7Facial and lower limb contouring

BOTOX FACIAL SCULPTING (FACIAL SLIMMING): REDUCTION OF INCREASED LOWER FACIAL WIDTH DUE TO MASSETERIC HYPERTROPHY AND PAROTID GLAND ENLARGEMENT WITH BOTULINUM TOXIN A

Botulinum toxin type A has the profound ability to decrease lower facial width and to sculpt the lower face by inducing an atrophy and hence decreases volume of the masseter muscle (especially if it is initially hypertrophied) (1–11). By reducing the volume occupied by the masseter muscle, the lower face is made narrower, there is better definition of the zygomatic arch and malar eminence, and the jawline becomes sharper and better defined (Fig. 7.1A,B). Over time, it is felt that prolonged atrophy of the muscle may lead to remodeling and narrowing of the mandible itself (5,8,11).

Previously, the lower face could only be narrowed by surgical reduction of the mandibular angles and/or the masseter muscle itself. While beautiful results can be obtained, there are numerous potential complications some of which can be difficult to correct (12–14).

The term BOTOX facial sculpting (5,8,11) was chosen because the power of botulinum toxin type A goes beyond mere facial width reduction. Depending on how much the masseter muscle is reduced, a variety of results can be achieved and a spectrum of emotional responses to the new look can be evoked ranging from slight width reduction with the effect of “losing some weight and puppy fat” to more visible sculpting that brings out the shape of the zygomatic arch and infrazygomatic hollows and confers a “supermodel-like” appearance. Conversely, overcorrection can sometimes make the face look overly gaunt and unattractive so aesthetic judgment has to be carefully exercised.

Some patients deliberately wish to look extremely thin and almost cachexic with the intent to evoke a fragile, vulnerable look that brings about feelings of sympathy and “wanting to protect.” For actors wishing to portray starved prisoners or victims of torture, this technique provides a safe and reversible way of achieving that look and gives added meaning to the term “method acting.”

Another cause of a squarish lower face is the enlargement of the parotid gland. This has been a previously underappreciated anatomic occurrence simply because we did not assess for it and if we had we did not know what to do about it. It is naturally occurring and indicates no disease or tumorous state. Some people just have prominent parotids (Fig. 7.2). This blunts the angles of the mandible and makes the lower face “heavy” and ponderous looking. In a man, it looks very beefy and in a woman, it looks very masculine and severe. Like everything else in aesthetic surgery, there must be an appropriateness of one’s features to one’s outlook, profession, and personality. In much the same way, as a low eyebrow looks correct in a younger individual and a higher more arched brow looks better in an older female, the width of the lower face also plays a role in creating the appropriate image for that person.

Hypertrophied parotid glands may look good in an older, authoritarian gentleman but a younger woman in the fashion industry may feel that this same look makes her appear older and more severe. Hence, botulinum toxin type A has a tremendous ability to help selected patients achieve their appropriate “look” without surgery. Surgery merely to reduce the size of a normally functioning (but large) parotid gland would never otherwise be contemplated.

YOUTH AND “SQUARE JAWS”

A youthful face is characterized by healthy clear skin, a taut firmly projected mid face, a smooth unbroken contour from the lower lid eyelash margin to the upper lip, a relaxed appearance with absence of muscle imbalance or strain, and a generally triangular face with highlights over the malar and chin prominences (8). Due to a myriad of reasons including volume depletion and soft tissue sagging, as the face ages, it takes on a more squarish appearance and eventually there is an inversion of the triangle of youth. Part of the rejuvenative process, whether by surgical or nonsurgical means, involves triangulating the face to restore the sharp, heart-shaped ideal of most cultures. This restores to some degree one aspect of a youthful look.

Even in youth, many individuals have square faces or “square jaws” due to masseteric muscle hypertrophy and in some cases due to benign and diffuse parotid gland enlargement. This gives the face the appearance of a boiled egg standing on its base. In a man, this confers on the individual a strong purposeful look provided he has the body size and proportions to match. If he is a thin person with a small body frame, the square face can look incongruous.

In a young woman, unless she is of striking beauty where a square jaw enhances her look, this squarish face can be undesirable making the face look too masculine or strong and in some cases much older as well.

For these reasons, reducing lower facial width is aesthetically necessary.

HISTORY

The author started using BOTOX→ (Allergan, Irvine) to treat patients with masseteric hypertrophy in 1998 initially for functional reasons and later purely for cosmetic indications. At that time, nothing had been written on the use of BOTOX→ to achieve cosmetic reshaping of the lower face. Two papers had been published in 1994 by Moore and Wood (1), and by Smyth (2) detailing the use of BOTOX→ in patients with medical symptoms arising from masseteric hypertrophy and this subsequently became the basis for the author to use BOTOX→ to cosmetically reshape the lower face.

The first patient (Fig. 7.1A,B) treated complained of headaches, grinding, and occasional temporomandibular joint pain. She had large asymmetric masseter muscles, a square face, and palpable mandibular angle spurs. These were not part of her initial complaint. About 20 units of onabotulinumtoxinA were administered directly into the muscle mass using a 30 G needle. After 2 weeks, the patient was recalled and it was noted that her symptoms had reduced but not been totally eliminated. The masseter could still clench but was noticeably reduced in size and was softer. A further 20 units per side was administered and the patient returned a month later. This time she was relieved of headaches and grinding but the muscle could still clench weakly. A further 20 units was given as the third dose and she was seen a month later. At this point, she realized that she looked thinner and claimed that many of her friends and family had remarked on her physical change. She felt that she had improved aesthetically and requested further reduction of lower facial width solely for cosmetic reasons. A further 20 units was given two more times a month apart before she was able to achieve the degree of slimness she desired and where there was no further movement of the masseter muscle on clenching. She had received a total dose of 100 units of onabotulinumtoxinA per side over a 4-month period. After a further

Figure 7.2 Normal and prominent parotid.

3 months, she returned with palpable movement of the muscle on clenching and a larger dose of 40 units was given. This time it lasted a further 5 months before she returned for another maintenance dose.

At the same time, a second patient (Fig. 7.3A,B) with a square face also requested nonsurgical reshaping and slimming of her face. She was commenced with 40 units of onabotulinumtoxinA into each masseter and returned a month later for a second dose. Her rate of facial slimming was seen to be faster and the degree of muscle paralysis more complete in a shorter time than the first patient. It was decided to adopt a monthly schedule of onabotulinumtoxinA injections starting at 40 units per side until all muscle movement had stopped and then the patient observed the duration of time before muscle activity returned. Since then we have treated more than 700 patients who sought lower facial width reduction purely for aesthetic reasons.

ANATOMICAL CONSIDERATIONS

The masseter muscle has three component parts or heads that arise from different sections of the length of the zygomatic arch and are inserted in a fan-like fashion into the ramus, condyle, angle, and lower border of the mandible (Fig. 7.4A). The deep head (yellow) arises from the inferior aspect of the posterior half of the zygomatic arch and is

inserted into the posterior half of the ascending ramus down to the angle of the mandible (Fig. 7.4B). The intermediate head (blue) arises from the middle third of the zygomatic arch and fans downward to insert into the anterior half of the ascending ramus, the condyle, and the angle of the mandible (Fig. 7.4C). The superficial head (red), which arises from the anterior half of the zygomatic arch including part of the malar eminence, is more strap-like and fans downward and backward to insert mainly into the angle of the mandible (Fig. 7.4D).

There is thus an overlapping of these three heads in the middle part of the muscle, which consequently is the thickest part that can be felt when a patient clenches their teeth. Palpation of the muscle on clenching firmly will also reveal a step-like, tiered form of the muscle. The anterior border of the muscle does not coincide with the anterior border of the mandibular ramus but in fact lies forward to this.

The surface markings are easy to identify as the anterior edge of the muscle is easily felt on clenching and the other borders are the zygomatic arch, the posterior edge of the ramus, and the lower border of the mandible. Injections of botulinum toxin type A in to the muscle are therefore easily administered. Care should only be taken not to inject into the coronoid notch as the pterygoid muscles, which are on the inner side of the mandibular ramus, can become unduly weakened and give discomfort on chewing.

PHYSIOLOGIC BASIS FOR USING BOTULINUM TOXIN TYPE A

Botulinum toxin type A not only causes a paralysis of muscles but also creates a temporary atrophy. We have seen this as an unwanted side effect of prolonged use in the lateral orbicularis oculi (crow’s feet region) where diffusion of the drug into the nearby temporalis muscle can create a wasted appearance of the temples.

In the masseter muscle, this atrophy is desired. What is interesting though is the long-term use of botulinum toxin type A to create not only muscular atrophy but also bony remodeling of the mandible and even the zygomatic arch itself. The author has noted in many patients on longterm botulinum toxin type A therapy of the masseter muscles, a gradual narrowing of the mandibular width over several months to years (15,16).

This is consistent with the findings of Moss, Enlow, and Rankow (17–20) who conceptualized the “bone-muscle-matrix” theory. Bones and the muscles that insert into them form an interrelated complex. If the muscles attached to that bone become weak or atrophic the bone also becomes less dense and thinner. This is seen in patients who have broken their legs and have had to endure a plaster cast for 12 weeks while the bone unites. As a result of muscle immobilization, when the cast is removed, the bone is invariably thinner and less radio dense.

Similarly, in people who constantly subject their bones to loading forces, the bones respond by becoming thicker and denser as can be seen in bodybuilders and manual workers. This is why we advise elderly patients to continue exercising in order to “strengthen” their bones.

Patients with masseteric hypertrophy invariably have mandibular angle spurs and it is interesting to note that with prolonged atrophy of

the muscle, these spurs become less prominent and the mandibular width more narrow.

INJECTION TECHNIQUE AND SCHEDULING

While I have used all forms of botulinum toxin type A to induce atrophy of the masseter muscle, I am most familiar with and prefer using

onabotulinumtoxinA. About 2.5 ml of saline is used to reconstitute the bottle of 100 units and therefore 1 cc will contain 40 units, 1.5 cc will be 60 units, etc. All injections use a normal half-inch 30-G Precision Glide needle (Becton Dickinson, Franklin Lakes, NJ). This is more than enough to make contact with the lateral mandibular surface even in patients with huge masseter muscles.

There are two parameters to consider in achieving a good result— dose and frequency.

The usual starting dose is 40 IU (1 cc) into each side in five to eight spaced out injections. This is repeated a month later and again a month after that. The patient should be assessed for residual muscle movement and/or bulk each time. If the muscle is still able to clench or feels bulky, then more onabotulinumtoxinA is given until no movement and atrophy has occurred.

Some patients may not wish to maximally reduce the size of the masseters and want only a slight thinning of the face. If they are satisfied with the result after the first one or two sessions they can then go into the maintenance phase of treatment.

For maintenance, the patient is asked to monitor the size of the muscle and is told to return either at 3 to 4 month intervals or if the muscle is able to clench strongly again, whichever is earlier. The usual maintenance dose is 32 to 40 units per side every 4 to 6 months.

When injecting the onabotulinumtoxinA into the muscle, more can be given to the lower half and the region of the overlap zone where the muscle is thickest. Care must be taken not to inject through the coronoid notch as this leads to unwanted weakening of the pterygoid muscles leading to difficulty in chewing. One should also avoid injecting too heavily into the upper half of the muscle as this will lead to accentuated scalloping out of the lateral side of the face. Even if the onabotulinumtoxinA is evenly distributed throughout, as the muscle begins to shrink, there is a natural tendency for this scalloping to develop because of two reasons: Firstly, the mandibular angle and spurs have yet to remodel so may appear to bulge and secondly, the skin over the jawline and jowls takes several months before it contracts fully and so may appear heavy and droopy.

In patients with very large masseters, up to 60 units (1.5 ml) can be injected in the initial setting. Beyond this it is risky as more than 1.5 cc would have to be injected into each side and this can lead to diffusion of the drug beyond the borders of the muscle thus giving rise to side effects as listed below.

It is preferable to see the patients monthly and adjust the dosage according to the result that is obtained from the previous treatment session. In a very large hypertrophic masseter, it is better to bring it down slowly over several months than to try to reduce it too aggressively. The result and side effect profile for giving 40 units every month for 5 months (40+40+40+40+40) is different from administering 60 units every month for 3 to 4 months.

BOTULINUM TOXIN TYPE A AND THE PAROTID GLAND

The use of botulinum toxin type A to decrease salivary production in the parotid and submandibular glands is documented in several articles (21–25). However, none have dealt with its use in reducing the size of the parotid gland for pure cosmetic sculpting or shaping of the face.

The parotid gland can be diffusely enlarged as part of a normal variation without any symptoms of either decreased or increased salivary production (Fig. 7.2). This broadens the lower face and gives a “bullnecked” appearance with blunting of the mandibular angle and sometimes a visible bulge that lifts the lobe of the ear upward.

Botulinum toxin type A can be used to shrink the size of the parotid in much the same way as the hypertrophic masseter muscle, the dose depending on the initial size of the parotid. Sometimes, the enlarged parotid only becomes noticeable after treating the masseter muscle and as the size of the muscle shrinks the parotid then becomes more evident.

In such cases, the parotid gland has to be treated at the same time in order to decrease lower facial width.

The author uses a loading dose of 40 units of onabotulinumtoxinA injected into the substance of each parotid gland, which lies one to two fingerbreadths in front of the ear, over and behind the mandibular angle, and tucking in under the earlobe. The gland can be felt as a diffuse, boggy “thickness.” Results can be seen within 3 weeks. Repeat injections of the same dose are given monthly until the gland has shrunk sufficiently and then maintenance injections of between 30 and 40 units of onabotulinumtoxinA are given every 4 to 6 months.

In 17 patients, we have not encountered any major side effects or signs of antibody development. There has been no clinical change in the amount of saliva produced and no complaints of “dry mouth.” We have not studied the composition of the saliva nor conducted any CT studies.

In patients, who are being treated for both the parotid gland and the masseter, they will receive 40 units into each parotid and 40 units into each masseter muscle bringing the total to 160 units of onabotulinumtoxinA at one sitting. This is much less than those patients who are being treated for calf hypertrophy in which case they would be receiving a total of 400 units of onabotulinumtoxinA divided into both calves per session.

BOTULINUM TOXIN TYPE A AND THE SUBMANDIBULAR GLAND

The author has used onabotulinumtoxinA to reduce the visibility of the submandibular gland in nine patients. These are patients who have noticed the gland as an unsightly bulge beneath the jawline or in those patients who have had a facelift and the gland has become more obvious.

The loading dose is much less at 25 to 32 units per side and the regime of monthly injections remains the same as for the parotid and masseter. The submandibular gland is much more difficult to isolate and immobilize as it tends to slip away. The patient should bend the head forward and turn to the contralateral side in order to make the gland pop out from under the border of the mandible.

While visible reduction has been seen in all cases, the degree and rapidity of reduction is not as dramatic as for the parotid glands. This may be a reflection of different receptor types within the different glands. It could also indicate that the submandibular gland although visible may not actually be enlarged and hence cannot be reduced any further than its base state and size.

COMPLICATIONS

The most frequent complications are as follows:

1.Loss of full smile and

2.Asymmetric smile. Both are due to diffusion of the botulinum toxin A forward to the risorius and levator anguli oris. This typically occurs when the onabotulinumtoxinA is injected too close to the anterior border of the muscle or when the injected volume is too much. I would not inject more than 1.5 cc volume into the masseter as there is a higher risk of diffusion beyond the muscle borders.

3.Weakness of and an aching sensation on chewing. Typically the patient finds difficulty in opening the mouth widely and then initiating biting such as in eating a hamburger or thick juicy steak. This occurs in the first 2 to 3 months of treatment and may disturb the patients but this then gradually recovers and seldom are patients bothered by this subsequently even with repeated and continued injections (7,26).

4.Jowling due to overrapid volume reduction and sagging of the overlying skin envelope. This occurs because the muscle atrophies faster than the overlying skin can accommodate. After 2 to 3 months, the skin contraction “catches up” with the devolumized muscle.

5.Overhollowing of the infrazygomatic region giving a cachexic appearance. This was explained above and may be desirable in some patients.

6.Bruising seldom occurs.

7.Hematoma is rare and I have encountered one instance only that resolved within a week.

8.Visible fasciculations of the muscles can sometimes occur in the first 2 to 3 weeks and represents an insufficient dose of onabotulinumtoxinA.

9.Neuropraxia is extremely rare.

RESULTS

OnabotulinumtoxinA and the Parotid Glands

Case 1

A 32-year-old Caucasian woman working as a model felt her face was “too big on camera” and desired cosmetic slimming of the face in order to look more fashionable and slimmer. She had no symptoms of grinding or headaches, etc. About 40 units of onabotulinumtoxinA into each side of the maasseter were given on two occasions a month apart. The patient is seen 1 month after the second dose (Fig. 7.5A,B).

Case 2

A 35-year-old male also complained that his face looked too chunky and did not photograph well. He wished to have a more defined jawline and a more sculpted appearance. About 40 units of onabotulinumtoxinA were injected at monthly intervals on three occasions before he achieved his desired “look” (Fig. 7.6A–F).

Case 3

This 38-year-old woman previously had an augmentation rhinoplasty, chin augmentation, blepharoplasty, and correction of prominent ears between the years 2002 and 2004 (Fig. 7.7A). In November of 2007, she complained of a “fat” face and was puzzled as to why her face looked so broad and “egg-like” when her body remained thin and her weight constant. Examination revealed bilateral grossly enlarged parotid glands, which classically lifted the lobes of her ears (Fig. 6B.7B). There were no symptoms of increased or decreased salivary flow and no alteration of taste. There was no evidence of tumor. Ultrasound examination showed enlarged parotid glands with normal architecture. All hematologic tests for parotid disease were negative including erythrocyte sedimentation rate (ESR), antinuclear factor (ANF), and antirheumatoid antibodies. Having treated other patients with diffusely enlarged parotid glands successfully with onabotulinumtoxinA, this was offered to the patient as a treatment option. Not wishing to undergo any additional surgery, she received her first injection of 60 units into each parotid gland as well as 40 units of onabotulinumtoxinA into each of the masseter muscles in December 2007. A second dose was given in

January 2008 where she received 40 units of onabotulinumtoxinA into each masseter as well as 40 units into each of the parotid glands. Significant shrinkage of the parotid gland was seen in February 2008. The lower facial width had improved and she felt she looked more normal. A third dose of onabotulinumtoxinA was given in February 2008 and when she returned in May 2008, there was further normalization of her facial contours. A fourth dose of 40 units was given into each parotid and masseter muscle at this time and this shrank her parotid to a normal size. She was seen in April 2009 with minimal recurrence of the parotid enlargement and an increase in volume of the masseter muscle. She was given a maintenance dose of 40 units onabotulinumtoxinA into each of the parotid glands and masseter muscles. She remained stable and only noticed slight enlargement of the glands and her masseter muscle in December 2009. She returned in January 2010 for a further maintenance dose of 40/40/40/40 units. It would appear that this dose of 160 units each session gives adequate shrinkage of parotid gland as well as masseter muscle for approximately 9 months (Figs. 7.7A–F, 7.8A–F, 7.9A–D).

Case 4

A 40-year-old man felt his lower face was too heavy and wanted facial slimming to look more aesthetic as well as younger. Clinically, he appeared to have an indistinct jawline and a widened lower face due to hypertrophic masseter muscles. A dose of 40 units of onabotulinumtoxinA was injected into each masseter muscle. A month later, despite a slight infrazygomatic hollow appearing to indicate muscle shrinkage, he still felt his face had not improved much and was still broad. A second dose of onabotulinumtoxinA 40 units into each masseter was given again. When he returned a month later, he still complained of a broad lower face despite further shrinkage of the masseter muscle. He pointed to the masses just under his earlobes and in front of the ear. Clinically, his parotid glands were also large and this continued to widen and enhance his mandibular angles and gave him a broad lower face. The large parotid glands had been missed at initial examination and only became unmasked after the masseter muscle volume had reduced. About 40 units of onabotulinumtoxinA were injected into each parotid on two separate occasions a month apart and this reduced their size to improve his facial balance (Figs. 7.10A–D and 7.11A–D).

Case 5

Submandibular gland injection (Fig. 7.12A,B): This 51-year-old woman had received a long threadlift (Woffles lift) to improve her jowling as well as to elevate her mid face. She subsequently complained of prominent submandibular glands (Fig. 7.12A) and received 28 units of

onabotulinumtoxinA into each gland every month for 3 months. Although visibly smaller the glands could not be reduced any further (Fig. 7.12B). However, the patient was satisfied with the reduction in size.

DISCUSSION

This chapter does not attempt to make a case that all faces look good or more youthful with narrower lower facial width but rather to illustrate that a nonsurgical technique exists for those who desire triangulation of the face or a slimming effect.

In fact, in some cultures, a squarish jaw can be desirable and certainly can make the face look younger provided other features of

the face are in harmony and consistent with the overall look. The use of mandibular body onlay grafts or implants made of silicone or calcium hydroxyl apatite attest to this flip side of the aesthetic ideal.

CONCLUSION

Botulinum toxin type A is a useful tool for reducing facial width by inducing an atrophy of the masseter muscle. It can also be used to good effect to reduce the size of benignly diffused and enlarged parotid glands as well as to a lesser degree the submandibular gland.

(C)

Figure 7.7 Case 3: (A) Before parotid enlargement. (B) After enlargement. (C) After first onabotulinumtoxinA treatment. (Continued)

(C)

Figure 7.8 Case 3: (A) Before parotid enlargement. (B) After enlargement. (C) After first onabotulinumtoxinA treatment, as seen from below. (Continued)

(F)

Figure 7.7 (Continued) Case 3: (D) After second onabotulinumtoxinA treatment. (E) After third onabotulinumtoxinA treatment. (F) January 2010.

(F)

Figure 7.8 (Continued) Case 3: (D) After second onabotulinumtoxinA treatment. (E) After third onabotulinumtoxinA treatment. (F) Parotid January 2010, as seen from below.

THE ROLE OF BOTULINUM TOXIN A IN COSMETIC CALF SLIMMING

AND CONTOURING

As the world moves toward nonsurgical, minimal pain, no-downtime procedures, simple and effective techniques delivered via injection have become increasingly popular and are most well tolerated by patients (15,16). In the last decade, onabotulinumtoxinA has become an important and viable option for achieving cosmetic calf contouring or reduction of calf size (27,28) and together with liposuction, partial resection of the gastrocnemius muscle (29–32), and selective denervation of the gastrocnemius muscles (33,34) has increased the palette of treatments for thick and bulky calves.

Patients who seek cosmetic calf reduction are predominantly females who wish to achieve esthetically sleek lower limbs where the legs appear as long, continuous fusiform columns flowing down from the pelvis to the ankles with only the slightest of undulations. These legs appear youthful and feminine in addition to being healthy and firm. Above all, they should look sensuous. The desired legs should also look good in and enhance the effects of high heeled shoes which are an essential part of a woman’s wardrobe (Fig. 7.13A,B). Popular culture and the media also places great emphasis on such legs, which are featured as selling points in movie billboards and contemporary art.

This treatment is more popular in Asia (35) than the West and there are several reasons for this. Firstly, Asian body morphology generalizes toward individuals with a higher trunk–lower limb height ratio, that is, Asian females tend to have shorter legs in relation to their torso. This is an unfortunate esthetic feature and causes Asian females to look more stumpy than their Western or African sisters. If the calves are thick and bulky, this further accentuates the physical disproportion and makes for a stocky, heavyset appearance of the legs.

Among many Asian females, thick or muscular calves are perceived as unrefined, inelegant, and masculine. “Radish” legs, “obese” legs, and “fat” legs are some of the common terms used for these thick, bulky calves (Fig. 7.14A,B). They also have connotations of belonging to the “working class”. This mind-set also explains why cosmetic skin whitening is so popular in Asian females as having a darker skin tone is also perceived in the same way.

Previously, the only options available to patients seeking cosmetic slimming of their calves was liposuction, partial resection of the gastrocnemius muscles, or denervation of the medial head of the gastrocnemius muscle, all three techniques having their own limitations and risks. These procedures are operations and can leave unsightly scars (to the patients). Wounds on the lower limbs do not heal well. Despite

the scars of liposuction and denervation being short, they invariably can be seen. The scar from partial debulking of the muscle is even more obvious. These wounds often result in hyperpigmented and/or keloid scars, which can prove to be a persistent nuisance to patients. These are patients who are concerned enough about the shape of their calves to seek treatment. Therefore, a small dark scar is instantly spotted and complained about despite good cosmetic improvement of the calf shape.

As a result, onabotulinumtoxinA calf slimming has become an excellent alternative as it leaves no scars and is potentially reversible should the patient have a change of heart. Its only drawback is its cost.

ASSESSMENT OF THE PATIENT WITH THICK CALVES

When a patient seeks cosmetic calf slimming, it has to be determined how much of this is contributed by fat and how much by muscle bulk.

The patient is first asked to stand on tip toes. In a lean individual, the definition of the two gastrocnemius muscles can be easily seen and delineated for treatment. In a fatty calf, the muscle definition is obscured and the calf looks doughy and shapeless. This fat usually continues down into the ankles blunting the esthetic hollows above and below the malleoli. If the skin is then pinched, the thickness of the fat can be felt and one can see a “cellulite” orange peel appearance.

If the patient has predominantly fatty calves and ankles, then liposuction is discussed including the possibility of visible and persistent scars. Due to the convexity of the calves, it has always been necessary to have several access points on either sides of the calf if a thorough liposuction is to be achieved. Limiting the number of scars limits the esthetic result of the contouring so potential scarring is a real issue that must be made known to patients.

If the calf bulk is due to hypertrophic or enlarged gastrocnemius muscles, then the alternatives of selective muscle denervation, partial muscle debulking, and onabotulinumtoxinA injection treatment are discussed.

My preference for those patients who can afford the long-term cost is to use onabotulinumtoxinA primarily because it is simple to perform but also because it lends itself to easily adjusting and refining the final result. With partial debulking of the gastrocnemius muscles, not only is it potentially bloody, the sural nerve can be accidentally severed and it has significant downtime, it is not easy to control the shape and the final esthetic outcome. In denervation of the medial gastrocnemius alone, a compensatory hypertrophy of the lateral head can occur, creating a distorted or bow legged appearance. This is in turn has to be addressed either surgically or with the use of

onabotulinumtoxinA. If onabotulinumtoxinA is used, any residual unsightly bulges can be targeted until a smooth appearance is achieved (Fig. 7.15).

PHYSIOLOGIC BASIS AND MECHANISM OF ACTION

OnabotulinumtoxinA in calf reduction works in exactly the same way as onabotulinumtoxinA in masseteric hypertrophy (26), bringing about a state of chemically induced “disuse atrophy” of the gastrocnemius muscles. The objective is to bring about muscle weakening or paralysis and finally an atrophy of the gastrocnemius muscle bulk.

The onabotulinumtoxinA can be injected into the medial, lateral, or both heads of the gastrocnemius muscle to selectively reduce its bulk. Even within each muscle, the onabotulinumtoxinA can be distributed in

such a way (either higher or lower) as to achieve the most fusiform appearance for the patient. Some patients have a more bulky medial head, others have hypertrophy of both.

The injections should be delivered directly into the muscle with a minimum of pain, bruising or swelling.

DILUTION AND INJECTION TECHNIQUE FOR ONABOTULINUMTOXINA

CALF SLIMMING

The author always uses a 100-unit bottle of onabotulinumtoxinA diluted with 2.5 ml of normal saline. The usual dose is 100 to 120 units per gastrocnemius head—a total of 400 to 480 units for both calves. This is repeated 4 to 6 weeks later to consolidate the atrophy and refine any residual bulges. An additional third dose can be given 8 to 12 weeks later. This gives a more thorough atrophy and

thus shaping of the gastrocnemius muscles. The result can last up to 18 months (36).

If only the initial dose is given without a second dose, the atrophy of the gastrocnemius muscles will be partial. A reduction in size of the calves will be seen but it will not be dramatic and it will only last for about 6 months before reverting to the preinjection size. The author’s intention is to achieve maximum slimming of the calves and to maintain it at this level rather than allow it to revert to a thickened state again. The same approach is used in the treatment of masseteric hypertrophy where repeated injections bring about maximal muscle size reduction after which maintenance doses are used to keep the muscles in their atrophied state (37).

Five 1 ml syringes containing 40 units each are prepared for each calf. Occasionally, a small amount of local anesthesia (2% lignocaine

(A)

Semitendinosus

Gracilis

Medial head of gastrocnemius muscle

Soleus

Aponeurosis of

gastrocnemius

Figure 7.15 Anatomy of the posterior compartment of the leg, highlighting the prominent gastrocnemius muscles.

and 1:200,000 adrenaline) can be included in the syringe. In such a case, 32 units (0.8 cc) is drawn into the 1 ml syringe and topped up with the anesthetic to make 1 ml of solution. Six such syringes are prepared in this way.

The patient is first asked to stand on tip toes and the muscle heads outlined. With the patient then lying supine and the muscles in a flaccid state, onabotulinumtoxinA is injected into the muscle in two vertical rows, each injection spaced about 1 to 2 cm apart.

A 30g needle is used. Although short, this needle with slight pressure more than adequately penetrates the gastrocnemius muscle. It is also less painful and seldom bruises. Larger needles are not necessary and

Patients can notice a reduction in muscle strength within two weeks and see a visible reduction in size within 3 to 4 weeks (Fig. 7.16A–D). Within 6 to 8 weeks, the muscle reduction is maximal and this is the best time to add a second dose to target any areas that may have been missed with the first session. Sometimes due to the lack of diffusion and placement of the initial injections, there may be asymmetric bulges or undulations in which case these areas can be targeted during the second session. If after 3 months, the muscle bulk is not sufficiently reduced, a further dose can be given (Fig. 7.17).

Patients are still able to engage in gym or sporting activities and none has reported any difficulty with running or diminished ability although slight weakness has been felt in the first 2 to 3 weeks.

COMPLICATIONS AND ADVERSE EVENTS

As with other onabotulinumtoxinA techniques, most complications are due to the injection of the product into muscles for which they are not intended. In this case, injecting the soleus muscle is to be avoided as this can give a noticeable weakness of the calves and potentially problems with balance in the upright position. The author has not encountered this complication.

Some other reported complications have included the following:

1.Ecchymoses and myalgia at the injection sites, usually lasting a few days only. This can be reduced by using the 30g needle as recommended by the author.

2.Transient weakness of the calf muscles for the first 2 weeks after the initial injection and fatigue of the calf muscles when hearing high heeled shoes, both of which improve after 2 to 3 weeks.

3.Compensatory hypertrophy of the lateral gastrocnemius if the medial head alone was injected. This can be avoided by injecting the lateral gastrocnemius at the same time. It increases the cost but the overall result is much better.

There have been no other adverse effects of note.

DISCUSSION

The use of Botulinum toxin type A to bring about cosmetic slimming of the calves is now well established. The dosing regimes among different authors are variable though. Lee et al. in 2004 conducted a study on

the effects of different doses of onabotulinumtoxinA on the medial gastrocnemius muscle. He used doses of 32, 48, and 72 units of onabotulinumtoxinA into each muscle and concluded that doses of up to 72 units are safe without major complications. In the author’s experience, these dosages are too low to achieve a significant clinical improvement that satisfies the patient’s esthetic requirements. Originally commencing with 80 units per gastrocnemius muscle head, the results were unsatisfactory and had to be increased to between 100 and 120 units per head (i.e., 200–240 units per leg). In some patients, even this dose was insufficient and whilst maintaining the dosage, the frequency of injections had to be increased.

In the treatment of masseteric hypertrophy, the author uses doses of 40 to 60 units per side and repeats this at monthly intervals (usually two or three times) until complete atrophy and lack of muscle movement is achieved. This allows the lower face to achieve maximal slimming. The gastrocnemius muscles are much larger in comparison to the masseter muscles and they are also subjected to much greater loads on a daily basis than the latter. It is therefore only logical that doses of anywhere from 32 to 80 units per muscle head would

not yield good clinical results and that much greater doses of onabotulinumtoxinA would be required. Another possible reason why greater doses of onabotulinumtoxinA are required is because of its lack of diffusion in muscles, a clinical feature useful when injecting in the face and neck but perhaps less so in the voluminous muscle bulk of the gastrocnemius where diffusion of the product may in fact be desirable (39,40).

Han et al. (4) has been able to achieve very good results for patients using 300 to 360 units of abobotulinumtoxinA per side and this may be due to the fact that it has a greater diffusibility in muscles than onabotulinumtoxinA.

The recurring cost is a significant consideration in this technique as between four and five bottles of onabotulinumtoxinA (100 units/bottle) are used each time and a patient may require two to three sessions to achieve the desired esthetic goals. While all patients have been delighted

with the initial results, fewer than half of the patients have continued with the technique beyond two years and the reason has invariably been about recurring costs. These same patients are however resistant to surgical alternatives for reasons of scarring and morbidity. As a result, they have allowed the calves to revert to their normal state.

CONCLUSION

Botulinum toxin A again demonstrates its versatility as a therapeutic and cosmetic product for calf slimming. It is a successful and viable alternative to traditional, surgical options for treating thick and bulky calves. The treatment is easy to administer, has no appreciable downtime, nor adverse effects profile and gives extremely pleasing results after several months of usage. It needs to be repeated periodically and its only drawback is the high recurring cost of the treatments.

REFERENCES

1.Moore AP, Wood GD. The medical management of masseteric hypertrophy with botulinum toxin type A. Br J Oral Maxillofac Surg 1994; 32: 26–8.

2.Smyth AG. Botulinum toxin type A treatment of bilateral masseteric hypertrophy. Br J Oral Maxillofac Surg 1994; 32: 29–33.

3.Mandel L, Tharakan M. Treatment of unilateral masseteric hypertrophy with botulinum toxin: Case report. J Oral Maxillofac Surg 1999; 57: 1017–9.

4.Von Lindern JJ, Niederhagen B, Appel T, Berge S, Reich R. Type A botulinum toxin for the treatment of hypertrophy of the masseter and temporal muscles: An alternative treatment. Plast Rec Surg 2001; 107(2): 327–32.

5.Wu WTL. Facial rejuvenation without facelifts—personal strategies. Regional Conference in Dermatological Laser and Facial Cosmetic Surgery 2002, Hong Kong. 13–15 Sep 2002.

6.Park MY, Ahn KY, Jung DS. Botulinum toxin type A treatment for contouring of lower face. Dermatolog Surg 2003; 29: 477–83.

7.Yu C, Chen PKT, Chen YR. Botulinum toxin A for lower facial contouring: A prospective study. Aesthetic Plast Surg 2007; 5: 445–51.

8.Wu WTL. Innovative uses of BOTOX and the Woffles lift. In: Panfilov D, ed. Aesthetic Surgery of the Facial Mosaic. Berlin Heidelberg: Springer, 2006: 636–49.

9.Kim HJ, Yum KW, Lee SS, Heo MS, Seo K. Effects of botulinum toxin type A on bilateral masseteric hypertrophy evaluated with computer tomographic measurement. Dermatol Surg 2003; 29: 484–9.

10.Kim KS, Byun YS, Kim YJ, Kim ST. Muscle weakness after repeated injection of botulinum toxin type A evaluated according to bite force measurement of human masseter muscle. Dermatol Surg 2009; 35: 1902–7.

11.Wu WTL. Botox facial slimming/facial sculpting: The role of botu- linumtoxin-A in the treatment of hypertrophic masseteric muscle and parotid enlargement to narrow the lower facial width. Facial Plas Surg Clin N Amer 2010; 18(1): 133–40.

12.Gurney C. Chronic bilateral benign hypertrophy of the masseter muscle. Am J Surg 1947; 78: 137.

13.Adams W. Bilateral hypertrophy of the masseter muscle: An operation for correction. Br J Plast Surg 1949; 2: 78.

14.Baek SM, Kim S, Bindinger A. The prominent mandibular angle: Preoperative management, operative technique and results. Plast Reconstr Surg 1989; 83: 272.

15.Wu WTL. Nonsurgical facial rejuvenation with the 4R principle: innovative uses of BOTOX and facelifting with the Woffles lift, a barbed suture sling (Chapter 72). In: Panfilov D, ed. Aesthetic Surgery of the Facial Mosaic. Berlin: Springer, 2006: 636–49.

16.Wu WTL. Botox facialslimming/facialsculpting: The role of botulinum toxin type A in the treatment of hypertrophic masseteric muscle and parotid gland enlargement to narrow the lower facial width. Facial Plast Surg Clin N Am 2010; 18: 133–40.

17.Moss ML. The primacy of functional matrices in orofacial growth. Dent Pract Dent Rec 1968; 19(2): 65–73.

18.Moss ML, Rankow RM. The role of the functional matrix in mandibular growth. Angle Orthod 1968; 38(2): 95–103.

19.Moss ML. The functional matrix hypothesis revisited. The role of an osseous connected cellular network. Am J Orthod Dentofacial Orthop 1997; 112(2): 221–6.

20.Enlow DH. Facial Growth, 3rd edn. Philadelphia: Saunders, 1990.

21.Fuster-Torres MA, Berini-Aytes L, Gay-Escoda C. Salivary gland application of botulinum toxin for the treatment of sialorrhea. Med Oral Patol Oral Cir Bucal 2007; 12(7): E511–E17.

22.Vargas H, Galati LT, Parnes SM. A pilot study evaluating the treatment of postparotidectomy sialoceles with botulinum toxin type

A.Arch Otolaryngol Head Neck Surg 2000; 126: 421–4.

23.Chow TL, Kwok SPY. Use of botulinum toxin type A in a case of persistent parotid sialocele. Hong Kong Med J 2003; 9: 293–4.

24.Giess R, Naumann M, Werner E, et al. Injections of botulinum toxin A into the salivary glands improve sialorrhoea in amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2000; 69: 121–3.

25.Manrique D. Application of botulinum toxin to reduce the saliva in patients with amyotrophic lateral sclerosis. Rev Bras Otorrinolaringol 2005; 71(5): 566–9.

26.Kim ST, Choi JH, Park MY, Ahn KY. The change of the maximal bite-force after botulinum toxin A injection for lower face contouring. J Korean Soc Aesthetic Plast Surg 2005; 11(1): 45–50.

27.Lee HJ, Lee DW, Park YH, et al. Botulinum toxin type A for aesthetic contouring of enlarged medial gastrocnemius muscle. Dermatol Surg. 2004; 30(6): 867–71; discussion 871.

28.Han KH, Joo YH, Moon SE, Kim KH. Botulinum toxin A treatment for contouring of the lower leg. J Dermatol Treat 2006; 17(4): 250–4.

29.Lemperle G, Exner K. The resection of gastrocnemius muscles in aesthetically disturbing calf hypertrophy. Plast Reconstr Surg 1998; 102: 2230–6.

30.Kim IG, Hwang SH, Lew JM, Lee HY. Endoscope-assisted calf reduction in Orientals. Plast Reconstr Surg. 2000; 106: 713–18.

31.Tsai CC, Lee SS, Lai CS, Lin SD, Chiou CS. Aesthetic resection of the gastrocnemius muscle in postpoliomyelitis calf hypertrophy: an uncommon case report. Aesthetic Plast Surg 2001; 25: 111–13.

32.Lee JT, Wang CH, Cheng LF, et al. Subtotal resection of gastrocnemius muscles for hypertrophic muscular calves in Asians. Plast Reconstr Surg. 2006; 118(6): 1472–83.

33.Tsai FC, Mardini S, Fong TH, Kan JH, Chou CM. Selective neurectomy of the gastrocnemius and soleus muscles for calf hypertrophy: an anatomical study and 700 clinical cases. Plast Reconstr Surg 2008; 122(1): 178–87.

34.Kim SC, Kang MH, Ock JJ. Calf-contouring surgery of gastrocnemius hypertrophy: selective neurectomy of the sural nerve. Aesthetic Plast Surg 2008; 32(6): 889–93.

35.Schuman M. Some Korean women go to great lengths to show a little leg. Wall Street Journal. February 21, 2001.

36.Schroeder AS, Erti-Wagner B, Britsch S, et al. Muscle biopsy substantiates long term MRI alterations one year after a single dose of botulinum toxin injected into the lateral gastrocnemius of healthy volunteers. Mov Disord. 2009; 24(10): 1494–503.

37.Tsai FC, Hsieh MS, Chou CM. Comparison between neurectomy and botulinum toxin A injection for denervated skeletal muscle with clinical implications. J Neurotrauma 2010 Jun 7 (Epub ahead of print).

38.Lee CJ, Park JH, Park SW. Compensatory hypertrophy of calf muscles after selective neurectomy. Aesthetic Plast Surg. 2006; 30(1): 108–12.

39.Aoki KR. Preclinical update on Botox-purified neurotoxin complex relative to other botulinum neurotoxin preparations. Eur J Neurol 1999; 6: S3–10.

40.Aoki KR. Pharmacology and immunology of botulinum toxin type

A.Clin Dermatol. 2003; 21: 476–80.