Glabellar rhytides

Historically, the ‘glabella’ was the area first and most described as a potential treatment site with BTX for aesthetic enhancement. Currently (at the date of publication) it is still the only facial site with FDA approval for the cosmetic use of BTX, specifically Botox Cosmetic. All other areas for which the toxin is used for cosmetic enhancement are considered ‘off-label.’ This means that under the physician’s discretion it is lawful to apply the drug in other areas with, of course, the appropriate patient consent. The glabella is loosely defined as the region depicted by the smooth elevation of the frontal region just above the bridge of the nose that extends laterally to each side onto and just above and lateral to the medial (head of) the eyebrow. The ‘glabellar complex’ often refers to a group of brow-associated muscles (mostly depressors in action) that function primarily for facial expression (Fig. 24-4). Muscles of the glabellar complex include the corrugator supercilii, procerus, depressor supercilii, and orbicularis oculi. Vertical glabellar frown lines arise naturally from the repeated activity of the corrugator supercilii and medial orbital orbicularis oculi muscles (plus depressor supercilii muscles) that not only induce vertical descent of the medial eye brow but cause adduction and depression of the surrounding soft tissue (Fig. 24-5).

Figure 24-4 The greater understanding of the muscular facial anatomy facilitates a higher level of injection latitude and reduces complications.

Figure 24-5 A, Young female with deep glabellar frown line with animation on command. The frown pattern can vary significantly in individuals. Demonstrated here are obvious deep vertical ‘frown’ lines that repeat laterally toward the central eyebrow as well as extend cephalad toward the hairline. B, Shown again here in animation after Botox treatment to the glabella region with 5 ‘standard’ injections, four units per injection site.

Horizontal lines at the proximal nasal bridge typically located at the most caudal aspect of the glabellar complex are a manifestation of the muscular activity of the procerus and depressor supercilii muscles (Fig. 24-6).

Figure 24-6 A, This patient exhibits the common finding of a combination of furrows relating to the brow depressors, specifically the corrugator supercilii and procerus muscles. The vertical furrows are primarily due to the actions of the corrugator muscles and the horizontal furrow at the bridge of the nose is mostly related to the depressor supracilii and procerus muscles. B, After treatment to the corrugator muscles, depressor supracilii and the procerus, there is a dramatic reduction in these furrows.

In 1992, Carruthers et al injected 18 patients with BTX-A for the treatment of glabellar frown lines.¹ Sixteen of 17 patients followed showed improvement for varying lengths of time with few side effects. This initial paper sparked a frenzy of interest across the globe. Following a number of publications, two randomized, placebo-controlled studies involving 537 patients confirmed the impressive safety and efficacy of the injection on the glabella. This led to the Food and Drug Administration (FDA) approval of BTX-A for the treatment of glabellar lines in 2002.^22–24 This region has still been the most readily adopted area for the use of BTX for a variety of reasons mentioned previously, as well as a lack of consistent prior effective treatment options.

Dosing

The strength and size of the muscles of the glabellar complex varies significantly from patient to patient. More importantly, despite similar anatomic components in most of us, a greater variable is the individual dynamics (i.e. the way we use our muscles). Although the most common treatment pattern utilizes two injections to each corrugator and one centrally to reduce procerus function (Fig. 24-7), individualizing treatment sites and doses to each patient will optimize clinical benefits. In addition, the exact effect desired may vary as well. In women, recent studies also suggest that higher doses may be longer lasting and give greater aesthetic benefit. A prospective, randomized, dose-ranging study of 80 women showed the greatest responses with the longest duration on glabellar lines with 30 and 40 U BTX-A, compared to the responses seen with only 10 or 20 U.^25,26 Moreover, higher doses (20–40 U) produce an additional benefit of eyebrow lift.²⁷ The likely cause for this effect resides primarily in the fact that with higher doses to the glabella region, there is enhancement of diffusion to the adjacent frontalis muscle.²⁸ With this phenomenon, attenuation of the central frontalis activity by BTX induces a secondary hyperdynamic contraction/recruitment of the untreated lateral and superior frontalis that yields this effect (Fig. 24-8). In addition, the desired effects will vary from individual to individual as well. For instance, some individuals might have a more elevated medial eyebrow and prefer a greater lateral arch (Fig. 24-9). Precise and isolated injection placement of toxin to the corrugators and secondary brow depressors (typically a more caudal placement of the injection at or about the brow cilia) could further elevate the medial eyebrow reducing any chance of enhancing the desired brow contour. In these individuals, a ‘high-glabellar’ technique (Fig. 24-10 and DVD) might be preferable. This will affect both the brow depressors and adjacent frontalis muscle, and will reduce the glabellar vertical frown lines as well as induce a varying degree of medial brow descent. This will also be influenced by additional injections (or not) to the more cephalad portions of the forehead and dose (discussed below) (Fig. 24-11).

Figure 24-7 Standard sites for treatment to the glabellar region.

Figure 24-8 This patient was treated with Botox to the glabella region only (4 units per site; 2 into each corrugator muscle and one to the central procerus muscle). No injections were given anywhere else. Note the brow position and arch with medial descent and lateral elevation.

Figure 24-9 A, This patient presented for improvement of upper facial lines and shaping of her eyebrows. Note the elevated medial eyebrow position associated with more centrally located forehead furrows. B, Precise placement of toxin accomplishes both line reduction and eyebrow shaping.

Figure 24-10 A, This patient exhibited minimal glabellar furrows but desired improvement of the upper face. B, After treatment to the lateral canthus and a ‘high glabella’ technique inducing medial brow height accentuating the arch of the eyebrow.

Figure 24-11 A, Patient with asymmetric brows who desires enhancement of symmetry and a more arching lateral eyebrow. B, After treatment with Botox with precise injection that improves the appearance of furrows yet also causes more of a medial brow depression and induces a lateral arch to the eyebrows left greater than right.

In general, men have a larger glabellar muscle mass compared with women. Studies comparing the efficacy and safety of the ranges of 20 to 80 U of BTX-A in men suggest that patients injected with doses as high as 80 U achieved a ‘better’ response rate than those injected with lower doses, without experiencing an increase in adverse effects.²⁹ This high level dosing produces enhanced efficacy as well as persistence of effect which are not only required due to the greater muscle mass in males, but are also better suited to the male’s gender aesthetics and attitude. As in all treated areas, the most effective applications are delivered with precise injection techniques.

The most effective format of application and technique to this region has generated healthy debate. As in most facial regions, precision (i.e. targeting the recipient muscle with exactitude) will yield the most predictable responses. Understanding underlying facial muscle anatomy allows precision as to how much toxin is injected and where it is injected. The corrugator muscles lie deep to the insertion of the frontalis muscle in this region and just superficial to the periosteum of the supraorbital rim. Superficial injections (intradermal, subdermal/subcutaneous) will very likely equally (if not more) affect the frontalis muscle and will depend on diffusion to arrive at the corrugator muscles. Deeper injections (into the belly of this large muscle) will more accurately affect the corrugators in isolation. However, it should be mentioned that two of the authors (AC and JC) performed an objective study on 24 women with asymmetric medial eyebrows using an asymmetric injection technique as described above. On objective photographs taken at rest (Canfield system) there was no differential change in eyebrow height demonstrated. The techniques of one of the authors (SF) to this region is as follows (Fig. 24-12 and see DVD): The injector uses the non-dominant hand to stabilize the eyebrow between the thumb and forefinger and can also easily distract the medial eyebrow above the orbital rim. At the same time the injector can place the thumb into the supraorbital notch to protect against toxin migration posteriorly into the orbit. The injecting hand then orients the syringe at 90 degrees to the skin surface and with a swift motion attempts placement of the needle tip into the mid-aspect of the muscle in two places (the lateral and medial components of the corrugators). This maneuver is then repeated on the opposite side. Care is also taken to avoid unnecessarily puncturing periosteum (as happened with techniques described in the past, which aimed to pass the needle to the periosteum, then withdraw slightly to the muscle) as this can be a cause of headache and post-injection pain, probably due to periosteal inflammation.

Figure 24-12 Injection technique to the glabella region. The non-dominant hand is used to stabilize and elevate the eyebrow over the superior orbital rim. The thumb can be placed, as shown here, in the supraorbital notch, while the dominant hand injects toxin with precision.

Finally, this section would be incomplete if there were not a mention of our aesthetic goals that include what constitutes a satisfactory endpoint and outcome with effective dosing. Unfortunately, the concept of ‘immobility’ has become, in the mind of some consumers, synonymous with ‘effective’ treatment. Patients will return to your office to display their ability to ‘frown’ with the most unusual and noble efforts that produce the vaguest glimmer of a vertical frown line (Fig. 24-13). As in most situations, educating your patients on what they should expect and what constitutes an aesthetic satisfactory result that might not include immobility will avoid many phone calls and return visits and ultimately a happier and well-informed patient.

Figure 24-13 A, This patient presented for treatment of glabellar furrows. Shown here in animation on command. B, 3 weeks after treatment to the glabellar region, only she feels there is a ‘slight’ furrow (that no one else could see), with this dramatic voluntary attempt at frowning.

Horizontal forehead rhytides

The frontalis is a large, quadrilateral muscle that originates in the galea aponeurotica. It inserts inferiorly into the procerus, orbicularis oculi, depressor supercilii muscles and anteriorly over the corrugator supercilii muscle, and terminates beneath the skin of the eye-brow. Although most figures (Fig. 24-4) depict the frontalis in two sections, it usually spans the forehead from one temporal fusion line to the other and may be thicker in certain portions of the forehead. The frontalis raises the eyebrows and skin over the root of the nose and also draws the scalp forward. Contraction of the frontalis primarily produces a series of horizontal forehead wrinkles and furrows. The most active portion of the frontalis muscle in most individuals is the 2 or 3 cm immediately above the brow. Activity in this portion produces horizontal rhytids that can appear as cephalad as the anterior hairline (Fig. 24-14). This finding is important when deciding at what locations BTX will be injected for a particular individual. Also, the effects of inducing brow ptosis will be greater if the lower portion of the forehead is injected (Fig. 24-15). In many individuals, a single row of treatment sites in the midforehead is effective in reducing or eliminating rhytids while preserving brow position (Fig. 24-16). Finally, as with most areas of the face, individual unique habitual animation and the desired aesthetic effects will dictate where the drug is applied. The lateral extent of the forehead injection sites will be influenced by a com-bination of aesthetic desires and the functional anatomy.

Figure 24-14 Where is the muscle location that causes these furrows? At times furrows can be seen clearly beyond (cephalad) to the hairline, however the induction of these lines can be caused by the action of the frontalis far caudal to them. This is best detected by palpating the forehead while the patient animates and will lead to a better result with fewer injections and reduced eyebrow descent.

Figure 24-15 A, This patient presented with desire for complete eradication of the horizontal forehead furrows that were accentuated with animation as shown here. Pan injection of the forehead with injections to the frontalis muscle within 2 cm of the eyebrow will induce significant brow ptosis (as seen in B) that may be acceptable in some males however objectionable for many others. B, After treatment. This patient, like some, will demand treatment as such rather than demonstrate any significant furrows with animation.

Figure 24-16 This is an example of a pattern of injection for an individual who presents for improvement of the appearance of mild to moderate horizontal forehead furrows. Note that although in many patients the frontalis muscle is two distinct (paired) quadrilateral muscles, the central injection allows for improvement either by diffusion to each side, or if the patient has a frontalis muscle that spans across the entire forehead region.

BTX-A injected across the forehead lessens undesirable horizontal forehead lines for a period of 4–6 months.³⁰ Although treatment is individualized for each patient, in most individuals injections should be placed 2.5–3 cm above the brow proper to avoid brow ptosis or a lack of natural expressiveness. In general, narrow brows receive fewer injections and lower doses than broader higher brows. The exact site and dosage will depend on each individual presentation and the desired effects.

Dosing

As in the glabella, prior research suggested that higher doses of BTX-A may be more effective than lower doses in the forehead. A randomized, double-blind, dose-ranging study examined 60 women injected with either 16, 32, or 48 U BTX-A in eight sites and found the greatest improvement and duration of response with 48 U.³¹ However, adverse effects (headache, eyelid swelling, and brow ptosis), though uncommon, were more frequently associated with the higher doses. For reasons less clear that might relate to muscle mass, the number of active neuromuscular junctions is less in the frontalis muscle,³² BTX-A effects in this region (for any combination of the postulated causes), usually last longer than any other facial area. Therefore despite a slight reduction in regional efficacy, lower dosages (and few injection sites) may allow for a more harmonious onset and dissipation of effects. Retained animation, reduction in the degree of induced brow ptosis and greater aesthetic benefits also result from more conservative dosing (Fig. 24-17). As mentioned, the frontalis is unusually ‘sensitive’ to even seemingly low doses of drug. The placement (whether intradermal, immediately subcutaneous, deep subcutaneous, or intramuscular) has less bearing on the result. Although a direct intramuscular injection usually gives the most effective treatment, the authors advocate a more superficial injection that helps avoid bleeding, bruising, significant pain, or hematoma that can ‘spoil’ an otherwise perfect application in selected individuals.

Figure 24-17 A, This patient presented for improvement of forehead furrows but did not desire a significant induction of brow ptosis. B, By placing the injections higher in this individual (greater than 2 cm above the eyebrow) induction of brow ptosis is minimized, while improvement of forehead lines is dramatic as desired.

Brow lift and contouring

As previously mentioned, treating glabellar rhytides can also result in a pleasing brow lift. Adept clinicians can now predictably produce elevations in the medial, central, and temporal eyebrow. Varying treatments to the brow depressors have been shown to be effective in elevating the eyebrow through a host of techniques. Isolating treatment to the procerus, depressor supra-cilii, and lateral orbital orbicularis oculi muscle alone will elevate the brow but preserve its natural arc. Injecting 7 to 10 U BTX-A in the procerus at the midline, followed by one injection on each side (5 U) into the superolateral eyebrow at the temporal fusion line²¹ has been shown to be effective. This technique is especially useful in those individuals who exhibit brow ptosis and whose vertical glabellar frown lines are less of a concern (Fig. 24-18). This dramatically reduces the possibility of further brow depression (with any diffusion to the adjacent frontalis). By ignoring the variations in eyebrow shape presentation and the potential effects of treating the brow depressors in isolation, we fall short of delivering the optimum aesthetics (Fig. 24-19). Other techniques described demonstrate isolated injection of the lateral brow depressors^13,14 by injection of 7–10 U into the superolateral orbicularis oculi at three sites below the lateral third of the brow, superior and lateral to the orbital rim, and produced significantly variable mid-pupillary and lateral brow elevations ranging from 1 to nearly 5 mm.^13,14 The cause for such variability, while at first appearing confusing, might be more explainable than previously thought. Such variability has also been shown with surgical brow lifts, whereby the identical technique performed on various individuals can produce dramatically different results. The explanation most likely lies in the fact that precise application to the brow depressors can cause their dense chemo-denervation. The ‘lift’ ultimately will also depend on increased tone in frontalis.¹⁵ Significant brow elevation will be achieved after treatment to the brow depressors if the technique is precise. It is important to avoid injections ‘too high’ that may produce diffusion to the lateral frontalis (Fig. 24-20).

Figure 24-18 A, This patient presented with complaints of periorbital rhytids including ‘crow’s feet’ and the horizontal furrows at the nasal bridge. She also wanted to improve the shape of her brows. She had received Botox elsewhere in the past and stated that despite avoiding the forehead and some obvious improvement, she always appeared a bit angry and had an exaggerated ‘arch’ to her eyebrow with ‘heaviness’ on the medial upper eyelid area. B, After Botox treatment to the lateral canthus and depressors of the central glabellar region, with particular avoidance of treatment to the lateral corrugator muscles (that might affect adjacent frontalis by diffusion).

Figure 24-19 This patient presented for upper blepharoplasty with complaints of the feeling of heaviness of the upper eyelids exacerbated by recent injections of BTX-A to her forehead performed elsewhere to eliminate regional rhytids. Over-treatment to the forehead, especially to the central portion, does not always result in profound brow ptosis, but can result in an unhappy patient that experiences discomfort with the inability to satisfactorily animate the forehead (shown here using great effort to raise her eyebrows) and the worsening of upper eyelid dermatochalasis and overall aesthetic appearance.

Figure 24-20 Technique of injection of lateral brow depressors (lateral orbital/infrabrow orbicularis oculi muscle) for a ‘brow lift’ effect. A ‘wheel’ of fluid (containing 2–6 U of BTX) is injected beneath the lateral brow cilia.

The potential effects and the ability to manipulate brow shape was a prelude to the recognition of the use of BTX for both the eradication of facial lines and as an agent for facial reshaping.⁴

Some patients experience eyebrow asymmetry, for which BTX-A has also been beneficial. There are many causes of eyebrow asymmetry, including facial nerve trauma following surgical brow lift or other surgically induced facial paralysis, ipsilateral eyelid ptosis, and asymmetric non-pathologic facial expression.⁹ BTX-A injections into the brow depressors on the lower brow side can reset the balance (Fig. 24-11). Extreme care must be taken when treating non-pathologic facial asymmetry, both for the treatment of rhytids and brow position. Patients may look aesthetically improved in repose, but they might appear unusual with even casual animation when mobility (i.e. of the forehead) is only seen on the untreated side (Fig. 24-21).

Figure 24-21 A, This patient is happy with her BTX injection only while in repose. BTX had been injected differentially to the forehead and infrabrow region to treat a marked asymmetry of the eyebrow position. B, When the patient animates and attempts to raise her brows, the areas of treatment are far more obvious. Care must be taken to consider asymmetric treatment effects on animation and aesthetics.

‘Crow’s feet’: treatment of the lateral periorbita and canthal region

The palpebral portion of the orbicularis oculi – the sphincter-like muscle of the eyelids – is thin and close to the skin, regulating the palpebral opening and acting largely involuntarily during blinking (pretarsal). The orbital portion is thicker, with mostly horizontal and oblique fibers. Contraction of the orbicularis oculi, whose fibers run vertically under the skin at the lateral angles of the eyelids, accentuates the lateral canthal rhytides or ‘crow’s feet.’

Dosing

BTX-A injections of 12–15 U per side (in two to four injection sites) placed subdermally or intradermally relax the muscle of the lateral periorbita without completely inactivating the orbicularis oculi, which could affect both voluntary and involuntary eyelid function (discussed in ‘Complications with treatment to the periorbita’) and the ability to fully close the eye.⁷ Results usually last in the range of 3–6 months with few adverse effects (Fig. 24-22).

Figure 24-22 A, This young female presented for treatment of ‘crow’s feet’ noted mostly with animation (smiling, squinting, etc.). B, After injections as noted, complete eradication of crow’s feet is achieved. Routine scheduled treatment sessions at 4-month intervals have prevented, in her, the onset of static rhytids.

Although historically the use of BTX-A was mostly considered an effective tool for the eradication or improvement of facial rhytids, a higher level of understanding and vision of improved aesthetics and rejuvenation has revealed that it is equally if not more effective in the improvement of facial shape.⁴ Precise application of the drug, with strong consideration of both direct and indirect effects with the ability to augment results by applying the drug in a variety of ways in multiple facial regions in coordination, has facilitated the next level of aesthetic results. Similarly, the treatment of ‘crow’s feet’ in most situations should not be considered as an isolated therapy for canthal rhytids, rather a coordinated treatment for improvement of these lines and contouring of both the lateral eyebrow, midface, as well as improvement of lower eyelid lines, and orbicularis muscle hypertrophy (next section). The extended application of injection sites while treating the lateral periorbita will depend on the patient’s presentation and aesthetic desires and will vary from individual to individual (Fig. 24-23). The preferred plane of injection is immediately subdermal, whereby a significant wheal is observed with each dermal puncture (Fig. 24-24, and DVD). This can reduce bruising, bleeding and discomfort, but additionally places the toxin most distant (superficial plane) from the orbit, allowing for safe and effective treatment. The sites of treatment for the lateral periorbita and canthal rhytids are usually lateral to the lateral orbital rim (Figs 24-24 & 24-25).

Figure 24-23 A, This patient presented for ‘crow’s feet’ treatment and ‘any other improvement of her eye appearance’ with BTX. B, After extended treatment to the infrabrow region and to the inferior aspect of the orbicularis oculi muscle that extends onto the malar process, the extended lateral canthal and lower eyelid lines are improved as well as the position of the tail of the eyebrow.

Figure 24-24 Typical injection sites for treatment of the lateral canthus. Injections may be as high as the infra-brow cilia and as low as the lateral malar region depending on the patient presentation and the desired effects.

Figure 24-25 Common areas for treatment of the lateral canthus. 3–5 injections are given depending on the patient presentation and desired effects.

Hypertrophic orbicularis

In some patients, particularly but not limited to individuals of Asian descent, the perceived size of the palpebral aperture diminishes noticeably while smiling, and they request ‘larger’ eyes as a component of aesthetic improvement. Other related phenomena include those who develop significant pretarsal ‘bulging’ in association with ‘smaller’ eyes (Fig. 24-26) from either chronic squinting (more common in those who either work or play outdoors in sunlight) or even those individuals who aesthetically desire a larger vertical palpebral aperture to improve appearance (see p. 317). Increasing the size of the palpebral aperture with carefully placed injections is another part of the new ‘art’ of BTX-A, and experience has shown that injections of 2 U into the lower pretarsal orbicularis will relax the palpebral aperture at rest and while smiling.^7,15 One study describes the injection of 2 U subdermally, 3 mm inferior to the lower pretarsal orbicularis and, on one side only, three injections of 4 U placed 1.5 cm from the lateral canthus, each 1 cm apart, in 15 women.¹⁹ Mean palpebral aperture increase in 86% of patients was 1.8 mm at rest and 2.9 mm at full smile, with the most dramatic results seen in the Asian eye. However, it is important to select patients with good lid tone and proceed with particular caution in those who have had previous lower eyelid ablative resurfacing or transcutaneous blepharoplasties, so that the lateral canthal support is not affected. Better candidates for this application are typically younger females, without prior surgery, and no history or symptoms consistent with dry eye syndrome. At times, onset or worsening of lower eyelid/cheek festoons can also be seen in particular individuals with these treatments to the lower eyelid.³³ This approach can also be used with caution in those individuals who experience and/or complain of worsening of the lower eyelid rhytids or ‘pretarsal bulge’ after traditional treatment to the lateral canthus.

Figure 24-26 A, This patient presented for treatment of lateral canthal rhytids, brow position, extended lateral lower eyelid and cheek lines, and ‘bulging’ of the lower eyelid ‘pretarsal’ region upon smiling. B, After treatment in the areas shown, lower eyelid, canthal, and cheek rhytids, lateral brow position, and lower eyelid ‘orbicularis hypertrophy’ is improved. Note that the vertical eyelid aperture is invariably affected by the treatment to the lower eyelid orbicularis muscle.

As with all applications of BTX-A, the facial regions in proximity to the injection sites can experience secondary effects from toxin diffusion. Unwanted and exaggerated ‘over-elevation’ of the lateral eyebrow can result from toxin injected too high at the lateral commissure (Fig. 24-27). Midface ptosis can be the result of toxin being injected in the region of the zygomatic notch (Fig. 24-28). Diffusion effects can influence the cheek elevators (zygomaticus complex). In addition, those individuals with the early notation of ‘malar bags,’ lower eyelid lymphedema, or even lower eyelid bags can experience a worsening of the appearance of these conditions (even with treatments limited to the lateral canthus) (Fig. 24-29). Reduction of the effect of the lymphatic pump and reduction of muscle tone to the preseptal orbicularis muscle can lead to a peri-orbital edema that can last up to 4 weeks in rare individuals (Fig. 24-30).

Figure 24-27 A, This patient was unhappy with her BTX treatment performed elsewhere. She realized a definite improvement in line reduction, especially in repose, but claimed that she thought she looked ‘strange’ at times but could not be more specific. B, With animation, there is an exaggerated effect of the lateral brow arch with complete immobility of the medial brow. These effects are often seen for a variety of reasons that include glabella injections given too high that affect the central frontalis muscles, as well as injections given to the lateral brow depressors. This can be easily improved with low-dose BTX to the lateral frontalis as shown, but are best avoided by accurate preinjection assessments and precise localization of drug. In these situations, recruitment of the more lateral and cephalad portion of frontalis can also sometimes be seen, with treatment to adjacent muscle. This can also be treated in various ways depending upon presentation.

Figure 24-28 A, This patient desired ‘extended’ treatment of the lateral canthus to improve brow position, reduce the appearance of upper eyelid ‘excessive’ skin, and reduce lower eyelid/canthal lines. B, After treatment as shown, the canthal rhytids, lower eyelid lines and lateral upper eyelid hooding is corrected. The position of the malar ‘bag’ however is directed caudally in a more visible position.

Figure 24-29 A, This patient presented for improvement of lower eyelid and canthal rhytids and was treated with BTX. B, After treatment lines were only modestly improved at the cost of undesirable worsening of her ‘lower eyelid bags’ that is from weakening of the orbicularis oculi hammock of the injected regions.

Figure 24-30 A, This patient presented for improvement of lateral canthal rhytids. She has had two prior lower blepharoplasty procedures (performed elsewhere) with resulting lower eyelid retraction. The risk and limited benefits were discussed; however she elected to undergo treatment. B, After treatment with Botox, lines are partially effaced; however the lower eyelid ‘bags’ and lower eyelid retraction are worsened. This might have been avoided by limiting injections to the extreme lateral canthus distant from the lower eyelid.

Dosing

Lower dosages, in the order of magnitude of 1–2 units per injection site are typical for these applications. Higher dosages (as in other facial regions where function may be affected such as the lips) can cause significant morbidity such as exposure keratopathy, or epiphora, as well as lack of aesthetic improvement. For mild to moderate upper eyelid ptosis, the starting dosages are usually around 1 unit applied to the pre-tarsal orbicularis (in the subdermal plane) at the extreme medial and lateral aspect (Fig. 24-35). Results can be dramatic (Fig. 24-36). Due to lower dosing, the effects are less long-lasting and usually are in the 2–3 month range.

Figure 24-35 Mild to moderate upper eyelid ptosis can be treated with ‘low-dose’ BTX to the pretarsal orbicularis oculi as shown.

Figure 24-36 A, This patient presented for BTX treatment in the most common areas (glabella and lateral canthus) for the first time after multiple sessions performed at several other physicians’ clinics in the past. The left upper eyelid ptosis was noted on examination and she was questioned if she had ever noted this and/or inquired about treatment. She was aware of this, but felt that the only treatment option was surgery for which she was not interested. B, After glabella and canthal treatment with Botox as well as 1.5 U BTX to the pretarsal region as shown in ‘A.’

Complications can be mild and include differential blink rate or more significant with lagophthalmos and exposure keratopathy that can be temporarily treated with topical emollients in most situations until the effects subside. Higher dosages can also yield diffusion effects to both Müller’s muscle and the levator muscle and worsen the lid ptosis. This can be avoided by starting with lower dosages and injection in the immediate subdermal plane, with sites as far medial and lateral as possible. Avoidance of injury to the globe must be cautioned and is also best facilitated by injecting as parallel to the skin surface as possible (much as with treatment in this region for ‘blepharospastic’ conditions). This is a safer technique, especially in the ‘new’ patient who has no prior experience with BTX-A or even your routine ‘jumpy’ patient.

Upper eyelid position has been shown to be influenced by manipulation of the eyebrow in several ways.¹⁵ As shown previously (Fig. 24-31), those individuals with compensated upper eyelid ptosis (i.e. those patients who raise their eyebrow to elevate the upper eyelid to the slightest degree when a mild upper lid ptosis exists) will negate this effect if Botox is used to counter the associated forehead furrows. Similarly, a small subset of individuals with mild to moderate upper eyelid retraction (interestingly, these patients commonly wear vision corrective contact lenses) who demonstrate this enhancement of the vertical palpebral aperture and do not raise their forehead for this effect, will show a reduction of the upper eyelid retraction when Botox is applied to raise the eyebrow (Fig. 24-37).

Figure 24-37 A, This patient presented for treatment of brow ptosis as well as glabellar and canthal rhytids. Mild upper eyelid retraction was noted on examination. B, After treatment in the sites shown, note the reduction of rhytids as well as the improvement of brow shape/position and reduced upper eyelid retraction (not as a cause from drug diffusion to the lid elevators).

Treatment to the lower eyelid can be applied to asymmetries that result from congenital effects, aging changes, prior surgery, stroke, and a host of other regions including bilateral lower eyelid treatment to ‘enlarge’ the eyes (enhance the vertical dimension of the palpebral aperture). Higher dosages to the lower eyelid region should also be avoided and the usual starting dose is 1–2 units per injection site. The location will depend on the effects desired (Figs 24-38 to 24-40).

Figure 24-38 Lower eyelid position asymmetries can be treated in selected patients by reducing lower eyelid orbicularis tone by injection with BTX.

Figure 24-39 A, This patient presented for ‘standard’ BTX treatments to the glabella and crow’s feet. Eyelid fissure asymmetry was noted that related mostly to a disparate position of the lower eyelid. B, After treatment to the glabella, lateral canthus, and right lower eyelid. Note the improvement of eyebrow shape and eyelid fissure symmetry in addition to the reduction of periorbital rhytids.

Figure 24-40 A, This young female model presented for BTX treatment. She exhibited no upper facial rhytids and requested an improved and more provocative appearance to the periorbita by making her ‘eyes look bigger.’ A high corrugator technique combined with treatment to the lateral brow depressors (as shown) was used to enhance the appearance of an arched brow while ‘splaying’ the brow head that gives an illusion of ‘widening’ the eyes horizontally (B). Lateral canthal injections were also extended to the lateral lower eyelid to widen the vertical palpebral aperture.

Nasalis ‘bunny lines’

Frequent contraction of the upper nasalis, which runs from the bony dorsum of the nose inferiorly, contributes to the development of fanning, radial rhytides obliquely across the radix of the nose called ‘bunny lines.’ Treatment allows the underlying mimetic musculature to relax, softening the lines. Inject anterior to the nasojugal groove on the lateral wall of the nose and well above the angular vein, and massage gently after injection to help diffuse the toxin. The lower nasalis fibers drape over the lateral nasal ala and can lead to repeated nasal flare, in which nostrils dilate involuntarily in social situations and give patients the embarrassing appearance of a race horse. Injection into the lower nasalis fibers will weaken this involuntary action (Fig. 24-41). Higher dose injections (5 units per side) or those administered caudal to these locations may affect the levator labii superioris aleque nasi and can be effective in further reducing the ‘bunny lines.’ Higher dosages to this region injected with precision can reduce the ‘gummy smile’ and soften the proximal nasolabial fold in the appropriate patient. Care should be taken to avoid or reduce the effects to the primary lip elevators (i.e. levator labii superioris) in most situations.

Figure 24-41 A, This patient presented for her standard BTX treatments and desired to reduce the appearance of her ‘bunny lines’ that seemed to be exaggerated after treatment to the glabella. B, After treatment to the glabella and to the lateral portions of the nasalis muscle (as shown). Note the medial brow elevation with precise treatment to the corrugator muscles and the softening of the ‘bunny lines’ with this additional treatment.

Photos courtesy of Rod Rohrich, MD.

Perioral lip rhytides (‘smokers’ lines’)

The orbicularis oris is the sphincter-like muscle that encircles the mouth, lying between the skin and mucous membranes of the lips and extending upward to the nose and down to the region between the lower lip and chin. Sometimes called the ‘kissing’ muscle, it causes the lips to close and pucker. Overactive orbicularis oris causes vertical perioral rhytides (which are referred to as smokers’ or lipstick lines but often have numerous causes, such as heredity, photodamage, playing musical instruments that require embouchure, whistling, and other personal habits). Very small amounts of BTX-A (1 to 2 U per lip quadrant) are usually sufficient to result in localized microparesis of the orbicularis oris and can be used as a primary agent for the treatment of dynamic lip rhytids^{3,4,9–11,30} (Fig. 24-42). Similar to treatment in the other facial areas, at these dosages the dynamic component is mostly satisfactorily affected, while deep static rhytids may have at best a modest improvement. In addition, the lower dosages are necessary to avoid lip dysfunction, while typically effects last in the range of 6–8 weeks. This application (using lower dosing) is especially useful when used adjunctively with a soft-tissue augmenting agent, and can greatly improve persistence of the filling agent by reducing the dynamic local activity that may be responsible for dissolution of the injected implant (Fig. 24-43). Symmetric injections (unless otherwise indicated) and careful placement of the injection sites to balance either side of the columella or the lateral nasal ala will help alleviate difficulty with post-injection asymmetry, lip proprioception, and aesthetics experienced with some patients. Patients who play a wind instrument or who are professional singers/speakers may not be ideal candidates.

Figure 24-42 A, This patient presented for improvement of upper lip rhytids with BTX. B, after asymmetric treatment for more numerous and deeper lines on the left portion of her upper lip and decentration of cupid’s bow (as shown). Note the improvement of rhytids and also the appearance of enhanced upper lip fullness and more central position of cupid’s bow.

Figure 24-43 This patient received injectable soft tissue augmentation just a few minutes prior to this photo. Local and regional anesthetic was administered prior to injections to eliminate pain and bruising. 1.5 units of BTX was administered to each of the four sites indicated by the blue dot at the vermilion border of the upper and lower lip after the injection of filler product. This effect allowed for greater persistence of the implant for volume augmentation as well as a longer lasting reduction of lip rhytids.

Midfacial asymmetry

Correction of midfacial asymmetry is another ‘artistic’ indication for BTX-A that requires a thorough knowledge of muscular anatomy and function. Physicians not comfortable with facial anatomy may benefit from the aid of an electromyograph (EMG) system for accurate placement of injections.

Although midfacial asymmetry may have multiple etiologies, asymmetry with innervational or muscular causes can be minimized or alleviated with BTX-A. In hemifacial spasm, for example, repeated clonic and tonic movements draw the facial midline toward the hyperfunctional side. BTX-A injections into the hyperfunctional zygomaticus, risorius, and masseter relax the muscles and allow the face to fall back into a centered position at rest. Likewise, hypofunctional asymmetry, such as Bell’s palsy, can be alleviated by small injections of 1–2 U into the zygomaticus, risorius, and orbicularis, and 5–10 U in the masseter on the normofunctional side.⁸ In patients with asymmetric jaw movements, intraoral injections of 10–15 U BTX-A in the internal pterygoid on the hyperfunctional side will relax the jaw and relieve discomfort. Surgical cutting or trauma to the orbicularis oris or the risorius muscle can result in an off-centered mouth caused by the unopposed action of the partner muscles in the normally innervated side. Correction can be achieved by treatment of the risorius immediately lateral to the corner of the mouth on the normally innervated side. In patients with congenital or acquired unilateral weakness, who cannot depress the corner of one side of the mouth, BTX-A injected into the partner depressor anguli oris will restore functional balance.

Depressor anguli oris

The depressor anguli oris (DAO) extends inferiorly from the modiolus to attach into the inferior margin of the mandible on the lateral aspect of the chin. DAO contraction causes a downward turn to the corner of the mouth, resulting in a negative, bitter appearance. Repetitive contraction over many years likely has a dramatic influence on volume loss to this region and the appearance of ‘perimental hollows’ and ‘jowling.’ Since direct injection of the DAO can cause intolerable paresis of the depressor labii, BTX-A injections are placed instead at the level of the mandible but at its posterior margin, close to the anterior margin of the masseter (easily felt when patients are directed to clench their teeth). The aim of treatment is to weaken, not paralyze, the DAO; doses of 3–5 U are usually sufficient to achieve the desired result (Fig. 24-44). In addition, the simultaneous injection of the DAO with injectable soft tissue augmentation to this region will enhance the result.

Figure 24-44 A, this patient presented for treatment of oral commissures, fine upper lip rhytids, and her ‘pebbly’ chin. B, After BTX treatment to the DAO, upper lip rhytids and mentalis. Note the improvement of the position of the lateral oral commissure, reduction of lip rhytids and improved lip shape and reduced chin ‘dimpling.’

Mental crease

The mental crease can be softened by injecting 3–5 U BTX-A into the mentalis just anterior to the mentum (Fig. 24-45). Injection higher at the level of the mental crease will also weaken the lower lip depressors and orbicularis oris, causing serious perioral weakness lasting 6 months or more. As in the perioral area, weakening, rather than paralysis, is the aim of treatment.

Figure 24-45 A, This male patient presented for treatment of nasolabial folds and for any improvement to the appearance of his chin region. B, After treatment to the nasolabial folds with Restylane and treatment to the mentalis to reduce chin ‘dimpling’ and reduce the mental crease.

Peau d’orange chin

A dimpled or ‘peau d’orange’ appearance in the aging chin occurs when a loss of subcutaneous fat and dermal collagen unmasks the mentalis and depressor labii muscle attachments. A combination of BTX-A into the mentalis plus soft-tissue augmentation leads to optimal results, although some patients fare well with BTX-A alone (Figs 24-44, 24-45).

Coordinated treatment of the mouth corners and chin

The opposing actions off the DAO (downward) and mentalis (upward) cause permanent downward angulation of the lateral corners of the mouth. When treating mouth frown with BTX-A, it is important to remember that treatment of a single muscle may positively or negatively affect adjacent muscles. Weakening the DAO or mentalis alone, while appropriate in some individuals, may be associated with unacceptable side effects in others. However, lower doses of BTX-A injected simultaneously into both muscles (3 U into each DAO and mentalis, for a total of 12 U) results in a synergistic and subtle effect that is safe and does not interfere with elocution or pursing of the lips (Fig. 24-46).

Figure 24-46 A, This is the same patient as shown in Figure 24-44. Also note the improvement of the ‘down-turn’ to the lateral oral commissure and depressions in that region as well as a smoother appearance to her chin as shown in ‘B.’

Lower facial asymmetry

Some patients experience surgical or traumatic cutting of the orbicularis oris or risorius, resulting in decentration of the mouth from the unopposed action of the partner muscles in the normally innervated side. BTX-A injected in the overdynamic risorius, immediately lateral to the lateral corner of the mouth will help to recenter the mouth when the face is in repose. Patients may have congenital or acquired (even iatrogenic) weakness of the DAO, resulting in inability to depress the corner of one side of the mouth; chemodenervation of the contralateral synergistic muscle will restore functional and aesthetic symmetry (Fig. 24-47).

Figure 24-47 Treatment of the asymmetry caused by a weakened or paralyzed depressor anguli oris (due to a variety of causes) as shown on this patient’s left side can be readily performed by focally treating the DAO on the contralateral side.

Masseteric hypertrophy

Contouring the lateral muscular jaw prominence – a relatively common aesthetic procedure especially among Asian patients – is yet another use for BTX-A. Park et al injected 25–30 U BTX-A per side in five to six sites evenly at the prominent portions of the mandibular angle in 45 Asian patients for aesthetic improvement and found a gradual reduction in masseter thickness during the first 3 months following injection.³⁴ The average change in masseter thickness, 1.5–2.9 mm, was equivalent to 17 to 19 percent of the original muscle thickness, as measured by ultrasound and computerized tomography. The response lasted 6–7 months before the muscle thickness retreated to its initial size; at 10 months, 36 patients expressed satisfaction with the results. Masseter hypertrophy is also a common byproduct of bruxism. This application in these individuals is not only an aesthetic enhancement, but also a dramatically effective cure for the sometimes significant focal pain associated with these disorders (Fig. 24-48). Local side effects, including mastication difficulty, transient muscle pain, and verbal difficulty during speech, were uncommon.

Figure 24-48 A, this patient had previously undergone surgical resection of the right masseter for severe bruxism and chronic pain a few years prior with complete return of the massive muscle enlargement and pain. B, After BTX treatment in three areas (total 15 U) only to the right masseter that not only eliminated his pain but reduced masseter size to near symmetry to the left side.

Horizontal necklace lines

Horizontal necklace lines of skin indentation, caused by the superficial musculoaponeurotic system attachments in the neck, often grace the chubbier neck and can be treated in selected individuals by ‘dancing’ along the lines, injecting small doses over multiple sites, for a total of 15–20 U per treatment session. Gentle massage following treatment will help alleviate potential bruising. Deep dermal, rather than subcutaneous, injections will avoid both the deeper venous perforators that can bleed and the underlying muscles of deglutition that can be affected. This application is limited in those with severe static rhytids in this region.

Vertical platysmal bands

When cervical skin loses its elasticity, the anatomy of the submental space changes: more submental fat becomes visible, and the platysma separates into two diverging vertical bands that tighten and become prominent during speech or other animation. Early banding can be seen in younger individuals that may reflect a hyperdynamic nature of the platysma. BTX-A injections can soften vertical platysmal bands in some patients^27,35; however, careful patient selection of those with obvious platysmal bands, good cervical skin elasticity, and minimal fat descent, is essential.³⁶ Younger patients with significant banding may require larger dosages in lieu of the hyperdynamic activity that is able to distract the cervical soft tissue, despite adequate skin elasticity and tone. On the other hand, in the elderly who exhibit a significant degree of descent and jowl formation, treatment with BTX-A may be entirely ineffective or actually worsen the appearance of the bands. Used as an adjunct to rhytidectomy, BTX-A can reduce the residual muscular banding that becomes apparent in the postoperative phase. In addition, some patients may prefer to use BTX as a kind of ‘rehearsal’ for the surgical alternative. Also, BTX-A into the platysma muscle may reduce the undesirable inferior pull of the platysma muscle on the facelift incision, thus resulting in a thinner and finer scar.³⁷

Since the platysma is external to the muscles of deglutition and neck flexion, large doses of BTX-A (i.e. 75 or 100+ U) have been known to cause profound dysphagia,³⁰ and must be used cautiously. Decreased phonation, difficulty with head posture, and worsening of dry mouth have also been reported with ‘over-dosing.’ Injecting 5 U with as few as three sites for each band (with sites that are 1–1.5 cm apart) and no more than 25–30 U over multiple sites per treatment session is typical. The safest effective plane is more superficial and the least likely to induce unwanted effects. It is far better to under-treat; additional ‘touch-up’ treatments can always be given if necessary during a subsequent treatment session (Fig. 24-49).

Figure 24-49 A, This patient presented for treatment of residual neck ‘bands’ after undergoing a lower face/neck lift several years prior. B, After BTX treatment in the areas indicated.

Adjunctive use in facial aesthetic enhancement

The adjunctive use of BTX-A with a host of other methods used for aesthetic facial enhancement has demonstrated a clear synergy when the appropriate combination of therapeutic modalities are applied. Improved and longer lasting results with a variety of energy/laser applications, injectable soft tissue agents, wound healing, brow lifts, canthopexy/plasty, suture suspension techniques, have been demonstrated^3,9–11,38 while this is only a shortlist of the potential adjunctive benefits (Figs 24-50 to 24-54).

Figure 24-50 A, This male presented for improvement of deep forehead lines. B, After a combination of 2 mL CosmoDerm applied to the superficial to mid dermis of the forehead lines and BTX to the brow depressors combined with lower-dose BTX (2 units given at 4 sites in the mid-forehead) facilitated the improvement of forehead rhytids while adequately maintaining eyebrow position.

Figure 24-51 A, This male patient presented for improvement of the deep glabellar furrows as well as the horizontal forehead furrows. Here using BTX alone would likely not completely eradicate the facial lines and would induce a significant degree of eyebrow ptosis. B, After treatment using CosmoDerm to the glabellar and forehead furrows, 30 units of BTX (total) to the glabella with direct injections to the belly of the corrugators, procerus, and superciliaris muscles, and low dose injection to the mid forehead (4 injection sites of 2 U each).

Figure 24-52 A, This patient presented for periorbital rejuvenation. B, After upper/lower blepharoplasty utilizing CO₂ laser skin resurfacing and lateral retinacular suspension canthopexy. BTX was administered at 2 weeks after surgery and requires this treatment three times per year to maintain this effect/result.

Figure 24-53 A, This patient had undergone upper blepharoplasty and endoscopic brow lift (elsewhere) and was disappointed when the brow elevation did not persist. B, After BTX to the areas shown for brow lift and shaping, reduction of lower eyelid and canthal rhytids as well as lower eyelid orbicularis muscle hypertrophy.

Figure 24-54 A, This patient presented for upper/lower eyelid rejuvenation and was most concerned with lower eyelid and canthal lines. B, After upper and lower blepharoplasty and CO₂ laser skin resurfacing to the lower eyelid and lateral canthus with lateral retinacular suspension canthopexy. BTX was administered at 2 weeks after surgery and at 4–6 month intervals to maintain the result that included the canthal re-suspension that can (with suture canthopexy alone) easily fail in patients with such active orbicularis muscle.

Documentation of pretreatment status and procedural reporting

Although an accurate history and examination of the patient will detect the pretreatment status of most individuals, the documentation of this is best accomplished by photography. Not infrequently patients will notice things after treatment of any sort that they claim were not present prior to your care. This occurs for many reasons that include, but are not limited to, their increasing awareness and curiosity to detect changes after your treatment while their observations prior to your procedures were less keen.

A clear diagrammatic operative note is also essential for both an explanation and documentation of treatment details and for your own record of treatment that might be amended in future sessions based on response (Figs 24-55, 24-56). This record should include lot number, dilution, site, number of units per site, and any other notations including unusual blemishes, bleeding, etc.

Figure 24-55 A facial drawing is most useful with individualized coding that will indicate the site and amount of drug injected for future reference.

Figure 24-56 An operative report might contain a drawing as shown here or in Figure 24-55, and can be more detailed as shown here. A brief history is contained here that is a review of medical history and medication that might have changed from the prior visits, as well as other information indicating the specific treatment and follow-up, lot number, total dose, etc.

Original figure courtesy of RJ Rohrich, MD, FACS. Used with permission.