Keywords
beauty and aesthetics centers - neck - neck muscles - submandibular gland - surgery,
plastic
Introduction
Neck aging is characterized by excessive skin, fat accumulation, and muscle sagging,
which is represented by the platysmal bands.[1]
[2] Neck deformity treatment is fundamental for overall facial rejuvenation.[3]
According to Ellenbogen and Karlin,[4] the attributes of a youthful neck are a good definition of the lower border of the
mandible, subhyoid depression, slight visualization of the thyroid cartilage protuberance,
visualization of the anterior border of the sternocleidomastoid muscle, and a cervicomental
angle ranging from 105 to 120°.[5]
The deep plane of the neck has four anatomical structures for evaluation and, if required,
treatment: the platysma muscle (PM), the subplatysmal fat, the anterior belly of the
digastric muscle (DGM), and the submandibular gland (SMG). Deep and superficial neck
structures need treatment to achieve improved facial rejuvenation.[6] Several authors have proposed PM treatment, including Aston,[1] Castro,[2] Connell,[3] and Feldeman.[7] Connell and Shamoun[8] proposed a subplatysmal plane approach through its medial elevation and partial
resection of the anterior belly of the DGM. Guyuron[9] corroborated this procedure, observing that it would enable better retropositioning
of the hyoid bone, resulting in a more acute cervicomental angle.
In 1987, Brazilian surgeon Pina[10] was the first to describe SMG resection after noting the significance of the gland
in cases of ptosis or increased volume compromising the cervical contour. Ptosis and
SMG hypertrophy cause bulging in the anterolateral region of the neck. Later, Connell
and Hosn,[11] Martens and Elyassnia,[12] Auersvald et al.,[13] Bravo,[14] O'Daniel,[15] and Miranda[16] made their contributions to SMG treatment. Studies showed that ptosis is more common
than hypertrophy.[15]
[17] The main reason for the gland descent is the laxity of the supporting structures[13]
[15] including the anterior belly of the DGM. In turn, SMG hypertrophy is related to
chronic alcohol use and overweight.[17]
[18]
Although the literature contains numerous studies on SMG treatment,[10]
[11]
[12]
[13] reports on the volume or weight of the resected gland are scarce. In this sense,
we highlight the publications by O'Daniel,[15] who measured the resected SMG volume by displacing the fluid volume of saline solution
in a syringe, and by McCleary et al.,[17] who calculated SMG volume using magnetic resonance imaging (MRI).
Objective
The current study aimed to measure the weight of resected SMGs and analyze its relationship
with the patients' age and sex.
Materials and Methods
We retrospectively evaluated, throughout 12 months, 44 patients who underwent partial
(that is, the ptosis area) SMG resection, located below the horizontal line formed
by the lower edges of the mandible bilaterally. We measured the weight of the resected
SMG of each patient, bilaterally, on a high-precision digital scale (GP Inox – Gp163).
The study was conducted at a private clinic in the city of Curitiba, state of Paraná,
Brazil, from January to December 2024. The Ethics in Research Committee of Faculdade
Evangélica Mackenzie do Paraná approved the study under number 7,215,665.
Surgical Technique
The surgical technique consists of a 3- to 5-cm incision in the skin and subcutaneous
tissue, approximately 0.5 cm posteriorly and parallel to the submental groove. A careful
lateral and superior dissection enables the release of the mandibular retaining ligament.
Next, we direct the dissection inferiorly in the subcutaneous plane, maintaining approximately
0.5 cm of fat in the skin flap until crossing the last horizontal adhesion fold of
the neck for wide release of all the fixation structures of the flap, or at least
up to the level of the thyroid cartilage. Laterally, the dissection is performed until
it surpasses the lateral border of the PM by approximately 3 cm.
With the dissected flap, we perform an open lipectomy in the preplatysmal plane using
scissors. After exposing and visualizing the decussation of the PM fibers, we elevate
its medial edges laterally to approach the subplatysmal plane (deep neck). Next, we
performe interplatysmal and subplatysmal lipectomy using electrocautery. At this point,
we visualize the anterior belly of the DGM and the SMG ([Figs. 1]
[2]). In cases of hypertrophy of the anterior belly of the DGM, we perform a partial
resection (myectomy) by removing a strip of muscle with a hemostatic clamp ([Figs. 3]
[4]
[5]).
Fig. 1 View of the deep neck muscles: digastric and mylohyoid muscles.
Fig. 2 (A) Digastric muscle; (B) submandibular gland; and (C) bilateral mylohyoid muscle.
Fig. 3 Schematic lateral view of the submandibular gland, the anterior and posterior bellies
of the digastric muscle, the hyoid bone, and the mandible.
Fig. 4 Partial resection of the right digastric muscle.
Fig. 5 Partial resection of the left digastric muscle.
After removing the fat from the deep plane, we observe the ptotic SMG, that is, the
portion below the lower edge of the mandible, and resect it ([Figs. 6]
[7]
[8]). Then, we move the PM away and pull the SMG. We perform a local anesthetic infiltration
with a vasoconstrictor agent in a volume of approximately 1 mL, followed by resection
using hemostatic forceps and electrocautery. We do not use botulinum toxin in SMGs.
Fig. 6 An imaginary line below the lower edge of the mandible serves as a parameter to evaluate
the part of the ptotic submandibular gland for resection.
Fig. 7 Ptotic submandibular gland resection using electrocautery.
Fig. 8 Resected submandibular gland removal.
After treating the fat, the anterior belly of the DGM, and the SMG, we plicate the
PM with 3.0 nylon in the midline, from the chin to the level of the hyoid bone. After
plication, we performe a horizontal myotomy of the PM, with an extension of 2 cm laterally
on both sides. The last step is the suture of the lateral platysma, as described by
Jacono,[19] using the hammock technique, up to the periosteum of the mastoid, with 2.0 Vicryl.
Statistical Analysis
The quantitative variables were expressed as mean, median, minimum, maximum, and standard
deviation values, and the qualitative variables, as frequencies and percentages. The
Student's t-test for independent samples determined the association between the SMG weight and
the patients' sex. Pearson's linear correlation coefficient assessed the association
between the SMG weight and the patients' age. Statistical significance was set at
p < 0.05.
Results
Throughout 12 months, we prospectively evaluated 44 patients, 4 male and 40 female
subjects aged between 41 and 79 years. The weight of the bilaterally-resected SMG
ranged from 6 to 24 g among women and from 14 to 16 g among men. There were 2 cases
of sialoma and 2 cases of hematoma, 1 in men and 1 in women. There were no cases of
nerve injury with paresis of the facial nerve branches.
Evaluation of the association between age and SMG weight
We tested the null hypothesis of a linear correlation between age and SMG weight equal
to zero (that is, no linear association) versus the alternative hypothesis of a non-zero
linear correlation (that is, existence of a linear association). The estimated linear
correlation based on the data was equal to 0.22, providing no evidence to reject the
null hypothesis (p = 0.144). [Fig. 9] shows the results obtained.
Fig. 9 Association of the submandibular gland (SMG) weight and the patients' sex.
Evaluation of the association between sex and SMG weight
We tested the null hypothesis of equal mean SMG weights in both sexes versus the alternative
hypothesis of different mean weights. [Table 1] presents the descriptive statistics of SMG weight in each sex and the p-value of the statistical test. [Fig. 10] shows the results obtained. [Figs. 11]
[12]
[13] present some pre- and postoperative cases.
Table 1
|
Sex
|
n
|
Mean
|
Median
|
Minimum
|
Maximum
|
Standard deviation
|
p-value*
|
|
Female
|
40
|
14.0
|
14.0
|
6.0
|
24.0
|
± 4.4
|
0.093
|
|
Male
|
4
|
15.5
|
16.0
|
14.0
|
16.0
|
± 1.0
|
|
Fig. 10 Association of the submandibular gland (SMG) weight and the patients' age.
Fig. 11 (A) 61-year-old patient, preoperative period, frontal view; (B) 61-year-old patient, 6 months after surgery, frontal view; (C) 61-year-old patient, preoperative period, lateral view; and (D) 61-year-old patient, 6 months after surgery, lateral view.
Fig. 12 (A) 62-year-old patient, preoperative period, frontal view; (B) 62-year-old patient, 8 months after surgery, frontal view; (C) 62-year-old patient, preoperative period, lateral view; and (D) 62-year-old patient, 8 months after surgery, lateral view.
Fig. 13 (A) 64-year-old patient, preoperative period of secondary cervicofacial lift, frontal
view. (B) 64-year-old patient, 8 months after secondary cervicofacial lift, frontal view;
(C) 64-year-old patient, preoperative period of secondary cervicofacial lift, lateral
view; and (D) 64-year-old patient, 8 months after secondary cervicofacial lift, lateral view.
Discussion
Neck treatment without an approach through the submental region to access deep cervical
structures often results in patient and surgeon dissatisfaction and leads to deformities
that are difficult to correct.[21] This approach may be justified in young patients with no cervical involvement and
complaints inherent to the middle third of the face,[22]
[23] but not in cases with signs or complaints of aging of the lower third of the face
and the neck. Regardless of the PM lateral traction strength to provide good cervical
structure support or lift, it is not effective enough due to the size and amount of
deep fat, the potential SMG hypertrophy and ptosis, and DGM sagging. In other words,
this concerns not only strength, but volume and weight as well.[12]
[13]
[14]
[15]
[16] Therefore, our concept is to remove the excess (fat and anterior part of the DGM)
and submental structure (PM plication) and then perform the lifting, or lateral suspension,
of the PM in the mastoid. We do not recommend an anterior belly of the DGM plication
as we only resect the distal and ptotic third of the SMG, and this, in our hands,
would lead to the medicalization of the gland, increasing the cervical midline volume.
Likewise, we do not perform a corset[7]
[13] plication below the thyroid cartilage because this could impair the superior and
lateral range of motion of the PM, as described by Jacono et al.[22] and Pace et al.,[23] and, more recently, by Talei et al.[24] e Brai e Talei,[25] using the crevasse technique. Incidentally, Talei et al.[24] e Brai e Talei[25] perform the same submental sequence proposed herein, corroborating our conduct.
Although the literature contains numerous studies on SMG treatment,[10]
[11]
[12]
[13] reports on the resected gland volume or weight are scarce. We highlight the studies
by O'Daniel,[15] who measured the resected SMG volume by displacing a fluid volume of saline solution
in a syringe; by McCleary et al.,[17] who calculated the SMG volume using MRI; by Saito et al.;[18] and by Swan et al.[26] In the case series of the current study, we measured the weight of the resected
SMG of each patient, bilaterally, on a high-precision digital scale. The weight ranged
from 6 to 24 g among women and from 14 to 16 g among men. It is worth remembering
that we injected local anesthetic with a vasoconstrictor before the resection. The
present study did not demonstrate statistical significance between the resected SMG
volume and patients' age, as the p-value was of 0.14. This data is consistent with those of the study by Swan et al.,[26] who stated that age has no relationship to the SMG size, and those of other studies[17]
[18]
[21] showing SMG ptosis instead of increased volume with advancing age.
While age does not interfere with SMG weight, the patient's sex does, as statistically
proven in the current study (p = 0.093) and consistent with other reports.[17]
[18]
[21] In addition to sex, another coincidence observed in the literature is the relationship
between SMG increase in alcoholics and patients with overweight or obesity.[17]
[18]
[21]
[26] However, we did not collect these data.
Two patients had sialoma and underwent treatment with 20 U of botulinum toxin, with
remission of clinical signs 3 days after application, remembering that we do not use
toxins during surgery.
We use the Auersvald et al.[13] hemostatic net routinely and remove it after 2 days in women and 3 days in men.
Even so, we observed 2 cases of hematoma, 1 in a male patient, and the other, in a
female patient.
We marked the SMG with the patient sitting and by palpating the ptosis area (below
the lower edge of the mandible). During surgery, with the patient in the supine position,
SMG dissection is complex because the gland moves posteriorly and sometimes traction
with forceps causes laceration and bleeding. We perform the infiltration of 1 mL of
local anesthetic with vasoconstrictor as, immediately after dissection, its capsule
emerges and becomes externalized, facilitating its visualization and dissection, with
a lower bleeding risk.
The limitation of the current study is its small sample size, of 44 patients. However,
this number does not differ from those of the literature.[21]
[26] In addition, the sample size was small because the study was conducted at a private
clinic, with all patients operated on by the same surgeon. Another limitation is the
lack of comparison between the body mass index and the SMG size.
Conclusion
We conclude that effective cervical aging treatment should address superficial structures
but, most importantly, deep structures of the neck, including the PM, the subplatysmal
fat, the anterior belly of the DGM, and the SMG through the submental approach, which
presents good esthetic outcomes and a low morbidity rate. In addition, there was no
relationship between age and SMG size, and men presented significantly larger SMGs
than women.
Acknowledgments
The authors would like to thank specially Ruth Graf, PhD, as well as André Auersvald,
MD, the North American surgeons, Dr. Sherrell Aston, Dr. Daniel Baker, and Dr. Ben
Talei, artist Vagner Coelho, and Professor Ari Sabbag.
Bibliographical Record
Lincoln Graça Neto, Susana Puga Ribeiro, Ana Clara Minguetti Graça. Análise da relação
entre o peso da glândula submandibular ressecada e a idade e sexo de pacientes submetidos
a lifting cervical profundo. Revista Brasileira de Cirurgia Plástica (RBCP) – Brazilian Journal
of Plastic Surgery 2025; 40: s00451807723.
DOI: 10.1055/s-0045-1807723
