Keywords: Face - Plastic surgery procedures - Esthetics - Cosmetic techniques - Facial nerve
- Learning curve
INTRODUCTION
Facial aging is a gradual, complex, and multifactorial process. It is the result of
changes in the quality, volume, and positioning of tissues[1 ]
[2 ]
[3 ].
Plastic surgeons have modified their technical approach to patients who wish to
undergo facial rejuvenation, including video endoscopy, cosmetic treatments such as
laser, botulinum toxin, and facial fillers, and extensive knowledge of anatomy,
highlighting the retaining ligaments of the face[4 ]
[5 ]
[6 ]
[7 ]. Retaining ligaments
connect the loose tissues of the face to deep bony structures.
Modern facial surgery was pioneered by Skoog[8 ], who described the elevation of the deep facial cervical
flap to the platysma and superficial fascia of the face. When talking about a deep
approach, Hamra[9 ]
[10 ] and Barton[11 ]
[12 ] added personal
modifications, but maintained the concept of the flap composed of skin with the
superficial muscular aponeurotic system (SMAS)[13 ].
After a better understanding and knowledge of the system of fat compartments, both
superficial and deep, described by Rohrich & Pessa[6 ]
[7 ], added to
publications by Aston[13 ] on FAME
(finger assisted malar elevation), Mendelson et al.[14 ]
[15 ]
described the importance of the facial ligaments and also the subSMAS spaces, the
ligaments forming a complex fibrous support system, and the spaces that are areas
delimited by the ligaments on the sides where no anatomical structures are crossing
inside, that is, they are safe spaces with all nerve branches being outside these
compartments.
More recently, the studies by Jacono[1 ] stood out, which in great detail showed the advantages of
releasing the retaining ligaments from the ptotic tissue of the midfacial third
followed by en bloc traction, fixation, and repositioning at the level of the malar
prominence and the fixed SMAS. The section of the cutaneous zygomatic ligament, the
strongest ligament on the face (according to biomechanical studies)[15 ], allows the elevation and
mobilization of the malar fat pad. Tissue mobilization allows great volumization of
the middle third, which is believed not to be possible with traditional SMAS flap
or
plication techniques, as they would not mobilize the loose tissue
structures[1 ]
[16 ]
[17 ]
[18 ]
[19 ]
[20 ]
[21 ]
[22 ] as studies by Gassner et al.[23 ]
demonstrated histologically, there is no SMAS tissue medial to the zygomatic
muscles.
Characteristics of Mendelson Studies
The ligaments of the face resemble a tree where the trunk are the ligaments that
unite the soft tissues to the facial skeleton, the larger branches cross the
SMAS, and their branches (small branches) connect the SMAS to the sub-dermis
(retinacular cutis fibers), forming a complex fibrous support system[14 ]
[15 ].
The subSMAS spaces are areas delimited by retaining ligaments on the sides where
no anatomical structures are crossing inside; that is, they are safe spaces with
all nerve branches being outside these compartments. As they allow the movement
of loose tissues, there may be sagging in these spaces and not in their limits
where the ligaments are located[14 ]
[15 ]. Dissection
in these areas presents less bleeding, edema, and risk of nerve injury.
Prezygomatic space: covers the zygomatic bone, the zygomatic muscles originate
below the floor, the roof or lining is by the orbicularis oculi muscle and the
SOOF (sub orbicular oculi fat), the upper edge by the orbicularis retaining
ligament (which does not is so resistant) and the lower edge by the zygomatic
ligament (this one is stronger).
Pre-masseteric space: covers the lower ½ of the masseter muscle, the platysma
forms the roof, the posterior edge by the platysma auricular fascia (PAF), the
anterior edge by the masseteric ligaments, and the weakness of the fixation of
the floor formed by the platysma in the inferior masseteric ligament allows the
formation of the jowl.
Limits of the premasseteric space:
a) Base: masseter/additional and anterior triangle;
b) Ceiling: platysma;
c) Later: transition to the PAF;
d) Superior: cutaneous masseteric ligaments;
e) Lower: membrane formed between the PAF and the mandibular ligament;
f) Anterior: membrane formed between the platysma and the masseter.
C) Chewing Space: also called the buccal space, this space contains the buccal
fat and the laxity in this area allows the formation of the nasolabial fold
(NLF).
When the term “deep Smas facelift” was introduced, it referred to subSMAS
dissection, but it was not clear whether it involved the face laterally (here in
the subcutaneous plane) until the transition of the orbicularis muscle and
zygomaticus major muscle on the anterior face[24 ]
[25 ].
Hamra[9 ]
[10 ]
[24 ]
[26 ] described access to the
anterior face through the lower eyelid and zygomatic orbicularis dissection.
Currently, the term compound lifting involves the dissection of the face
anteriorly, always in the subSMAS plane, but with lateral access coming over the
middle 1/3 of the face (mid cheek) used in our study and also recommended by
Jacono[1 ]
[18 ]
[19 ]
[20 ].
Different facelifting techniques offer good results. However, a deeper analysis
allows us to observe that the balance between skin tension and volume or shape
will determine the harmony of the face.
There are 3 areas or layers where tension can be applied to treat sagging: skin,
SMAS, and periosteum. Advantages of subSMAS: spaces are naturally pre-dissected,
fast, bleed little and atraumatic.
Features of Hamra Studies
Initially, Hamra[9 ]
[26 ] described his “Deep Plane”
deep dissection technique that aimed to treat sagging cheek fat that made the
NLF more evident and deeper. Traction superiorly would promote attenuation of
the NLF. One characteristic that stood out was that the fatty tissue was over
the zygomatic muscles, was easy to dissect, and remained connected to the SMAS
(“cheek fat” + platysma).
Evolving over time, he described the Composite Face Lift, which formed a flap
composed of the orbicularis oculi muscle (MOO) + “cheek fat” + platysma. The
incision in the arcus marginalis (junction of the septum with the orbital
rhyme)[10 ].
Finally, he described the Zygomatic Orbicularis Flap and Septal Reset, incising
the orbital septum inferiorly and “redraping” the tissue superiorly, treating
the nasal jugal groove, leaving it more youthful[27 ].
Jowl
The “jowl” is a protrusion of soft tissues in the lower and anterior third of the
face[14 ]
[15 ]
[28 ]
[29 ]
[30 ], being the main stigma of
facial aging[30 ]. Its anterior
limit is the mandibular ligament and the labrum mandibular groove; it is located
in the supraplatysmal plane as a redundancy of the subcutaneous tissue (fat)
covered by facial skin[28 ]. The
subplatysmal anatomical structures are not related to the formation of the jowl,
but the adjacent structures are Bichat fat (buccal fat pad) and the
submandibular gland when very prominent[30 ]. The Auersvald brothers[28 ] believe that the main factors involved in the
formation of the “jowl” are subcutaneous fat, excess skin, descending SMAS
sliding and infiltrating the fat, and Bichat fat.
OBJECTIVE
The objective of this study is to analyze 100 patients operated on using the deep
SMAS (Extended Deep Plane Face Lifting) technique, evaluating its applicability,
effectiveness, morbidity and surgical results.
METHOD
One hundred patients were analyzed between January 2020 and November 2022 who
underwent facial plastic surgery using the deep SMAS technique - “Deep Smas”, and
were followed up for 6 months postoperatively (PO). The study was carried out in a
private clinic in Curitiba-PR, observing the number of complications, number of
reoperations, risks, and advantages of the technique. The study was previously
approved by the Research Ethics Committee of Faculdade Evangélica Mackenzie do
Paraná, with number 5,281,745.
Operative technique
Previous marking with methylene blue on the skin, starting at the contour of the
rib of the hair, going around the entire ear, positioning post-tragal in the
anterior region, in the posterior region at the transition between the turbinate
cartilage and the mastoid, extending to the foot of the hair in the posterior
region.
Skin incision followed by subcutaneous dissection approximately 3 cm anteriorly
to where the transition line for the deep plane is located. This line runs from
the lateral corner of the orbit to the angle of the mandible (gonion) ([Figure 1 ]).
Figure 1. Marking area to be incised in the SMAS, the gateway to the deep
plane.
Access to the subSMAS plane is achieved through a scalpel incision. Next, using
electrocautery, dissection is made in the loose areolar tissue with the branches
of the facial nerve (zygomatic, buccal and marginal of the mandible) being below
this plane protected by the masseteric fascia. It is followed anteriorly with
blunt dissection and release of the masseteric ligaments in the superior,
middle, and inferior pre-masseteric spaces. More superiorly, with the section of
the cutaneous zygomatic ligament, access to the prezygomatic space is gained,
and this allows communication with the premasseteric space. The zygomaticus
major muscle is located in this region, below which the zygomatic branch of the
facial nerve passes. The malar region is suspended after performing
FAME[13 ] using the index
finger ([Figure 2 ]).
Figure 2. FAME - “finger assisted malar elevation”.
Blunt dissection continues anteriorly to the level of the NLF and inferiorly to
the transition of the premasseteric space with the subplatysmal space ([Figures 3 ] and [4 ]). With the entire subSMAS plane dissected, the “cuff” is created,
which is, on average, 2cm, a SMAS flap that will serve as anchorage supporting
the traction of the fasciocutaneous flap ([Figure 5 ]). There are approximately 5 to 6 traction points made with
Vycril® plastic 4.0, starting more inferiorly in a
posterosuperior direction until the fixed SMAS ([Figures 6 ] and [7 ]).
Figure 3. Dissection extended to the nasolabial fold (NLF).
Figure 4. Extensively dissected deep plane: prezygomatic space (A); upper,
middle, and lower masseteric spaces; (B) and masticatory space
(C).
Figure 5. “Cuff.”
Figure 6. Vycril 4.0 stitches fixing the SMAS flap.
Figure 7. Around 6 simple stitches to fix the flap.
The last step is to suture the lateral platysma, as described by Jacono1, using
the hammock technique, to the mastoid periosteum ([Figures 8 ], [9 ], [10 ], and [11 ]). Finally, the excess skin is resected, hemostasis is reviewed,
and drainage with a suction drain, accommodating the tissues without tension,
with simple 4.0 Monocryl sutures in the subdermis and continuous 5.0 nylon in
the skin.
Figure 8. Marking of the lateral platysma.
Figure 9. Opening of the lateral platysma.
Figure 10. Traction of the lateral platysma flap - “Platisma
hammock”.
Figure 11. Fixation of the “Platisma hammock” on the periosteum of the
mastoid.
Statistical analysis
Quantitative variables were described using the statistics of mean, median,
minimum value, maximum value, and standard deviation. Qualitative variables were
summarized using frequencies and percentages. To evaluate the association
between sex and the presence of injury, the Fisher’s Exact test was considered.
The association between age and presence of injury was assessed using Student’s
t-test for independent samples. The association between surgery order and the
presence of injury was assessed using the Cochran-Armitage test. P values lower
than 0.05 indicated statistical significance.
RESULTS
One hundred patients were operated on over 3 years. Age ranged from 41 to 79 years,
mean age of 58.7 years, with 95% female and 5% male ([Tables 1 ] and [2 ]).
Table 1.
N
Average
Median
Minimum
Maximum
Standard
deviation
100
58.7
59
41
79
8,1
Table 2.
Sex
N
%
Feminine
95
95.0%
Masculine
5
5.0%
Total
100
100.0%
The complications were 8 cases (8%) of injuries to branches of the facial nerve, of
which 4 cases of zygomatic injury, 3 cases of mandibular injury, and 1 case of
buccal injury; there was 1 case (1%) of post-auricular keloid; 1 case (1%) of
hematoma ([Figure 12 ]). All nerve injuries were
transient, treated with oral peripheral nerve neuroregenerators and lasting 45 to
60
days.
Figure 12. 44-year-old patient, on the 10th postoperative day, presenting with a
lesion of the mandibular branch on the left.
Regarding surgical revisions, there were 8 cases (8%) of surgical completion due to
patient dissatisfaction due to sagging skin or little projection in the middle third
of the face, which were carried out between 6 and 8 months postoperatively. The vast
majority of patients undergoing surgical revision were over 60 years old (75%)
([Table 3 ]).
Table 3.
Age
Patients
Reviews (%)
<
49
2
1
50-59
17
1
60-69
57
4
70-79
24
2
Total
100
8
Assessment of the association of sex with the presence of injury
The null hypothesis that the probability of the presence of a lesion in female
patients is equal to the probability of the presence of a lesion in male
patients was tested versus the alternative hypothesis of different
probabilities. The table below presents the results obtained in the study, as
well as the p -value of the statistical test ([Table 4 ]).
Table 4.
NN injury
Sex
Feminine
Masculine
N
%
N
%
No
87
91.6%
5
100.0%
Yes
8
8.4%
0
0.0%
Total
95
100.0%
5
100.0%
Assessment of the association of age with the presence of injury
The null hypothesis of the mean age in cases without injury equal to the mean age
in cases with injury was tested versus the alternative hypothesis of different
means. The table below presents the descriptive statistics of age in each injury
classification, as well as the p -value of the statistical test
([Table 5 ]).
Table 5.
NN injury
N
Average
Median
Minimum
Maximum
Standard deviation
p -value*
No
92
58.9
59
41
79
8.3
0.504
Yes
8
56.9
57.5
45
64
6.1
Evaluation of the association between the order of surgery and the presence
of injury
The null hypothesis of an association between the order in which surgeries are
performed and the probability of presence of injury was tested versus the
alternative hypothesis of no association between the order in which surgeries
are performed and the probability of presence of injury. To apply the test, the
surgeries were grouped into classes with 20 surgeries considering the order in
which they were performed. This way, the first 20 were carried out before the
next 20 and so on.
The results obtained in the study are presented in the table below ([Table 6 ]).
Table 6.
Surgeries
Surgeries
% with injury
With NN injury
No NN injury
Total
1 to 20
3
17
20
15.0%
21 to 40
3
17
20
15.0%
41 to 60
1
19
20
5.0%
61 to 80
1
19
20
5.0%
81 to 100
0
20
20
0.0%
Total
8
92
100
8.0%
The result of the statistical test indicated the rejection of the null hypothesis
(p =0.037), providing evidence for the finding that there is
a tendency for the probability of the presence of an injury to decrease as
experience with performing surgery increases.
The results obtained in the study can be seen in the graph below ([Figure 13 ]).
Figure 13. Graph showing the relationship between the percentage of nerve injuries and the number
of surgeries performed.
Below, some preand postoperative cases are presented ([Figures 14 ], [15 ], [16 ], [17 ], [18 ], [19 ], [20 ] and [21 ]).
Figure 14. 63-year-old patient in preoperative profile image.
Figure 15. 63-year-old patient in profile image 6 months
postoperatively.
Figure 16. 63-year-old patient in preoperative frontal image.
Figure 17. 63-year-old patient in frontal image 6 months
postoperatively.
Figure 18. 52-year-old patient in preoperative profile image.
Figure 19. 52-year-old patient in profile image 7 months
postoperatively.
Figure 20. 52-year-old patient in preoperative frontal image.
Figure 21. 52-year-old patient in profile image 7 months
postoperatively.
DISCUSSION
The learning curve was described in 1936 by Wright[31 ] and can be defined as the graphic expression
representing the period of incorporation of new knowledge. In practice, it has been
confused with the number of procedures necessary to reach the point of proficiency,
with the point of proficiency being understood as the moment at which the
optimization of this procedure is achieved or, better said, it is the moment at
which the surgeon can perform the procedure without supervision[32 ].
The Sociedade Brasileira de Vídeo Cirurgia (Brazilian Society of
Video Surgery) establishes the minimum number of procedures performed at 25 for the
surgeon to be considered qualified[33 ]. In plastic surgery, data are sparse, but Tapking et
al.[34 ] reviewed 29 articles
that indicate that the learning curve reaches a plateau between 45-100 cases
operated in breast reconstruction. This translates into a higher success rate,
shorter surgical time, and lower complication rate.
The deep approach in facial surgery, also called deep lifting, subSMAS, or deep
plane, began with the publications by Hamra[9 ]
[10 ] and
Barton[11 ]
[12 ], but it was only after the studies by Mendelson et
al.[14 ]
[15 ] that it was understood that more clearly and in
detail the anatomy of this region. The diffusion and “popularization” of the
technique, so to speak, among plastic surgeons around the world and even among lay
people occurred mainly through the studies of Jacono[1 ]
[18 ]
[19 ]
[20 ].
Both Jacono[1 ] and Mendelson et
al.[14 ] propose the
dissection and approach of the prezygomatic space, all premasseteric spaces, and the
masticatory space. From here onwards, Jacono[1 ] proposes the realization of FAME, but in a different way
from Aston[13 ]. This approaches with
the index finger sliding below the orbicularis muscle to the malar fat pad, while
Jacono[1 ] advises the use of
the index finger over the orbicularis muscle, as a way of protecting the zygomatic
branch of the facial nerve.
Another distinct characteristic occurs in the treatment of the platysma muscle.
Jacono[1 ] proposes blunt
dissection anteriorly to the level of the NLF and inferiorly to the transition of
the premasseteric space with the subplatysmal space. With the subplatysmal
dissection performed both via the middle third of the face and through the lateral
platysma, there is a platysma flap called a hammock platysma (swing hammock) that
will be anchored in the periosteum of the mastoid process with suture threads.
Jacono[1 ] recommends the use of
nonabsorbable monofilament threads to fix the composite flap, with an average number
of 6 sutures. It justifies the use of nylon so that, if in the future there is a new
reintervention of the face, the surgeon can find the threads and that they serve as
a guide or parameter for a new sub-SMAS plane dissection. In this study, absorbable
multifilament 4.0 Vycril® plastic threads were used, which, due to
technical characteristics, would cause a greater inflammatory reaction and
consequently greater adhesion and fixation of the flap than monofilament thread
(nylon). Disadvantages include the risk of visualizing the black nylon threads in
the subdermis and the palpation of knots in the event of a foreign body reaction
(nonabsorbable threads).
The biggest concern for the patient and the facial surgeon is the risk of nerve
injury, which is the reason to avoid some techniques that involve wider dissections
such as subSMAS or deep plane. Despite speculation, most individual case series
consider rates of temporary nerve injury to be between 1% and 2%, regardless of the
technique used. Permanent injuries vary from 0.04% to 0.08%35. Jacono[18 ]
[22 ], in 584 patients, reported 1% of temporary injuries and 0%
of definitive injuries, mainly attributing to the connections between the buccal and
zygomatic branches, the possibility of direct vision of the branches, and the
protection of the parotid masseteric fascia.
In this study, it was observed, after completing the learning curve - that in plastic
surgery, between 45-100 cases[34 ]
can be considered, values equal to those of other techniques and also to those of
Jacono[18 ]
[22 ], with a regressive character tending to 0% in the
last 20 operated cases. Furthermore, there were also no cases of definitive nerve
damage, which is also similar to the literature[18 ]
[22 ]
[35 ] (p =0.037).
Regarding surgical revision rates, Jacono[1 ]
[18 ]
[22 ] cites values between 3% and 5% in more than 2000
cases operated in around 11 years. Moreover, it corroborates its results with the
publication by Kamer & Frankel[36 ], who cite values of 3.3% of surgical revisions in other studies
in which the techniques were SMASectomy, SMAS imbrication, and SMAS plication.
Surgical revisions within 1 year were between 11.4% and 21.7%[36 ]. Jones & Lo[37 ], in turn, showed a 69% recurrence
of flaccidity in the angle of the mandible and cervical region in a 5.5-year
follow-up period. In this study, values of 1% were found in patients under 60 years
old, 4% between 60 and 70 years old, and 2% between 70 and 79 years old. This is
similar to literature data, as Jacono[1 ] mentions that revisions increase in older patients, reaching
100% in patients over 80 years old and 50% in patients between 70 and 79 years
old.
Different facelifting techniques can offer good results, leaving both the patient
and
the surgeon satisfied, and each surgeon needs to develop their own approach that
provides desired and long-lasting results. However, a deeper analysis allows us to
observe that the balance between skin tension and volume or shape will determine the
harmony of the face. The deep approach to facial surgery, also called deep lifting,
subSMAS, or deep plane, provides more effective and long-lasting results with a low
rate of surgical revisions[1 ]
[36 ]
[37 ].
CONCLUSION
The deep facial lifting technique or subSMAS (Extended Deep Plane Face Lifting) has
proven to be effective, providing good aesthetic results, and has a low recurrence
rate and low morbidity rate; however, it requires a long learning curve.
Bibliographical Record
