Botulinum toxin (BoNTA) has become the modern generation’s treatment of choice for facial aging. Advanced uses of neurotoxin have treated specific areas of the face, in addition to the glabella, which is the only site for injection approved by the Food and Drug Administration. This article suggests that BoNTA has replaced surgical procedures that treat oral commissures, mild brow ptosis and brow asymmetries, and hypertrophic orbicularis oculi muscles. It is becoming increasingly used for lip asymmetry, platysmal banding, and necklift, although it has not replaced traditional procedures for the correction of these areas.
Key points
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By understanding the opposing pull of the muscles of facial expression, neurotoxin injections can be precisely placed to enhance certain facial features.
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Neurotoxin injections, either alone or in combination with filler agents, have probably replaced open procedures for elevation of the oral commissure, hypertrophy of the orbicularis oculi muscles, improvement of the gummy smile, and liplift.
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Although severe brow ptosis requires surgical intervention, mild ptosis or mild brow asymmetries can be corrected with carefully planned placement of neurotoxin injections.
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Neurotoxin injections cannot be considered a definitive treatment for necklift; however, mild platysmal banding can be treated to either delay open surgery or improve a less than perfect surgical result.
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Creative uses like the Nefertiti necklift can be used to replace or delay the need for an open procedure.
Introduction
Without question, the cosmetic use of botulinum toxin (BoNTA) has changed the practice of facial plastic surgery. Since its approval by the Food and Drug Administration in 2002 for treatment of glabellar frown lines, creative uses of the product have allowed surgeons to noninvasively shape the face. By understanding the underlying facial anatomy and the push-pull relationships of the muscles of facial expression, surgeons are now able to increase the muscular pull in one direction by eliminating the opposing force with neuromodulators.
The use of nonsurgical procedures is popular with today’s patients because they can receive in-office treatments without taking time off from work. Some treatments with neurotoxins have become so effective that they have replaced traditional surgical procedures. This article present 5 of these procedures, which are off-label uses of neurotoxins.
Introduction
Without question, the cosmetic use of botulinum toxin (BoNTA) has changed the practice of facial plastic surgery. Since its approval by the Food and Drug Administration in 2002 for treatment of glabellar frown lines, creative uses of the product have allowed surgeons to noninvasively shape the face. By understanding the underlying facial anatomy and the push-pull relationships of the muscles of facial expression, surgeons are now able to increase the muscular pull in one direction by eliminating the opposing force with neuromodulators.
The use of nonsurgical procedures is popular with today’s patients because they can receive in-office treatments without taking time off from work. Some treatments with neurotoxins have become so effective that they have replaced traditional surgical procedures. This article present 5 of these procedures, which are off-label uses of neurotoxins.
Chemical browlift
Facial rejuvenation of the upper third of the face has often focused on achieving the ideal brow contour and position. When analyzing the aesthetics of the brow, the supraorbital rim and the upper eyelid crease are key factors to be taken into consideration. The ideal position of the female brow should be at the supraorbital rim medially, with the arc above the supraorbital rim laterally. The ideal male brow is described as positioned just above the supraorbital rim following a horizontal course along the rim. The ideal shape of the female brow is broad medially and tapering laterally, with its highest point at the lateral limbus or the lateral canthus according to individual preferences. The male brow is thicker and its shape does not taper. Lower brows are the product of aging and are often associated with feelings of sadness, grief, anger, and tiredness. Additionally, the position of the eyebrows can exacerbate the appearance of dermatochalasis of the upper eyelid. Traditionally, forehead lifts have been used to rejuvenate the upper third of the face and improve brow position. More recently, neuromodulation of the brow depressors and elevators with BoNTA has been used to contour the brows to individual preference.
Surgical techniques available for the forehead include coronal, pretrichial, midforehead, direct and endoscopic approaches. Traditional methods achieve brow repositioning by excising scalp skin and weakening of the muscular brow depressors. Endoscopic lifting often relies on skin redraping within the forehead and brow suspension. Since the introduction of the endoscopic browlift, it has gained rapid popularity due to its smaller incisions hidden in hair bearing surfaces. Browlifts are performed under general anesthesia and require 1 to 2 weeks of recovery. Although complications with forehead lifts are low, hematomas, seromas, alopecia, poor scarring, forehead dysesthesias, and injury to the frontal branch of the facial nerve are possible.
A new alternative to the surgical approaches for brow rejuvenation has emerged with refinement in the use of BoNTA, in what is referred to as the chemical browlift . The effects of BoNTA on the brow were initially noted as a side effect when treating hyperdynamic glabellar rhytides. Increased interbrow distance and medial brow elevation was an unintended consequence of treatment. Currently, BoNTA is used to intentionally achieve a browlift by selectively weakening brow depressors and allowing brow elevators to lift the brow. The frontalis muscle is responsible for brow elevation and its contraction results in horizontal rhytides along the forehead. Procerus, corrugator supercilii, and lateral orbicularis oculi are the main brow depressors. Inactivation of the depressor muscles permits the elevation of the brow by allowing the frontalis muscle to overcome its downward pull. Procerus originates in the nasal bones and inserts on the lower forehead in skin between both brows acting as a brow depressor. Corrugator supercilii is also a medial depressor that originates in the superciliary arch and inserts into the skin of the medial brow and is primarily responsible for the vertical rhytides in the glabella. The lateral orbicularis oculi is responsible for lateral brow depression and so-called crow’s feet rhytides. During a chemical browlift, medial elevation is mediated by weakening of corrugators and procerus muscles, and lateral elevation by weakening of the lateral orbicularis oculi muscles.
Treatment Goals in Browlift
A moderate browlift can be achieved by selectively weakening the brow depressors and allowing the frontalis to exert brow elevation.
Preoperative Planning
The injection sites medially and laterally are determined by examining the brow position during facial animation. Palpating the orbital rim prevents injection into the orbit that may lead to ptosis by affecting the levator palpebrae superioris. Having a patient frown and relax repetitively helps identify the length of the belly of the corrugator supercilii. Examining the area between the medial brows allows for identification of procerus muscles. Having a patient squint and smile demonstrates the crow’s feet. When planning the injections, it is imperative to preserve muscle function in the forehead by not overly relaxing/treating the frontalis muscle with neurotoxin. If the frontalis muscle is not able to elevate the brow, brow ptosis may occur. It is important to notice that patients with severe brow ptosis are less likely to get a significant lift from a neurotoxin and might be better candidates for traditional or endoscopic browlifts.
Additional variations can be planned in cases where only certain portions of the brow are to be addressed or in cases of brow asymmetries. Frequently, some female patients request injections for contouring of the brow and elevation of the lateral brow only. In such cases, weakening the medial frontalis lowers the medial brow accentuating the lateral brow and providing the desired brow contour. Brow asymmetries where one brow is higher than the other can be addressed by attempting to lower the higher brow and raise the lower brow.
Procedural Approach
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Neurotoxin is placed into the procerus and corrugators muscles using approximately 5 to 7 injection sites.
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In addition, the lateral orbicularis muscle can be treated to increase the lateral lift.
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To treat the whole brow, a total of 20 to 25 BoNTA units (BU) or 60 to 75 abobotulinumtoxinA (Dysport) units (DU) may be necessary.
Note: The frontalis muscle superior to the brows should not be weakened, because it is the only mechanism to allow brow elevation.
Fig. 1 shows pretreatment and post-treatment results for a patient who underwent chemical browlift.
Potential Complications and Their Management
The treatment area is in close proximity to the muscles of the orbit and neurotoxin effect may spread to intraocular sites affecting the levator palpebrae superioris leading to ptosis. Care should be taken to keep the injection close to the surface of the skin to avoid deeper spread. Apraclonidine (Iodipine) 0.5% eyedrops are an α-adrenergic agonist used to correct this problem. By causing Müller muscle contraction, apraclonidine raises the eyelid margin by 1 to 2 mms.
Not all patients obtain the same degree of brow elevation using this technique. Overtreatment of the frontalis muscle may negate any possible brow elevation achieved. The limitation of the degree of brow elevation is dictated by the unopposed action of frontalis muscle; after reaching the point of maximal weakening of brow depressors, further elevation requires surgical intervention. Patients with severe brow ptosis are less likely to get a significant lift from a neurotoxin.
Immediate Postprocedural Care and Recovery
Post-treatment instructions are controversial. Although some physicians instruct their patients not to push on the injection sites, exercise, lay flat, or bend over for 4 hours, there are no data that show this prevents ptosis. Similarly, there are no studies that show movement of the injected muscles increases neurotoxin uptake.
Clinical Results in the Literature
Researchers have attempted to quantify the degree of brow elevation obtained by targeting different brow muscles. Table 1 summarize the available literature on the effects of BoNTA treatment for brow elevation.
| Article | Study Type | Patient Population | Injection Site and Dose | Timeframe | Results |
|---|---|---|---|---|---|
| Huilgol et al, 1999 | Prospective case series | 7 Patients | 7–10 BU to glabella and 0–2.5 BU to lateral orbicularis oculi | 1 mo | 1–3 mm of Brow elevation in 5 of 7 patients |
| Frankel, 1999 | Prospective case series | 30 Patients | 20 BU to glabella | 2 wk | 32% Had an increase in medial brow and 48% in the central brow |
| Huang et al, 2000 | Case series | 11 Patients | 10 BU to glabella and 10 BU superficially along the superior orbital rim | 7–10 d | Average 2–3 mm elevation |
| Ahn et al, 2000 | Prospective case series | 22 Patients | 10 BU to lateral orbicularis oculi | 2 wk | Average elevation of 1 mm at midpupillary line and 4.83 mm at the lateral canthus |
| Carruthers and Carruthers, 2007 | Retrospective case series | 79 Patients | 20–40 BU to glabella | Every 2 wk for 20 wk | Central, medial, and lateral elevation peaked at wk 12 with up to 3 mm of elevation |
Studies examining the effect of treatment limited to the glabella only have shown that up to 3 mm of brow elevation can be achieved. In 2007, Carruthers and Carruthers published the largest series to date examining the effect of 20 BU to 40 BU to the glabella in 79 female patients. In their study, patients were examined every 2 weeks and maximum effect was seen at 12 weeks after injection, where up to 3 mm of brow elevation was seen in the lateral, central, and medial brow. In the study of treatment limited to the glabella, only 10 BU lead to medial brow ptosis. Different injection techniques have also achieved similar elevation. Huang and colleagues reported on brow elevation after injection of 10 BU to the glabella and 10 BU superficially along the orbital rim with 4 evenly spaced injections, similar to the technique the authors describe, achieving up to 3 mm of brow elevation.
Studies that target the lateral orbicularis have also been published. Huilgol and colleagues treated 7 patients by injecting 7 BU to 10 BU into the glabella and 0 BU to 2.5 BU to the lateral orbicularis, resulting in a 1 to 3 mm brow elevation in 5 of the 7 patients. Ahn and colleagues treated the lateral orbicularis only at a dose of 10 BU and achieved an average of 4.83 mm of lateral brow elevation.
Hypertrophic orbicularis oculi
Orbicularis oculi muscle hypertrophy is a condition that affects the lower eyelid and results in fullness when smiling or squinting, producing a tired look at rest.
The orbicularis oculi muscle surrounds the eye and is divided into 3 parts: orbital, preseptal, and pretarsal. The primary function of pretarsal muscle is involuntary closing of the eye. Hypertrophy of the muscle in this region may cause bunching of the skin, infraorbital rhytides, and narrowing of the palpebral aperture during contraction. Fullness in the pretarsal portion is different from fullness in the preseptal portion of the eye. Although often overlooked, pretarsal fullness is due to muscular hypertrophy, whereas preseptal fullness is due to the more traditional concept of orbital fat prominence. To treat orbicularis oculi hypertrophy during lower eyelid blepharoplasty, a subciliary incision is necessary to allow for resection of a strip of the hypertrophic muscle at the pretarsal region. The risk of this approach is scar contraction with lower eyelid retraction, eyelid malposition, scleral show, and ectropion. Although eyelid retraction after lower eyelid blepharoplasty is an infrequent complication, it is feared given that correction is difficult.
Hypertrophy of the orbicularis oculi can now be addressed with BoNTA. The lower eyelid can be treated with neurotoxin to improve fullness and flatten the appearance of the eyelid. Additionally, benefits of treating the lower eyelid include decreasing rhytides and widening of the palpebral aperture, which is considered more attractive. These effects become more pronounced when the crow’s feet region is concomitantly treated.
Treatment Goals in Hypertrophic Orbicularis Oculi
Hypertrophy of the orbicularis oculi muscle can cause a fullness of the lower eyelid when smiling or squinting. By weakening the muscle with neurotoxin, flattening of the lower eyelid roll is achieved.
Preoperative Planning
Accurate diagnosis is key in these patients who complain of lower eyelid bags. Patients must be counseled on the differences between lower lid fat herniation and orbicularis muscle hypertrophy and treated appropriately. Check for ectropion and dry-eye or Sjögren symptoms before injections because weakening of the orbicularis may exacerbate these conditions. The tone and elasticity of the lower eyelid should be evaluated before injection by performing a snap test.
Procedural Approach
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BoNTA (1–2 BU or 3–6 DU) is injected at the midpupillary line approximately 3 mm below the lash line.
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A single injection is placed per eyelid.
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The injection is immediately subcutaneous.
Note: Because of the increased zone of effect for Dysport, BoNTA may be preferred for these injections.
Fig. 2 shows pretreatment and post-treatment results for a patient smiling before and after neurotoxin injection to the lower eyelid roll.
Potential Complications and Their Management
Widening of the palpebral aperture may result in dry eyes and disturb normal blinking. Inject with caution in patients with lax lower eyelids or with dry eye syndrome. Bruising may occur after injection.
Immediate postprocedural care
No specific care is necessary immediately after treatment. Cold compresses may be applied for comfort or possible mild bruising. Patients may return to regular activities immediately after injection.
Clinical Results in the Literature
The first report of BoNTA to the lower eyelid was published in 2001 by Flynn and colleagues, describing direct injections of 2 BU in the lower eyelid for infraorbital rhytides. In addition to the effect on the rhytides, there was an increase in the palpebral aperture in 40% of patients. This increase was seen as a favorable cosmetic change. The effect in the palpebral aperture was accentuated when the crow’s feet were treated at the same time achieving an increase of 1.3 mm at rest and 3 mm when smiling. The investigators comment that the results were more notable in Asian patients. Subsequently, the same group conducted a study to evaluate the effect of different doses to the lower eyelid ranging from 1 BU to 8 BU. Increasing doses progressively widened the palpebral aperture; however, an unacceptable rate of side effects was encountered at higher doses. When 2 BU were used per eyelid, no patients experienced any side effects, whereas more than half of the patients had problems with incomplete sphincter function and edema at 8 BU doses.
Rejuvenation of oral commissure
Downward turn of the oral commissure is a sign of an aging mouth that gives an appearance of being tired, sad, or even bitter. The lateral oral commissure can extend, forming a groove, and contribute to the marionette appearance. In severe cases, particularly in older patients, it can be a site for drooling and angular cheilitis may develop. This area can represent a problem even after successful rejuvenation with facelift. During facelift, correction of the corner of the mouth would require excessive pulling that would result in a fishmouth deformity, an unnatural and obviously operated look. Although patients can be bothered by this appearance, improvement of the corner of the mouth can be achieved by treating the oral commissure.
Commissuroplasty
Traditionally, a commissuroplasty or lift of the oral commissure has been the procedure used to address this area. The technique involves a full thickness excision of skin superiorly and laterally to the oral commissure to elevate the corner of the mouth while camouflaging the incision parallel and immediately outside to the vermilion border. As a result of the procedure, a visible scar is created. Although most patients find the incision not noticeable and easily concealed, hypertophic scarring is always a possibility. Another potential disadvantage of commissuroplasty is overcorrection of the lift where the commissures are turned upwards, creating an unnatural look often referred to as a joker appearance .
Filler and Neurotoxin
Presently, commissuroplasty has been replaced by augmentation filling to efface the oral commissure groove and neurotoxin injection to the depressor anguli oris (DAO). Neurotoxin alone can be used in this area but most often must be combined with filler injections to the oral commissure. The DAO is a facial muscle that originates in the outer surface of the mandible at the oblique line of the mandible and inserts into the modiolus at the angle of the mouth. Its function is to depress and lateralize the lips and, together with the mandibular ligament, form the mentolabial groove. Direct injection into the DAO with BoNTA allows for weakening of the muscle and results in elevation of the corner of the lips by action of the levator anguli oris and the zygomaticus major and minor muscles. DAO injection is an outpatient procedure that allows patients to return to their regular activities immediately after injection. The risks of permanent scarring are avoided, although it does require repeat injection.
Treatment Goals of Oral Commissure Neuromodulation
The main objective of neuromodulation of the DAO is lip rejuvenation by lifting the downward turn of the corner of the lip.
Preoperative Planning
Careful assessment of the perioral muscles should always be done at rest and with contraction. The DAO muscle may be palpated while having patients actively frown from the origin in the mandible to its insertion into the corner of the mouth. Patients should be appropriately counseled that DAO injection does not improve severely depressed oral commissures, which most likely require filler injection in addition to DAO injection, and does not elevate the marionette lines.
Procedural Approach
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A single injection per muscle is suggested and well tolerated.
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The DAO muscle should be palpated while having patients actively frown. If the belly of the muscle cannot be palpated, an approximate estimate of its location can be made by going 1 cm lateral to the oral commissure and then 1 cm inferiorly.
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Inject approximately 2–5 BU (or 6–15 DU) deeply into each muscle.
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Alternatively, to avoid other perioral muscles, injections may be placed into the muscle along the mandibular border.
Fig. 3 shows pretreatment and post-treatment photographs.
