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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_537_Библиотеки_им_академика_М_И_Перельмана
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Botulism toxin selectively induces flaccid paralysis in facial muscles,
preventing Acetylcholine release from presynaptic nerve terminals and
effectively blocking signal transmission. In addition to reducing the
appearance of wrinkles, this approach helps to improve facial asymmetry
and eyebrow position. Patients will see finalized results after 1–4weeks
postprocedure, although many notice significant changes after just 2days.
Repeated botulism toxin injections contribute to muscle atrophy in the
affected muscles after about 5 treatments, which benefits the longevity of
facial rejuvenation [114, 115].
There are various serotypes available, each with specific indications and
advantages. The toxin itself is produced with fermentation of Clostridium
botulinum bacteria, and there are several varieties. For the purposes of
facial rejuvenation, we will discuss the relevant cosmetic applications,
which use serotypes A and B. Different formulations are available for these
serotypes, which include onabotulinumtoxinA, abobotulinumtoxinA,
incobotulinumtoxinA, and rimabotulinumtoxinB [116].
The latter is negatively associated with decreased longevity and
potential for widespread diffusion, but the aesthetic improvement has a
much earlier onset compared with serotype A formulations. The
rimabotulinumtoxinB formulation is also more acidic, which tends to be
more painful for patients when injected. OnabutilinumtoxinA,
abobotulinumtoxin A, and incobotulinumtoxinA are frequently combined in
a 1:2.5:1 ratio, respectively, and these serotypes tend to last longer
compared to their B counterpart [117].
5.1 Discussion of Relevant Anatomy
Careful injection is required with all injectable therapy, especially in the
facial muscles. The superficial musculoaponeurotic system (SMAS) is
unique to the face, and delicate muscles of expression are attached to
overlying cutaneous tissues within this plane. Wrinkles tend to develop
perpendicular to the orientation of these cutaneous attachments, although
presentation can vary between patients [114, 118]. Muscles of relevance in
the upper face are detailed in Table 1, along with the changes associated
with aging or damage.
Table 1 Muscles of the upper face are listed above, along with their action and changes with aging
Muscle Action Changes with damage/aging
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Muscle Action Changes with damage/aging
Orbicularis oculi Depression of eyebrows,
eye closure
Lateral canthal rhytids (or “crow’s feet”),
eyebrow depression
Corrugator supercilia Furrowing of eyebrows Vertical interbrow rhytids
Levator palpebrae
superioris
Elevation of eyelids Ptosis
Procerus Inferomedial brow
movement
Vertical glabellar and upper nasal rhytids
Frontalis Elevation of eyebrows Horizontal forehead rhytids
Additional complexities are observed with the placement and depth of
these muscles. The corrugator supercilii are bulkiest directly beneath the
eyebrows, medially deep, and laterally superficial in relation to the frontalis
[119–123].
The position of the eyebrows is dependent on the integrity of these
muscles and their attachments [125]. In women, the medial eyebrows
should be positioned above the orbital rim, originating directly above the
bilateral nasal alar cartilages. They should reach a maximal height just
above the lateral canthus (lateral eye-opening) and maintain this height until
termination. In contrast, the male eyebrows are positioned at the orbital rim,
reaching their maximal height just above the pupils [124]. Relevant muscles
of the middle and lower face are detailed in Table 2, and Fig. 17 provides a
visual illustration of all the facial muscles.
Table 2 Muscles of the lower face are listed above, along with their action and changes with aging
Muscle Action Changes with damage/aging
Nasalis Wrinkling of the
nose
“Bunny lines”: dynamic wrinkles on the lateral or dorsal nose
(may extend upward to the lower eyelids or cheeks)
Depressor
septi nasi
Decreases nasal
tip projection
Drooping nasal tip
Orbicularis
oris
Mouth closure
and lip protrusion
Vertical perioral wrinkles
Depressor
anguli oris
Frowning Corners of the mouth are pulled downwards
Masseter Mastication
(chewing)
Hypertrophy, widening of the lower face (lending to contour
deformities)
Mentalis Lower lip
protrusion
Dimpled chin
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Muscle Action Changes with damage/aging
Platysma Depression of
mouth corners
Décolleté wrinkles (also referred to as necklace lines)
Fig. 17 The facial muscles and their relative locations are illustrated in the above image [127]
5.2 Preprocedural Patient Assessment
Botulism toxin injections are not beneficial for all patients, and the
aesthetician or surgeon should perform a thorough physical examination
and obtain detailed past medical history prior to treatment.
Contraindications include [128]:
1. Pregnancy/breastfeeding
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To date, adverse effects cannot be sufficiently correlated to
neuromodulator injection, but this remains contraindicated until it can
be proven otherwise
2.
Neuromuscular conditions (ALS, myasthenia gravis, multiple sclerosis)
3.
Allergy: botulism toxin, ingredients in therapeutic formulation
4.
Untreated facial infection and skin inflammation
5.
Static wrinkles (present without facial movement) or significantly deep
rhytids
These aesthetic deformities are indicated for surgical correction
After the patient is cleared for the procedure and the toxin has been
reconstituted to the desired concentration, it can be drawn up into a syringe.
Typically, aestheticians and surgeons use smaller 30- or 31-gauge needles
on a 1 mm syringe for injection. Patients are instructed to remove any
makeup prior to treatment, and the skin is cleaned with an isopropyl alcohol
pad. The injection technique varies between providers, although there are
certain factors that should be considered regardless of technique. Men
usually require additional units for similar aesthetic results compared to
women, due to the larger and stronger facial muscles. Techniques used to
locate the facial muscles, as well as commonly used dosages, are discussed
below. The depth of injection varies, depending on the muscle’s location
and adjacent structures [122].
5.3 Injection Technique
The powdered form of botulinum toxin is originally packaged into 100-unit
sealed vials, diluted with normal saline directly before the procedure or
stored as a dilution for about 4weeks in a refrigerator. Depending on the
area to be injected and available supplies on hand, the provider chooses
from a variety of dilution techniques to create reconstitutions with 4, 5, or
10units/0.1mL. Higher concentrations incur additional risk of unwanted
dispersion into adjacent facial muscles [116, 117, 129].
Prior to injection and directly after, patients should avoid using vitamins
and medications that are shown to increase bleeding, as this can result in
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unaesthetic bruising. Topical anesthetics before injection, as well as the use
of vibrational devices, can be safely incorporated to reduce intraprocedural
pain [130, 131].
5.3.1 Glabellar Rhytids
Regardless of gender, rejuvenation of the glabellar complex is most
frequently pursued. Neuromodulator injection will target the corrugator
supercilii to correct dynamic vertical rhytids in this region, as well as the
procerus if horizontal rhytids are present [122]. The superficial frontalis lies
directly above the deeper corrugator supercilii at its medial aspect, requiring
deeper penetration of the needle to the supraperiosteal plane. The lateral
aspect of the corrugator m. is superficial to the frontalis and should be
targeted with superficial needle placement.
Many providers will have the patient furrow their eyebrows when
locating these muscles, as the lateral insertion point can be visually
identified and the deeper muscle belly beneath the eyebrows is more easily
palpated. The injections should be kept at least 1 cm above the eyebrow to
avoid accidental paralysis of the levator palpebrae and resultant ptosis [115,
131]. The procerus can be selectively paralyzed using interbrow injections
placed about 4 mm below the surface of the skin [118, 122].
5.3.2 Forehead Rhytids
Horizontal rhytids in the forehead are attributed to the frontalis, which can
be injected either subcutaneously or intramuscularly. The ideal female
eyebrow has a raised lateral aspect, and this appearance can be recreated by
reducing the injection volume in the lateral frontalis [118, 122].
5.3.3 Periorbital Rhytids
The orbicularis oculi muscle (OOM) can be superficially injected (1–2 mm
below the skin) if it is deemed contributory to eyebrow lowering. Injectors
can perform a simple test to confirm its involvement by having the patient
close their eyes tightly while assessing the level of downward brow
movement.
Injections placed in the OOM should be kept at least 1 cm away from
the lateral canthus to avoid incidental toxin dispersal to the
eye/nerves/surrounding structures. Lateral injections into the OOM induce
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lifting of the lateral eyebrows at rest, and medially placed injections will
induce lifting of the medial eyebrows [117].
Selective paralysis of the depressor supercilii is performed with
superficial injections directly into the eyebrows, which helps to reduce
downward dynamic movement with natural expressions [120].
5.3.4 Nasalis Muscle (“Bunny Lines”)
The nasalis takes on a horseshoe shape, curving transversely over the
dorsum of the nose and moving inferiorly along the external lateral nasal
wall. Correction of bunny lines is performed using 2 superficial injections
(one on each side) about 1 cm above the lateral upper nostril, with the
needle maintained at a 45-degree angle to the nasal bone [126] (Fig. 18).
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Fig. 18 The relative injection depth for glabellar m., frontalis m., periorbital m., and nasalis m. are
identified in the figure, along with optimal placement. Careful technique is required to avoid
accidental paralysis of adjacent muscles [127]
Dynamic nasal tip drooping can be corrected with injection of the
depressor septi nasi muscle, which originates just below the nasal septum
and moves superiorly around the nose. One injection is used, with the
needle inserted deeply (at least 1/3 submerged) and perpendicularly at the
columellar base [126].
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5.3.5 Perioral Rhytids
The fibers of orbicularis oris encircle the oral commissure and serve as an
attachment point for adjacent muscles, including levator/depressor labii
(elevate/depress the lips) and commissure retractors. Four injections along
the upper vermilion border (upper lip-skin junction) are utilized, with two
bilateral injections 1.5 cm medially from the corners of the mouth and 1
mm lateral to the philtrum (midline of upper lip). In addition to wrinkle
reduction, upper lip projection and fullness are improved [132].
The depressor anguli oris (DAO) is targeted with injection to reduce
frown lines, originating lateral to the chin at the base of the jaw (linea
obliqua mandibulae) and inserting at the mouth corner. As it moves
superiorly, the DAO overlaps the depressor labii inferioris and angles
outward, passing over the marginal mandibular nerve at its lower half [133,
134]. Superficial injection into the subcutaneous adipose layer is placed in
the upper quarter of the muscle, lateral to the orbicularis oris [135].
5.3.6 Masseter Hypertrophy
Masseter hypertrophy is reduced with three bilateral injections (six total)
into the muscle. The masseter originates superiorly at zygomatic arch and
inserts at the mandibular ramus and lateral mandibular angle. Injectors can
easily locate this muscle by asking the patient to clench their teeth while
palpating. Three evenly spaced injections are placed inferior to the earlobemouth corner line and at least 15–20 mm superior to the mandibular angle
border, with 1/3 of the needle submerged perpendicularly [126, 136].
5.3.7 Chin
The mentalis muscle runs perpendicularly, originating from the medial
mandible and inserting into the skin below the lips. It is most easily located
by palpating the skin while the patient moves the lower lip upward toward
the nose. On average, there is 12 mm of medial space between denser
muscle fibers, indicating two injection points bilaterally. These are placed
just above the bony jawline close to the midline, with 1/3 of the needle
submerged perpendicularly [137].
5.3.8 Jowls and Neck Laxity
Platysmal injections are indicated for patients with a relatively thin neck
and minimal skin laxity, as the injected toxin will not correct sagging or
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drooping tissues. Platysmal banding occurs when the muscles separate or
strain over time with contraction, and can be easily identified as patients
pronounce the letter E. While grasping each band, the injector places 2–12
injections evenly along the entire length of the muscle. Additional
injections (up to 10units) may be administered along the mandibular
border, keeping at least one finger width away from the mandible to avoid
inadvertent paralysis and dysphagia [138].
Table 3 details the appropriate range of dosages necessary for rhytid
correction, which vary depending on location [122, 126].
Table 3 The facial muscles are listed in the table above, along with the recommended number of
injection points and the number of units
Muscle Recommended dosages (units) Number of injection points
Glabellar complex (CS & Procerus) 8–40 3–7
Frontalis 8–25 4–8
Orbicularis oculi 4–15 (per side) 1–5 (per side)
Nasalis 5–10 (per side) 1 (per side)
Depressor septi nasi 10 1
Orbicularis oris 4–12 4–6
Depressor anguli oris 5–10 (per side) 1 (per side)
Masseter 30–60 (per side) 3 (per side)
Mentalis m. 10–20 2
Platysma m. Maximal dose: 50 (per side) 2–12
5.4 Complications and Outcomes
The most common side effect with botulism toxin injection is
ecchymosis/bruising at the injection site, most frequently near orbicularis
oculi injection. Nearly one in four patients are estimated to develop
transient bruising after the procedure. Severe bleeding can result in
hematoma formation, and patients are advised to avoid anticoagulant
medications (NSAIDS, aspirin) and supplements (ginkgo biloba, garlic) to
avoid severe adverse effects [139]. Ice and pressure can additionally reduce
or slow hematoma formation. Short-term headaches and hypoesthesia occur
in many patients for up to 48h after injection, as well as dry mouth and
malaise [130].
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As discussed above with injection techniques, careful needle placement
can help to avoid unintentional injection and paralysis of local muscles.
Glabellar injections are implicated in unilateral eyelid ptosis and may result
from increased skin laxity or poor technique. Additional complications with
injections near the periorbital area include ectropion (outward turning of the
lateral eyelid), diplopia (double vision), strabismus (crossed eyes), orbital
fat pad herniation, and dry eyes [130, 139, 140].
Careful and consistent placement is key to avoiding incidental paralysis
of local muscles or asymmetric paralysis of target muscles. Patients whose
occupation is reliant on their appearance or ability to communicate
nonverbally (e.g. newscasters, actors, teachers) would benefit from a
prediscussed undertreatment strategy [139].
Serious adverse effects are 33 times less likely to occur with cosmetic
use of botulism toxin compared to therapeutic treatments, and the dose is 4
times lower [141]. Of these adverse effects, the most prevalent to cosmetic
augmentation are dysphagia, allergic reaction, and muscle weakness [142].
Dysphagia usually presents as mild neck discomfort a few days after
injection, and difficulty with swallowing occurs around day 10. Poor
injection technique or toxin dispersion with platysmal injections are
common causes of dysphagia, as the neck muscles are prone to diffusion
[143].
Botulism is a severe condition with various presentations and is
generally associated with local or systemic muscle weakness, paralysis,
dysarthria, and respiratory arrest. The latter is indicative of severe botulism
and requires the use of mechanical ventilation. These effects may appear
years after injection, although they are most common after 10 or 11
repeated treatments [38]. Certain medications can alter the effects of
injected botulism toxin, including aminoquinolones, magnesium sulfate,
cyclosporine, and muscle relaxants (especially succinylcholine). Patients
are recommended to discontinue these drugs temporarily or in the long term
to avoid injection-related complications [144–146].
Generally, the aesthetic improvement to wrinkles and fine lines is
maintained for 3months after injection. Half of the patients treated with
Botox® (onabotulinumtoxinA) maintained their results at 3months,
compared to 40–50% with Dysport® (abobotulinumtoxinA) and 15–25%
with Xeomin® (incobotulinumtoxinA) [147]. Patients who received
botulinum toxin type A injections were most satisfied with their results after
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