport^® groups, respectively, based on modified intention to treat population. Adverse events were similar in both groups and mostly mild and well-tolerated.

CONCLUSION

Treatment of moderate to severe glabellar lines with Dyston^® was effective, tolerable, and non-inferior compared to Dysport^® .

Human Frontalis Muscle Innervation and Morphology

Due to its clinical importance and due to a suggestion regarding the afferent innervation, the microscopic appearance of the frontalis muscle was investigated.

Plasma Metabolomic Changes in Children with Cerebral Palsy Exposed to Botulinum Neurotoxin

The long-term effect of botulinum neurotoxin A (BoNT-A) on children with cerebral palsy (CP) is unclear, and how the dynamic changes of metabolites impact the duration of effect remains unknown. To tackle this, we collected 120 plasma samples from 91 children with spastic CP for analysis, with 30 samples in each time point: prior to injection and 1, 3, and 6 months after injection. A total of 354 metabolites were identified across all the time points, 39 of which exhibited significant changes (with tentative IDs) (p values <0.05, VIP > 1). Principal component analysis and partial least-squares discriminant analysis disclosed a clear separation between different groups (p values <0.05). Network analysis revealed the coordinated changes of functional metabolites. Pathway analysis highlighted the metabolic pathways associated with energy consumption and glycine, serine, and threonine metabolism and cysteine and methionine metabolism. Collectively, our results identified the significant dynamic changes of plasma metabolite after BoNT-A injections on children with CP. Metabolic pathways associated with energy expenditure might provide a new perspective for the effect of BoNT-A in children with CP. Glycine, serine, and threonine metabolism and cysteine and methionine metabolism might be related to the duration of effect of BoNT-A.

Botulinum Toxin Type A for Glabellar Frown Lines: What Impact of Higher Doses on Outcomes?

Botulinum toxin serotype-A (BoNT-A) preparations are widely used to improve the appearance of wrinkles. While effective and well tolerated, patients require retreatment over time to re-establish the effects. There is growing interest from patients as to whether higher doses can prolong response without significantly increasing side effects. We reviewed the efficacy and safety evidence for high-dose BoNT-A treatment of glabellar lines, by evaluating high-dose studies published since 2015. Toxins approved for glabellar line treatment in the US or Europe were considered. "High-dose" indicated doses above the licensed dose for each BoNT-A preparation. Five studies met the inclusion criteria and most were randomized, double-blind trials; designs and population sizes varied. Findings suggested that higher-dose BoNT-A treatment is feasible and may improve response duration without increased safety issues. Around 9 months' median duration was achieved with a 2-2.5-fold increase of the abobotulinumtoxinA on-label dose, or with a 5-fold increase in incobotulinumtoxinA dose. A 2-4-fold increase of the onabotulinumtoxinA on-label dose yielded a median duration of around 6 months. Importantly, patient satisfaction and natural look remained with increasing abobotulinumtoxinA doses. While more data are needed, these findings may lead to more effective, individually tailored treatment plans to meet patient expectations.

Ratings of Emotional Expressions in Static and Dynamic Facial Recordings Before and After Upper Face Botulinum Injections-An Observational Prospective Study

BACKGROUND

Botulinum toxin A (BTX), a neurotoxin widely used for facial aesthetics, causes dose-dependent muscle paralysis. It was hypothesized that treatment of mimic muscles with BTX might have a positive impact on emotional expression in static images (photographs), but a negative impact in dynamic recordings (videos).

OBJECTIVES

The aim of this study was to compare of emotional expression recorded in photographs and videos before and after treatment with BTX.

METHODS

Twenty healthy women (mean age, 45 years) received a dose of 19 mouse units of XEOMIN (Merz, Frankfurt am Main, Germany) into the procerus, occipitofrontalis, and orbicularis oculi muscles. Photographs and videos of the participants' faces with neutral and happy expressions were recorded before treatment and 2 weeks later. Recordings were rated by naive raters blind to the conditions and in balanced order.

RESULTS

Videos were generally rated as more pleasant, arousing, attractive, and genuine than photographs (all Ps > 0.001). This was especially the case for videos with neutral expression (P = 0.003). Independent of presentation mode and facial expression, women were rated as more attractive after BTX treatment (P = 0.03).

CONCLUSIONS

In contrast to the hypothesis, the reduced mobility had no detectable negative impact on dynamic emotional expression, but videos received more positive ratings, particularly for neutral expressions. It is thus recommended to assess emotional expression with dynamic recordings to evaluate the effects of treatment with BTX. BTX seems to improve perceived attractiveness, although the cause of this effect remains unclear.

[New botulinum toxins for aesthetic dermatology : A comprehensive review]

Facial rejuvenation is gaining immense popularity among patients and clinicians. Botulinum toxins derived from bacteria are well-tolerated options as minimally invasive interventions for facial rejuvenation or other aesthetic procedures. These products have revolutionized aesthetic treatments. Several types of botulinum toxins (BoNT) are available. Currently type A and B are clinically used and only BoNT‑A products are approved for use for cosmetic indications in the Germany and the United States. Each product is unique in terms of its composition. Understanding the various BoNT‑A products is essential in choosing the optimal treatment for our patients. In this article we discuss different BoNT‑A products used for aesthetic intervention.

Patient Satisfaction with AbobotulinumtoxinA for Aesthetic Use in the Upper Face: A Systematic Literature Review and Post-hoc Analysis of the APPEAL Study

BACKGROUND: AbobotulinumtoxinA (AboBoNT-A; Dysport^®; Ipsen, Boulogne-Billancourt, France/Azzalure^®; Galderma, Lausanne, Switzerland) is a botulinum neurotoxin type A approved for aesthetic use in the treatment of glabellar lines in adult patients under 65 years in Europe, the United States, and other countries. OBJECTIVE: We sought to analyze current literature on patient satisfaction with aboBoNT-A for upper facial aesthetic indications. METHODS: A systematic review of literature databases (PubMed/MEDLINE, Embase, the Cochrane Library, and Google Scholar) was performed to identify English-language publications reporting on patients with aesthetic indications (including glabellar lines and wrinkles) receiving aboBoNT-A, that assessed patient and/or physician satisfaction with treatment, with no restrictions on comparator studies. Structured data extraction was used to enable inter-study analysis. A post-hoc analysis was also performed to assess patient satisfaction by sex and age, using results from the noninterventional APPEAL study of patients' satisfaction with aboBoNT-A for treating glabellar lines. RESULTS: Overall, 22 original research papers were identified. Patient satisfaction rates for aboBoNT-A treatment were significantly higher versus placebo from two weeks to between three and five months postinjection. At two to three weeks postinjection, patient satisfaction rates were 52% and 99% across studies. In studies with later time points, patient satisfaction rates were 85 to 87 percent at 5 months and between 25 and 100 percent at 6 months post-injection. Physician satisfaction was also high (97%-100%, across three treatments). No notable differences in patient satisfaction by sex or age were observed in the APPEAL study. CONCLUSION: High rates of patient satisfaction have been achieved with aboBoNT-A treatment for upper facial aesthetic indications. Despite the current recommended interval of ≥12 weeks, satisfaction with the aesthetic results of aboBoNT-A therapy is still evident up to 6 months post-injection in some patients.

Effectiveness of Botulinum Toxin A in Treatment of Hemiplegic Shoulder Pain: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the effectiveness of botulinum toxin A (BTX-A) in the treatment of hemiplegic shoulder pain.

DATA SOURCES

PubMed, EMBASE, Elsevier, Springer, Cochrane Library, Physiotherapy Evidence Database, CNKI, and VIP were researched from the earliest records to September 1, 2020.

STUDY SELECTION

Randomized controlled trials that compared shoulder BTX-A injections vs a control intervention in patients with a history of hemiplegic shoulder pain after stroke were selected. Among the 620 records screened, 9 trials with 301 eligible patients were included.

DATA EXTRACTION

Outcome data were pooled according to follow-up intervals (1, 2, 4, and 12 wk). The primary evaluation indices were pain reduction (visual analog scale [VAS] score) and range of motion (ROM) improvement. The second evaluation indices were upper limb functional improvement, spasticity improvement, and incidence of adverse events. Cochrane risk-of-bias was used to assess the methodological quality of studies independently by 2 evaluators.

DATA SYNTHESIS

Meta-analysis revealed a statistically significant decrease in the VAS score in the BTX group vs the control group at 1, 4, and 12 weeks postinjection (wk 1: standardized mean difference [SMD], 0.91; 95% confidence interval [CI], 0.27 to 1.54; wk 4: SMD, 1.63; 95% CI, 0.76 to 2.51; wk 12: SMD, 1.96; 95% CI, 1.44 to 2.47). Furthermore, the meta-analysis demonstrated a statistically significant increase in abduction at 1, 4, and 12 weeks postinjection (wk 1: SMD, 3.71; 95% CI, 0 to 7.41; wk 4: SMD, 8.8; 95% CI, 2.22 to 15.37; wk 12: SMD, 19.59; 95% CI, 9.05 to 30.13) and external rotation at 1, 2, 4 weeks postinjection (wk 1: SMD, 5.67; 95% CI, 0.88 to 10.47; wk 2: SMD, 9.62; 95% CI, 5.57 to 13; wk 4: SMD, 6.89; 95% CI, 2.45 to 11.33) in the BTX group.

CONCLUSIONS

BTX-A injection provided greater analgesic effects and increased shoulder abduction and external rotation ROM compared with steroid or placebo injection for the treatment of HSP.

Onset and Duration of AbobotulinumtoxinA for Aesthetic Use in the Upper face: A Systematic Literature Review

OBJECTIVE: We sought to analyze the current literature regarding time to onset and duration of effect of abobotulinumtoxinA (aboBoNT-A, Dysport®/Azzalure®) for upper facial aesthetic indications. METHODS: We conducted a systematic review of literature databases (PubMed/MEDLINE, Embase, Cochrane Library, and Google Scholar) to identify English-language publications relevant to: population (patients with aesthetic indications [including glabellar lines and wrinkles]); interventions (aboBoNT-A); comparators (no restrictions); outcomes (efficacy, including onset of action and duration of effect); and settings (clinical). A manual search of review paper bibliographies was performed. Structured data extraction was used to enable interstudy analysis. RESULTS: Overall, 42 original research papers relevant to aboBoNT-A onset and/or duration were identified. All 24 studies assessing efficacy within one week post-injection demonstrated some response at the first time point assessed, and all 37 studies assessing duration showed some response after 12 weeks. Although methodologies for assessing onset and duration differed, when outcomes were refined by reported mean/median, at least 50 percent of patients responding to treatment, or significance versus placebo or baseline at a given time point, onset was most often reported within 2 to 3 days (7 studies), and as early as 24 hours (2 studies). Duration was most often reported as four months (18 studies), although four studies provided evidence that aboBoNT-A efficacy was maintained at five months and three studies at or after six months post-injection. CONCLUSION: This review indicates that aboBoNT-A has a median onset of efficacy of 2 to 3 days and a longer duration of action (3-6 months across studies) than the current labelled minimum treatment interval (12 weeks).

An Italian experience of a new personalized injective protocol (Botutouch) for botulinum toxin application in aesthetic medicine

Botulinum toxin typeA (BoNTA) is widely used in aesthetic medicine as primary treatment to reduce facial wrinkles. Major unmet needs in the field of the injection techniques include dilution factor, injected volume and site. Since 2013, an innovative protocol has been developed in our clinic that works on a double dilution volume, identifies the injection site according to the specific anatomical-functional characteristics of each patient's musculature and applies a gentle massage to the injected area to optimize the toxin spread in the muscle. We retrospectively retrieved medical records of subjects that underwent aesthetic treatments in our outpatient Italian clinics from 2013. In cobotulinum toxin A was used in double dilution (100 AU in 5 mL of physiologic solution) and followed by a gentle massage after the injection to increase the distribution into the muscle. 197 subjects, most of them drug-naïve (81.7%), underwent 869 BoNTA treatments. On average, higher total units and volumes were applied in first visits or older subjects whereas the lower ones were preferred in following visits or younger subjects. As perceived by the patients, the effects of BoNTA lasted more than 6 months in about 38% of the cases. 95.9% of subjects declared to be satisfied,whereas 5.2% of adverse events were observed (4.8% hematoma, 0.2% ptosis, and 0.2% tenderness). To date, we offer a BoNTA treatment with the aim to maximize the results and consequent patient's satisfaction, with low incidence of complications.

Efficacy, Safety, and Subject Satisfaction After AbobotulinumtoxinA Treatment for Moderate to Severe Glabellar Lines

BACKGROUND

The aesthetic use of botulinum toxins is widely accepted in routine treatment of glabellar lines.

OBJECTIVE

To strengthen existing efficacy and safety data, and examine subject satisfaction concerning abobotulinumtoxinA (ABO) treatment for moderate to severe glabellar lines.

MATERIALS AND METHODS

A 150-day prospective, single-dose, multicenter, randomized, parallel-group, placebo-controlled, double-blind study of 300 subjects treated with ABO (50 Units [U]). Response was defined as having no or mild glabellar lines after treatment (primary objective was Day 30 response). Glabellar line severity, onset and duration of effect, satisfaction, treatment emergent adverse events (TEAEs), and treatment-related adverse events (TRAEs) were assessed.

RESULTS

Median time to onset of effect was 2 days. Day 30, ABO treatment response was 89% and 85% for investigator and subject assessments, respectively (p < .001 vs placebo). At Day 120, 60% of subjects demonstrated ≥1 grade improvement and 45% at Day 150. Subject satisfaction concerning glabellar line appearance was high (93%) at Day 14 and maintained by 35% through Day 150 with ABO treatment. No serious AEs were related to study treatment.

CONCLUSION

Most ABO-treated subjects sustained ≥1 grade glabellar line improvements over 120 days, and satisfaction was maintained by >30% of subjects throughout 150 days. ABO was well tolerated.

Clinical Assessment of 2 Licensed AbobotulinumtoxinA Injection Volumes for the Treatment of Glabellar Lines

BACKGROUND

Two licensed reconstitution volumes may be used to achieve the recommended abobotulinumtoxinA (ABO) dose for glabellar line correction.

OBJECTIVE

Comparison of efficacy, safety, and subject satisfaction concerning treatment of moderate to severe glabellar lines with 2 different ABO reconstitution volumes.

MATERIALS AND METHODS

Phase IV, prospective, randomized, multicenter, subject- and evaluator-blinded study: 60 subjects received 1 ABO (50 units) treatment, administered as a 1.5- or 2.5-mL reconstitution. Primary objective was Day 30 improvements (≥1-point) in glabellar line severity. Onset of effect, duration, subject satisfaction, and treatment-related adverse events (AEs) were assessed.

RESULTS

At Day 30, 90.0% and 86.7% of subjects achieved ≥1-point improvements with 1.5- and 2.5-mL reconstitutions, respectively. Median time to onset of effect was 48 hours after treatment. At 24 hours, 26.7% achieved ≥1-point improvements with the 2.5-mL reconstitution versus 6.7% with the 1.5-mL reconstitution. Maximum response was at Day 14, and >40% maintained efficacy through Day 120 in each group. High subject satisfaction was sustained throughout observation. Most AEs were mild. No serious AEs were reported.

CONCLUSION

Both ABO reconstitutions were well tolerated and effective in correcting glabellar lines with no significant differences concerning efficacy or duration of effect. No serious AEs were reported.

Neurotoxin Impurities: A Review of Threats to Efficacy

Recently launched esthetic botulinum toxin serotype A (BoNT/A) products include Nabota/Jeuveau, Meditoxin/Neuronox, and Botulax, which contain nontoxic accessory proteins and excipients. Clinical evidence supporting these formulations, including their purity and potential immunogenicity or their link to treatment failures, is limited. Any nonhuman protein, including nontoxin accessory proteins, can initiate immune reactions, especially if administered repeatedly, yet the issue of BoNT/A-induced immunogenicity is widely contested. However, there have been multiple reports of treatment failures and observations of BoNT/A-induced neutralizing antibodies. Compared with the purified formulation in Xeomin, these recently launched toxins contain higher total neurotoxin quantities, much of which is inactive and exposes patients to potentially immunogenic nontoxin proteins or inactive neurotoxins that increase their risk of developing treatment failure. Well-established products [especially abobotulinumtoxinA (Dysport), onabotulinumtoxinA (Botox) and Xeomin] are accompanied by comprehensive and long-ranging clinical evidence on safety and efficacy in esthetic facial indications, which still remains undisclosed for many of the recently introduced toxins. Clinicians need this information as patients will require repeated BoNT treatments and may be unnecessarily but cumulatively exposed to potential immunogens. To underscore the need for caution and further evidence, we review some of the issues surrounding BoNT/A-induced immunogenicity and antibody-induced treatment failures and argue that using highly purified toxins that do not negatively impact patient outcomes is a prudent clinical decision.

Liquid Formulation of AbobotulinumtoxinA: A 6-Month, Phase 3, Double-Blind, Randomized, Placebo-Controlled Study of a Single Treatment, Ready-to-Use Toxin for Moderate-to-Severe Glabellar Lines

Background

Safety and efficacy of botulinum toxin A for glabellar line (GL) treatment are well established. Currently approved formulations require reconstitution before injection.

Objectives

The authors sought to assess 6-month efficacy, safety, and patient satisfaction of new ready-to-use abobotulinumtoxinA solution for injection (ASI) in patients with moderate-to-severe GL at maximum frown.

Methods

The authors conducted a phase 3, double-blind, randomized, placebo-controlled trial (NCT02353871). Patients (N = 185) were randomized (2:1) to receive ASI 50 U or placebo. GL severity was evaluated at days 8, 15, 29, 57, 85, 113, 148, and 183 employing a 4-point scale for investigator’s live assessment (ILA) and subject's self-assessment (SSA). Primary endpoint was ILA of GL at maximum frown at day 29, and secondary endpoints were ILA and SSA of GL at maximum frown (all time points), patient satisfaction with GL appearance, time to onset, and duration of action.

Results

Responder rates were significantly higher for ASI vs placebo (88.3% vs 1.4%; P < 0.0001) at day 29 by ILA and all time points by ILA (P < 0.0001-0.0441) and SSA (P < 0.0001-0.0036). Sixty percent of patients reported onset of treatment response on or before day 3 (P < 0.0001 vs placebo), and in 5% of patients, efficacy by ILA lasted 6 months (day 183; P = 0.0441 vs placebo). Patient satisfaction rates were significantly higher for ASI vs placebo at all visits (P < 0.0001). Safety was comparable with the known abobotulinumtoxinA profile.

Conclusions

ASI was significantly efficacious for improving moderate or severe GL vs placebo by investigator and patient assessment. ASI was associated with high patient satisfaction, a long duration of action, and comparable safety profile to abobotulinumtoxinA.

Level of Evidence: 1

AbobotulinumtoxinA for Facial Rejuvenation: What Affects the Duration of Efficacy?

AbobotulinumtoxinA (Dysport) has a long history as a safe and effective treatment option for aesthetic rejuvenation. One of the key measures of botulinum toxin efficacy is the persistence of clinically meaningful results. The duration of efficacy depends on different factors, many of which can be controlled by the clinician to better achieve their desired results. In this review, we discuss how dose, individual patient variation, and injection technique affect the duration of botulinum toxins. Increased duration may result from increased dose or more precise placement of the toxin in the muscle. The varying anatomy and behavior of patients can affect duration as well. Measures of duration in clinical studies vary, but both a 1-grade improvement on the glabellar line severity scale and patient-reported outcomes are key measures. The clinical effects of Dysport can last up to 5 months, and patients in Dysport clinical studies remained satisfied with treatment for up to 6 months. Dysport has a legacy of safety, efficacy, and high subject satisfaction demonstrated through studies and clinical experience. Building on that legacy by correctly dosing the subject, properly accounting for the individual subject anatomy and behavior, and using specific injection techniques can help ensure that your patients have the longest lasting results.

IncobotulinumtoxinA for the Treatment of Glabellar Frown Lines: A Prospective, Multicenter, Single-arm Study in Taiwan

Objective: We assessed clinical effectiveness, longevity of treatment effects, and patient satisfaction with incobotulinumtoxinA for glabellar frown lines (GFL) treatment in Asian patients. Design, Setting, and Participants: This was a prospective, multicenter, single-arm, open-label study at six sites in Taiwan. Patients aged 20 to 65 years with mild to very severe GFLs (Merz scale: 1-4 points) were eligible; 45 patients [including 23 BoNT/A-naïve and 22 previously-treated ("switch") patients were enrolled. Patients received intramuscular incobotulinumtoxinA injection at up to five injection points. Total doses ranged from 12 to 20U. Measurements: Investigators assessed improvements in dynamic GFLs at Days 14 and 120 using the validated five-point Merz scale (0=no lines; 4=very severe lines). Treatment satisfaction was self-reported by patients via questionnaire. Results: All patients showed excellent response to treatment in that Merz scores at Day 14 were 0 or 1 point(s). Both groups showed a mean improvement of 2.9 points; the response rate (1-point improvement or more from baseline) was 100 percent. GFL improvement was maintained over at least four months in both groups (mean improvements at Day 120: 1.5 points, naïve; 1.7 points, switch). Patient satisfaction ratings remained high (almost 100% in both groups) throughout the study. There were no statistically significant differences between groups regarding treatment satisfaction or GFL improvement (Merz score) at Days 14 and 120. No adverse events occurred. Conclusion: In Asian patients, incobotulinumtoxinA treatment for dynamic GFLs is effective and long lasting, with no expected differences between BoNT/A-naïve patients and those switching from other BoNT/As. IncobotulinumtoxinA yields consistent and natural-looking results for first and subsequent treatments.

Botulinum Toxin Application in Facial Esthetics and Recent Treatment Indications (2013-2018)

Background

Ever-changing perception of beauty from childhood to old age is changing with the revolution in cosmeceuticals science. Esthetics is an individual's perception since time immemorial. Standards of beauty have changed through centuries with increased awareness about esthetics. The face remains main source of information for identification and discrimination. It constitutes a structural ground for many nonverbal messages including the emotional state of a person, so the proverb "Face is an index of mind" holds good. The wrinkles and laxity are considered to be one of the factors for aging. Hence, escalating demand for cosmetic treatment to reduce facial wrinkles and laxity has stimulated us to search for published literature for nonsurgical techniques for enhancement of facial beauty. The review analyzed the published data to provide narrative basic review in a concise way to the beginners, clinicians, and students.

Materials and Methods

We have adopted search criteria using keywords: Botox, Botulinum toxin, incobotulinumtoxinA, esthetics, face, uses of Botox, with various Boolean operators and or in title, and abstract using PubMed search engine. The database search limited to PubMed only from January 2013 to June 2018.

Results

Various search results have been appended as annexures at the end of the article for further reference for the readers. Finally, 17 references were selected to write narrative review to meet our objectives.

Conclusion

The advancing front in the use of toxins is an emerging science for the beautification of a face. Botox exploded in to market because of efficacy, tolerability, and minimally invasive nature. The present review gives brief about the history of Botulinum toxin, types, mechanism of action, clinical indications, preparations, storage, and technique for various uses with a brief note on patient selection, contraindications, and complications.

Nonsurgical Management of Facial Masculinization and Feminization

BACKGROUND

Transgender patients may seek nonsurgical methods for facial masculinization and feminization as an adjunct or alternative to undergoing surgical procedures.

OBJECTIVES

The authors reviewed the existing literature regarding this topic and provided an overview of nonsurgical techniques for facial masculinization and feminization.

METHODS

A comprehensive literature search of the PubMed and MedLine databases was conducted for studies published through December 2017 for techniques and outcomes of nonsurgical facial masculinization and feminization. Keywords were used in performing the search. Data on techniques, outcomes, complications, and patient satisfaction were collected.

RESULTS

Four articles fit our inclusion criteria. Given the lack of published literature describing facial injectables in transgender patients, data from the literature describing techniques in cisgender patients were utilized to supplement our review.

CONCLUSIONS

Facial feminization can be achieved through injectables such as neurotoxin and fillers for lateral brow elevation, lip augmentation, malar augmentation, and improvement of rhytids. Facial masculinization can be achieved with injectables used for genioplasty, jawline augmentation, and supraorbital ridge augmentation. One must develop best practices for these techniques in the transgender patient population and increase awareness regarding nonsurgical options.

LEVEL OF EVIDENCE: 4

Simulation: An Effective Method of Teaching Cosmetic Botulinum Toxin Injection Technique

BACKGROUND

Learning to inject botulinum toxin for cosmetic purposes is difficult for beginners, given the nature of the procedure and patient population. Simulation training is an effective modality for medical professionals to acquire skills in an environment that provides low stress and ample opportunity for questions and correction of mistakes.

OBJECTIVES

Compare posttraining comfort, knowledge, and practical botulinum toxin injection scores among trainees who underwent simulation vs video training only.

METHODS

A total of 20 nurse practitioners, physician assistants, and resident physicians underwent cosmetic botulinum toxin injection training either through lecture and video, or lecture and hands-on simulation training. Comfort, knowledge, and practical test scores were recorded and compared between the groups.

RESULTS

There was no evidence of a statistically significant difference in comfort or knowledge scores between simulation and video groups. The median (range) practical score was significantly higher in the simulation group compared to the video group (59.0 [31-60] vs 44.5 [27-57]; P < 0.01).

CONCLUSIONS

Despite feeling similarly comfortable and having similar written knowledge test scores, the trainees who underwent simulation training had significantly higher hands-on practical test scores compared to trainees who underwent video training only for cosmetic botulinum toxin injections.

Botulinum neurotoxin formulations: overcoming the confusion

Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity). In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed.

The Use of Botulinum Neurotoxin Type A in Aesthetics: Key Clinical Postulates

BACKGROUND

The most common aesthetic procedure performed worldwide is the injection of botulinum neurotoxin Type A (BoNT-A). Aesthetic providers must fully comprehend the objective scientific data, theoretical mechanisms of action, and differences between brands of BoNT-A.

OBJECTIVE

To determine and review the relevant clinical postulates for the use of botulinum toxin in aesthetics.

MATERIALS AND METHODS

The BoNT-A clinical postulates presented here discuss how each brand of BoNT-A acts identically, how the molecular potency may vary between the different products, how patient age, gender, genetics, and muscle mass cause variation in toxin receptor number and density, and how both practitioner and patient can affect toxin distribution.

RESULTS

A total of 8 clinical postulates have been identified that are key to understanding the use of botulinum toxin in aesthetics and to obtaining the best clinical results.

CONCLUSION

All of these factors affect the potential efficacy of the injected toxin and hence the aesthetic results obtained.