The management of hyperfunctional facial lines with botulinum toxin. A collaborative study of 210 injection sites in 162 patients

Update on Non-Interchangeability of Botulinum Neurotoxin Products

The growing use of botulinum neurotoxins (BoNTs) for medical and aesthetic purposes has led to the development and marketing of an increasing number of BoNT products. Given that BoNTs are biological medications, their characteristics are heavily influenced by their manufacturing methods, leading to unique products with distinct clinical characteristics. The manufacturing and formulation processes for each BoNT are proprietary, including the potency determination of reference standards and other features of the assays used to measure unit potency. As a result of these differences, units of BoNT products are not interchangeable or convertible using dose ratios. The intrinsic, product-level differences among BoNTs are compounded by differences in the injected tissues, which are innervated by different nerve fiber types (e.g., motor, sensory, and/or autonomic nerves) and require unique dosing and injection sites that are particularly evident when treating complex therapeutic and aesthetic conditions. It is also difficult to compare across studies due to inherent differences in patient populations and trial methods, necessitating attention to study details underlying each outcome reported. Ultimately, each BoNT possesses a unique clinical profile for which unit doses and injection paradigms must be determined individually for each indication. This practice will help minimize unexpected adverse events and maximize efficacy, duration, and patient satisfaction. With this approach, BoNT is poised to continue as a unique tool for achieving individual goals for an increasing number of medical and aesthetic indications.

Botulinum Toxin Type A and Hyaluronic Acid Dermal Fillers in Dentistry: A Systematic Review of Clinical Application and Indications

Background

Botulinum toxin type A (BoNT-A) and hyaluronic acid (HA) dermal fillers are increasingly utilized in dentistry for therapeutic and aesthetic purposes. However, a comprehensive synthesis of their clinical applications and indications in dentistry is lacking. This systematic review aimed to analyze the clinical application and indications of BoNT-A and HA dermal fillers in dentistry, providing insights into their efficacy, safety profiles, and limitations.

Methods

A systematic search was conducted in PubMed/MEDLINE databases to identify relevant studies published between 2018 and 2024. Medical Subject Headings (MeSH) terms and keywords related to BoNT-A, HA dermal fillers, dentistry, clinical applications, and indications were used. Study selection criteria included randomized controlled trials (RCTs) and non-RCTs involving human participants of any age group. Data extraction and synthesis followed established guidelines, focusing on study characteristics, participant demographics, intervention details, outcome measures, and key findings related to BoNT-A and HA dermal fillers' clinical application in dentistry.

Results

Systematic searches across electronic databases and grey literature identified 857 records, with an additional 73 from hand searches. After screening titles and abstracts, 542 records were excluded, leaving 374 full-text publications for evaluation. Ultimately, 12 RCTs and 13 non-RCTs were included. The systematic review encompassed diverse geographic locations: Brazil, Italy, Spain, Syria, India, Egypt, Korea, and the Netherlands, involving samples sizes ranging from 14 to 143 participants. The review synthesized findings on HA's efficacy in various areas, including bone repair, gingivitis management, temporomandibular joint disorders, postoperative swelling reduction, periodontal defect treatment, chin and check projection and lips augmentation. BoNT-A exhibited promising efficacy in managing orofacial pain conditions, gummy smile treatment and neuromodulation of the lower third muscles. Safety profiles varied among studies, with some reporting minimal adverse effects while others noted dose-related concerns.

Conclusion

BoNT-A and HA dermal fillers offer a wide array of clinical applications in dentistry, ranging from therapeutic interventions to aesthetic enhancements. Despite promising efficacy, careful consideration and monitoring of safety outcomes are essential when integrating these interventions into clinical practice. Further research addressing methodological limitations and safety concerns is warranted to optimize their utilization and improve patient care in dentistry.

Treatment of glabellar lines with Botox (onabotulinumtoxinA): Development, insights, and impact

OnabotulinumtoxinA is an injectable medication that produces muscle relaxation through local chemical denervation at the neuromuscular junction. Discovery of onabotulinumtoxinA's aesthetic benefits occurred serendipitously in the 1980s at the intersection of several medical disciplines, including ophthalmology, neurology, otolaryngology, and dermatology. Patients receiving onabotulinumtoxinA for blepharospasm, hemifacial spasm, and dystonia noticed their periorbital wrinkles disappearing, particularly frown lines between the eyebrows called glabellar lines (GL). Aesthetic use of onabotulinumtoxinA necessitated rigorous training programs and vigilant monitoring by Allergan. Approval for the GL indication was based on 2 similarly designed, double-blind, randomized, multicenter clinical studies. Subjects with moderate to severe GL receiving onabotulinumtoxinA achieved significantly greater improvement in GL severity than those receiving placebo. In subsequent studies, more than 80% of subjects were satisfied with onabotulinumtoxinA treatment through day 60, and many reported looking approximately 4 years younger at weeks 4 and 12 than at baseline. OnabotulinumtoxinA has a rapid onset of action, and peak effect occurs between 30 and 60 days. The median duration of response for dynamic GL in the initial studies was 120 days and response progressively improved with subsequent treatments. OnabotulinumtoxinA was well tolerated, and the 2 most common adverse events, headache and blepharoptosis, tended to decrease in frequency with repeat treatment. The novel use of onabotulinumtoxinA for treating GL was an important step in addressing the clinical need for a noninvasive, straightforward, office-based procedure for facial lines that also left patients extremely satisfied with its treatment effects and represented the beginning of its widespread use for numerous aesthetic indications.

The pluripotential evolution and journey of Botox (onabotulinumtoxinA)

Clinical use of onabotulinumtoxinA evolved based on strategic, hypothesis-driven applications, as well as serendipitous observations by physicians and patients. The success of onabotulinumtoxinA in blepharospasm and strabismus led to its study in other head and neck dystonias, followed by limb dystonia, tremor, and spasticity. The aesthetic use of onabotulinumtoxinA followed initial reports from patients of improved facial lines after injections for facial dystonias and hemifacial spasm. Although patients with dystonias and spasticity regularly reported that their local pain improved after injections, onabotulinumtoxinA was not systematically explored for chronic migraine until patients began reporting headache improvements following aesthetic injections. Clinicians began assessing onabotulinumtoxinA for facial sweating and hyperhidrosis based on its inhibition of acetylcholine from sympathetic cholinergic nerves. Yet another line of research grew out of injections for laryngeal dystonia, whereby clinicians began to explore other sphincters in the gastrointestinal tract and eventually to treatment of pelvic sphincters; many of these sphincters are innervated by autonomic nerves. Additional investigations in other autonomically mediated conditions were conducted, including overactive bladder and neurogenic detrusor overactivity, achalasia, obesity, and postoperative atrial fibrillation. The study of onabotulinumtoxinA for depression also grew out of the cosmetic experience and the observation that relaxing facial muscle contractions associated with negative emotions may improve mood. For approved indications, the safety profile of onabotulinumtoxinA has been demonstrated in the formal development programs and post-marketing reports. Over time, evidence has accumulated suggesting clinical manifestations of systemic effects, albeit uncommon, particularly with high doses and in vulnerable populations. Although onabotulinumtoxinA is approved for approximately 26 indications across multiple local regions, there are 15 primary indication uses that have been approved in most regions, including the United States, Europe, South America, and Asia. This review describes many uses for which AbbVie has not sought and/or received regulatory approval and are mentioned for historical context only.

Complications of Botulinum toxin A: An update review

Cosmetic surgery procedures have increased manifolds all over the world owing to the ever-increasing demand of people to look beautiful and young. Injectable treatments like botulinum toxin are becoming more popular owing to their rapid, well-defined, and lasting results for the reduction of facial fine lines, wrinkles, and facial rejuvenation. These emerging treatments are quite safe but can have certain adverse effects. In this article, we have highlighted the complications and side effects of botulinum toxin based on the anatomical location. The possible causes and precautions to prevent these complications are also discussed. The search of literature included peer-reviewed articles including clinical trials and scientific reviews. Literature was identified from electronic databases (MEDLINE/PubMed) through January 2021 and references of respective articles and only the articles published in English language were included.

Ethyl Alcohol Versus Botulinum Toxin A: A Comparative Study of the Visual and Histopathological Outcomes in the Rabbit Anterior Auricular Muscle Model

BACKGROUND

Botulinum toxin has long been known for its paralytic effects at the neuromuscular junction. Although it has been widely used for vascular and nervous tissues, there has been no study of the aesthetic effects of the application of ethanol to muscle tissues to date.

OBJECTIVE

The authors aimed to demonstrate the effects of the application of ethanol to muscle tissues after an intramuscular injection and to compare the effects of botulinum toxin A (BTA) and ethanol.

METHODS AND MATERIALS

A total of 28 rabbits were divided into 4 groups (n = 7 each). Botulinum toxin A (5 units) and different concentrations of ethanol (5 cc) were injected into the left and right anterior auricular muscles of all rabbits, respectively. Ear ptosis was assessed, and histopathological examination was performed after all rabbits were euthanized in the eighth week.

RESULTS

Muscle function was affected earlier in ethanol-treated ears than in botulinum-treated ears; however, the ptotic effect lasted for a significantly shorter duration in ethanol-injected ears than in BTA-applied ears.

CONCLUSION

Ethanol can block muscle function reversibly and can serve as an alternative to BTA, particularly when rapid results are desirable.

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.

Auxiliary usage of botulinum toxin A in plastic surgery in China

BACKGROUND

Currently, botulinum toxin A (BTA) is mainly used in the treatment of muscle spasms and in cosmetic procedures, and its cosmetic indications are expanding rapidly. There have been sporadic reports focused on the preoperative usage of BTA complementing plastic surgery. We briefly summarize the current experience of BTA complementing plastic surgery in China based on clinical experience.

METHODS

We reported a brief review of the preoperative use of BTA as an accessory to plastic surgery (blepharoplasty, chin augmentation, mandibular angle ostectomy, rhinoplasty, hyaluronic acid fillers injection for wrinkle reduction) based on previous studies and our experience.

RESULTS

Preoperative treatment with BTA in plastic surgery helps surgeons operate and results in better cosmetic results.

CONCLUSIONS

Preoperative BTA treatment can reduce the occurrence of surgical complications as well as improve the surgical results in some plastic surgeries. The procedure is suitable for clinical application and worth promoting.

Complications of botulinum toxin and fillers: A narrative review

BACKGROUND

Cosmetic surgery and esthetic procedures have become a billion dollar industry owing to the ever-growing demand of the population to stay young. The injectable treatments including fillers and botulinum toxin have become highly popular because of their quick, predictable and lasting results in the management of facial wrinkles and rejuvenation. Although these treatment modalities are relatively safe, they are associated with certain side effects.

AIMS

In this review, we will focus on the complications of fillers and botulinum toxin.

PATIENTS/METHODS

The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles. Only articles available in English were considered for this review.

RESULTS

Brow ptosis and asymmetry are common adverse effects of botulinum toxin while the most common adverse effects associated with fillers are the local injection related effects manifesting as erythema, edema, pain, and ecchymosis.

CONCLUSION

It is important that the treating physician is well verse with the various fillers and botulinum toxin complications and their management as some of the complications can be severely debilitating.

Safety, efficacy, and onset of a novel botulinum toxin type A (Nabota) for the treatment of glabellar frown lines: a single-arm, prospective, phase 4 clinical study

Background

Safety, efficacy, and time to onset of effect of botulinum toxin type A is of importance to persons who seek improvement in glabellar frown lines, but this has not been well studied. The aim of this study was to determine the safety, efficacy, and onset of action of a newly developed botulinum toxin type A (Nabota) for the treatment of glabellar frown lines.

Methods

This was a single-arm, open-label, and phase 4 clinical study. Forty-two subjects with glabellar lines were treated with five times of intramuscular injection of 0.1 mL (4 U/0.1 mL) for a total of 20 U of Nabota. Efficacy and safety were assessed at 2, 3, 4, 5, and 14 days. Efficacy was assessed by the investigator and it was defined as a 1-point change on a 4-point scale.

Results

Improvement in glabellar frown lines at maximum frown was observed in 85.4% of subjects 2 days after administration. Improvement in glabellar lines at rest was observed in 51.2% of subjects 2 days after administration, and the proportion of subjects showing improvement increased with time. No severe adverse events were recorded.

Conclusion

Onset of action was observed in the majority of subjects by 2 days after administration of Nabota. In addition, Nabota was found to be safe and effective for the treatment of glabellar frown lines.

Modification of Chin Projection and Aesthetics With OnabotulinumtoxinA Injection

Importance

Because of the soft-tissue envelope and the dimensional complexity of the muscular contraction of the mentalis muscle, the projection and shape of the chin is not determined by only the bony projection. In a subset of patients with a seemingly underprojected chin, a hyperactive, high-riding mentalis muscle contributes to a blunted chin contour.

Objective

To evaluate the use of onabotulinumtoxinA (botulinum toxin A) for improving chin aesthetics in patients with an underprojected bony chin and a high-riding hyperactive mentalis muscle.

Design, Setting, and Participants

This case series and photographic analysis included 11 patients presenting with an underprojected bony chin and a high-riding hyperactive mentalis muscle at a private facial plastic surgery practice from August 25, 2006, to November 10, 2012. Data were analyzed from November 13, 2012, to April 9, 2013.

Interventions

Injection with 12 to 15 U of onabotulinumtoxinA into the mentalis muscle.

Main Outcomes and Measures

Photographic analysis of the vertical and horizontal positions of the pogonion relative to fixed facial points before and after injection. A patient satisfaction scale was also used to assess improvement in overall chin aesthetic.

Results

Eleven patients (3 men and 8 women; mean [SD] age, 46.3 [16.4] years) participated in the study, including 2 who had undergone prior chin implantation. The vertical position of the pogonion was more inferior after injection in 10 of 11 patients (mean [SD] vertical position, 1.36 [0.18] preinjection and 1.44 [0.18] postinjection; P = .005). Although the horizontal position of the pogonion changed in all patients, this change was not statistically significant (mean [SD] horizontal position, 0.11 [0.13] preinjection and 0.14 [0.13] postinjection; P = .32). All patients experienced improvement in their overall chin aesthetic and a subjective decrease in chin tension. Chin contour was improved, with soft-tissue volume overall displaced more inferiorly with a rounded rather than blunted appearance. No adverse effects were reported after injection.

Conclusions and Relevance

OnabotulinumtoxinA is effective at improving chin aesthetics by altering the position of the pogonion. In this first photographic analysis to date of the influence of onabotulinumtoxinA treatment, patients demonstrated a measurable change in the position of the pogonion, in addition to improvements to the chin contour on profile. This nonsurgical mentoplasty may be used as an independent procedure or as an adjunct to optimize traditional chin augmentation in carefully selected patients.

Level of Evidence

4.

Injectable and topical neurotoxins in dermatology: Indications, adverse events, and controversies

The use of neuromodulators for therapeutic and cosmetic indications has proven to be remarkably safe. While aesthetic and functional adverse events are uncommon, each anatomic region has its own set of risks of which the physician and patient must be aware before treatment. The therapeutic usages of botulinum toxins now include multiple specialties and multiple indications. New aesthetic indications have also developed, and there has been an increased utilization of combination therapies to combat the effects of global aging. In the second article in this continuing medical education series, we review the prevention and treatment of adverse events, therapeutic and novel aesthetic indications, controversies, and a brief overview of combination therapies.

Evolution of Facial Aesthetic Treatment Over Five or More Years: A Retrospective Cross-sectional Analysis of Continuous OnabotulinumtoxinA Treatment

BACKGROUND

Little information exists on how facial aesthetic treatments are incorporated into aesthetic regimens.

OBJECTIVE

Assess the evolution of facial aesthetic treatments in patients receiving long-term continuous onabotulinumtoxinA treatment.

METHODS

This international retrospective chart review included patients with ≥5 years of continuous onabotulinumtoxinA treatments including ≥1 glabellar lines treatment/year. Charts were reviewed for facial areas treated, number of treatments, doses/treatment visit, concomitant aesthetic procedures, and onabotulinumtoxinA-related adverse events.

RESULTS

Data were collected from 5,112 onabotulinumtoxinA treatment sessions for 194 patients over an average of 9.1 years. Dosing was relatively stable over time; however, interinjection intervals increased. Glabellar lines' treatment temporally preceded crow's feet lines and forehead lines' treatment. A majority of patients (85%) also received treatment with fillers. Cumulative increases in onabotulinumtoxinA treatments occurred over time and by facial area corresponding with increases in treatments with injectable fillers, energy-based devices, and prescription topical creams. The longer the patients were treated, the younger they perceived themselves to look. Rates of adverse events were low.

CONCLUSION

OnabotulinumtoxinA treatment evolved over time, coinciding with growth of the facial aesthetics market. Additional treatment modalities were added as complements to onabotulinumtoxinA. Long-term continuous onabotulinumtoxinA injections are an important component of contemporary facial aesthetic treatment regimens.

Sebum Production Alteration after Botulinum Toxin Type A Injections for the Treatment of Forehead Rhytides: A Prospective Randomized Double-Blind Dose-Comparative Clinical Investigation

BACKGROUND

Research has investigated the decrease in human skin sebum after the application of botulinum toxin. Few studies of the mechanism and objective assessments of this phenomenon have been conducted and the correlation between the sebum production and injection dosages or techniques remains unclear.

OBJECTIVES

We prospectively investigated the sebum regulation and its gradient around the injection site in patients who received intramuscular injections of botulinum toxin A (BTX-A) for forehead rhytides, comparing two injection doses.

METHODS

Forty-two female volunteers with rhytides on the forehead region were randomly assigned to receive 10 or 20 units of BTX-A, which was administered in five standard injection sites. The baseline and post-treatment sebum production was measured using a Sebumeter.

RESULTS

Treatment with BTX-A exhibited significant sebum alteration at the injection site of both groups, with a sebum gradient surrounding the injection point. The efficacy did not improve at higher injection doses, with the four-unit regimen generally not being more potent than the two-unit regimen. The sebum production recovered to normal levels at the 16 week follow-up for both treatment groups, indicating that a higher dosage (four units) did not result in a longer duration until relapse compared with the two-unit dose.

CONCLUSIONS

We determined that the sebum production has a positive correlation with the distance away from the injection point. Intramuscular injection of BTX-A significantly reduces sebum production at the injection site but increases the sebum production of the surrounding skin at a radius of 2.5 cm at the 2, 4, and 8 week follow-ups.

LEVEL OF EVIDENCE

2 Therapeutic.

Optimal dosage of botulinum toxin type A for treatment of glabellar frown lines: efficacy and safety in a clinical trial

BACKGROUND

Various preparations of botulinum toxin type A (BTX-A) are used to reduces glabellar (frown) lines. However, dose-related safety and efficacy of intramuscular injections of a widely used, locally produced BTX-A in China has not been established.

OBJECTIVE

Assessment of dose-dependent safety and efficacy of Chinese botulinum toxin type A (Hengli BTX-A [HBTX-A]) intramuscular injections on glabellar lines.

METHODS

Four hundred eighty-eight BTX-A-naive participants were included in the double-blind trial and randomly divided into placebo (n = 122), low-dose (n = 183), and high-dose (n = 183) treatment groups for injection with saline solution, 10 units and 20 units of HBTX-A, respectively, at 4 sites in the corrugator muscle and 1 site in the procerus muscle. Outcomes were recorded before treatment and after 7, 30, 60, and 120 days, including glabellar line severity at maximum contraction and relaxation.

RESULTS

Significantly greater improvement was observed in both HBTX-A groups in comparison with the placebo group (p < .05). Better efficacy was obtained in the high-dose treatment group. More participants developed adverse events after treatment with HBTX-A doses, than with the placebo (p < .05).

CONCLUSION

Twenty-unit HBTX-A provided optimal improvement in glabellar lines, and its use might minimize injection frequency while maintaining acceptable safety.

Evaluation of headache relief with cosmetic onabotulinumtoxinA injections

Chronic headaches are common and can have a significant effect on quality of life. Approved treatment options are vast and include the use botulinum toxin injections. The objective of this study is to evaluate the effects of purely cosmetic onabotulinumtoxinA (BOTOX) injections on the frequency and severity of chronic headaches. Patients seeking treatment of hyperfunctional facial lines were enrolled to complete pre- and posttreatment questionnaires assessing headache symptoms. Quantitative data was compared using paired two-tailed student t-tests between groups of patients who received onabotulinumtoxinA injections, both onabotulinumtoxinA and hyaluronic acid (Restylane) injections, and hyaluronic acid injections. One hundred and ten patients were enrolled; 73 completed the study. Of the 45 patients with pretreatment headaches, 76% (22/29) that received cosmetic onabotulinumtoxinA injections alone and 69% (27/39) that received onabotulinumtoxinA with or without hyaluronic acid injections reported overall improvement in headaches. Patients who received only onabotulinumtoxinA reported a significant decrease in the frequency (P = 0.0016) and severity (P = 0.0002) of headaches, and the number of days over-the-counter medications were taken (P = 0.0238). It took an average 9.5 days for headache improvement vs. 4.4 days for an appearance change. In patients who received only hyaluronic acid injections (n = 6), no significant improvement in headaches was reported. Overall satisfaction was high and unaffected by whether patients experienced headache relief. The majority of patients (93%) reported that they would "definitely" or "likely" receive onabotulinumtoxinA injections again in the future. Purely cosmetic onabotulinumtoxinA injections of doses between 15-50 units can significantly decrease the severity and frequency of headaches.

Changes in masticatory function after injection of botulinum toxin type A to masticatory muscles

This study examined changes in masticatory function after botulinum toxin type A (BTX-A) injection using objective and subjective tests during 12 weeks. Also, we compared differences in masticatory function between group in which only masseter muscle (M group) was injected and group in which masseter and temporal muscle (M-T group) were injected. Forty subjects were assigned into two groups; M group (n = 20) and the M-T group (n = 20). The Meditoxin(®) was used as BTX-A injection. The mixing ability index (MAI) was used as the objective indicator, and visual analogue scale (VAS) and food intake ability (FIA) index were used as subjective indicators. Overall, the masticatory function drastically declined after 4 weeks and gradually recovered with time. Compared with the pre-injection state, the masticatory function decreased by 89·2% (MAI), 12·2% (FIA) and 32·2% (VAS) 4 weeks after the injection (P < 0·05). When the results between M group and M-T group were compared, scores of VAS and FIA were significantly different 4 weeks after the injection (P < 0·05), but the MAI score showed no significant difference between two groups. In conclusion, this study showed that masticatory function was significantly decreased after BTX-A injection into the masticatory muscle after 4 and 8 weeks from injection. However, masticatory efficiency measured using MAI could completely recover after 12 weeks. Furthermore, after 8 weeks from the injection, the masticatory function measured after injection into only the masseter muscle was similar to that measured after injection into both masseter and temporal muscle.

Onset and duration of effect of incobotulinumtoxinA, onabotulinumtoxinA, and abobotulinumtoxinA in the treatment of glabellar frown lines: a randomized, double-blind study

Background

Three botulinum neurotoxin type A preparations (incobotulinumtoxinA, onabotulinumtoxinA, and abobotulinumtoxinA) are widely approved in Europe and in the US for the treatment of glabellar frown lines. The purpose of this study was to determine and compare the time to onset and duration of treatment effect of incobotulinumtoxinA, onabotulinumtoxinA, and abobotulinumtoxinA for the treatment of glabellar frown lines.

Subjects and methods

Subjects aged 20–60 years with moderate to severe glabellar frown lines received one treatment of either 21 units (U) incobotulinumtoxinA, 21 U onabotulinumtoxinA, or 63 U abobotulinumtoxinA. Assessments were made over a period of 180 days. Onset of treatment effect was defined as the day that the observer noted a decrease in glabellar muscle activity compared with baseline photographs and videos. Duration of treatment effect was defined as the time until glabellar muscle action returned to the baseline level. Analyses were performed using a Weibull log(T) regression model.

Results

The study enrolled 180 subjects; 60 per group. For all three products, onset of treatment effect occurred earlier in female subjects compared to male subjects. For both sexes, a significantly earlier time to onset of treatment effect was seen for incobotulinumtoxinA compared to onabotulinumtoxinA and abobotulinumtoxinA; in female subjects these times were 3.02 days, 5.29 days, and 5.32 days, respectively. The duration of treatment effect was longer for incobotulinumtoxinA compared to onabotulinumtoxinA and abobotulinumtoxinA; for all products, treatment effect duration was longer in females than in males. Time to onset was not a predictor of treatment duration.

Conclusion

IncobotulinumtoxinA demonstrated a more rapid onset and a longer duration of treatment effect than onabotulinumtoxinA (1:1 dose ratio) and abobotulinumtoxinA (1:3 dose ratio). Onset of effect was faster and duration of effect was longer in female subjects compared to male subjects.

Onset, longevity, and patient satisfaction with incobotulinumtoxinA for the treatment of glabellar frown lines: a single-arm, prospective clinical study

BACKGROUND

IncobotulinumtoxinA (Bocouture(®)) is free from complexing proteins and effective for treating glabellar frown lines.

PURPOSE

To determine the efficacy, onset, and duration of action of incobotulinumtoxinA for the treatment of glabellar frown lines.

PATIENTS AND METHODS

In this single-arm, prospective, proof-of-concept study, 23 patients were treated with 25 U incobotulinumtoxinA, equally split between five injection sites in the glabella. Severity of glabellar frown lines was rated by an independent rater from standardized photographs using the validated Merz 5-point scale at several visits over 5 months following treatment. To assess patient satisfaction, patients completed a questionnaire before and 2 weeks after treatment.

RESULTS

The percentage of responders at maximum frown 2-4 days after treatment was 95.2% and 85.0% when responders were defined as patients with ≥ 1-point and ≥ 2-point improvement on the 5-point scale compared with baseline, respectively. At this time point, 84% of the maximum effect had occurred. The responder rate at maximum frown, according to both definitions, was 100% for at least the next two visits (days 8 ± 1 and 14 ± 2). At all visits, the change from baseline in the mean glabellar frown-line score at maximum frown was statistically significant, with on average an almost 1-point improvement from baseline 5 months after treatment.

CONCLUSION

IncobotulinumtoxinA is an effective and well-tolerated treatment for glabellar frown lines, with a rapid onset of action and a long duration of effect lasting for more than 5 months.

Development and validation of a new clinically-meaningful rating scale for measuring lateral canthal line severity

BACKGROUND

Several scales have been employed for evaluating the effects of cosmetic treatments in the periorbital area. The Food and Drug Administration (FDA) has recently issued new recommendations specifying a rigorous process to validate new aesthetic scales.

OBJECTIVES

The authors describe and validate a new clinical rating scale: the Investigator's Global Assessment of Lateral Canthal Line (IGA-LCL) severity scale.

METHODS

The new FDA recommendations were utilized to validate the new scale. The first step was concept elicitation (based on direct input from clinicians, patients, and literature) and evaluation of content validity (appropriateness of concepts). The resulting five-point scale provided detailed descriptions of the lateral canthal lines (LCL), including quantitative assessment of LCL length and depth. Performance parameters, including intra- and interrater reproducibility and construct validity, were then evaluated in clinical studies. Finally, the scale's threshold for clinically-meaningful benefit and the ability of the scale to detect change were confirmed in two Phase 2b clinical studies involving a total of 270 subjects.

RESULTS

Content validity was established and the IGA-LCL scale showed excellent interrater reliability (weighted Kappa = 0.89) and interrater reliability (weighted Kappa = 0.77; Kendall's coefficient of concordance = 0.89). In clinical trials, the scale was sensitive enough to detect clinically-meaningful one- and two-point changes in LCL severity following treatment with topical botulinum toxin type A (BoNT-A). The authors observed statistically-significant correlations between the physician-rated IGA-LCL results and patient-reported outcomes.

CONCLUSIONS

The IGA-LCL scale was shown to be reliable, appropriate, and clinically meaningful for measuring LCL severity.

Effectiveness of type A botulinum toxins for aesthetic indications and their relative economic impact

BACKGROUND

It is accepted that the three commercially available type A botulinum toxins (BoNT-As) are different, their units of potency are not interchangeable and no fixed dose conversion ratio exists between them. To date, there is no clear evidence demonstrating the superiority of one toxin over another clinically.

OBJECTIVE

The study aims to identify evidence confirming the equivocal efficacy of the formulations and to justify that attention can therefore be reasonably turned to their differing costs as a means of aiding choice of treatment. This is achieved via the development of the cost calculator presented herein, to enable direct economic comparisons to be made between the three commercially available BoNT-A formulations licensed for aesthetic indications in the UK.

METHODS

An online literature search using PubMed was undertaken and the latest available information on the cost for each BoNT-A treatment was accessed via the British National Formulary (BNF). Predicated on the evidence review, a cost calculator was developed which takes into account for the glabella: the number of treatments needed per patient with each product over a year and the number of treatments available with differing dilutions of each vial of each product over a year. A range of cost prices can also be introduced allowing a direct cost-comparison to be made for treating the glabella of a set number of patients over a year between different products.

RESULTS

Azzalure(®) (abobotulinumtoxinA) was the most cost-effective in almost all scenarios tested, whilst Vistabel(®) (onabotulinumtoxinA) was the least cost-effective. Of the two products with published non-inferiority with respect to each other, onabotulinumtoxinA and Bocouture(®) (incobotulinumtoxinA), incobotulinumtoxinA offered a lower overall cost to treat the glabella of the same number of patients when compared with Vistabel.

CONCLUSION

In most scenarios, BoNT-A treatment with abobotulinumtoxinA will result in significant annual cost savings when compared with treatment with onabotulinumtoxinA or incobotulinumtoxinA.

Exaggeration of wrinkles after botulinum toxin injection for forehead horizontal lines

There have been no long-term complications or life-threatening adverse effects related to botulinum toxin treatment for any cosmetic indications. Nevertheless, there are well-known, mild side effects of botulinum toxin treatment on the upper face, though most of them are self limited with time. However, excluding brow ptosis, reports about site specific side effects are few and anecdotal. We experienced cases of exaggeration of wrinkles after botulinum toxin injection for forehead horizontal lines, and report them here. In our cases, new appearance of a noticeable glabellar protrusion following botulinum toxin injection on the forehead was observed in 2 patients. Also, a new deep wrinkle on one side of the forehead just above the eyebrow appeared in another 2 patients. The exaggerated wrinkles nearly disappeared without treatment by week 4 in all subjects. These exaggerations of wrinkles may be caused by hyperactivity and overcompensation of untreated muscles. With the increasing availability of diverse botulinum toxin for cosmetic purposes, physicians and patients should be aware of this temporary change after therapeutic injections. We recommend explaining this possible effect prior to injection, for better understanding of treatment for cosmetic indications.

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.

Treating glabellar lines with botulinum toxin type A-hemagglutinin complex: a review of the science, the clinical data, and patient satisfaction

Botulinum toxin type A treatment is the foundation of minimally invasive aesthetic facial procedures. Clinicians and their patients recognize the important role, both negative and positive, that facial expression, particularly the glabellar frown lines, plays in self-perception, emotional well-being, and perception by others. This article provides up-to-date information on fundamental properties and mechanisms of action of the major approved formulations of botulinum toxin type A, summarizes recent changes in naming conventions (nonproprietary names) mandated by the United States Food and Drug Administration, and describes the reasons for these changes. The request for these changes provides recognition that formulations of botulinum toxins (eg, onabotulinumtoxinA and abobotulinumtoxinA) are not interchangeable and that dosing recommendations cannot be based on any one single conversion ratio. The extensive safety, tolerability, and efficacy data are summarized in detail, including the patient-reported outcomes that contribute to overall patient satisfaction and probability treatment continuation. Based on this in-depth review, the authors conclude that botulinum toxin type A treatment remains a cornerstone of facial aesthetic treatments, and clinicians must realize that techniques and dosing from one formulation cannot be applied to others, that each patient should undergo a full aesthetic evaluation, and that products and procedures must be selected in the context of individual needs and goals.

Botulinum toxin type A gives adjunctive benefit to periorbital laser resurfacing

OBJECTIVE

Periorbital aging and lines are a result of intrinsic skin aging, ultraviolet damage, and repetitive action of periorbital muscles. Rejuvenation of this area should therefore be optimized by combining treatments that approach the different causative factors.

METHODS

This was a single-center, prospective, randomized, placebo-controlled study comparing the efficacy and safety of combining Botox injections (18 units per area) with ablative laser resurfacing versus laser resurfacing alone without Botox in the treatment of periorbital rhytids.

RESULTS

We have concluded a bilateral study comparing the effects of Botox versus saline placebo injections to the periorbital areas before and following erbium: YAG laser resurfacing of the areas in 33 patients. The results demonstrated that the Botox-treated side with laser resurfacing improved significantly more than the contralateral area treated with saline and laser in diminishing periorbital rhytids as well as textural, pigmentation, and other features of periorbital skin aging.

CONCLUSION

This study illustrates the benefits of a combined approach to treating periorbital skin aging.

Meige syndrome: what's in a name?

Frequently, blepharospasm is associated with involuntary movements of the platysma, lower face and masticatory muscles. Similarly, masticatory dystonia may occur in isolation or in combination with dystonia of other cranial and cervical muscles. The non-possessive and possessive forms of Meige and Brueghel syndromes have been variably and imprecisely ascribed to various anatomical variations of craniocervical dystonia. Herein, the origin of eponymic terms as applied to craniocervical dystonia is reviewed as support for proposed elimination of these eponyms from clinical usage. Although the term "segmental craniocervical dystonia" more accurately captures the combination of blepharospasm and dystonia of other head and neck muscles, delineation of craniocervical subphenotypes is essential for etiological/genetic and treatment studies. To conclude, the clinical features, epidemiology, pathophysiology and therapeutic management of segmental craniocervical dystonia are examined with a particular focus on "blepharospasm-plus" subphenotypes.

Advances in minimally invasive facial rejuvenation

PURPOSE OF REVIEW

Current cosmetic surgical practice for facial rejuvenation has undergone a significant change due to the introduction of technologies to improve the age-associated changes of the face. The most widely adopted methods of minimally invasive facial rejuvenation include the use of neuromuscular blocking agents and injectable fillers. The topic of minimally invasive procedures might include a variety of subjects including nutritional and hormonal modulation, light-based and laser-based therapies, minimal incision surgical procedures, as well as the use of botulinum toxin and fillers. The focus of this study will be on the minimally invasive facial rejuvenation efforts achieved by injection techniques.

RECENT FINDINGS

Botulinum A neurotoxin has been shown to be effective in the reduction of hyperfunctional lines in the upper and lower face. Anatomic areas that have been found to benefit include the glabella, the forehead, the periorbital area, lips, and the platysma muscle. The more recently introduced hyaluronic acid and other injectable fillers are receiving increasing usage. These temporary fillers have been found to improve creases and wrinkles, augment deep nasolabial folds, augment thin lips, and improve hollowing in the periorbital and other depressions and deformities.

SUMMARY

There has been a significant paradigm shift in the field of rejuvenation surgery. Injectable minimally invasive methods have been offered to remedy age-related and other acquired deformities of the head and neck region. These methods have provided temporary correction of undesirable characteristic that were traditionally approached with more invasive surgically oriented modalities.

Botulinum neurotoxins: fundamentals for the facial plastic surgeon

The most commonly performed nonsurgical cosmetic procedure in the facial plastic surgery armamentarium involves the various commercial preparations of botulinum neurotoxins. These drugs have undergone a transformation from public health scourge to near ubiquitous therapeutic modality across the entire medical spectrum. Herein, the history of botulinum neurotoxins is reviewed, including an exploration of their pharmacology, neuromuscular junction physiology, a description of the commercially available preparations, and the recent research concerning the practicalities of their clinical use.

A randomized, evaluator-blinded, two-center study of the safety and effect of volume on the diffusion and efficacy of botulinum toxin type A in the treatment of lateral orbital rhytides

BACKGROUND

There has been considerable discussion about the effect of the degree of dilution of botulinum toxin (BTX) but very few scientific studies.

OBJECTIVE

The objective was to observe as to whether a fivefold difference in concentration of BTX solution would produce a difference in clinical effect or duration of effect.

METHODS AND MATERIALS

Twenty individuals were enrolled at two sites and a within-subject paired-comparison study was performed on the lateral orbital area with a single injection of 5 U of BTX (BOTOX Cosmetic, Allergan Inc., Irvine, CA). The results were assessed both clinically and using a computer-assisted estimation of the degree of wrinkling.

RESULTS

No statistically significant differences were observed between the two sides.

CONCLUSIONS

This is a small study and it may be that dilution does affect BTX result. We were, however, unable to detect any difference in this study, which suggests that the degree of dilution, at least within a fivefold margin, has only a small effect on the results of BTX injection in the lateral orbital area.

Botulinum Toxin (Botox) to Enhance Facial Macroesthetics: A Literature Review

Dental implants have emerged as a predictable treatment option for partial edentulism. Their ability to preserve bone and soft tissue yields highly esthetic results in the long term. Increasingly, patients are demanding not only enhancements to their dental (micro) esthetics but also to their overall facial (macro) esthetics. Dynamic wrinkles (caused by hyperfunctional muscles) in the perioral, glabellar, and forehead regions can cause a patient's expressions to be misinterpreted as angry, anxious, fearful, or fatigued. An emerging treatment option to address these issues is the use of a paralyzing material such as botulinum toxin A (Botox) to decrease the appearance of the wrinkles, which yields a more esthetic and youthful facial appearance. Botox is a deadly poison that is produced by the bacterium Clostridium botulinum and causes muscle paralysis by inhibiting acetylcholine release at the neuromuscular junction. When used in areas of hyperfunctional muscles, a transient partial paralysis occurs that diminishes the appearances of wrinkles, Therefore, wrinkles not attributable to hyperfunctional muscles (eg, wrinkles caused by aging, gravity, photodamage, trauma, and scarring) will not be amenable to treatment with the toxin. As a result, proper case selection is essential. A thorough understanding of the indications, techniques, dosages, and complications and their management is imperative to achieve a satisfactory result. This article will review the pathogenesis of facial wrinkles as well as the history, techniques, clinical controversies, and other important considerations for successful treatment of facial wrinkles with Botox.

Complications of Botulinum Toxin Type A

Introduced over 30 years ago for the treatment of strabismus and blepharospasm, botulinum toxin type A (BTX-A) now has established uses for various therapeutic and cosmetic purposes. Although remarkably safe and effective, BTX-A is a potent toxin. Complications can occur, particularly when used by the inexperienced injectors. Through knowledge of its mechanism of action and effect and careful attention to dosing and technique can minimize the risk of more serious adverse events.

Botulinum toxin injections as a method for chemically denervating skeletal muscle to test functional hypotheses: a pilot study in Lepomis cyanellus

In this study, we demonstrate that botulinum toxin can be used to chemically denervate muscles to test functional hypotheses. We injected research-grade type A botulinum toxin complex into pectoral fin abductors (abductor superficialis) of green sunfish (Lepomis cyanellus) to determine whether chemical denervation would eliminate the ability of a particular muscle to contribute to overall pectoral fin movements. Reduction of target muscle activity occurred within 8 d of the injection, and paralysis was confirmed using electromyography. No paralysis was seen in the adjacent muscles (abductor profundus) or in positive controls (saline injections). Paralysis occurred more slowly and at lower doses than previously documented for mammals. However, botulinum toxin complex (500 kDa) was used here, whereas previous studies have used purified toxin (150 kDa). Therefore, differences in physiological responses between fish and mammals cannot yet be distinguished from differences caused by the toxin type. However, we note that the toxin complex is less likely to diffuse across muscle fascia (because it is large), which should minimize paralytic effects on adjacent muscles. We suggest that botulinum toxin holds great promise as a chemical denervation agent in functional studies of animal locomotion and feeding behaviors.

Asymmetrical Smiles Corrected by Botulinum Toxin Serotype A

OBJECTIVE

The objective was to identify the cause of an asymmetrical smile and to ascertain whether or not it would be correctable by injections of Botulinum toxin A (BTX-A).

METHODS

Five patients with asymmetrical smiles were identified and found to lower one side of their lower lip in an exaggerated fashion when smiling or laughing. After close observation, it was determined that the ipsilateral depressor labii inferioris of the lower lip was hyperkinetic and retracted that side of the lips lower than its contralateral side when smiling or laughing. Injections of low-volume and low-dose BTX-A (BOTOX, Allergan, Inc.) were placed into the depressor labii inferioris on the side where the lower lip retracted the lowest.

RESULTS

All of the five patients with asymmetrical smiles presented with unilateral hyperkinetic depressor labii inferioris and responded to injections of BOTOX. Their lower lips became level and their smiles were symmetrical within 1 week of the BOTOX treatments. Their lip symmetry lasted for at least 6 months after their initial treatment. With each additional treatment, the duration of BOTOX lasted even longer, averaging approximately 7 months.

CONCLUSION

BOTOX is an effective, safe, and long-lasting treatment for lower lip asymmetries caused by a hyperkinetic depressor labii inferioris.

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.