Botulinum toxin type A: history and current cosmetic use in the upper face

Neuromodulator Assessment and Treatment for the Upper Face: An Update

Neuromodulator treatment of the upper face has been extensively studied and serves as an excellent tool to enhance facial appearance, non-verbal communication, and social functioning. Optimal outcomes are best achieved when health care providers take an individualized approach, based on knowledge of structural and functional anatomy, thorough facial assessment, and customized injection techniques and patterns.

A new Chinese crow's feet grading scale based on the DermaTOP system

Many Chinese wrinkle studies continue to use non-Chinese scales because few Chinese-based wrinkle scales have been developed. The study aims to develop a crow's feet grading scale for Chinese individuals. We enrolled 608 healthy Chinese subjects and measured data through the DermaTOP system. We chose exploratory factor analysis (EFA) to reduce the dimensions of the data. A three-factor structure was obtained by using EFA, and it explained a cumulative total of 89.551% of the variance. A computational formula was obtained by calculating the total factor tilt scores and taking the variance contribution rate of three factors as the weight. Based on the computational formula, a grading map was designed and tested. The model validation was conducted using both subjective assessments from the expert panel and objective results from the model calculations. The results showed that our grading scale model is stable. This study developed a Chinese crow's feet (CCF) grading scale, which included a parameter, a grading map, and literal descriptions. The CCF grading scale is a validated tool for evaluating the effects of cosmetics or specific therapies. More importantly, the CCF scale was developed based on objective data, which may inspire new ideas for wrinkle grading scale development in the future.

Incorporating Cosmetic Procedures into Your Dermatology Practice

Cosmetic procedures can be a nice addition to many different types of dermatology practices. It is part of our specialty, and the author would encourage anyone interested to pursue adding a few procedures to their current practice. Why perform cosmetic procedures? It can be esthetically pleasing for many dermatologists, there is a growing demand for esthetic procedures, and it is a source of additional increased revenue not tied to Medicare.

Expert Opinion on Non-Surgical Eyebrow Lifting and Shaping Procedures

Eyebrow elevation and reshaping are common concerns that we handle in everyday practice, and we have noticed that the trend is shifting from a medical concern to a cosmetic one. Several eyebrow lift methods are available, both invasive and non-surgical. The method of choice depends on several factors, such as patient expectations and beliefs, financial budget, acceptance of downtime and the available tools in the practice. In this article, we review the recent literature on non-surgical eyebrow lift methods to provide an overview of the current state of this field. We discuss seven different methods for eyebrow lift and reshaping, including botulinum toxin, dermal fillers, fractional radiofrequency, high-intensity focused ultrasound, thermo-mechanical ablation, lasers, and threads. Moreover, we provide practical insight into the procedure, injection techniques, expected results, and patient satisfaction rate.

Quantitative assessment of change in upper extremity muscle stiffness following fluid injection using shear wave elastography

OBJECTIVE

To quantitatively assess changes in muscle stiffness following intramuscular saline injection using shear wave elastography (SWE).

MATERIALS AND METHODS

Thirty muscles (lateral deltoid (LD), biceps brachii (BB), brachialis, pronator teres (PT), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU)) from fresh-frozen cadaveric specimens were injected with saline under ultrasound guidance. Pre- and post-injection muscle thickness (MT) (mm) and SWE (kPa) measurements were recorded.

RESULTS

All muscles demonstrated a decrease in the mean SWE value post-injection, with the largest differences ± standard error noted in the LD (14.76 ± 3.55 kPa, p = 0.021) and brachialis muscles (12.02 ± 2.51 kPa, p = 0.013). Muscle thickness increased following injection, although the degree of changes poorly correlated with the change in SWE.

CONCLUSION

In summary, following intramuscular injection of saline injection, a decrease in upper extremity muscle stiffness is detected using SWE. It is important to note that if performing a longitudinal assessment of muscle stiffness after intramuscular injection, saline will likely contribute to a decrease in muscle stiffness in the immediate post-injection time period.

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.

The One21 Technique: An Individualized Treatment for Glabellar Lines Based on Clinical and Anatomical Landmarks

PURPOSE

Botulinum toxin type A is an effective treatment for glabellar dynamic wrinkles. As the muscular group involved in the contraction of the glabella varies among people, individualized treatment can achieve optimal results. This study evaluates a customized assessment for the treatment of glabellar lines with Incobotulinumtoxin-A, leading to an individualized points distribution and dosage.

PATIENTS AND METHODS

A single-center, evaluator-blinded, therapeutic cohort study enrolled 130 women with moderate or severe glabellar wrinkles. They underwent Incobotulinumtoxin-A injection following the standard 5-point injection at the glabellar muscles (n = 65) or an individualized assessment and scheme treatment based on anatomical references of contraction, the One21 technique (n = 65). All the patients were photographed under maximum contraction before treatment (T0) and after 4 weeks (T28). The photos were randomly assessed by two blinded, experienced raters to consensually grade the severity according to the Merz Aesthetics Scales (MAS). The primary clinical efficacy was defined as a 2-point reduction in the MAS score, on Day 28.

RESULTS

The groups were homogeneous regarding age, phototype, and baseline MAS scores. On Day 28 (T28), 64 (98.5%) patients from the One21 group and 52 (80%) from the 5-point group reduced the MAS score by at least two points (p < 0.01). When adjusted by age and phototype, both groups reduced the MAS score at T28 (p < 0.01); nevertheless, patients from the One21 group significantly performed better (p < 0.01), with a much higher rate response rate at T28, in comparison to the 5-point group. Of patients enrolled in the 5-point group, 83.1% utilized muscle groups other than the procerus and corrugator in glabellar wrinkle formation, and 17 (24.6%) presented asymmetrical contraction. Patients from the 5-point group with glabellar asymmetry and those who utilized the frontalis and orbicularis presented inferior performance (p < 0.05), reinforcing the importance of an individualized assessment and treatment plan.

CONCLUSION

The One21 technique yielded better results than the standard 5-point treatment in reducing glabellar dynamic lines with Incobotulinumtoxin-A, especially for asymmetric lines of the glabella or the involvement of muscle groups other than the procerus and corrugator.

Botulinum Toxin to Treat Horizontal Forehead Lines: A Refined Injection Pattern Accommodating the Lower Frontalis

BACKGROUND

When treating horizontal forehead lines with botulinum toxin type A the traditional approach requires that injection points should stay 1.5 to 2 cm above the orbital rim to avoid brow ptosis. Failure to treat the lower frontalis may potentially cause worse rhytides in the lower forehead.

OBJECTIVES

The aim of this study was to present a refined injection pattern accommodating the lower frontalis and evaluate its clinical efficacy and safety.

METHODS

Patients were categorized into 4 types according to the patterns of their forehead wrinkles. Moderate and severe wrinkles in the upper forehead were treated by the "safe zone" technique. Mild wrinkles and rhytides in the lower forehead were treated by the Microbotox technique. Standard photographs and measurements were taken before and after treatment. The effect on wrinkle reduction and changes in brow heights were assessed.

RESULTS

In total, 330 treatments were followed up in the clinic, and 246 treatments were followed up by telephone. Among the 330 treatments, 213 were evaluated in our clinic 2 to 4 weeks later, and the patients who received these treatments were recruited for effect evaluation and brow height measurements. The posttreatment severity of forehead wrinkles was significantly reduced (P < 0.05), and brow heights remained unchanged (P > 0.05). No severe adverse events were documented. Patient satisfaction was quite high.

CONCLUSIONS

The refined injection pattern is an effective and safe technique to treat horizontal forehead lines. The Microbotox technique enables treatment of the lower frontalis without changes in brow position.

LEVEL OF EVIDENCE: 3

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.

Sixth nerve palsy following botulinum toxin injection for facial rejuvenation

BACKGROUND

Botulinum toxin A (BTX) has been widely used for a variety of facial esthetic procedures within the last couple of decades. Efficacy and safety of BTX for facial rejuvenation has been extensively studied in multiple randomized prospective controlled trials. Focal weakness is among the most commonly reported adverse effects. Adverse reactions tend to occur most commonly due to errors in dosing formulation and errors with the techniques of the application. No serious long-term complications have been reported.

MAIN OBSERVATION

We present the case of a 52-year-old female presenting with diplopia one week following the injection of BTX for facial rejuvenation at glabella, forehead and crow's feet areas.

CONCLUSIONS

Injection of BTX adjacent to periorbital area may be associated with extra-ocular muscle paralysis.

Botulinum toxin for the treatment of hyperfunctional lines of the forehead

Background:

In the 21^st century, we live longer and a more active life. However, while our adult longevity continues to extend, society does not welcome a tired and aged appearance. We wish to continue to look as young as possible. Most facial rejuvenation techniques such as surgery and injection of collagen, silicone, or autogenous fat do not address the fact that these lines are functional, i.e. they do not target the cause of hyperfunctional lines: the underlying facial mimetic musculature.

Aim:

To find the efficacy of Botulinum toxin for the treatment of hyperfunctional lines of the forehead.

Materials and Methods:

The present study consisted of 25 subjects in the age group of 25–65 years with forehead wrinkles, who visited the Department of Oral and Maxillofacial Surgery, CIDS, Virajpet. The materials used for Botulinum toxin treatment were Botulinum toxin A, a standard freezer, sterile saline solution, alcohol swabs, and insulin syringes with 30 gauge needles.

Results:

Of the 25 patients, 21 patients showed satisfactory improvement of their hyperfunctional facial lines within 72 h. Maximum improvement was noted in the age group of 25–40 years, while the older age group of 50–65 years showed less improvement. Maximum improvement was seen in type 5 skin, followed by type 4 and type 3 skin. Type 2 skin showed the least improvement.

Conclusion:

We conclude that Botulinum toxin A is a safe and efficacious method of nonsurgically eliminating hyperfunctional facial lines of the forehead in the aesthetic patient for a period of 4–6 months.

Report of Allergic Reaction After Application of Botulinum Toxin

Botulinum toxin is a widely used treatment with satisfactory results, and it is relatively safe in the doses used for cosmetic procedures. The authors report a case of allergic reaction to Chinese botulinum toxin serotype A (CBTX-A). Although this is a rare adverse event, it is nonetheless clinically relevant to healthcare professionals. A 44-year-old woman presented to the authors' hospital complaining of dynamic wrinkles. CBTX-A was used to treat her. Minutes after application, she developed urticarial plaques proximal to the injection site. The patient had an allergic reaction, as documented by a positive skin test, which was controlled by the administration of antihistamines and systemic corticosteroids. This report is intended to guide healthcare professionals faced with this type of adverse event regarding how to proceed without hindering the delivery and effectiveness of the treatment. When performed by a qualified health professional, this treatment brings excellent results in the vast majority of cases.

LEVEL OF EVIDENCE

5 Risk.

Effectiveness of botulinum toxin (type-A) administered by the fixed-site dosing approach versus the muscle area identification

INTRODUCTION

Botulinum toxin is widely used in glabellar musculature. The authors express the need to individualize the approach by means of muscular identification to improve effectiveness. Despite these guidelines, the fixed-point technique is still used.

OBJECTIVE

Comparison of effectiveness of botulinum toxin administration in the glabellar zone by using fixed-site application versus objective-muscle-identification.

MATERIALS AND METHODS

Prolective dynamic cohort study. Patients (after previous informed consent) were assessed on their facial expressions, level of satisfaction, re-interventions, adverse effects, dosage, dilution, and number of injections. All patients who experienced either of both techniques of botulinum toxin administration (fixed-site or objective-muscle-identification) were subjected to followup by the following parameters: statistical analysis: student's t Test (inter-group mean comparisons), paired student's t test (intra-group mean comparisons), χ (2) with Fisher exact text.

RESULTS

Sixty-two patients were evaluated (31 fixed-site approach, 31 objective-muscle-identification). No patient abandoned the trial during followup. Fixed-site injections required larger doses (16 vs 12 U, p = 0.001), greater volume (0.48 vs. 0.37 ml, p = 0.001), and more application sites (4 vs 2, p = 0.001), compared to the objective-muscle-identification approach. Under the objective-muscle-identification technique, facial expressions were better attenuated (52 vs 65%, p = 0.001), with a higher initial satisfaction level (6 vs 9, p = 0.001) and final satisfaction level (9 vs 9.9, p = 0.001).

CONCLUSIONS

Botulinum toxin application is more effective when administered through the objective-muscle-identification approach (less frowning, lower doses, less fixed sites injected, and patients more satisfied at the end).

LEVEL OF EVIDENCE III

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.

Current status of surgery in dermatology

An article titled "Current issues in dermatologic office-based surgery" was published in the JAAD in October 1999 (volume 41, issue 4, pp. 624-634). The article was developed by the Joint American Academy of Dermatology/American Society for Dermatologic Surgery Liaison Committee. A number of subjects were addressed in the article including surgical training program requirements for dermatology residents and selected advances in dermatologic surgery that had been pioneered by dermatologists. The article concluded with sections on credentialing, privileging, and accreditation of office-based surgical facilities. Much has changed since 1999, including more stringent requirements for surgical training during dermatology residency, and the establishment of 57 accredited Procedural Dermatology Fellowship Training Programs. All of these changes have been overseen and approved by the Residency Review Committee for Dermatology and the Accreditation Committee for Graduate Medical Education. The fertile academic environment of academic training programs with interaction between established dermatologic surgeons and fellows, as well as the inquisitive nature of many of our colleagues, has led to the numerous major advances in dermatologic surgery, which are described herein.

Efficacy and safety of a novel botulinum toxin type A product for the treatment of moderate to severe glabellar lines: a randomized, double-blind, active-controlled multicenter study

BACKGROUND

A new botulinum toxin type A (NBoNT) produced from the same strain of Clostridium botulinum as onabotulinumtoxinA (OBoNT) is widely used in Asia.

OBJECTIVES

To compare the efficacy and safety of NBoNT and OBoNT for moderate to severe glabellar wrinkles.

METHODS

A double-blind, randomized, active-controlled, phase III study was performed. Three hundred fourteen patients were randomized at a 1:1 ratio to receive 20 U of toxin. The primary end point was the responder rate according to investigator live assessment at maximum frown at week 4. Secondary end points were responder rates according to investigator live assessment with frowning and at rest at weeks 8, 12, and 16, with additional photographic assessment by a panel of blinded raters 4 weeks after injection. Subjective satisfaction scores were also evaluated.

RESULTS

Four weeks after treatment, responder rates for maximum frown were 93.7% (133/142) in the NBoNT group and 94.5% (138/146) in the OBoNT group. For secondary end points, there was no significant difference between the two groups for any variable at any time point. Noninferiority of NBoNT was confirmed. There were no serious adverse effects with either toxin.

CONCLUSION

NBoNT is equally as effective as OBoNT for the treatment of glabellar frown lines. Both toxins were well tolerated.

Noncosmetic periocular therapeutic applications of botulinum toxin

Botulinum toxin blocks acetylcholine release at the neuromuscular junction. The drug which was initially found to be useful in the treatment of strabismus has been extremely effective in the treatment of variety of conditions, both cosmetic and noncosmetic. Some of the noncosmetic uses of botulinum toxin applications include treatment of spastic facial dystonias, temporary treatment of idiopathic or thyroid dysfunction-induced upper eyelid retraction, suppression of undesired hyperlacrimation, induction of temporary ptosis by chemodenervation in facial paralysis, and correction of lower eyelid spastic entropion. Additional periocular uses include control of synchronic eyelid and extraocular muscle movements after aberrant regeneration of cranial nerve palsies. Cosmetic effects of botulinum toxin were discovered accidentally during treatments of facial dystonias. Some of the emerging nonperiocular application for the drug includes treatment of hyperhidrosis, migraine, tension-type headaches, and paralytic spasticity. Some of the undesired side effects of periocular applications of botulinum toxin inlcude ecchymosis, rash, hematoma, headache, flu-like symptoms, nausea, dizziness, loss of facial expression, lower eyelid laxity, dermatochalasis, ectropion, epiphora, eyebrow and eyelid ptosis, lagophthalmos, keratitis sicca, and diplopia.

Botulinum toxin in facial rejuvenation: an update

Since its initial approval by the US Food and Drug Administration (FDA) 20 years ago for the treatment of strabismus, hemifacial spasm, and blepharospasm in adults, botulinum toxin (BTX) has become one of the most frequently requested products in cosmetic rejuvenation around the world. After years of clinical success and consistent safety in the upper face, the use of BTX has expanded and evolved to include increasingly complicated indications. In the hands of adept injectors, the focus has shifted from the treatment of individual dynamic rhytides to shaping, contouring, and sculpting, alone or in combination with other cosmetic procedures, to enhance the aesthetic appearance of the face. Although recent reports have questioned the safety of BTX, 25 years of therapeutic and over 20 years of cosmetic use has demonstrated an impressive record of safety and efficacy when used appropriately by experienced injectors.

Recombinant botulinum neurotoxin A heavy chain-based delivery vehicles for neuronal cell targeting

The long half-life of botulinum neurotoxin serotype A (BoNT/A) in cells poses a challenge in developing post-exposure therapeutics complementary to existing antitoxin strategies. Delivery vehicles consisting of the toxin heavy chain (HC), including the receptor-binding domain and translocation domain, connected to an inhibitory cargo offer a possible solution for rescuing intoxicated neurons in victims paralyzed from botulism. Here, we report the expression and purification of soluble recombinant prototype green fluorescent protein (GFP) cargo proteins fused to the entire BoNT/A-HC (residues 544-1295) in Escherichia coli with up to a 40 amino acid linker inserted between the cargo and BoNT/A-HC vehicle. We show that these GFP-HC fusion proteins are functionally active and readily taken up by cultured neuronal cells as well as by neuronal cells in mouse motor nerve endings.

Nonsurgical modalities to treat the aging face

Injectable shaping agents include neurotoxins (botulinum toxin type A products), replacement fillers (hyaluronic acid [HA] agents), and biostimulatory fillers (calcium hydroxylapatite [CaHA], polymethylmethacrylate [PMMA], and poly-L-lactic acid [PLLA]). This article presents an overview of the agents currently available for use in facial rejuvenation in the United States.

Tandem fluorescent proteins as enhanced FRET-based substrates for botulinum neurotoxin activity

The light chain of botulinum neurotoxin A (BoNT/A-LC) is a zinc-metalloprotease that requires two extended exosites for optimal substrate binding and recognition of its intracellular target SNAP25. CFP and YFP connected through SNAP25 peptide (141-206) containing both exosites (CsY) has been used in a FRET-based assay for BoNT/A. To further improve the FRET efficiency in this BoNT/A substrate for in vitro high-throughput assays, we explored the feasibility of enhancing the capture of CFP emission by doubling the number of YFP acceptors. In comparison to CsY, the tandem fluorescence substrates CsYY and YsCsY enhanced the ratiometric fluorescence signal between YFP and CFP. YsCsY, containing two substrate sites, offered the greatest fluorometric change upon toxin-catalyzed cleavage. In addition to known approaches for enhancing fluorescence yield through various mutations, this alternative tandem substrate approach can boost the FRET signal and is particularly useful for substrates requiring extensive exosite recognition for specificity.

Efficacy and safety of botulinum toxin type A in the treatment of lateral crow's feet: double-blind, placebo-controlled, dose-ranging study

BACKGROUND

Botulinum toxin type A (BoNT-A) is frequently used to treat crow's feet; the optimal dose for each toxin preparation should be established.

OBJECTIVE

To compare the efficacy and safety of three doses of BoNT-A with placebo to treat crow's feet.

METHODS

Subjects with moderate to severe crow's feet at maximum smile (mild to severe at rest) were randomized to a single bilateral BoNT-A treatment (15, 30, or 45 U) or placebo. Outcome measures included evaluation of crow's feet by an independent panel from blinded photographs at maximum smile, investigator assessment, and patient satisfaction.

RESULTS

Independent panel assessments (Week 4) showed that all BoNT-A doses resulted in significant improvements in crow's feet severity at maximum smile (p<.001); a clear dose-response effect was seen. Improvement over placebo was seen in the 30-U and 45-U groups to Week 12. Investigator assessment showed significant improvement for all doses for 12 weeks at maximum smile and rest (p< or =.01). Patient satisfaction was significantly greater for all doses than for placebo for 16 weeks (all p<.05). All doses were well tolerated. CONCLUSION BoNT-A (15, 30, or 45 U) is an effective and safe treatment for mild to severe crow's feet.

Dose equivalence of two commercial preparations of botulinum neurotoxin type A: time for a reassessment?

BACKGROUND

The units of different preparations of botulinum neurotoxin type A (BoNT-A) have different potencies, and dosing recommendations for each product are not interchangeable. Historically, there has been debate concerning the dose-equivalence ratio that should be used in clinical practice.

METHODS

Published evidence was considered to establish an appropriate dose-conversion ratio for the two main commercially available preparations of BoNT-A--Dysport (Dp) and Botox (Bx).

RESULTS

Four key areas of evidence were identified: nonclinical and preclinical studies; studies exploring the diffusion characteristics and effects of complexing proteins; comparative experimental data from human studies; and clinical studies. Nonclinical data indicate that the principal reasons for differences in unit potency between the two products are dilution artefacts in the mouse assay. Use of saline as a diluent, at high dilutions, results in significant loss of potency in the Bx assay, whereas use of gelatin phosphate buffer in the Dp assay procedure protects the toxin during dilution. The published data on mouse assays show a Dp : Bx unit ratio range of 2.3-2.5 : 1 in saline and 1.8-3.2 : 1 in gelatin phosphate buffer. Data indicate that complexing proteins or size of the complex, which is highly pH sensitive, play no role in toxin diffusion and that Dp and Bx have similar diffusion characteristics when used at comparable doses. Randomized, controlled clinical studies indicate that 3 : 1 is more appropriate than 4 : 1, but the two products are not equivalent at this ratio. Comparative human experimental studies using the extensor digitorum brevis test, facial lines and anhidrotic action halo tests support dose-conversion ratios less than 3 : 1.

LIMITATIONS

Data comparing dose equivalence ratios from the non-clinical setting should be extrapolated into the clinical setting with some caution.

CONCLUSIONS

Dose-conversion ratios between Dp and Bx of 4 : 1 and greater are not supported by the recent literature.

Growth effects of botulinum toxin type A injected into masseter muscle on a developing rat mandible

OBJECTIVES

Botulinum toxin type A (BTX-A) reduces the muscular contractions by temporarily inhibiting the release of acetylcholine at the neuromuscular junction. The purpose of this study was to investigate the effects of the BTX-A injected into the masseter muscle of a developing rat mandible.

MATERIALS AND METHODS

Four-week-old male (no. 80) Sprague-Dawley rats were divided into four groups: control group, saline group, BTX-A group and baseline control group. Rats of baseline group were sacrificed at 0 day to provide baseline values of the mandibular measurements. The masseter muscle of rats in the saline and the BTX-A group were administered with saline and BTX-A solutions respectively. Experimental animals were sacrificed after 4 weeks.

RESULTS

The BTX-A group demonstrated smaller mandibular dimension compared with the other groups (P < 0.05). Their condylar cartilages showed increased apoptosis at the proliferation stage of the reserve zone and masseter muscle fibers demonstrated atrophic changes.

CONCLUSIONS

The result demonstrated BTX-A influence on inhibitory action of the developing mandible because of apoptosis at the proliferation stage of the reserve zone of the condylar cartilage in developing rat mandible.

Botulinum Toxin in Facial Palsy: An Effective Treatment for Contralateral Hyperkinesis

BACKGROUND

The treatment of facial paralysis aims to recover symmetry in both static and dynamic states, which are seriously affected by the progressive contralateral hyperkinesis. Botulinum toxin may be used to reduce facial asymmetry in patients suffering from facial paralysis.

METHODS

Eighteen patients (12 female and six male patients) with facial palsy and contralateral hyperkinesis were injected with 112.5 units (0.9 ml) of Dysport (botulinum toxin type A) distributed evenly in the muscles of the perioral area. The patients were examined at 14, 28, 42, 56, 90, 150, and 180 days after the injection. Patients evaluated the degree of improvement at each time point. In addition, three evaluators made static (relaxed state) and dynamic (maximum contraction while smiling) assessments using a series of measurements obtained with a digital caliper, and the mean was used as the reference value.

RESULTS

The quantitative analysis demonstrated a significant reduction in hyperkinesis that lasted approximately 180 days. There was a significant or moderate improvement in most of the cases. All of the patients were very satisfied with the treatment. Adverse events were short-lived (mainly during the first 15 days) and related to difficulty in drinking without liquid loss (nine of 18) and difficulty in chewing without food loss (three of 18).

CONCLUSION

Injection of botulinum toxin was effective in reducing muscular hyperkinesis in the hemiface opposite that affected by facial paralysis, with mild and short-term side effects.

A Pilot Study on the Effect of Epinephrine on Botulinum Toxin Treatment for Periorbital Rhytides

BACKGROUND

Relaxation of hyperactive facial muscles by injection of botulinum toxin type A (BOTOX, Allergan Inc., Irvine, CA) represents the most common cosmetic procedure performed in the United States.

OBJECTIVE

The objective of this split-face randomized double-blind study was to determine the effect of epinephrine (EPI) on the efficacy of BOTOX treatment of muscle hyperactivity in the upper face.

MATERIALS AND METHODS

Fourteen subjects (ages 39-57 years) with moderate to severe periorbital rhytides were enrolled. Study patients were blinded to the two treatment arms, BOTOX and BOTOX plus EPI 1:100,000. Subjective and objective evaluations were performed at 0 and 4 days and 1, 3, and 6 months, and clinical improvement was assessed using a nominal scale from 0 to 4, corresponding to 0, 1% to 25%, 26% to 50%, 51% to 75%, and 76% to 100% improvement, respectively. The incidence of adverse events was also recorded. RESULTS Fourteen subjects with moderate to severe periorbital rhytides were treated with BOTOX or BOTOX plus EPI. One subject was discontinued from the study after receiving asymmetric doses of BOTOX. At 4, 30, and 90 days after treatment, subjective and objective improvement scores revealed that EPI enhanced the efficacy of BOTOX when compared to BOTOX alone. By 3 months, the effect of BOTOX and BOTOX plus EPI had peaked and continued to fall through 6 months. One of 14 patients did not appear to respond to BOTOX treatment. Both treatments were well tolerated with no serious adverse events.

CONCLUSION

To our knowledge, we are the first to test under randomized double-blind conditions the effect of EPI on efficacy of BOTOX. Our data suggest that addition of EPI may accelerate the rate of onset as well as the short-term efficacy of BOTOX for treatment of periorbital rhytides.

Pilot study comparing the diffusion of two formulations of botulinum toxin type A in patients with forehead hyperhidrosis

BACKGROUND

Different formulations of botulinum toxin type A (BoNTA) may have different diffusion characteristics.

OBJECTIVE

The objective was to compare the diffusion characteristics of two formulations of BoNTA.

MATERIALS AND METHODS

A total of 20 patients with forehead hyperhidrosis received four injections of BoNTA in their forehead (one medial and lateral injection of one formulation randomly assigned to one forehead side, one medial and lateral injection of the other formulation to the other forehead side). Patients received 3 U/injection of BoNTA(1) (BOTOX, Allergan, Inc.) and were randomly assigned to receive BoNTA(2) (Dysport, Ipsen Ltd.) at a dose ratio of 1:2.5, 1:3, or 1:4. The area of anhidrosis was highlighted using iodine and starch and determined by software from standardized photography.

RESULTS

During the 6 months after treatment, the area of anhidrosis was larger with BoNTA(2) in 93% (195/210) of medial-medial or lateral-lateral comparisons of the two products and at all dose ratios. The smaller area of anhidrosis with BoNTA(1) did not compromise its efficacy in inhibiting contraction of frontalis muscle.

CONCLUSION

BoNTA(2) has a greater area of diffusion in the forehead than BoNTA(1), even with identical injection volumes. This may hinder accurate localization of clinical effect, thereby increasing the potential for adverse effects.