Botulinum A exotoxin for glabellar folds: a double-blind, placebo-controlled study with an electromyographic injection technique

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 .

Efficacy and safety of Botulinum toxin A for improving esthetics in facial complex: A systematic review

AIM

To evaluate efficacy and safety of Botulinum toxinA for improving esthetics in the facial complex and correlating them to the dosage and side effects through a systematic review.

METHODS

A literature search was performed using PubMed, Medline, Web of Sciences, and Scopus databases. Quality of studies was appraised through the GRADE system. This review follows the 'Preferred reporting items for systematic review and meta-analysis protocols' (PRISMA-P) 2015 statement. Efficacy was analyzed through improvement rate and effect sizes. Graphical comparison of efficacy and ocular adverse effects (adverse effects around the eye) at various anatomical locations was made by calculating the average improvement rate and adverse events.

RESULTS

Twenty-five studies were included in this systematic review after application of the inclusion criteria. Moderate to severe cases in glabellar, lateral canthal, and forehead regions showed higher improvement rates between 20U to 50U, with an effect lasting up to 120 days. Gender and age seemed to have a direct effect on efficacy. Headaches were the most common adverse effect, followed by injection site bruising; all adverse effects resolved within 3-4 days.

CONCLUSIONS

Treatment with Botulinum toxinA to enhance esthetics of facial complex is efficient and safe at all recommended dosages. Presence of complexing proteins influenced the efficacy of BoNT-A. undesirable muscular adverse effects around the eyes were more predominant when treating the glabellar region. There was no correlation found between the BoNT-A dosage and side effects, however, an increase in dosage did not always lead to an increase in efficacy.

Tissue Modification in Nonsurgical Facelift Options

Nonsurgical facelifts are a term for a heterogeneous group of procedures used by physicians to improve facial rejuvenation without the use of operative techniques. Patients demand these services due to the reduced recovery time and generally lower risk. However, nonsurgical techniques, to be effective, must induce conformational change in the cells and tissues of the face. Therefore, these techniques are significant procedures that have associated risks. Understanding the tissue modifications and mechanisms of action of these techniques is vital to their safe and effective use. The purpose of this article is to provide a background of tissue modification in nonsurgical facelift options.

A review of the longevity of effect of botulinum toxin in wrinkle treatments

Botulinum toxin is widely used in facial rhytide treatments. The duration of its effects influences treatment intervals, cost and convenience to the patient. These are key factors in successful aesthetic procedures. A review of the literature found that duration of effect was between two and six months, with most experiencing loss of maximal contraction for three to four months. Treatments may last between three to four months, and occasionally up to six months. No specific definition of effectiveness/efficacy has been described and used to measure comparable end points. Additional research should help clarify the impact of brand, age, gender, ethnicity, repetition of treatment and zinc-phytase supplementation.

Injectable and topical neurotoxins in dermatology: Basic science, anatomy, and therapeutic agents

Botulinum toxin is a potentially deadly anaerobic bacterial toxin that acts by inhibiting release of acetylcholine at the neuromuscular junction, thereby inhibiting contraction of the exposed striated muscle. There are currently 4 botulinum toxin preparations approved by the US Food and Drug Administration (FDA): onabotulinumtoxin, abobotulinumtoxin, incobotulinumtoxin and rimabotulinumtoxin. While significant overlap exists, each product has unique properties and specifications, including dosing, diffusion, and storage. Extensive physician knowledge of facial anatomy, coupled with key differences of the various neurotoxin types, is essential for safe and successful treatments. The first article in this continuing medical education series reviews key characteristics of each neurotoxin, including new and upcoming agents, and provides an anatomic overview of the most commonly injected cosmetic sites.

A Comparative Assessment of Three Formulations of Botulinum Toxin Type A for Facial Rhytides: A Systematic Review with Meta-Analyses

BACKGROUND

Three formulations of botulinum toxin are available for facial rhytides. It is unclear which formulation offers the greatest balance of benefits and harms. The objective of this study was to conduct a systematic review with meta-analyses to compare formulations of botulinum toxin for reduction of facial rhytides at the glabella.

METHODS

The authors' protocol was registered with the International Prospective Register of Systematic Reviews (CRD4201200377). A systematic literature search was performed identifying double-blind studies. The authors assessed 1-, 3-, and 4-month follow-up. The authors performed pairwise meta-analyses using random effects models to compare response rates among the three botulinum formulations and a network meta-analysis.

RESULTS

A total of 18 studies (3082 patients) were included. At 30-, 90-, and 120-day follow-up, all medications with available data showed statistically significantly increased treatment response versus placebo. Only high-dose onabotulinum toxin (compared to standard-dose onabotulinum toxin) offered additional benefit at 30 days. Exploratory analysis using network meta-analysis mostly suggested insufficient evidence of incremental benefits when comparing specific formulations.

CONCLUSIONS

Evidence supporting benefits versus placebo of the different formulations was clear over time. Comparisons between active formulations were rare and typically based on single trials of small to moderate sample size. The data suggest some gains with high-dose onabotulinum toxin (relative to standard dose), whereas exploratory indirect comparisons between active formulations were largely associated with inconclusive findings. Future studies should undertake head-to-head comparisons of the different formulations and ensure longer follow-up to best inform the accumulating evidence base.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

OnabotulinumtoxinA: a meta-analysis of duration of effect in the treatment of glabellar lines

BACKGROUND

Duration of effect of aesthetic treatments with botulinum toxin potentially influences subject satisfaction, treatment frequency, and annual costs, but quantitative outcomes for measuring duration of effect and correlations with subject satisfaction have yet to be fully elucidated.

METHODS AND MATERIALS

Phase III clinical trials with similar designs were identified and their data pooled to ascertain duration of clinical effect of onabotulinumtoxinA in glabellar muscles. Duration was calculated using the Kaplan-Meier method for investigator-rated Facial Wrinkle scale (FWS) scores and subject global assessment (SGA) of glabellar lines. Responders were determined according to FWS score at maximum contraction and at repose 30 days after injection.

RESULTS

Data from four trials with 621 onabotulinumtoxinA-treated (20 U) subjects were analyzed, 523 of these (84.2%) were identified as day-30 responders on the FWS at maximum contraction. Pooled median duration of effect for day-30 responders was 120 days for FWS at maximum contraction and 131 days for FWS at repose. Higher day 30 SGA scores were correlated with a greater duration of effect on dynamic, but not static lines.

CONCLUSION

Treatment of glabellar lines with 20 U of onabotulinumtoxinA resulted in sustained clinical benefit for 4 months in more than 50% of responders; subject satisfaction increased with duration of effect.

Botulinum toxins for facial lines: a concise review

This is a concise review of the uses of botulinum toxins (BTXs) in dermatology and cosmetic procedures. It is a clinical rather than a basic science, pharmacological review. BTX had been initially used for selectively reducing and balancing periorbital muscle activity; thereby, reducing childhood strabismus and blepharospasm. This clinical research was initiated by Dr. Alan Scott over 40 years ago. BTX type A (BTX-A) was serendipitously observed to reduce forehead frown lines in patients being treated for blepharospasm. Extensive clinical research and development resulted in widespread aesthetic uses for BTX-A by reduction of selected hyperfunctional facial muscles. BTXs are also used for reduced localized hyperhidrosis. A topical BTX-A is being developed as a potential alternative to injected BTX.

The use of botulinum toxin type A in cosmetic facial procedures

Over the past decade, facial cosmetic procedures have become more commonplace in dentistry and oral and maxillofacial surgery. An increasing number of patients seek minimal invasive procedures. One of the most requested procedures is treatment with botulinum toxin type A (BoNTA). Treatment of dynamic rhytids and lines with BoNTA is effective and produces high rates of improvement with rapid onset and long duration of action (longer than 4 months for some patients) compared with placebo. This paper considers the history and pharmacology of this neurotoxin, and focusses on the literature concerning the treatment of different facial areas with BoNTA. It also presents clinical guidelines on the treatment of glabellar lines, the frontalis muscle, peri-orbital lines, gummy smile and masseter muscle hypertrophy. Knowledge about the mechanisms of action and the ability to use BoNTA as an adjunctive treatment are mandatory for those working in the field of cosmetic facial surgery.

A phase IIa open-label dose-escalation pilot study using allogeneic human dermal fibroblasts for nasolabial folds

BACKGROUND AND OBJECTIVE

The correction of soft tissue contour defects and dermal atrophy is a growing area driven by medical and aesthetic need. Deterioration of the skin's appearance occurs as a result of age and trauma, such as surgery, infections, and acne. Typically, imperfections are treated with volume-correcting fillers. This study evaluated allogeneic human dermal fibroblasts (HDFs) for the treatment of nasolabial folds as an alternative strategy to improve the structure, texture, and quality of the skin.

METHODS AND MATERIALS

In this phase IIa study, a suspension of allogeneic HDF (2 × 10(6) cells/mL or 2 × 10(7) cells/mL) was injected intradermally along the nasolabial fold; line severity was assessed using a photographic scale.

RESULTS

Mean investigator satisfaction was 7.4 (range 4.7-9.5) at 12 weeks and 7.6 (range 4.4-9.8) at 24 weeks. Subject satisfaction scores were 7.0 (range 0.1-10.0) at 12 weeks and 7.8 (range 1.5-10.0) at 24 weeks. All patients experienced adverse events, the majority of which were deemed treatment related. Most were mild to moderate in severity and resolved completely.

CONCLUSION

This study demonstrated that allogeneic HDF can produce an improvement in aesthetic appearance with minimal adverse events and warrants further investigation and development. Intercytex provided financial support for this study. John Roberts is an employee of Intercytex.

Dosing, efficacy and safety plus the use of computerized photography for botulinum toxins type A for upper facial lines

INTRODUCTION

Several studies confirm that botulinum toxins type A (BTX-A) are effective for reducing facial lines caused by hyperactive muscles. Two different commercial types of BTX-A currently available are BTX-A-1 (Botox) and BTX-A-2 (Dysport). This paper reports further comparison of dosing, efficacy and safety.

METHODS

Sites treated: glabellar, horizontal forehead lines and crow's feet. Different dilutions and dosages were studied with BTX-A-1 and BTX-A-2. The reduction of facial lines was evaluated by investigators and patients. Computerized photographic numerical assessment was also studied in determining the efficacy of BTX-A for crow's feet lines.

RESULTS

Study 1: Injecting glabellar lines at doses of BTX-A-1 (30 units) and BTX-A-2 (75 units) (2.5:1 ratio BTX-A2:BTX-A1) showed similar efficacy. Study 2: BTX-A-2 (256 units total) was significantly more effective than BTX-A-1 (64 units total) (i.e. a dose ratio of 4:1) for upper face lines. No differences in the side-effect profiles between the two toxins were observed in either study. Study 3: A computerized photographic numerical assay was an objective assessment of crow's feet severity. Using a dose ratio of BTX-A-2 to BTX-A-1 of 3:1 showed a trend towards BTX-A-2 superiority.

CONCLUSION

Two different botulinum toxins type A were shown to be effective and safe for hyperfunctional facial lines. The choice of dose, dilution and placement is critical for each individual toxin. Computerized photography gave numerical severity scores of crow's feet severity.

Botulinum toxin type A for the management of glabellar rhytids

There is an increasing demand for minimally-invasive cosmetic procedures to arrest the aging process. Botulinum toxin type A injections are the most commonly used nonsurgical cosmetic procedures in the United States. There has been research spanning over two decades dedicated to safety, efficacy, dosing, and complications of botulinum toxin type A. There are now two Food and Drug Administration (FDA) approved botulinum toxin type A options in the United States: Botox(®) and Dysport(™), with new advances being made in the field.

Botulinum toxin type A for the treatment of glabellar lines in Chinese: a double-blind, randomized, placebo-controlled study

BACKGROUND

This is the first well-controlled study of the use of botulinum toxin type A (BoNTA) for glabellar lines in China.

OBJECTIVES

To evaluate the safety and efficacy of BoNTA in the treatment of glabellar lines in Chinese subjects.

MATERIALS AND METHODS

A total of 227 subjects received a single treatment in a 3:1 randomization ratio of BoNTA (20 U):placebo and were observed for 120 days after injection. Effective outcome measures included investigator's rating of wrinkle severity at maximum frown and rest and subjects' global assessment and self-perception of age.

RESULTS

A significantly higher responder rate at maximum frown, ranging from 94.1% at day 30 to 52.9% at day 120, was noted in the BoNTA group. The proportion of subjects with none or mild glabellar lines at rest was 66.7% in the BoNTA group at day 30. Most (95.3%) of the subjects treated with BoNTA reported better than 50% improvement at day 30, and self-perception of age was less than chronological age. There were no statistically significant differences in adverse events reported between the two groups (p=.06).

CONCLUSION

A single treatment of 20 U of BoNTA was effective and safe in reducing glabellar lines in Chinese subjects.

Facial aesthetics: is botulinum toxin treatment effective and safe? A systematic review of randomised controlled trials

BACKGROUND

The use of botulinum toxin type A (BTA) in facial aesthetics for the treatment of wrinkles has recently become more popular as an alternative to surgical techniques. However, its true efficacy and potential adverse effects are still unclear.

OBJECTIVES

The primary objective of this study was to review the efficacy of BTA in facial aesthetics. A secondary objective was to determine whether there are any adverse effects associated with the procedure of using BTA in facial aesthetics.

SEARCH STRATEGY

We conducted literature searches on Medline (1977 to January 2009), Cochrane Controlled Trials Register (CENTRAL), EMBASE (1977 to January 2009) and CINAHL (1977 to January 2009). The search strategy also included reference lists of located articles and hand searching for randomised controlled trials (RCTs). We contacted authors of studies for further information where required.

SELECTION CRITERIA

Randomised studies comparing BTA with placebo in facial aesthetics in a double-blind and crossover or parallel group design.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. The area of face injected, assessment methods, outcome measures, duration of action of BTA and associated adverse effects were reviewed.

RESULTS AND DISCUSSION

A total of eleven RCTs involving 1,603 subjects were found, of which 1,203 were enrolled for treatment with BTA. The 11 trials were not directly comparable to each other due to differences in the areas of the face injected with BTA, length of study period, concentration of BTA used and outcome measures. The studies showed similar trends. The use of BTA showed improvements in facial wrinkles over placebo, with a peak effect reported at around one month and the effects lasting between 4-6 months. No studies reported any severe adverse effects. The incidence of blepharoptosis in glabellar lines treated with BTA was reported to be between 0-5.4%, and may be related to the technique of injection into the muscles. The incidence of other side-effects such as headache, pain at injection site and mild bruising was similar in both the BTA and placebo groups.

AUTHORS' CONCLUSIONS

The use of BTA in facial aesthetics is more effective than placebo. The incidence of adverse effects associated with BTA is similar to placebo, with the exception of blepharoptosis which is reported to be 0-5.4% after treatment of glabellar lines with BTA.

Safe botulinum toxin type A injection in patients with history of eyelid ptosis

BACKGROUND

Ptosis is an important side effect of frown correction by botulinum toxin type A (BTX-A). The most likely reason of eyelid ptosis is the diffusion of the toxin to levator palpebrae superioris muscle through orbital septum while the toxin is injected into the corrugator muscle.

OBJECTIVES

In this pilot study, to prevent ptosis, we evaluated the efficacy of BTX-A injection at superior middle aspect of the corrugator muscle instead of the common injection site located above the medial eyebrow head.

METHODS

Fifteen patients were selected from those referred to our clinic with history of eyelid ptosis due to previous BTX-A (dysport; Ipsen) injection. They received three injections of BTX-A; 10 U into the procerus muscle and 20 U into the superior middle aspect of each corrugator muscle, instead of injecting into the belly of the corrugator muscles.

RESULTS

We observed excellent, good and moderate responses in 66.66%, 13.33% and 20% of our patients 2 weeks post-injection respectively. The outcomes were improved to excellent in the latter two groups by injecting 5 U of BTX-A (dysport; Ipsen) into the contractible corrugator in patients with good and 5 U in each corrugator (total of 10 U) in patients with moderate responses.

CONCLUSION

Employing this method a very satisfactory outcome was obtained while no ptosis was observed. Therefore, we recommend this safe technique for treating patients with a history of eyelid ptosis.

Overview of botulinum neurotoxins

Dr Alan Scott's seminal investigations in the 1970s into the use of botulinum neurotoxin for strabismus represent the pivotal moment in its clinical research. In the decades that followed, botulinum neurotoxin was increasingly studied for therapeutic and aesthetic use. Currently, several botulinum neurotoxin products are available worldwide, with only a few investigated for cosmetic applications, and only one currently approved for facial aesthetic use in the United States. Comparisons among the agents are challenging due to a limited number of controlled studies. The few comparative studies published have contributed to a better understanding of the relative efficacy and safety of these products, but factors such as a broad clinical research experience, approved indications, and pharmacologic characteristics of each agent also influence choice of therapy. Issues such as botulinum neurotoxin resistance and selection of injection sites have also emerged as considerations for treatment selection. This article provides an overview of currently available botulinum neurotoxin products, including a review of key comparative aesthetic data and a discussion of issues related to botulinum resistance and injection site selection from leading experts in the fields of dermatology and plastic surgery.

Reproducibility of two four-point clinical severity scores for lateral canthal lines (crow's feet)

BACKGROUND

Several clinical scoring systems have been used to evaluate the efficacy of botulinum toxin A in the treatment of hyperkinetic wrinkles. So far very few have been investigated for their reproducibility.

OBJECTIVE

The aim of this study was to investigate the reproducibility of two clinical four-point scales for lateral canthal lines (crow's feet), at rest and at maximum smile.

MATERIAL AND METHODS

Based on standardized photographs, a consensus atlas depicting the different severity grades [from 0 (none) to 3 (severe)] was developed. After training based on the atlas, 49 photographs at rest and 48 at maximum smile were graded by the same group of investigators on 2 consecutive days (n=9 on Day 1; n=8 on Day 2). The scores were compared for reproducibility using kappa statistics.

RESULTS

Overall, reproducibility was good for both scales. Interobserver reproducibility showed an agreement of 0.6 at rest and 0.58 at maximum smile (unweighted kappa). Intraobserver reproducibility showed an agreement between 0.47 and 0.86 at rest and between 0.62 and 0.81 at maximum smile (unweighted kappa). Using weighted kappa analysis, the agreement ranged between 0.63 and 0.91 at rest and between 0.71 and 0.85 at maximum smile.

CONCLUSION

The clinical scales using scores of 0 to 3 for crow's feet, both at rest and at maximum smile, show a good inter- and intraobserver reproducibility. The use of these scores in clinical trials can be recommended.

Botulinum toxin: Clinical use

Since its development for the use of blepharospasm and strabismus more than 2.5 decades ago, botulinum neurotoxin (BoNT) has become a versatile drug in various fields of medicine. It is the standard of care in different disorders such as cervical dystonia, hemifacial spasm, focal spasticity, hyperhidrosis, ophthalmological and otolaryngeal disorders. It has also found widespread use in cosmetic applications. Many other indications are currently under investigation, including gastroenterologic and urologic indications, analgesic management and migraine. This paper is an extensive review of the spectrum of BoNT clinical applications.

Interaction of botulinum toxin type A with local anesthetic agents: an experimental study with rabbits

Injection of botulinum toxin is a painful procedure, limiting the number of patients treated. This study was designed to establish whether infiltration of local anesthetics plays a role in the effectiveness of botulinum toxin. For the study, 24 New Zealand white rabbits were divided into three groups. In all three groups, local anesthetics (prilocaine, lidocaine, lidocaine, and epinephrine) were injected into the right anterior auricular muscle before a 2.5-U injection of botox A. The contralateral anterior auricular muscle of all the rabbits was injected with the same dose of the toxin to serve as a control. Photographic documentation was recorded; electromyographic study was performed; and results were statistically analyzed. The results show that local anesthetics do not play a role in the efficacy of botulinum toxin. Thus, the use of infiltrative local anesthetics before botulinum toxin injection is a safe method for achieving a less painful procedure for the patient.

Botulinum toxin - an update on its use in facial rejuvenation

The role of botulinum toxin in facial rejuvenation has been greatly expanded in the last several years. In this article, we first review the traditional approach to botulinum toxin therapy in the forehead and glabella. For the advanced reader, we then discuss both the literature and our personal approaches to treatments of the periocular region, mid face, lower face, and neck. Throughout the discussion, attempts are made to include a description of relevant anatomy, the physiologic result of specific muscle activity and denervation, and perhaps most importantly, precise directions for patient treatment.

Managing adverse events associated with botulinum toxin type A: a focus on cosmetic procedures

Botulinum toxin A (BTXA) has become a widely used drug in cosmetic dermatology, not only to treat focal hyperhidrosis but also hyperkinetic facial lines, platysma bands, décolleté bands, and other skin features. The spectrum of possible adverse effects of BTXA is broad but fortunately those that have been observed with cosmetic use of this product are generally mild and transient. The major tools for preventing adverse effects from BTXA are knowledge and skill. Use of correct injection techniques is mandatory since most unwanted effects are caused by incorrect technique. Knowledge of the target structures, e.g. the facial and extrafacial muscles, allows physicians to select the optimal dose, time and technique. The most common adverse effects are pain and hematoma. In the periocular region, lid and brow ptosis are important adverse effects. Adverse effects such as pain, hematoma, ecchymosis, and bruising may also occur in the upper and lower face and at extrafacial sites. Other possible adverse effects seen in other indications that the user of BTXA in cosmetic dermatology should be wary of include induction headaches and possible interaction with concomitant medications. Induction of neutralizing antibodies due to cosmetic BTXA treatment has not been observed. This article also outlines recommendations regarding use of BTXA. Of these, the most important for avoiding most unwanted adverse effects are the proper techniques of dilution, storage, and injection, as well as the careful exclusion of patients with any contraindications. Pain, hematoma, ecchymosis, and bruising can be prevented by cooling the skin before and after BTXA injection. Upper lid ptosis may be partly corrected using apraclonidine or phenylephrine eyedrops. If simple rules relating to the indications for and application of BTXA are followed, this is a safe and effective drug in cosmetic dermatology.

Measurement of the Anatomic Position of the Corrugator Supercilii

OBJECTIVE

To standardize the location of the corrugator supercilii by using known facial landmarks.

METHODS

The corrugator supercilii points of origin, insertion, and maximal muscle thickness were measured relative to the nasion and supraorbital notch in 21 cadavers. Comparisons of measurements between male and female cadavers were performed using a two-tailed t-test.

RESULTS

The location of the corrugator supercilii was variable but was not significantly different between males and females. From the nasion, the mean point of origin was 4 mm lateral and 6 mm superior, the mean point of insertion was 33 mm lateral and 16 mm superior, and the mean maximal muscle thickness was 16 mm lateral and 10 mm superior. At their point of greatest thickness, most corrugators were found to lie below the upper border of the superciliary arch.

CONCLUSIONS

There is variability in the location of the corrugator supercilii that is not gender dependent. When injecting botulinum toxin into the corrugator supercilii, it might be advantageous if the lower forehead skin of the brow is elevated, thus allowing for more precise injection. This may achieve weakness of the targeted muscle with lower doses of botulinum toxin, thus lessening the risk of eyelid and brow ptosis.

Complications of botulinum toxin A use in facial rejuvenation

The esthetic application of botulinum toxin type A (Botox) is a safe treatment modality; nevertheless complications can occur as a result of patient-and physician-related factors. Fortunately, adverse effects and undesirable sequelae after Botox injections are temporary. Complications may be more serious in patients who have more severe rhytids (which require more Botox), previous facial plastic surgery (altered anatomy), and those who have pre-existing neuromuscular disease. The physician can reduce complications by using proper injection techniques, appropriate regional Botox dosing, and by being conservative in the overall approach to Botox-mediated facial rejuvenation.

Consensus recommendations on the use of botulinum toxin type a in facial aesthetics

The use of botulinum toxin type A for facial enhancement is the most common cosmetic procedure currently undertaken in the United States. Overall clinical and study experience with botulinum toxin type A treatment for facial enhancement has confirmed that it is effective and safe in both the short and long term. Nevertheless, consistent guidelines representing the consensus of experts for aesthetic treatments of areas other than glabellar lines have not been published. Therefore, a panel of experts on the aesthetic uses of Botox Cosmetic (botulinum toxin type A; Allergan, Inc., Irvine, Calif.) was convened to develop consensus guidelines. This publication comprises the recommendations of this panel and provides guidelines on general issues, such as the importance of the aesthetic evaluation and individualization of treatment, reconstitution and handling of the botulinum toxin type A, procedural considerations, dosing and injection-site variables, and patient selection and counseling. In addition, specific considerations and recommendations are provided by treatment area, including glabellar lines, horizontal forehead lines, "crow's feet," "bunny lines" (downward radiating lines on the sides of nose), the perioral area, the dimpled chin, and platysmal bands. The review of each area encompasses the relevant anatomy, specifics on injection locations and techniques, starting doses (total and per injection point), the influence of other variables, such as gender, and assessment and retreatment issues. Factors unique to each area are presented, and the discussion of each treatment area concludes with a review of key elements that can increase the likelihood of a successful outcome. Summary tables are provided throughout.

Dilution, storage, and electromyographic guidance in the use of botulinum toxins

Botulinim toxin A (BTX-A) is available commercially in two formulations: Botox (Allergan, Inc. Irvine, California) and Dysport (Ipsen Limited, Berkshire, United Kingdom). To use BTX-A successfully for cosmetic purposes, it is important to understand the basic principles of BTX-A therapy and the specific guidelines for its use, including dilution and storage. Injection using electromyographic guidance is helpful in achieving correct placement of BTX-A by locating the muscle responsible for a particular facial line.

A multicenter, randomized, double-blind, placebo-controlled study of efficacy and safety of 3 doses of botulinum toxin A in the treatment of glabellar lines

BACKGROUND

Botulinum toxin A (BTX-A) is used to treat glabellar lines but the rigorous demonstration of its efficacy in a well-designed study had never been reported.

OBJECTIVE

This study was designed to evaluate the efficacy and the safety of 3 doses of BTX-A in the treatment of glabellar lines.

METHODS

A total of 119 patients with moderate to severe glabellar lines at rest were treated with 25, 50, or 75 U of BTX-A (Dysport, Ipsen) or placebo divided into 5 intramuscular glabellar sites. Outcome measures included evaluations of glabellar lines by independent experts from blinded standardized photographs at rest 1 month after treatment, physician evaluations, and patient assessments during a 6-month period.

RESULTS

A significant efficacy was reported for the 3 BTX-A groups for at least 3 months after injection (at least P <.015). Investigator and patient evaluations suggested that 50 U was the optimal dose. BTX-A was well tolerated. No blepharoptosis was reported. An evaluation in blinded conditions by independent experts was necessary because the results were overestimated by the investigators.

CONCLUSION

BTX-A is an effective and safe treatment for glabellar lines.

A Validated Rating Scale for Hyperkinetic Facial Lines

OBJECTIVE

To test the reliability of a simple rating system to describe hyperkinetic facial lines.

METHODS

A rated numeric kinetic line scale was developed and presented to 11 postresidency physicians specializing in aesthetic facial care. These physicians independently reviewed photographs of 20 patients, first at rest, then with activation of the frontalis, corrugator, and orbicularis oculi muscles. Kappa statistics for multiple raters were used to assess interobserver reliability.

RESULTS

The nonweighted kappa values were between 0.4 and 0.8 for the frontalis, corrugator, and orbicularis muscle groups. This represents moderate to substantial observer agreement and is highly significant for each muscle group.

CONCLUSIONS

A new rating scale for hyperkinetic facial lines accounts for facial appearance at rest and with expression. It is easily used and has interobserver reliability. As the only objective and validated scale for hyperkinetic facial lines, this rated numeric kinetic line scale is recommended for the evaluation of pretreatment and posttreatment results in patients undergoing therapy for this problem. Moreover, an alternative scale rating resting and kinetic lines as independent variables is also being developed. Both must be considered to evaluate treatment outcomes when using neurotoxins.

Botulinum toxin type A for the treatment of glabellar rhytides

Injections of BTX-A improve the appearance of glabellar rhytides by relaxing the underlying musculature in a quick and relatively painless procedure that can be performed over the lunch hour and causes few adverse effects. Alone or in combination with filling agents, BTX-A has become one of the most popular cosmetic procedures performed. Cosmetic facial aesthetics is a dynamic, rapidly evolving field, however, and producing the most optimal benefits means understanding the dynamics of facial musculature and principles of BTX-A therapy and remaining abreast of the latest clinical developments.

Type A botulinum toxin in the upper aspect of the face

The use of botulinum toxin type A (BTX-A) for facial rejuvenation was first systematically developed by Carruthers and Carruthers on the upper aspect of the face. In the early 1990s, the first studies of the cosmetic use of BTX-A were published. BTX-A was only approved in 2002, however, by the U.S. Food and Drug Administration when extensive cosmetic studies were evaluated. The treatment of facial wrinkles with BTX-A has truly changed the concepts held by physicians regarding facial rejuvenation, mainly on the upper aspect of the face. It is one of the most common cosmetic procedures currently performed by physicians.

Botulinum toxin A: its expanding role in dermatology and esthetics

The use of botulinum toxin A in cosmetic dermatology has increased in popularity due to the efficacy and relative safety of the treatment. Botulinum toxin A is one of eight exotoxins produced by Clostridium botulinum, a Gram-positive, spore-forming anaerobe. Flaccid paralysis results from the denervation of muscle fibers at the neuromuscular junction after botulinum toxin A administration. While treating blepharospasm, the Carruthers incidentally found that botulinum toxin A improved glabellar frown lines. Dynamic rhytides occur in areas of dynamic motion. These types of lines may be improved with botulinum toxin A. There are two types of botulinum toxin A commercially available (BOTOX and Dysport); only BOTOX is currently available in the US. The efficacy and tolerability of BOTOX was best demonstrated with a multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines in 264 patients. There was a significantly greater reduction in glabellar line severity with BOTOX. The effect was maintained for the duration of the study (120 days). There was low occurrence (5.4%) of mostly mild blepharoptosis in the BOTOX group. In another prospective study, it was found that about 1% of BOTOX patients reported severe headache. Botulinum toxin A can provide an alternative treatment of palmar and axillary hyperhidrosis when options such as topical agents (aluminum chloride) and iontophoresis have failed.

Cosmetic uses of botulinum toxins for lower aspects of the face and neck

The ability of botulinum toxin A (BTX-A) to improve the appearance of facial lines was first reported among patients who had been receiving injections for facial dystonias or surgical procedures. Since that time, there has been very extensive use of this treatment for relaxation of a wide variety of facial muscles and also for platysmal lines of the neck. Considerable experience over the last decade or longer confirms the safety and efficacy of BTX-A in the treatment of upper facial lines. BTX-A has been used also lower facial indications, but published papers are mainly uncontrolled observations on patients. Unlike the placebo-controlled studies on the upper face, there is a lack of controlled studies for lower face and neck BTX-A treatment. This article will summarize the use of BTX-A for the lower face and its role as combination treatment. Examples of combinations that may be used with BTX-A resurfacing, nonablative skin rejuvenation and skin fillers. Although little used at present, Botulinum Toxin B will be briefly discussed.

Botulinum toxin types A and B: comparison of efficacy, duration, and dose-ranging studies for the treatment of facial rhytides and hyperhidrosis

One of the most common etiologic forces for the persistence of facial rhytides is the repetitive contraction of the intrinsic muscles that are necessary for facial expression. These include the forehead lines, crow's feet, glabellar rhytides, and wrinkles in the lower face. Although filling agents such as collagen and laser procedures can help reduce the appearance of these lines, they do not address the underlying forces that cause these wrinkles to persist. Botulinum toxin type-A and type-B are neurotoxins that address these issues and result in the relaxation of the intrinsic facial muscles and subsequent resolution of these dynamic facial rhytides. This article will compare the efficacy, duration, dose ranging studies, and safety in the treatment of facial rhytides with both types of toxins. In addition, the treatment of hyperhidrosis with type-A and type-B botulinum toxin will also be discussed.

The role of botulinum toxin type B (Myobloc) in the treatment of hyperkinetic facial lines

Botulinum toxin type B was studied for the management of hyperkinetic facial lines. It showed clinical longevity of up to 12 weeks on subjective rating scales and 8 weeks on objective rating scales. Botulinum toxin type B has shown relative safety but can have autonomic side effects at higher total doses, which limits the possibility of continued dose escalation. Although these findings may preclude its use as a primary modality for the use in hyperkinetic facial lines, botulinum toxin type B still has a role in the treatment of the aesthetic patient and is yet another tool in the armamentarium of aesthetic practitioners.

History of the clinical use of botulinum toxin A and B

The history of the cosmetic use of botulinum toxin (BTX) must begin with the clinical use of BTX in humans. This came out of Alan Scott's work, which was initially an attempt to find a nonsurgical treatment for some forms of strabismus. Alan Scott put together the idea of Ed Maumenee to use BTX to affect extraocular muscles, Art Jampolsky's electromyographic control delivery system, and Ed Schantz' work on the purification of BTX.