Treatment of the upper face

Botox® Cosmetic has been proven to be a safe and effective modality for treating wrinkles of the upper face. This area has provided the majority of clinical experiences with Botox®. Glabellar frown lines, horizontal forehead lines and crow’s feet are the most common manifestation of the aging upper face. With the success of Botox® treatment in the upper face, clinicians have been expanding this therapy into other areas of the face.⁶ However, Botox® is only approved by the Food and Drug Administration for the treatment of glabellar frown lines.

Glabellar frown lines

The underlying muscular activity of the procerus, corrugator supercilli and depressor supercilli muscles is responsible for the formation of the glabellar frown lines. The synergetic hyperactivity of these muscles produces the usually undesired facial appearance of age, fatigue and frustration. The procerus is a thin, narrow brow depressor muscle. Once contracted, it draws the medial aspect of the eyebrows down, producing transverse wrinkles over the nasal bridge. This muscle should be injected in the midline, slightly caudal to the root of the nose. The contraction of the corrugator supercilli muscle adducts and depresses the eyebrow, moving it inferiorly and medially. Repetitive contraction of the corrugator supercilli muscles produces the vertical glabellar creases. There are two well distinct patterns of this muscle. It can have a short, pyramidal shape located at the medial end of the supraorbital ridge (Fig. 71.1A) or a long and narrow shape extending along the supraorbital ridge reaching or even going beyond the mid-brow (Fig. 71.1B). Treatment of this muscle with Botox® should follow the respective anatomical pattern of the muscle. The depressor supercilli is a brow depressor and believed to be part of the orbicularis oculi muscle. The appropriate knowledge of the existence of this muscle allows for proper inactivation with Botox® injections. Several factors of the glabellar complex should be observed prior to treatment. Physical characteristics, such as brow arch, brow asymmetry, brow ptosis and muscle mass of the glabellar varies between male and females. Males tend to have a stronger muscle mass; therefore, higher doses in the range of 60 to 80 U of Botox® are often necessary to achieve the desired effect. Doses in the range of 30 to 40 U are usually sufficient to produce a satisfactory result on females. Injection techniques vary by clinicians. The following injection technique is used by the authors’ clinic:

Fig. 71.1 A, Short square corrugator pattern. B, Broad flat corrugator pattern.

From Carruthers A, Carruthers J, eds. Procedures in cosmetic dermatology, 2nd edn. Botulinum toxin. London: Saunders Elsevier, 2008.

Fig. 71.2 Injection placement for glabellar frown lines.

Horizontal forehead lines

The frontalis muscle main function is to elevate the eyebrows. This muscle can have two clinical functional patterns. The most common shape of the frontalis is by a single continuous broad band (Fig. 71.3A). With chronic brow elevation this pattern produces contiguous transverse forehead lines. The second pattern, not very often seen clinically, has two broad bands with a central separation producing a smooth mid-section with a corrugated lateral forehead when the frontalis elevates the brow (Fig. 71.3B). Treatment of the forehead horizontal lines should be done with caution and only after the glabellar complex has been successfully treated and there is no presence of brow ptosis due to compensatory response by the overactive use of the frontalis. Over-weakening of the frontalis muscle will exacerbate brow ptosis and might yield a lowered brow producing an undesired angry and aggressive expression on patients with normal brow position. This can be avoided if the corresponding depressors are also properly treated. After careful evaluations of the brow height, a conservative approach must be utilized in order to slightly weaken the frontalis muscle action with small doses ranging from 2 to 3 U injected at 1.5 cm intervals in five evenly distributed points. The injection sites must be maintained well above the brow (Fig. 71.4). Patients with low-sitting foreheads and droopy upper eyelids are poor candidates for treatment of forehead rhytides because their eyelids may descend to the point of obstruction of their vision, if the frontalis muscle is treated. In contrast, injections into the brow depressors may be very effective for these patients.

Fig. 71.3 A, Frontalis muscle with two bellies. B, Frontalis muscle: most common pattern as a single broad band.

From Carruthers A, Carruthers J, eds. Procedures in cosmetic dermatology, 2nd edn. Botulinum toxin. London: Saunders Elsevier, 2008.

Fig. 71.4 Injection placement for horizontal forehead lines.

Brow elevation

Brow shape, height and position are determined by a delicate interaction between depressor and elevator muscles. Brow configuration varies from patient to patient. The muscles responsible for brow movement are the frontalis (brow elevator), procerus, orbicularis oculi and corrugator supercilli (brow depressors). Botox® injections have the potential benefit of producing a brow lift if injected properly. Botox® can be used to shape the brow for a more aesthetically pleasing eyebrow on female patients as well as to treat brow asymmetry. Many clinicians have observed that treating the glabellar complex alone as described above can have an effect on brow elevation. It has been suggested that this is the result of diffusion of BTX-A into the medial fibers of the frontalis which causes partial inactivation and an increased resting tone of this muscle.⁷ In addition Botox® can be injected into specific points of the orbicularis oculi muscle to produce a lateral brow lift which widens the eye leading to a more youthful appearance.⁸ This requires a single lateral injection with 1–2 U of Botox® into the tail of each eyebrow approximately 1.5 cm from the orbital rim (Fig. 71.5).

Fig. 71.5 Injection placement for crows’ feet and end of brow.

Crow’s feet

Wrinkles radiating from the lateral canthal region usually in fan-shaped distribution are referred to as crow’s feet. These lines are caused by the contraction of the orbicularis oculi and occasionally in some patients by contraction of the zygomaticus major. Careful examination of the patient’s crow’s feet should be done previous to overall treatment since in some patients, crow’s feet are distributed equally above and below the lateral canthus. In some patients, crow’s feet develop mainly below the lateral canthus. Botox® injections dramatically reduce the appearance of crow’s feet rhytides by temporarily weakening the lateral orbicularis oculi muscle on patients with mild to moderate deep lateral canthal rhytides. Typically, three injection sites are treated with 2–5 U of Botox® each into the lateral orbital rim as determined while the patient is smiling maximally. It is important that the injections are performed when the patient is not smiling since this can cause diffusion of the toxin into the ipsilateral zygomaticus complex, causing ptosis of the upper lip. Always inject above the zygomatic arch. The first injection should be in the center of the area of maximal wrinkling. The second and third injection sites are approximately 1 to 1.5 cm above and below the first injection site, respectively. In addition to the three injection sites, 2 to 4 U are injected into the inferior orbicularis oculi below the mid pupillary line to widen the eye (Fig. 71.5). It is important to remember that a snap test should always be performed before injecting the lower eyelids with botulinum toxin to test for the retraction of the skin, as patients with a delayed retraction of the lower eyelid may experience ectropion of the injected eye when the periocular muscles are rendered inactive by the toxin. Ecchymoses is common when treating this area so ice compresses are recommended after each side is treated.

Treatment of the midface and lower face

The midface complex musculature represents a challenging anatomical area for the average physician. This area should be treated with Botox® by experience physicians only. Botox® of the midface can address lip rhytides, asymmetrical smile, lip malposition, and gummy smile. The midface consists of the zygomaticus major, zygomaticus minor, levator labii superioris, levator labii superioris alequae nasi, levator anguli oris, risorious, nasalis and depressor septi. Treatment of the zygomaticus major is only indicated if there is a presence of facial asymmetry associated with facial nerve dysfunction or severe hemifacial spasm. If this muscle is over treated, a profound droop of the corner of the mouth may occur. Botox® treatment of the levator labii superioris smoothes out the nasolabial folds and prevents the elevation of the upper lip when smiling. Treatment of this muscle is only indicated for facial asymmetry. Denervation of the levator labii superioris alequae nasi is challenging. This muscle is responsible for the formation of oblique lines with maximal contraction, often referred to as “bunny lines” and for producing an exaggerated gingival smile or “gummy smile” on some patients. Contraction of this muscle can be felt while the patient is smiling before injection. Injecting 2–4 U of Botox® on each levator labii superioris alequae nasi helps with these conditions. Caution must be taken not to inject surrounding muscles to prevent an asymmetrical smile. In addition, if migration of toxin occurs into the orbicularis oris, this will result in an undesired inability of the patient to pucker the lips.

To ameliorate perioral fine rhytides, the superficial fibers of the orbicularis oris are injected with 0.5–1 U at six points 2–3 mm above the vermillion border. The same technique can be applied to the lower lip; however, on four points only (Fig. 71.6). The depressor anguli oris muscles are injected at the most inferior portion with 2–4 U placed on either side on an imaginary line drawn as a continuation of the nasolabial fold to elevate the corner of the mouth. This is usually done at about 1 cm above the intersection of this line and the angle of the jaw (Fig. 71.7). Many patients realize that the texture of their chin changes with various expressions. An injection of 5–10 U of botulinum toxin into the inferior portion of the mid chin (mentalis muscle) helps in smoothing out the dimpling of the chin (Fig. 71.8). Care should be taken to avoid injecting the depressor labii inferioris.⁹

Fig. 71.6 Injection placement for treatment of the perioral rhytids.

Fig. 71.7 Injection placement to lift the corner of the mouth.

Fig. 71.8 Single injection of the mentalis muscle.

Treatment of the neck

The complete understanding of the anatomical complexity of the lower face is an essential factor for an effective treatment outcome. The procedure described here is for experienced physicians who are very familiar with the agonist-antagonist muscles and dynamic contraction force vectors that compromise the lower face and neck. The clinicians must understand that the BTX-A dosing for the neck area differs from the upper face and the importance of placement and injection technique cannot be further emphasized for safety and optimal results.

Overlapping the sternocleidomastoid muscle, the platysma is a superficial flat and broad muscle generally considered as the inferior most portion of the superficial musculoaponeurotic system (SMAS). The muscle originates inferiorly as two independent sheets from the upper chest connecting to the fascia overlying the pectoralis major and deltoid muscles. The muscle approaches anteriomedially with fibers eventually blending with the masseter, depressor anguli oris, mentalis, risorius and orbicularis oris. These medial fibers of the platysma exhibit considerable anatomical and thickness variations and are responsible for the aging appearance of the neck. There are three main variants of the platysma muscle which are categorized as type I, II and III (Fig. 71.9). Approximately 75% of patients have the type I variant where the medial fibers are separated approximately at a 1–2 cm level of the submental region. Fifteen percent of patients present the type II variant where the entire submental region is covered with the platysma muscle and the muscle decussation is at the level of the thyroid cartilage. Type III occurs in fewer than 10% of patients where there is no decussation of the platysma muscle resulting in the two muscles running independently.

Fig. 71.9 Anatomical variants. A, Medial fibers are separated in the suprahyoid region. They interlace with those of the opposite side below the chin (75% of patients). B, Medial fibers decussate at the level of the thyroid cartilage, forming a single muscular layer covering the submental region (15% of patients). C, Fibers do not interlace, they run separately towards their cutaneous insertions in the chin (10% of patients).

From Carruthers A, Carruthers J, eds. Procedures in cosmetic dermatology, 2nd edn. Botulinum toxin. London: Saunders Elsevier, 2008.

The hyperfunctional platysma bands may be effectively treated with Botox®. No anesthesia is required for this procedure. In order to better visualize the platysma bands, the patient is asked to contract their anterior neck by strongly clenching their teeth and depressing the lateral oral commissures. This facial expression exacerbates the platysma bands. Using the non-dominant hand, the clinician then grasps each band between the thumb and index finger (Fig. 71.10). Each band is injected with a 30-gauge needle three to four times at intervals of 1–1.5 cm apart with 3–10 U from the jawline to the lower neck (Fig. 71.11). Thinner bands will require a total of 15–20 U, while thicker bands may require up to 30 U. It is not unusual to inject the platysmal muscle with 150 U. However, it is important to understand that with higher doses, adverse events such as sternomastoid weakness and dysphagia increases. With experience, the injecting clinician will learn to identify the resistance of the platysma bands and tailor the appropriate BTX-A dosage. Intradermal injections of the horizontal neck rhytides, commonly referred to as necklace lines, with 1–2 U at 1 cm intervals also effectively ameliorate the appearance of these fine lines.

Fig. 71.10 Botox injection technique for neck rejuvenation.

Fig. 71.11 Placement of injections for neck rejuvenation and lifting.