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1.8 Anterior Digastric and Mylohyoid Muscles
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Bordering on the neck from above, it is formed in part by the mandibular ligament at its caudal apex. The labiomandibular fold, comprising skin-wrapped cheek fat lateral to the crease, commonly requires consideration when choosing between a cheek lift (which improves this) or an isolated neck lift (which does not).
37
Just below the chin, the submental liga­ments provide an anchor to the submental skin crease, likely a result of direct attachment to the platysma by fasciocutaneous adhesions, while the platysma has its own independent attachment to the underlying bone by separate osteofascial fibers.
Laterally, the neck is attached behind the ear to both the periosteum of the mastoid bone and the investing deep fascia over the origin of the sterno­mastoid muscle by a patch of dense connective tis­sue, the osteofasciocutaneous mastoid-cutaneous ligament.
39
The only separation between the skin from the deep fascia in this region is a thin layer of yellow and white fibrofatty areolar tissue. Within this thin layer, the terminal mastoid branches of the great auricular nerve and the lesser occipital nerve are found.
Meshing with the above-mentioned mastoid-
cutaneous ligaments are the fasciocutaneous platysma-auricular ligaments, which radiate out­ward from the skin around the base of the earlobe and converge with the superficial fascia (platysma– SMAS layer) below and in front of the ear as well as the medial sternomastoid-cutaneous filaments and the upper lateral sternomastoid-cutaneous ligaments.
40
Typically, at least the most superficial of these fibers comprising the platysma-auricular ligament must be cut to free the skin around the lower ear whenever an earlobe-base incision is used for a neck lift procedure.
10
In patients presenting with an attached earlobe, or more severely those who have a congenital pix­ie earlobe that is pulled caudally toward the angle of the jaw, there is a thick linear stretch of the platysma-auricular ligament that forms a distinct white band tethering the earlobe downward. By way of a simple electrocautery release of this liga­mentous tether, the earlobe can be corrected to allow for upward retraction and a more pleasant
15
contour.
Lateral (thicker) and medial (thinner) sternomastoid-cutaneous retaining ligaments in
the neck form the fibrous connection between the muscle and the skin in the plane of dissection in neck lift surgery. The relative thickness of these re­taining ligaments can often determine the level of
diculty of neck skin flap elevation, particularly in the lateral neck. Further medial in the neck are the medial platysma-cutaneous filaments, the vertical columns joining the medial edges of the platysma muscle bellies to the skin.
12
These filaments are likely responsible for static muscle bands in the me­dial neck.
10
Finally, the skin crease retaining filaments are
a set of organized retinacula cutis holding the deep horizontal anterior and lateral neck skin creases as well as the lateral neck vertical skin creases rela-
38
tively tightly adhered to the underlying fascia. Typically, severing these retaining filaments while undermining the neck skin containing the crease significantly reduces the crease. However, in some cases the dermis within the crease is thinner and more compact than it is in the surrounding skin, making it harder to achieve full eradication of the crease with skin undermining alone.
10
1.7 Subplatysmal Fat
The subplatysmal fat lies subcutaneously beneath the superficial fascia of the neck, and as such is at­tached to the underlying investing deep fascia and periosteum. As such, this layer of fat tends to be more fibrous, making it more dicult to remove than supraplatysmal fat. An equivalent example of this fatty tissue layer in the face would be the sub­SMAS fat in the cheek.
42
At the neck midline, the fat sitting between the medial edges of the platys­ma muscle bellies is often referred to as interpla­tysmal fat or midline subplatysmal fat. Strongly anchoring this interplatysmal fat to the hyoid bone, perihyoid fascia, digastric muscles, and in­vesting deep fascia of the midline neck is the hyoid ligament. The quantity of subplatysmal fat can be quite variable depending on the patient.
1.8 Anterior Digastric and Mylohyoid Muscles
The submental triangle is comprised of two anterior bellies of the digastric muscles and the body of the
hyoid bone, with the mylohyoid muscles acting as a common oral diaphragm between the floor of the submental triangle and the floor of the mouth. main actions of the anterior digastric muscles are to elevate the hyoid bone and provide stabilization during speech and swallowing, as well as to pull the jaw downward against resistance. The main action
41
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The
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of the mylohyoids is to also elevate the hyoid bone, in addition to the floor of the mouth and tongue during speech and swallowing. In the majority of patients, the mylohyoid muscles are hidden from view during neck lift surgery, as the anterior digas­tric muscles are completely covering them.
10
The anterior belly of the digastric muscle emerges from the digastric fossae of the mandible, connecting with the posterior bellies by way of a round inter­mediate tendon (splitting the stylohyoid muscle) held in place by a fascial sling attached to the body and greater horn of the hyoid bone.
43
The mylohyoid muscles arise from the mylo-
hyoid line at the inner surface of the mandible, ex­tending diagonally across the entire length of the body of the lower jaw (from below the third molar to between the mental spine and digastric fossa). The mylohyoid line creates a separation between the fossa for the sublingual salivary gland from the fossa for the submandibular salivary gland, allow­ing for the fibers of the mylohyoid muscles to run inferomedially and insert into the body of the hyoid bone and join its opposite along a median raphe extending vertically from the hyoid to the mandible. Posteriorly, the muscle has an oblique trajectory and is free.
It is not uncommon for gaps between the fibers of the mylohyoid muscle to lead to herniation of soft tissues in the floor of the mouth (e.g., the sub­lingual glands), which can produce a mass bulging from the submandibular triangle.
10
Neurovascular supply to the mylohyoid and an­terior digastric muscles comes from the mylohyoid nerve and the submental artery and vein (in addi­tion to a small mylohyoid artery). This neurovascu­lar bundle runs together just under the lower bor­der of the mandible atop the mylohyoid muscle within the capsule of the submandibular salivary gland to the lateral edge of the anterior digastric.
1.9 The Facial Nerve and Lower Lip
Likely of greatest clinical significance to surgeons performing neck rejuvenation procedures is the anatomical layout of the facial nerve branches pro­viding lower lip depressor innervation, as the iatrogenic injury to these branches can commonly cause deformities characterized by the absence of downward motion on the aected side during smile and/or speech, as well as a slight rise of the aected hemilip margin.
44
These deformities can
be temporary or permanent, as discussed earlier in this chapter, with the vast majority of cases dem­onstrating signs of injury being mild and transient. Complete recovery from the neuropraxia (local conduction blocks) of these nerve branches by segmental remyelination tends to occur within 6 weeks postoperatively.
45
Should the nerve be in­jured to the point of axonotmesis, the nerve regen­erates at a rate of 1 to 3 mm per day following sur­gery, with full recovery typically occurring within 4 months postoperatively.
10
1.9.1 Mandibular and Cervical Nerve Branches
The main trunk of the facial nerve typically bifur-
2
cates within the parotid gland, just posterior to the ramus of the mandible approximately one­third of the way from the angle of the mandible to the mandibular condyle. This bifurcation typically provides two main divisions: the temporofacial di­vision (cephalic) and the cervicofacial (caudal). There are rare cases of main trunk division into more than two subsidiaries. While considerable variation exists in the exact pattern of subdivision of these nerve branches within the parotid gland (even from one side to the other in the same pa­tient), the iconic branches are termed frontal (tem­poral), zygomatic, buccal, marginal mandibular, and cervical, making their way toward the muscles of facial expression.
Of particular relevance and anatomical impor­tance to neck rejuvenation procedures are the marginal mandibular branch and the cervical branch of the facial nerve. The first (marginal man­dibular) innervates the depressor anguli oris (dis­cussed previously), depressor labii inferioris, and/ or the mentalis muscles, while the latter (cervical) innervates the platysmaexclusively.
The marginal mandibular nerve (or nerves) exits the anteroinferior edge of the parotid gland ap­proximately 0.5 to 1.5 cm anterior to the posterior border of the mandible, and from 1.5 cm above the angle of the mandible to 1 cm below the angle. emerges in variable numbers: as a single nerve (40%), two branches (50%), or three to four branches (10%), with each branch traversing forward above, along, or below the jawline within a horizontal bandwidth extending from 2 cm above the inferior border of the mandible to 3 cm below. branches that remain above the jawline are typically encapsulated by the parotideomasseteric fascia,
46
2
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Those
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References
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running forward over the masseter into the buccal fat pad, which is also protected by the same deep fascial membrane.
50
Those branches that exit the parotid gland below the jawline tend to remain be­neath the investing deep fascia before perforating the deep fascia just below the anterior tip of the pa­rotid to enter the subplatysmal plane, then continu­ing forward just superficial to the capsule of the submandibular salivary gland. Interestingly, most if not all marginal mandibular nerve branches that run below the jawline end up taking turns in their trajectory to end up above the jawline before enter­ing their target muscles of innervation in the lower
2
lip.
As the marginal mandibular branch of the fa­cial nerve traverses the path of the facial vein and facial ar tery along th e jawline, the nerve branch is found superficial to the facial vein over the lower masseter muscle edge in 95% of cases, while the nerve branch traverses superf icial to the more anteriorly situated facial artery in (the­oretically) 100% of casesalthough there may be some occasional rami that do pass deep to the facial artery.
10
The main branch of the cervical nerve typically descends within the parotid gland posterior to the ramus of the mandible, then splitting ofrom the marginal mandibular branch prio r to emerging at the caudal tip of the gland accompanied by the retromandibular vein (eventually becoming the external jugular vein, discussed previously). The main cervical branch gives oeither a single or multiple superior cervical branches, which pierce the investing deep fascia at or just inferior to the jawline. These branches then turn forward and travel parallel to the jawline on the deep surface of the platysma before splitting into several smaller branches entering the platys ma 2 to 3 cm medial to the medial edge of the sternomastoid muscle to in nervate the superior two-thirds of the platysma muscle.
51
The somewhat more predictable inferior cervi­cal branch runs downward for 3 to 4 cm beneath the investing deep fascia along or just below the anterior edge of the sternomastoid muscle, then penetrating the investing deep fascia before con­tinuing forward parallel to the mandible just be­neath the platysma. The rami also emerge at this point to innervate the remaining inferior one-third of the platysma muscle, commonly anastomosing with the sensory transverse cutaneous nerves of the neck.
1.10 Conclusion
The importance of precision in ones knowledge of facial and neck anatomy cannot be overstated. The techniques forthcoming in this textbook, both sur­gical and nonsurgical, to rejuvenate the neck are bound by the limits of the aforementioned ana­tomical structures. We hope this can serve as an accurate and clinically relevant reference to the important anatomy as these techniques are dis­cussed herein.
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2 Neck Rejuvenation: Evaluation and Management
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Jose Foppiani and Samuel J. Lin
Abstract
This chapter thoroughly discusses surgical and nonsurgical modalities of treatment of neck reju­venation. It highlights the aesthetics of the neck as well as its evaluation and how that evaluation can guide the choice of therapy for the patient. There is a vast array of old and new treatment options in this growing realm of cosmetic surgery, and an attempt to present them holistically is provided in this chapter. These include various minimally inva­sive procedures such as the use of injectables and lasers, as well as surgical procedures such as suction lipectomy and neck lifts. Granularities exist between and within procedures, and this chapter explores these in detail to highlight the indications, techni­ques, complications, and excepted results of each technique. Ultimately, patients with minimal excess skin but an excess of preplatysmal submental fat are indicated to undergo nonsurgical procedures. In contrast, patients with excess skin or significant platysmal banding should undergo a surgical ap­proach tailored to their characteristics. As neck re­juvenation grows in popularity, aesthetic surgeons have the chance to personalize treatment for their patients to ensure exceptional results with minor complications.
Keywords: aesthetics of the neck, neck rejuvena­tion, surgical and nonsurgical intervention, com­plications, postoperative care
The choice of technique and the approach should be guided by the specific characteristics of each patient.
Poor outcomes tend to be the result of inappro­priate patient evaluation leading to suboptimal choice of surgical procedures.
Well-planned postoperative care improves the outcomes and significantly decreases the rate of complications.
2.1 Introduction
2.1.1 Demographic of Neck Lift/ Rejuvenation Procedures
Neck rejuvenation is one of the most commonly performed aesthetic surgical procedures in the
1
world.
It represented over 260,000 of all aesthetic procedures in 2016. States alone encompassed over 181,000 procedures in 2019 and over 160,000 procedures in 2020. popularity thus requires the aesthetic surgeon to possess an in-depth knowledge of surgical and non­surgical neck rejuvenation procedures. This knowl­edge must include a solid comprehension of the aesthetic principles of the neck area, the anatomy of the neck, surgical techniques, and potential com­plications. This knowledge then enables the aes­thetic surgeon to discuss with their patients the most appropriate procedures to achieve their goals.
2
Furthermore, the United
1
This
Key Points
The Ellenbogen Brooks criteria provide a compre­hensive guideline for an aesthetically pleasing neck.
The evaluation of the neck’s anatomical fea- tures guides the choice of procedures and sig­nificantly influences the outcomes of given procedures.
Patients with minimal skin excess and mostly preplatysmal fat should undergo minimally invasive procedures such as lasers, injectables, and other techniques described in this chapter.
Patients with excess skin, subplatysmal fat, and other deeper neck defect should undergo surgical procedures.
2.1.2 Criterion for a Youthful Aesthetically Pleasing Neck
The concept of beauty has been explored from the very inception of mankind. As far back as antiq­uity, artists and philosophers pondered on the char­acteristics of beauty. Most notably, Plato explored it in great depth in his time. nomic changes arose in history, what and how to determine if a feature is aesthetically pleasing has proven a challenge. view exi st on the matter. Yet, commonality may be found within them. Some culture favor lean body and faces, while others prefer curves. More­over, symmetry is usually the unifying ground. Mathematicians have long tried to establish a
3,4
However , as socioeco-
3,4
Many theories and points of
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Fig. 2.1 Characteristic of the youthful neck in (a) male and (b) female patients. NLCP, nose–lip–chin plane; SCM, sternocleidomastoid muscle. (These images are provided courtesy of MUDr. Roman Kufa and MUDr. Lukáš Frajer.)
clear definition of beauty, but despite the existing controversy , the golden ratio and Fibonacci sequence have proven crucially insightful. They stress again the importance of symmetry and proportions.
7,8,9,10
As of today, the Ellenbogen Brooks crit eri a ha v e pro­vided a fairly universal set of guidelines in defining a youthfully aesthetic neck and thus what surgeons should strive toward (Fi g. 2.1).
11,12
These criteria
include the follo wing:
A distinct inferior mandibular border.
A visible subhyoid depression.
A visible thyroid cartilage bulge.
A visible anterior border of the sternocleido­mastoid muscle.
A cervicomental angle of 105 to 120 degrees.
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2.1.3 Criteria for an Aging Neck
Similarly to the face, the neck is subject to the aging process. This aging process induces transformations that are usually classified as either chronological or photo induced. sis of the shape, texture, and color of the neck region. of the quality and quantity of soft tissues. A lifetime of facial expression, elastosis, gravitational forces, and tissue atrophy have a significant impact on the appearance of the neck. This appearance is uniq ue to each patient, but trends may be found within popu­lations. exposure to the sun), specific populations and ethnic
13,14
This results in the metamorpho-
13,14
This change is caused by the degradation
13,14,15
Based on their lifestyle (especially skin
groupsmayhaveverydifferent neck morphology requiring distinctive interventions. Individuals with a Fitzpatrick phototype of V or VI, for example, have a higher amount of melanin protecting them from the eects of photoaging more so than individuals with Fitzpatrick phototype I or II.
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This relativ e low­er loss of collagen and elastin usually translate into a younger appearance.
15
This may imply that for indi­viduals of the same age, an aesthetic surgeon may prefer to choose an invasive versus a noninvasive method because of the patient’s characteristics. Ad- ditionally, the characteristic histological dierences and wound healing of individuals of dierent ethnic origin may warrant dierent approaches. Fibroplasia in these groups may be more significant than in others, and thus careful consideration of tensions on incision sites is necessary.
15,16
Despite the inherent dierences between ethnic groups, the following criteria represent a unified definition of an aging neck region:
An obtuse cervicomental angle, caused by loose/ excess skin with an excess of subplatysmal fat and a low position of the hyoid bone.
Aging chin and lower face with the eacement of sharp mandibular border.
12,17
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2.2 Neck Evaluation
An evaluation of the neck depicting the anatomical relationship between the platysma and preplatysmal fat is shown in Fi g. 2.2.
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Fig. 2.2 Anatomical relationship between platysma and
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preplatysmal fat.
2.3 Neck Rejuvenation Procedures
2.2.3 Platysma
The key in platysma evaluation is to define the degree, direction, and location of banding both passively and dynamically.
21,22
2.2.4 Digastric Muscle
The preeminence of the digastric muscle is imper­ative to evaluate. It can form a subtle but neverthe­less visible distortion of the contour of the inferior border of the mandible. erance may be created by the digastric muscle fol­lowing submental fat removal. This leads to poor aesthetic results for the patient. While preopera­tive assessment is possible in an emaciated neck, a surgeon should evaluate/reevaluate the digastric muscle intraoperatively.
12,21
Additionally, a protub-
12,21,22
2.2.1 Skin
The evaluation of the patients skin is paramount to present to the plastic surgeon initial informa­tion he or she needs to devise the optimal treat­ment strategies. The quality of the skin, notably its elasticity, as well as the quantity of the skin, notably any absolute/ relative excess, should be investigated.
12,18,19
Additionally, rhytids forming both passively and actively should all be thor­oughly evaluated.
12,18,19
Skin in relative excess will typically solely require redra ping followed by recontouring. On the other hand, skin with poor elasticity will require skin excision as well.
12,18,19
One should note that worse skin quality will ne­cessitate a potentially longer skin incision.
12,18,19
A recent framework proposed suggests evaluating the quality of the skin in three categories: vis ible, mechanical, and topographical.
20
This would uni­formly codify the approach to skin evaluation among aesthetic surgeons.
2.2.2 Adiposity
The next step is the evaluation of the adipose tis­sue distribution, which is key in defining the ap­proach that the aesthetic surgeons should follow. The adipose tissue accumulates in either the pre­platysmal or subplatysmal plane. mental pinching maneuver is used in order to identify the total amount of fat. while still pinching the same location, the patient is instructed to contract their platysma. The re­maining fat felt during this contraction reflects the fat present in the preplatysmal layer (Fig. 2.3).
21
A midline sub-
12,21
Afterward,
21
2.2.5 Submandibular Gland
As part of the intraoperative evaluation, the extent of the submandibular protrusion/bulging should also be assessed.
12,21,22
The surgeon will need to ad­dress the submandibular gland that is ptotic, either surgically or with the patient preoperatively.
2.2.6 Chin
The chin plays a crucial role in relation to facial proportion and should thus be ev aluat ed accordingly including its angle classification. Any abnormalities of the chin can result in suboptimal contouring of the neck.
12,21,22
2.3 Neck Rejuvenation Procedures
The treatment algorithm for patients neck rejuve­nation procedures is complex. The most consistent approach following the aforementioned evaluation of the patient is to take a targeted layer approach to the patients
Superficial:
Skin.
Subcutaneous fat.
Intermediate:
Platysma (muscle banding target).
Deep:
Digastric muscle.
Submandibular gland.
Suprahyoid fascia.
Subplatysmal fat pad.
12,21,22
:
12,21,22
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Fig. 2.3 Evaluation of submental fat in a (a) male and (b) a female patient. (These images are provided courtesy of MUDr. Roman Kufa and MUDr. Lukáš Frajer.)
2.3.1 Nonsurgical Procedures
Botulinum Toxin
Botulinum toxin has long been used in the field of aesthetic surgery.
14
23,24,25,26,27,28
It has an especially
important role in the head and neck region. Young patients with minimal/moderate active banding, minimal rhytids/jowls, and with minimal skin laxity requiring minor cervicomental angle contouring are
2.3 Neck Rejuvenation Procedures
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all good candida t es for botulinum toxin use.25On the other hand, patients with excess skin or passive platysma banding would not be indicated for sole botulinum toxin therapy. As a rule of thumb, the preliminary dosage in patients is 5 to 20 injections per platysmal band.
24
A grand total of 40 to 100 units are thus used in most patients per treatment. Overall, good results are achieved in young people where minimal/moderate active banding is present. Botulinum toxin can successfully be used to tighten neck jowls, reduce horizontal neck rhytids, and im­prove skin laxity.
23
It is important to note that botu­linum toxin also has good results in correcting minor defects as an adjunct in other procedures.
26
Its use delays the need for surgical procedures, but one should note that another procedure will most often be needed down the line. Common complications in­clude muscle paralysis, dysphagia, erythema, edema, ecchymosis, and hyperpigmentation.
24
Due to its versatile nature, botulinum toxin injections remain one of the leading nonsurgical aesthetic procedures worldwide, with an excellent rate of ecacy and pa­tient satisfaction. The accumulation of clinical evi­dence with botulinum toxin has led to refinements in treatment planning and implementation over the years. Internationally, the Global Aesthetics Consen­sus Group has repeatedly advocated an ontology­driven, patient-tailored approach to enable optimal ecacy and safety in patient populations that are rapidly diversifying with respect to ethnicity , gender,
28
and age.
Microfocused Ultrasound System
The Ulthera microfocused ultrasound system has received an increasing level of attention over the last decade. the years including a 103-patient study in 2014 in the United States. microcoagulative zones and collagen neosynthesis eect, the Ulthera system achieved promising re­sults in skin tightening. Indeed, up to 60% decrease in skin laxity was reported using this system. Since then, another study in 2019 was conducted, which included 50 adult patients. were treated with the Ulthera 3.0-mm probes to target the deep dermis and the 4.5-mm Ulthera probe to target the superficial muscular aponeur­otic system. skin laxity in this patient population. Ulthera system may be a tool for the aesthetic sur­geon for targeting skin laxity in neck rejuvenation. This system may be advantageous in populations
29,30
It underwent multiple studies over
29
This study showed that via its
30
The subjects
30
It showed up to 93% improvement in
30
Overall, the
with darker Fitzpatrick skin types where unlike laser devices or ultrasound therapy, it does not target melanin. lasers for these populations.
30
This makes it a safer choice over
30
Patients with a body mass index (BMI) over 30 tend to have a high degree of subplatysmal fat, making the Ulthera system sub-
24
optimal to use in that population.
29
Some complica­tions to keep in mind with this system include immediate posttreatment pain, erythema, edema, and bruising.
30
Lasers/Radiofrequency Devices
Lasers and other radiofrequency devices are an­other emerging toolbox for the aesthetic surgeon when targeting skin laxity and fat debulking. Similarly to the Ulthera system, treatments with these devices cause adipocytes to coagulate as well as stimulating dermal neocollagenesis. Multiple devices currently exist within this category:
The PrecisionTx introduced in 2012 is a bidirec­tional dual-wavelength laser at 1,320 and 1440 nm that leads to fat cavitation. This laser fires forward in the direction of the cannula at a 90-degree angle, enabling the clinician to rotate his or her wrist and thus treat both deep and superficial dermis.
The ThermiTight system introduced in 2013 is a
30
percutaneous monopolar electrode causing the dermis to reach 50 to 70 °C while keeping the epidermis at a temperature of 45 °C. The whole preplatysmal fat area may be targeted in this way, one of the most advantageous features of this system.
The NeckTite system introduced in 2016 is a
30
percutaneous bipolar electrode that may be used with radiofrequency lipolysis devices to improve neck contouring.
30
Other topics will be covered in detail in later chap­ters of this book. As a group, the percutaneous thermal devices have multiple advantages. These
29
include single-treatment modality, the capability to contour and adjust the location of adipose tissue re­moval, and its eectiveness in achieving excellent skin tightening.
30,31
Common complications include
swelling, bruises, pain, and a risk of skin burn.
Cryolipolysis
Cryolipolysis is a technique implemented using Zeltiqs Cool Sculpting and its CoolMini applicator handpiece available since 2015 following the
30
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approval of the device by the Food and Drug Administration (FDA).
31
This system utilizes the cold sensitivity of adipocytes to sele ctively induce their apoptosis. Indeed, the target pre platysmal fat is kept at a temperature of –10 °C for 45 minutes. Patients usually have to undergo one to two treat­ments in order to see noticeable changes.
31
Overall, this technique has been shown to decrease superfi­cial fat thickness by 2mm and up to 77% of patients report improvements in submental appearance. However, it is important to note that similarly to other devices covered in this chapter, the final reduction in the cervicomental angles occurs over the course of 3 or 4 months posttherapy. The advantages of this modality include the ability to debulk large areas of submental fat and a low risk of complications in addition to the noninvasive na­ture of the procedure. Like all other devices, some disadvantages do exist. These include the inability to treat skin laxity and platysmal band, the need for multiple costly sessions, and lack of precise target­ing of fat debulking. There is a rare risk of paroxys­mal adipose hypertrophy (PAH), which results in the hypertrophy of adipose cells following treat­ment. However, it is important to note that the per­sistence or growthof fat may also be due to weight gain and not PAH. It is also important to note that a butter stickappearance of the sub­mental may occur for a few minutes posttherapy.
31
Deoxycholic Acid
Deoxycholic acid is a chemical substance that can be used to target excessive submental adiposity. It usually requires four to six treatment sessions with 4 to 6 mL of the chemical per treatment. 30-gauge needle is used, and 20 to 30 injections of
0.2 mL are given in a 1-cm grid pattern over the submental area.
12,31
Overall, the treatment may decrease the submental fullness/adip ose content as exhibited by two phase 3, randomized, doubl e­blind, placebo-contr olled clinical studies con­ducted in 57 centers in Germany, France, Spain, Italy, Belgium, and the United Kingdom. cholic acid is a treatment with good co ntrol over area and amount of adipose fat reduc ti on and moderate skin tightening eect. Complications include pain with administration, lack of clinical improvement, or hematoma formation in up to 72% of the patient; swelling; and the possibility of exposing the platysmal bands if the adipose layer is skeletonized. Patients with bleeding disorders are usually contraindicated for this treatment.
32
12,31,32
12,31
Deoxy-
Stromal Vascular Gel
Stromal vascular fraction (SVF) gel is another in­jectable indicated for use in neck rejuvenation spe­cifically to target horizontal neck wrinkles. preparation of lipoaspirate necessitates multiple steps. It requires two centrifugations with collec­tion of the middle layer following the first centri­fugation and re-centrif ugation of that collected layer. Various protocols to produce SVF gel exist.
31
Once produced, the SVF gel is injected via a subcision underneath neck wrinkles. A beveled hypodermic needle is used to loosen up the tissue to which the wrinkles are bound. Injections should be performed at points 0.5cm apart along the horizontal neckline s, depositing 0.05 to 0.1 mL of SVF gel at each injection
33
point.
Overall, improvement in horizontal wrinkles is evident. However, it is important to note that com­plication rates tend to be higher with SVF gel. Com­plications include erythema, edema, ecchymosis, and hyperpigmentation.
2.3.2 Surgical Procedures
An overview of surgical treatment options based on patient anatomical characteristics is presented in Table 2.1.
Liposuction
Liposuction gery procedure is one of the most commonly per­formed treatment modality worldwide.
Multiple subtypes of liposuction devices exist:
Suction-assisted liposuction (SAL).
Ultrasonic-assisted liposuction (UAL).
A
Laser-assisted liposuction (LAL).
Radiofrequency-assisted liposuction (RFAL).
Liposuction has developed significantly since its first use in the field of aesthetic surgery. Articles dating back to 1996 described the comparative benefits of suction lipectomy. It was then de­scribed that the marriage of SAL and UAL en­hanced results and minimized complications. of 2018, authors thoroughly explored the benefits of UAL and LAL over SAL. the following:
UAL over SAL in the treatment of gynecomastia.
LAL and UAL over SAL with decreased hemoglo­bin/hematocrit in high-volume lipoaspirate.
LAL over SAL with skin tightening in select areas notably the submental area.
29,31,34,35,36,37
as a general aesthetic sur-
36
These notably include
33
The
33
1
35
As
16