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

Cosmetic Treatment Using Botulinum Toxin in the Oral and Maxillofacial Area: A Narrative Review of Esthetic Techniques

Botulinum toxin (BoNT) is an anaerobic rod-shaped-neurotoxin produced by Clostridium botulinum, that has both therapeutic and lethal applications. BoNT injection is the most popular cosmetic procedure worldwide with various applications. Patients with dynamic wrinkles in areas such as the glabella, forehead, peri-orbital lines, nasal rhytides, and perioral rhytides are indicated. Excessive contraction of muscles or hyperactivity of specific muscles such as bulky masseters, cobble stone chins, gummy smiles, asymmetric smiles, and depressed mouth corners can achieve esthetic results by targeting the precise muscles. Patients with hypertrophic submandibular glands and parotid glands can also benefit esthetically. There are several FDA-approved BoNTs (obabotuli-numtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, letibotulinumtoxinA, prabotulinumtox-inA, daxibotulinumtoxinA, rimbotulinumtoxinB) and novel BoNTs on the market. This paper is a narrative review of the consensus statements of expert practitioners and various literature on the injection points and techniques, highlighting both the Asian and Caucasian population separately. This paper can serve as a practical illustrative guide and reference for optimal, safe injection areas and effective doses for application of BoNT in the face and oral and maxillofacial area. The history of BoNT indications, contraindications, and complications, and the merits of ultrasonography (US)-assisted injections are also discussed.

Pore Size-Dependent Stereoscopic Hydrogels Enhance the Therapeutic Efficiency of Botulinum Toxin for the Treatment of Nerve-Related Diseases

Botulinum toxin (BoNT) is a major neurotherapeutic protein that has been used at low doses for diverse pharmacological applications. However, the pleiotropic effect of BoNT depends on multiple periodic injections owing to its rapid elimination profile, short-term therapeutic effect, and high mortality rate when administered at high doses. In addition to low patient compliance, these drawbacks represent the significant challenges that limit the further clinical use of BoNT. This study developed a new hydrogel-based single dosage form of BoNT by employing a one-step cross-linking chemistry. Its controlled porous structures and composition facilitated uniform drug distribution inside the hydrogel and controllable release of BoNT mediated by slow diffusion. A single dose remained stable for at least 2.5 months and showed sustained effect for at least 20 weeks, meeting the requirements for a single-dose form of BoNT. Additionally, this dosage form was evaluated as safe from all aspects of toxicology. This delivery system resulted in a 100% survival rate after administering a BoNT dose of 30 units, while a dose of more than 5 units of naked BoNT caused a 100% mortality rate within a few days. Overall, this strategy could provide patients with the first single-dose treatment option of BoNT and improve their quality of life.

Botulinum toxin type A for facial wrinkles

BACKGROUND

Botulinum toxin type A (BontA) is the most frequent treatment for facial wrinkles, but its effectiveness and safety have not previously been assessed in a Cochrane Review.

OBJECTIVES

To assess the effects of all commercially available botulinum toxin type A products for the treatment of any type of facial wrinkles.

SEARCH METHODS

We searched the following databases up to May 2020: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trials registers, and checked the reference lists of included studies for further references to relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

We included RCTs with over 50 participants, comparing BontA versus placebo, other types of BontA, or fillers (hyaluronic acid), for treating facial wrinkles in adults.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcomes were participant assessment of success and major adverse events (AEs) (eyelid ptosis, eyelid sensory disorder, strabismus). Secondary outcomes included physician assessment of success; proportion of participants with at least one AE and duration of treatment effect. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included 65 RCTs, involving 14,919 randomised participants. Most participants were female, aged 18 to 65 years. All participants were outpatients (private office or day clinic). Study duration was between one week and one year. No studies were assessed as low risk of bias in all domains; the overall risk of bias was unclear for most studies. The most common comparator was placebo (36 studies). An active control was used in 19 studies. There were eight dose-ranging studies of onabotulinumtoxinA, and a small number of studies compared against fillers. Treatment was given in one cycle (54 studies), two cycles (three studies), or three or more cycles (eight studies). The treated regions were glabella (43 studies), crow's feet (seven studies), forehead (two studies), perioral (two studies), full face (one study), or more than two regions (nine studies). Most studies analysed moderate to severe wrinkles; mean duration of treatment was 20 weeks. The following results summarise the main comparisons, based on studies of one treatment cycle for the glabella. AEs were collected over the duration of these studies (over four to 24 weeks). Compared to placebo, onabotulinumtoxinA-20 U probably has a higher success rate when assessed by participants (risk ratio (RR) 19.45, 95% confidence interval (CI) 8.60 to 43.99; 575 participants; 4 studies; moderate-certainty evidence) or physicians (RR 17.10, 95% CI 10.07 to 29.05; 1339 participants; 7 studies; moderate-certainty evidence) at week four. Major AEs are probably higher with onabotulinumtoxinA-20 U (Peto OR 3.62, 95% CI 1.50 to 8.74; 1390 participants; 8 studies; moderate-certainty evidence), but there may be no difference in any AEs (RR 1.14, 95% CI 0.89 to 1.45; 1388 participants; 8 studies; low-certainty evidence). Compared to placebo, abobotulinumtoxinA-50 U has a higher participant-assessed success rate at week four (RR 21.22, 95% CI 7.40 to 60.56; 915 participants; 6 studies; high-certainty evidence); and probably has a higher physician-assessed success rate (RR 14.93, 95% CI 8.09 to 27.55; 1059 participants; 7 studies; moderate-certainty evidence). There are probably more major AEs with abobotulinumtoxinA-50 U (Peto OR 3.36, 95% CI 0.88 to 12.87; 1294 participants; 7 studies; moderate-certainty evidence). Any AE may be more common with abobotulinumtoxinA-50 U (RR 1.25, 95% CI 1.05 to 1.49; 1471 participants; 8 studies; low-certainty evidence). Compared to placebo, incobotulinumtoxinA-20 U probably has a higher participant-assessed success rate at week four (RR 66.57, 95% CI 13.50 to 328.28; 547 participants; 2 studies; moderate-certainty evidence), and physician-assessed success rate (RR 134.62, 95% CI 19.05 to 951.45; 547 participants; 2 studies; moderate-certainty evidence). Major AEs were not observed (547 participants; 2 studies; moderate-certainty evidence). There may be no difference between groups in any AEs (RR 1.17, 95% CI 0.90 to 1.53; 547 participants; 2 studies; low-certainty evidence). AbobotulinumtoxinA-50 U is no different to onabotulinumtoxinA-20 U in participant-assessed success rate (RR 1.00, 95% CI 0.92 to 1.08, 388 participants, 1 study, high-certainty evidence) and physician-assessed success rate (RR 1.01, 95% CI 0.95 to 1.06; 388 participants; 1 study; high-certainty evidence) at week four. Major AEs are probably more likely in the abobotulinumtoxinA-50 U group than the onabotulinumtoxinA-20 U group (Peto OR 2.65, 95% CI 0.77 to 9.09; 433 participants; 1 study; moderate-certainty evidence). There is probably no difference in any AE (RR 1.02, 95% CI 0.67 to 1.54; 492 participants; 2 studies; moderate-certainty evidence). IncobotulinumtoxinA-24 U may be no different to onabotulinumtoxinA-24 U in physician-assessed success rate at week four (RR 1.01, 95% CI 0.96 to 1.05; 381 participants; 1 study; low-certainty evidence) (participant assessment was not measured). One participant reported ptosis with onabotulinumtoxinA, but we are uncertain of the risk of AEs (Peto OR 0.02, 95% CI 0.00 to 1.77; 381 participants; 1 study; very low-certainty evidence). Compared to placebo, daxibotulinumtoxinA-40 U probably has a higher participant-assessed success rate (RR 21.10, 95% CI 11.31 to 39.34; 683 participants; 2 studies; moderate-certainty evidence) and physician-assessed success rate (RR 23.40, 95% CI 12.56 to 43.61; 683 participants; 2 studies; moderate-certainty evidence) at week four. Major AEs were not observed (716 participants; 2 studies; moderate-certainty evidence). There may be an increase in any AE with daxibotulinumtoxinA compared to placebo (RR 2.23, 95% CI 1.46 to 3.40; 716 participants; 2 studies; moderate-certainty evidence). Major AEs reported were mainly ptosis; BontA is also known to carry a risk of strabismus or eyelid sensory disorders.

AUTHORS' CONCLUSIONS

BontA treatment reduces wrinkles within four weeks of treatment, but probably increases risk of ptosis. We found several heterogeneous studies (different types or doses of BontA, number of cycles, and different facial regions) hindering meta-analyses. The certainty of the evidence for effectiveness outcomes was high, low or moderate; for AEs, very low to moderate. Future RCTs should compare the most common BontA (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, daxibotulinumtoxinA, prabotulinumtoxinA) and evaluate long-term outcomes. There is a lack of evidence about the effects of multiple cycles of BontA, frequency of major AEs, duration of effect, efficacy of recently-approved BontA and comparisons with other treatments.

Facial aesthetic injections in clinical practice: Pretreatment and posttreatment consensus recommendations to minimise adverse outcomes

Facial aesthetic treatment with injectable neuromodulators and hyaluronic acid fillers is well established, with favourable safety profiles and consistent outcomes. As with any medical treatment, adverse events and complications may occur. Adverse events associated with these products are typically transient and mild to moderate in severity. Serious adverse events, such as infection and intravascular occlusion, are rare. Proper patient selection, consent and counselling, preparation and impeccable injection technique are important risk reduction strategies. Both clinicians and patients must be alert to the signs and symptoms of complications so that appropriate treatment can be started promptly. In this article, the authors review the current literature and provide their consensus recommendations for minimising adverse outcomes when treating patients with botulinum toxin or hyaluronic acid fillers.

Clinical uses of botulinum toxin A in smile aesthetic modification

In this article we review the pharmacodynamics of commercially available preparations of botulinum toxin type A, and discuss the potential uses of the drug in smile modification. A major emphasis is placed on applications relevant to modern dental practice, and to the complications arising from its use. Botulinum toxin A, when applied correctly, is a safe and effective means of achieving aesthetic smile modification, with limited data on any demonstrable long-term adverse effects.

A systematic review of botulinum toxin in the management of patients with temporomandibular disorders and bruxism

Introduction The medical and cosmetic use of botulinum toxin (BTX) is now widespread. With an increased number of clinicians adopting the use of BTX in the management of temporomandibular disorders (TMD) and/or bruxism, as either a standalone treatment or as an adjunct, affirmation is required in regards to whether it has a clinically justifiable position among the current spectrum of available treatment modalities.Objectives To establish the usefulness of BTX when treating patients with TMD and/or bruxism, and thereby determine whether there may be an appropriate purpose for the prescription of BTX in the management of these patients.Data sources and data selection A systematic review of the relevant literature was conducted. The literature search was carried out by applying key terms to appropriate data sources (Medline, Embase, Pubmed, Cochrane Central Register of Controlled Trials, and OpenSIGLE). The resultant papers were subjected to inclusion and exclusion criteria, which were then assessed for bias using a framework outlined in the Cochrane Handbook.Results A total of 11 trials met the inclusion criteria. The primary outcome measure was changes in pain experience in groups that had been treated with BTX, relative to an appropriate control group. Secondary outcomes included changes in the frequency of bruxism events, changes in maximum mouth opening, changes in occlusal force and changes in electromyography (EMG) readings of muscles of mastication.Conclusion The evidence to support the use of BTX in the management of TMD and/or bruxism is not entirely unequivocal. A number of studies that have met the inclusion criteria have shown promising results and thereby justify further investigation. Given the current evidence, BTX should certainly be considered but due to financial implications and possible side effects, it seems appropriate that conservative options, such as self-management with explanation and physical therapies, should be exhausted first.

Safety and Patient Satisfaction of AbobotulinumtoxinA for Aesthetic Use: A Systematic Review

A systematic review of the published literature (from January 2000 to January 2016) to ascertain the safety of, and patient satisfaction with, the aesthetic use of abobotulinumtoxinA was conducted. In addition to the licensed indications, other special populations were considered for discussion. The potential impact of neutralizing antibodies and systemic toxicity were also addressed. A total of 364 papers were screened and 86 were found to be relevant to the population, intervention(s), and outcomes stipulated in the protocol. The safety and patient satisfaction data from these publications are discussed in this review.

Are nurse injectors the new norm?

PURPOSE

As Botox(®)/filler use has increased in recent years, a growing number of nonaesthetic health professionals have emerged to perform these procedures. Since studies have shown that patients identify training as the most important factor in considering these procedures, this study seeks to summarize the perspective of plastic surgeons regarding these paradigm shifts.

METHODS

In the summer of 2013, an eight-question survey was sent to members of ISAPS, ASAPS, and ASPS (approximately 26,113 plastic surgeons globally). Two questions assessed practice location and membership affiliation and six questions assessed various healthcare practitioners' capability to administer Botox, fillers, and vaccines (control). Healthcare practitioners included plastic surgeons and dermatologists, gynecologists, dentists, nurses in plastic surgery and dermatology, or nurses in other fields.

RESULTS

On three e-mail notifications, 14,184 plastic surgeons opened the survey and 882 responded: 36.6 % from North America, 29.1 % from Europe, 12.9 % from South America, 10.1 % from Asia, 4.5 % from the Middle East, 3.4 % from Australia, 1.9 % from Africa, and 1.6 % from Central America. Seventy-seven percent believed nurses were not as capable as plastic surgeons in administering Botox; 81 % felt the same for fillers. Conversely, 84 % agreed that nurses were as capable as plastic surgeons in administering vaccines. Plastic surgeons ranked nurses in other fields (48 %) as most capable in administering vaccines, then plastic surgeons (42 %), nurses of plastic surgeons (9 %), gynecologists (1 %), and dentists (<1 %). When asked about Botox/fillers, responders ranked plastic surgeons (98 %) most capable, then nurses in plastic surgery (2 %), gynecologists (<1 %), dentists (<1 %), and nurses in other fields (<1 %). When asked to rank according to patient perception, the order remained the same.

CONCLUSION

Based on responses from over 880 plastic surgeons from around the world, plastic surgeons consider themselves and dermatologists the most capable injectors. However, they still believe nurses in other fields to be the most capable of administering vaccines. This dichotomy may define the role of various practitioners in an increasingly more competitive injectable environment to improve patient satisfaction and outcomes. Given that the majority of growth in cosmetic injectables is being driven by providers other than plastic surgeons and dermatologists, further clarification on training requirements and practice guidelines may be necessary to ensure a consistent, reproducible experience for the patient.

Aesthetic uses of the botulinum toxin

The cosmetic use of botulinum toxin (BoNT) is the most common cosmetic procedure performed in the world today. Common adverse events seen in the aesthetic use of the BoNT include swelling, localized bruising, headaches, injection site discomfort, excessive muscle weakness, and unintended paresis of adjacent muscles. BoNT has a wide array of cosmetic uses, including treatment of glabellar lines, chemical browlift, forehead wrinkles, periorbital, and perioral lines. The future formulations and applications of BoNT type A will be plentiful, and are exciting to consider.

Safety of botulinum toxin A in aesthetic treatments: a systematic review of clinical studies

BACKGROUND

The use of botulinum toxin A (BoNT-A) for aesthetic treatments is growing steadily, and new safety data have been reported in recently published studies.

OBJECTIVE

To investigate the safety data on the use of the three BoNT-A formulations approved for facial aesthetics from recent studies and to confirm their safety profiles.

METHODS

The literature search was conducted using three online databases restricted to the timeframe from January 2000 to June 2012. Only clinical trials, randomized or open label, with safety as the primary or secondary endpoint, were included.

RESULTS

Thirty-five papers were selected, with a total of subjects 8,787 studied. OnabotulinumtoxinA was used in 60.0% of the studies, abobotulinumtoxinA in 37.1%, and incobotulinumtoxinA in 2.8%. The glabella was the most investigated area (51.4%), followed by the upper face (25.7%), crow's feet (11.4%), and lower face (11.4%). Treatment-related adverse events were blepharoptosis (2.5%), brow ptosis (3.1%), and eye sensory disorders (3%) in the upper face and lip asymmetries and imbalances in the lower face (6.9%). All of these events resolved spontaneously.

CONCLUSION

The short-term safety profile of BoNT-A in cosmetic nonsurgical procedures was confirmed for all the three commercial formulations.

A comparative assessment of three formulations of botulinum toxin A for facial rhytides: a systematic review and meta-analyses

BACKGROUND

Botulinum toxin A is a commonly used biological medication in the field of facial plastic surgery. Currently, there are three distinct formulations of botulinum toxin A, each with their purported benefits and advantages. However, there is considerable confusion as to the relative efficacy and side-effects associated with each formulation. Therefore, the purpose of this paper is to systematically assess published studies and perform a meta-analysis to determine if there is a significant advantage of any of the individual formulations.

METHODS/DESIGN

A systematic literature search was performed for all relevant English language randomized controlled trials using Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), MEDLINE, World Health Organization (WHO) International Clinical Trials Registry Platform, European Union (EU) Clinical Trials Register, Cochrane Library databases of clinical trials, and ClinicalTrials.gov. Inclusion criteria included any randomized controlled trial (RCT) that assessed the use of botulinum toxin for cosmetic purposes. The included articles were also analyzed for bias using the Cochrane Collaboration's tool for assessing the risk of bias in RCTs.

DISCUSSION

The results of this review will provide clinicians with an unbiased, high level of evidence of the comparative efficacy of individual preparations of botulinum toxin A.

Facial rejuvenation for middle-aged women: a combined approach with minimally invasive procedures

Facial rejuvenation is a significant process involved in restoring youthfulness. The introduction of less invasive procedures has increased acceptance of such procedures. Often a combination of different techniques allows individualized treatment with optimal outcomes. Furthermore, this leads to a natural look without a significant downtime. We report herein the use of such a combined approach in middle-aged women with particular emphasis on botulinum toxin type A, dermal fillers, and chemical peels.