Keywords
hyaluronic acid - dermal fillers - aging - aesthetics - rejuvenation
Nowadays, aesthetic medical procedures have become of great interest all over the
globe. This trend continues growing every year since decades, especially considering
minimal invasive treatments since the results are immediate and the downtime minimal.
Hence, treatments with hyaluronic acid fillers have become extremely popular and routinely
used in common practice. According to The American Society for Aesthetic Plastic Surgery,
∼1.3 million dermal fillers have been utilized in 2020 only in the United States.[1]
The facial aging process is multifactorial and principally given by tissue atrophy
and loss of skin elasticity, causing the comparison of more lines and wrinkles all
over the face.[2] Considering the tissue atrophy reduces volume key in the treatment is the volume
replacement, for example, with different types of hyaluronic acid fillers.[3] Along the different facial fat compartments described by Rohrich and Pessa, numerous
areas of treatment were identified and described in the last years.[4]
[5]
[6]
[7] Therefore, for an optimal treatment of the facial volume loss, it is necessary to
treat multiple areas to restore younger facial appearance without enhancing only one
area creating unnatural look.
In the following article, we present four key treatment areas for optimal overall
facial rejuvenation of what the authors define the social profile, commonly identified
as ¾ profile view ([Fig. 1]). This type of facial visualization shows best the tridimensionality of the face
and is therefore taken in consideration for an overall rejuvenation with injectables
though our social profiloplasty. Of each area an assessment, anatomical considerations,
danger zones, and the preferred personal technique of the authors are described.
Fig. 1 Social profiloplasty areas: (A) Temporal region, (B) malar region, (C) nasolabial region, and (D) jaw region.
Temporal Region
Assessment
The temporal region plays a key role on the aesthetics of the upper face; no matter
the gender, it should appear full, having a slight convex look with no depressions
or concavities responsible for an older appearance. Even the eyebrows contribute on
the aspect of this region. From an aesthetic point of view, in female patients the
eyebrow tail should be at least 6 to 8 mm above the upper bony contour of the orbit,
while in men it should not be below. The head of the eyebrow instead should always
be at a lower level of the tail in both genders.[8]
In the temporal region, hyaluronic acid fillers represent mostly the second choice
since good results especially for the eyebrow can be obtained with botulinum toxin.[9]
Anatomy
Topographically, the temporal region represents the area limited anterosuperiorly
by the curved superior temporal line, the periorbital septum and the lateral brow
thickening, anteroinferiorly by the frontal process of the zygomatic bone, inferiorly
by the zygomatic arch, and posteriorly by the temporal hairline.
The tissue layers, from the more superficial to deeper, are represented by the skin,
subcutaneous tissue, superficial temporal fascia, loose areolar tissue and deep fatty
layer, superficial layer of the deep temporal fascia, superficial temporal fat pad,
deep layer of deep temporal fascia, deep temporal fat pad, temporalis muscle, periosteum,
and lastly the bone.[10] Under the skin in the subcutaneous tissue, it is possible to find hair follicles
depending on the area; however, no major neurovascular structures are present. The
superficial temporal fascia is the superior extension of the superficial musculoaponeurotic
system (SMAS), and, at the level of the temporal crest, continues with the galea.
At the level of the superficial temporal fascia, it is possible to identify the superficial
temporal artery and the frontal branch of the facial nerve that runs inside or just
beneath to the superficial temporal fascia.[11] The superficial temporal artery enters into this layer 1 cm anterior and 1 cm superior
to the apex of the tragus and exits by this fascia when it crosses the temporal crest
to become more superficial to the frontalis muscle before merging with the supraorbital
artery. Underneath, it is possible to identify four temporal fat compartments: two
superficial, the temporal-cheek, and the lateral orbital fat compartment; this last
one is crossed by the frontal branch of the facial nerve; and two deeper compartments,
the upper and the lower temporal fat compartments. While the deep temporal fascia
represents a direct continuation of the cranial periosteum extended from the temporal
crest to the zygomatic arch, within it we can find the middle temporal vessels which,
along with the deep temporal artery and vein, supply the temporalis muscle.[12] Above the bone is the temporalis muscle, a large fan-shaped muscle that covers laterally
the cranium, it origin from the temporal line and ends, with a large temporalis tendon
passing beneath the zygomatic process, on the coronoid process.
Dangerous Zones
The major risk for intravasal injection in the temporal region lies in the intermediate
plane; the aim must be avoiding injecting into this plane, placing instead the filler
either superficially just below the dermis, or deep on the preperiosteal plane.[13] Injecting superficially, just under the dermis, permits to avoid the frontal branch
of the superficial temporal artery, which lies in this plane. Injecting deep on the
preperiosteal plane, staying within one fingerbreadth from the arc, or more than 25 mm
above the arch allows avoiding inadvertent cannulation of the middle temporal vein.
The frontal branch of the superficial temporal artery and vein must be avoided in
the eyebrow region as well; the artery arborizes with the supraorbital vessels at
the lateral brow, creating also potential routes for retrograde embolization to the
ophthalmic system.[14]
Injection Technique
To archive an optimal volume and convexity of the temporal area normally, this region
requires ∼0.5 to 1 mL of filler per side; however, severe volume loss of the temple
region may require multiple session.
For the treatment of this area, we suggest a double approach either with the needle
as well as with the cannula. Needle injection (27 gauges, 14 mm length) is used instead
for the deep plane where we recommended the use of fillers with higher G' due to the
depth and the higher volume effect required. This preperiosteal injection allows further
reduction in the temporal depression, reducing the profile of the temporal crest and
at the same time helps to slightly elevate the eyebrow's tail.[15] The injection is performed 1 cm superior to the lateral orbital rim and 1 cm lateral
to the temporal crest, right perpendicular to the bone. The needle is inserted perpendicular
to the skin until bone contact is established; constant bony contact should be maintained
during the procedure; we further suggest stabilizing the syringe with the nondominant
hand. The injection has to be performed slowly, avoiding filler's spread, always remembering
to suck before injecting minimizing the risk of intravascular injury ([Fig. 2]).
Fig. 2 Needle injection performed 1 cm superior to the lateral orbital rim and 1 cm lateral
to the temporal crest, right perpendicular to the bone.
Afterward with the blunt cannula (25 gauges, 50 mm length), the injections should
be placed in the superficial subcutaneous plane, in this case it's preferable use
fillers with low G', so that the material isn't going to be visible considering the
thin overlying tissue. For the superficial plane treatment, we suggest a single access
point above of the zygomatic arch at pretrichial level. The filler is administered
via a retrograde fanning technique across the entire area. Tilting the cannula against
the skin allows the injector to reach the proper subdermal position, as the sharp
contours of the cannula are visible, whereas in an incorrect deep plane the cannula
is less appreciable ([Fig. 3]).
Fig. 3 Cannula injection performed in the superficial subcutaneous plane with a single access
point above of the zygomatic arch at pretrichial level.
For the brow shaping, we suggest to use a single access point with the needle, inserting
it on the lateral end of the eyebrow, just above to the supraorbital rim, always sucking
before starting to inject, and injecting very slowly in a preperiosteal plane. Generally,
a bolus of 0.3 mL is injected while afterward it is important to massage upward to
shape the brown tail. Remember to feel the orbital rim and protect it with a finger
avoiding migration of the filler to the upper eyelid. We suggest to not to perform
an overcorrection of the eyebrow with filler to avoid excessively prominency and possible
eyelid edema; if necessary, we suggest to do another session at least 15 days from
the first ([Fig. 4]).[16] In some cases, it is possible to have a postinjection headache and discomfort with
mastication, which generally resolves spontaneously within 24 to 48 hours.[17]
Fig. 4 Needle injection in a preperiosteal plane just above to the supraorbital rim.
Malar Region
Assessment
The malar region is responsible for the shape of the lateral segment of the middle
third of the face. Ideally it should appear round and full, since a flat hypoplastic
malar region makes the face appear dull and contributes to a premature aged look.[18] It is well known that strong cheekbones make the face appear youthful.[19]
Anatomy
In this region, five different layers are present: the skin, the subcutaneous fat
tissue, the SMAS, the deep fat compartments, and the deep fascia. However, these layers
can differ a lot as the skin can be very thin and the subcutaneous tissue almost assent
reaching the infraorbital region.[20] The subcutaneous fat is represented by seven bilaterally distinct subcutaneous fat
compartments that are separated by delicate fibrous septae. The SMAS connects the
mimetic muscles in a way that they can act together and represents the cranial prolongation
of the platysma it continues in turn superiorly with the temporoparietal fascia. Between
the SMAS and the deep fascia is possible to identify the deep fat compartments that
include the deep infraorbital fat pad and the medial and lateral suborbicularis fat
pad.[21] The blood supply of this region is principally given by the infraorbital artery,
which originates from the infraorbital foramen; this is localized ∼6 to 8 mm inferiorly
to the arcus marginalis.[22]
Dangerous Zone
In this area, the primary danger zone is represented by the infraorbital foramen that
should be carefully localized and marked before any treatment. A lateral approach
is always advised when injecting with a needle in the deep plane as the bony hood
over the foramen may add protection when using a lateral approach. In addition, particular
attention should be paid to not inject to near to the lid–cheek junction because the
periorbital area is considered a high-risk area due to multiple communications between
the internal and external carotid circulations. The most important complication to
be aware also in this area is embolization of the ophthalmic artery, which can lead
also to blindness. Generally, to minimize the risk of intravascular injection, regardless
of instrument, filler should only be injected under low pressure, in a discontinuous
and retrograde manner.
Technique
For a harmonious result to treat this region, ∼0.5 to 1 mL hyaluronic acid fillers
are maximal required. Also, for the zygomatic malar region considering the deep injection,
plane fillers with a higher G' are preferred.
The first thing to do when treating this region is to identify the maximal projection
of the cheekbone. Ideally, this position should be identified 10 mm lateral and 15 mm
inferior to the lateral canthus. However, drawing a simple line from the alar base
to the tragus and from the mouth angle to the lateral cantus can help identify this
area, already elsewhere identified as G Suspension Point (GSP) point.[23] We utilize a needle (27 gauges, 14 mm length) for supraperiosteal injections entering
90 degrees the skin. Inaccurate needle angulation carries high risk of vascular compromise
([Fig. 5]).
Fig. 5 Needle injection in a supraperiosteal injections in a point of line intersection.
Before placing the bolus of filler aspirate for 4 to 6 seconds while stabilizing the
needle tip. In addition, slow injection speed and low extrusion force are mandatory.
When clinically indicated, place an additional bolus anterior and then posterior to
the first point and to add volume the malar eminence. This will also allow a nice
and more gentle transition.[24]
Nasolabial Region
Assessment
The nasolabial region plays a decisive role in the aesthetics of the middle third
of the face itself; its characteristics varies depending on race, gender, age, and
weight but usually the nasolabial fold has to be not so marked to have a younger appearance,
while a deep nasolabial fold contributes to an older look.[25] In young people, this fold is usually observed during smiling, but as we age the
nasolabial fold becomes to be deeper, due to tissues ptosis, to the volumetric reduction
of the fat compartments and also to regional bony atrophy.
In this region, fillers are generally primarily used. In general, deep nasolabial
folds do not disappear after filling but become milder. Therefore, it should always
be explained to the patient beforehand that the aim is to soften the groove rather
than eliminate it.
Anatomy
The nasolabial fold is a thin and linear depression that extends lateral from the
alar cartilage, and descends in a diagonal, to the angle of the mouth. This line does
not represent a simple cutaneous fold, but instead a true anatomical border between
the cheek and lips; moreover, it represents an anchorage area for the facial expressions
muscles that connects to the dermis, resulting in a change of subcutaneous architecture
where no clear distinction between muscle fibers, fat, connective tissue, and skin
can be seen.[26]
At the nasolabial sulcus level, beneath the skin, it is possible to identify two distinct
fat compartments, which belong to the six fat compartments that characterize the mid-face,
the superficial nasolabial, and the deep medial cheek fat compartment. The first one
is placed medially to the nasolabial fold and laterally to the mid-cheek groove, and
his upper boundary forms the lower edge of the tear trough, while the medial border
forms the lateral line of the nasolabial fold. Instead, the deep medial cheek fat
compartment is located below and medial to the suborbicularis oculi fat pad and below
the mid-cheek groove.[4] Under the fat compartments, we find a muscular layer; at the nasolabial sulcus,
it is possible to identify the malar levator muscle, a tubular muscle placed between
the orbicularis oculi muscle and levator labii superioris alaeque nasi muscle.[27] The vascularization is provided by the facial artery and its branches: the inferior
and superior labial, inferior alar, lateral nasal, and angular arteries. The venous
drainage is provided by the facial vein and its tributaries. The nasolabial area has
both sensory, provided by the infraorbital nerve, and motor innervation, supplied
by the buccal branch of the facial nerve.[28]
Dangerous Zone
The major risk in the nasolabial region is represented by the injection into the nasolabial
artery; which is closely associated with the location of the nasolabial fold. The
nasolabial fold is the second most common injection site for tissue necrosis and the
third most common site leading to visual loss. To prevent this complication, it is
very important to know the depth and course of the artery. The artery travels medial
almost parallel to the nasolabial fold. In the lower two-thirds, it tends to be in
a deeper plane below the muscle or in the deeper plane above the muscle, while in
the upper third it tends to become more superficial, near the alar base.[29] It is important to consider that in a fuller face, the facial artery is more lateral
in the upper third of the nasolabial fold and in a face with more periapical hypoplasia,
the facial artery is more medial. In consideration of the facial artery that generally
travels medial to the nasolabial fold, the key in augmenting the nasolabial fold is
to stay slightly lateral to the fold to prevent vascular complication.[30]
Technique
To archive a harmonious transition between the cheek and lips, not a deep marked nasolabial
fold ∼1 to 1.5 mL filler per side is required. It is preferable to use a high or medium
G' type of hyaluronic acid; however, patient's evaluation is mandatory.
We suggest to use a blunt cannula (25 gauges, 50 mm length) to treat the inferior
and middle third of nasolabial fold entering at the modiolus[31]; here, the injection has to be placed at a superficial plane direct under the skin.
It is possible to use two different techniques to inject: the linear threading or
fanning technique ([Fig. 6]).
Fig. 6 Cannula injection, to treat the inferior and middle third of nasolabial fold, entering
at the modiolus; the injection has to be placed at a superficial plane direct under
the skin.
While we recommend to use needles only for the upper portion (27 gauges, 14 mm length),
in particular the pyriform fossa filling deep to the bone because here the vascular
component is superficial.[32] If larger quantities of filler are required, it is advisable to perform the injections
in different times to avoid hypercorrections and above all deformities visible during
facial expressions ([Fig. 7]).
Fig. 7 Needle injection, to treat the upper third of nasolabial fold; the injection has
to be place deep to the bone because here the vascular component is superficial.
Jaw Region
Assessment
A well-defined jawline starts from the angle of the jaw and ends at the chin, giving
a perception of beauty and youth; while the presence of breaks, for example, at the
level of the labiomandibular sulcus gives an aging and unattractive aspect.[33] Moreover, the jawline can define and enhance the feminine and masculine characteristics;
in a female a softer jaw angle with a more oval shape is preferred, while in a male,
it should ideally be square with a pronounced jaw angle.[34] Also, the chin plays a role in the jawline and should ideally be sharp, round, and
delicate in a female and larger and stronger in male patients. Furthermore, treating
the jawline can produce a lifting effect also of the neck.
To correct and define the jawline, hyaluronic acid fillers are primarily used; however,
in the chin area combination therapies with botulinum toxin can give also better results.
Anatomy
Anatomically speaking, the chin and jaw line have to be considered as two separate
entities, even though these form a closely associated aesthetic unit. The jawline
represents the area from the menton (most protruding part of the chin) and the gonion
(the angle of the mandible). In this region, we can also identify four different fat
compartments: the superior and inferior mandibular fat compartments are over the inferior
mandibular border, the submandibular fat compartment, and the last that covers the
parotid-masseteric fascia.[7] The superior and inferior superficial jowl compartments are divided from the more
caudal submandibular fat compartment by the platysma mandibular ligament (PML). Cranially
to the PML, we can find another important ligament: the mandibular osseocutaneous
ligament, which has a role in the aging processes since it contributes to the tissue's
stability of the mandibular region. Regarding the muscles in this region, the platysma
is situated superficially, while deeper there is the masseter, this last one has anatomical
relationship with the buccinator anteriorly and with the parotid gland posteriorly
from which departs the Stenson's duct that crosses both the masseter and the buccinator
ending in the oral cavity.[35] The facial artery, with its vein, lies deep to the platysma, and represents the
most important vascular anatomical structure of the jawline region; the anterior boundary
of the masseter is a good reference point to identify it, normally to 1 cm anteriorly
from it. However, variations in this artery are not so rare, therefore relevant for
injections.
In the chin region, following layers are present: the skin, superficial fat compartment,
muscles, deep fat compartment, and bone. The skin is thicker and richer in sebaceous
glands when compared with the jawline skin. In this area, we find only one fat compartment
that is delimited by the mentolabial groove superiorly, the submental ligaments inferiorly
and the labiomandibular grooves laterally; while the muscular component is represented
by the orbicularis oris, the depressor labii inferior, the depressor anguli oris,
and the mentalis. The mental and submental arteries, which are branches of the inferior
alveolar artery and facial artery, respectively, supply the chin.[36]
Dangerous Zone
The primary danger zone is at the level of the mandible body at a deep plane; generally,
0.3 to 1 cm anterior to the border of the masseter muscle is possible to identify
the facial artery and vein, which can also be palpated. To avoid complication, also
here, we suggest using a cannula and to remain in a subcutaneous plane avoiding so
to go to deep.[37] Instead, at the level of the chin we can find the submental artery. This artery
originates from the facial artery and can anastomose with the arteria mentalis. Therefore,
chin augmentation warrants a deep injection in the midline to avoid the paramedian-located
branches of the mental and submental arteries.
Technique
When aiming to define the jawline starting from the chin until the mandible angle,
the necessary quantity of hyaluronic acid filler can vary strongly from patient to
patient, therefore, starting from 0.5 to 1.5 mL can be utilized per side.
To treat this area, there are different approaches that can be combined with each
other using either a needle or/and a blunt cannula. In our experience, to treat the
mandible angle, the prejowl area and the chin hyaluronic acid fillers with a high
G' give the best results also considering a good resistance to deformation without
compromising the volume effect.[38] Usually primarily a supraperiosteal bolus of filler is placed with a needle direct
over mandibular angle with an injection angle of 90 degrees ([Fig. 8]). Here, we prefer to use a needle (27 gauges, 14 mm length) because we want to place
a deep bolus and with a needle it's much easier. In female patient caution should
be placed to not exaggerate with this bolus since this tends to masculinize the face.
If a greater lifting effect is required, at the same access level, an injection of
filler with a blunt cannula (25 G cannula, 50 mm in length) allows to better definite
the jaw. In this case, small aliquots are injected with a retrograde and fanning technique
in the subcutaneous plane to create a smooth mandibular border and to lift and pull
the jowl ([Fig. 9]). Furthermore, the canula offers the advantage of its length and since the area
is wide we require a single-access point.[39] Considering the prejowl area, it is very important to fill the depressed area; this
area has a triangular form and extends from the mental foramen to the midlateral zone
of the mandible. Also, here the blunt-tip cannula is suggested, once again with a
retrograde fanning technique. In this area, the canula is very important considering
the presence of the mental artery and vein ([Fig. 10]).
Fig. 8 Needle injection in a supraperiosteal plane at the level of mandibular angle with
an injection angle of 90 degrees.
Fig. 9 Cannula injection, at the same access level, in a subcutaneous place, to create a
smooth mandibular border and to lift and pull the jowl.
Fig. 10 Cannula injection, with a single access point, allows to fill the triangular depressed
area extend from the mental foramen to the midlateral zone of the mandible.
Regarding the chin if the only objective is to improve the projection, the filler
should be placed mainly in the anterior portion, for more length otherwise in the
pogonion, in both cases, the product is placed deep supraperiosteal. In most cases,
a single injection point with the needle (27 gauges, 14 mm length) is used direct
at the level of the midline of the chin; however, from this point two more lateral
bolus at the same depth can be placed. In all cases, we suggest using two fingers
to pinch the treated area to avoid not desired displacement of the filler ([Fig. 11]).
Fig. 11 Needle supraperiosteal injection at the level of the midline of the chin.
In some cases with very intensive mentalis muscular activity, we suggest to utilize
botulinum toxin at least 2 weeks before using hyaluronic acid filler to relax the
muscle and avoid displacement of the filler. Lastly, for obtaining a good projection
of the chin, it is also important to consider the lower perioral area for the presence
of a pronounced labiomental sulcus or marionette lines.
