Anatomy of the Platysma Muscle

Pharmacologically Induced Accommodation Palsy and the Bioelectrical Activity of the Muscular System: A Preliminary Investigation

The aim of this study was to pharmacologically induce accommodative paralysis and evaluate its effects on the bioelectrical activity of the muscular system. The study included two participant groups: those with myopia and those with normal vision (emmetropes). Electromyographic assessments were performed using the Noraxon Ultium DTS 8-K MR 3 myo Muscle Master Edition system. The muscles analyzed in this study were the temporalis, masseter, sternocleidomastoid, trapezius, abdominal muscles, biceps brachii, and the external oblique muscles of the abdomen. It is important to acknowledge that, based on the current findings, it cannot be definitively stated that the observed effects have clinical significance, and additional studies are encouraged.

The Platysma Contraction Pattern in Healthy Adults: A Vector Analysis Study

BACKGROUND

The platysma muscle's role in lower face dynamics is complex. Multiple insertion points to soft-tissue structures at various levels in the lower face create a multifaceted contraction pattern. To avoid adverse effects in cosmetic procedures when targeting the platysma, its anatomy and physiology must be understood. Clinical observations hint at a bidirectional contraction pattern.

METHODS

Eighteen healthy volunteers (13 women and five men) with a mean age of 44.2 ± 10.1 years were enrolled. Skin displacement vector analysis was used on maximal platysma contraction to characterize and calculate the movement of the neck and lower face skin.

RESULTS

In all of the participants, a bidirectional movement of the skin was observed: the skin of the lower face and inferior to the jawline moved caudally, whereas the skin of the lower neck moved cephalad. Both movements converged at a line situated at 54% ± 10% and 55% ± 8% of the length between the clavicle and the inferior base of the ear lobe in men and women, respectively ( P = 0.70).

CONCLUSIONS

The platysma is a bidirectional muscle with a line of convergence. Whereas the superior portion acts as lip depressor, the lower portion elevates the skin of the upper chest and lower neck. This transition can explain some of the clinically observed adverse effects of neuromodulation of the neck area. It can potentially direct neuromodulation injections to focus above the convergence line to better address lower face descent.

Cone-Beam Computed Tomography for Objective Diagnosis of Age-Related Soft Tissue Changes in Lower Face and Neck

BACKGROUND

An objective assessment of the causes of age-related contour deformities of the soft tissues of the face and neck is very important in esthetic surgery, especially as minimally invasive techniques gain increasing popularity.

METHODS

To visualize the tissues that cause age-related soft tissue changes, we performed cone-beam computed tomography (CBCT) in 37 patients who underwent facial and neck rejuvenation procedures in 2021-2022.

RESULTS

Vertical CBCT enabled visualization of the causes and degree of tissue involvement in age-related changes in the lower third of the face and neck. CBCT showed the location and condition of the platysma (hypo- [ptosis], normo-, or hyper-tonus), position, thickness, and location (above and/or below the platysma) of fat tissue, presence of ptosis of the submandibular salivary glands, condition of the anterior bellies of the digastric muscles, and the degree of their participation in contours of the cervicomandibular angle, and location of the hyoid bone. Moreover, CBCT enabled demonstrating for the patient the facial and neck contour deformations and discussing the suggested corrective methods using a clear objective visual image.

CONCLUSIONS

CBCT in the upright position enables objective assessment of each soft tissue in the age-related deformity of the cervicofacial region and provides an opportunity to plan the appropriate impact on the particular anatomical structures during rejuvenation procedures and estimate their results. This is the only study to date to objectively and clearly visualize the entire topographic anatomy of the soft tissues of the face and neck vertically for plastic surgeons and patients.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Distribution of the Nerves and Arteries of the Platysma for Clinical Applications

This study aimed to provide anatomical data on the platysma for clinical procedures. The authors obtained 25 specimens from 15 adult Korean cadavers (9 men, 6 women; mean age, 72 years; range, 61-85 years). Lines connecting the gonion with the gnathion (G-GN) and the acromial end (acromial end of the clavicle) with the sternal end (sternal end of the clavicle) were used as references. Modified Sihler staining was used to trace the nerves distributed in the platysma. The superior border values of the platysma were 12.1 ± 2.7 mm, 31.5 ± 5.3 mm, 42.4 ± 5.6 mm, and 61.7 ± 6.4 mm, respectively, for sections 2 through 5 on the G-GN line. The inferior border values of the platysma were 83.6 ± 19.1 mm, 80.1 ± 14.0 mm, 74.8 ± 14.5 mm, 67.2 ± 13.7 mm, and 54.6 ± 7.1 mm, respectively, for the 5 sections on the acromial end of the clavicle-sternal end of the clavicle line. In the hyoid bone, cricoid cartilage, and jugular notch, the mean distance between the bilateral platysma was 14.4 ± 2.2 mm, 22.6 ± 10.6 mm, and 51.1 ± 15.7 mm, respectively. The mean angle at the cervical branch of the facial nerve and the anterior border of the sternocleidomastoid muscle sternal head was 28.7 ± 2.6 degrees and 53.4 ± 7.7 degrees from the G-GN line, respectively. The upper third of the platysma was supplied by branches of the facial artery and submental artery. The middle third was supplied by branches of the occipital artery and received its direct blood supply from branches of the external carotid artery. The lower third was supplied by branches of the transverse cervical artery. The authors hope that the results of this study will be helpful for rejuvenation procedures of the neck.

Delineation and histological examination of the intramuscular innervation of the platysma: Application to botulinum neurotoxin injection

This study aimed to identify the whole innervation pattern of the platysma using the Sihler's staining, and the axonal composition profile of the sensory-motor anastomosis identified by immunofluorescence assays. The findings provide a comprehensive understanding of the neural anatomy of the platysma and facilitate efficient and safe manipulation for neurotoxin injection. Ten fixed and two fresh hemifaces were included in this study. Sihler's staining was used to the study 10 fixed hemifaces and two fresh hemifaces were used for immunofluorescence assays. In all cases, the cervical branch of facial nerve (Cbr) broadly innervated the platysma, and the marginal mandibular branch of facial nerve (MMbr) provided supplementary innervation to the uppermost part of the platysma. The transverse cervical nerve (TCN), great auricular nerve (GAN), and supraclavicular nerve (SCN) were observed in the lower half of the platysma. In 30% of all cases, there was a communicating loop between the Cbr and TCN. In 20% of all the cases, a communicating branch joined between the Cbr and GAN. For successful esthetic rejuvenation procedures, a clinician should consider the Cbr distribution to the overall platysma and additionally innervation by individual nerves (MMbr, GAN, TCN, and SCN) to the middle and lower portions of the platysma muscle.

Treatment of Facial Flaccidity and Sagging after Botulinum Toxin A Injection into the Masseter

BACKGROUND

Botulinum toxin A injection for masseter reduction is generally considered minimally invasive, safe, and effective. However, this approach may lead to facial flaccidity and sagging, especially in older patients with reduced elasticity of the skin and the soft tissue.

METHODS

The authors analyzed 27 cases of patients who presented with the above complications and treated them with botulinum toxin A injections into the platysma and the depressor anguli oris muscle. The efficacy of treatment was evaluated by both patients and physicians.

RESULTS

Ninety-six percent of patients were satisfied with the treatment outcome. One patient considered the treatment outcome unsatisfactory because of the lack of significant improvement in nasolabial folds. Physician evaluation suggests significant improvement in all patients, including the one who considered the treatment outcome unsatisfactory.

CONCLUSION

Botulinum toxin A injection into the platysma and the depressor anguli oris muscles is a safe, convenient, and effect treatment to correct the complication of facial flaccidity and sagging after masseter reduction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

The Underappreciated Role of the Platysma Muscle in the Perioral Expressions in Young Adults

BACKGROUND

The platysma is involved in lower face movement, yet limited information on its functional role when making perioral expressions is available.

OBJECTIVES

The aim of this study was to use 3-dimensional (3D) photogrammetry to analyze platysma activity when making expressions.

METHODS

Standardized frontal-view 3D images were obtained from 54 volunteers. Three perioral expressions were analyzed: a full smile, mouth corner depression, and a grimace to show the lower teeth. Positive volume change in the "heat map" of the neck skin surface-determined by the superimposed image subtraction technique-served as a sensitive indicator of platysma contraction.

RESULTS

When making the 3 expressions, the proportions of platysma contraction were 42.6%, 75.9%, and 92.6%, respectively. The platysma worked as a more critical dynamic force than expected. In most smiles involving the platysma, its upper portion contracted. With the laterally downward traction on the lower lip increasing, the upper and lower portions of the platysma contracted together and formed muscular bands. The platysma contracted extensively in the other 2 expressions. In some cases, platysma bands were observed to form due to vigorous contraction of muscle fibers. In addition, the platysma was found to be highly functionally active in young individuals.

CONCLUSIONS

This study introduced a simple method that can sensitively identify the functional status of the platysma. The results showed the platysma's highly active function in perioral expressions in young adults. These findings may assist surgeons in personalized decision-making toward platysma muscle-weakening strategies and work as an objective tool for outcome evaluation.

LEVEL OF EVIDENCE: 4

Atavistic and vestigial anatomical structures in the head, neck, and spine: an overview

Organisms may retain nonfunctional anatomical features as a consequence of evolutionary natural selection. Resultant atavistic and vestigial anatomical structures have long been a source of perplexity. Atavism is when an ancestral trait reappears after loss through an evolutionary change in previous generations, whereas vestigial structures are remnants that are largely or entirely functionless relative to their original roles. While physicians are cognizant of their existence, atavistic and vestigial structures are rarely emphasized in anatomical curricula and can, therefore, be puzzling when discovered incidentally. In addition, the literature is replete with examples of the terms atavistic and vestigial being used interchangeably without careful distinction between them. We provide an overview of important atavistic and vestigial structures in the head, neck, and spine that can serve as a reference for anatomists and clinical neuroscientists. We review the literature on atavistic and vestigial anatomical structures of the head, neck, and spine that may be encountered in clinical practice. We define atavistic and vestigial structures and employ these definitions consistently when classifying anatomical structures. Pertinent anatomical structures are numerous and include human tails, plica semilunaris, the vomeronasal organ, levator claviculae, and external ear muscles, to name a few. Atavistic and vestigial structures are found throughout the head, neck, and spine. Some, such as human tails and branchial cysts may be clinically symptomatic. Literature reports indicate that their prevalence varies across populations. Knowledge of atavistic and vestigial anatomical structures can inform diagnoses, prevent misrecognition of variation for pathology, and guide clinical interventions.

Essential Surgical Anatomy for Facelift

It is crucial for a facelift surgeon to have a comprehensive understanding of ageing-related changes on the volume, elasticity, and relative position of various facial tissues and layers. These changes lead to an alteration in the surface topography, contour, and ultimately shape of the face. The depressions and sagging of tissues created as a result of ageing then has a bearing on one's perceived age. This article describes the various layers of the face and neck affected by ageing. The fat compartments, superficial musculoaponeurotic system (SMAS), potential facial spaces, facial ligaments, and facial nerve are discussed in detail. Safe and effective execution of facelift requires a thorough understanding of the intricate relationship between the various layers of face and neck, in particular the path of facial nerve, as it negotiates between these layers. The emphasis of this article is on integrating this knowledge to generate practical tips for safe dissection, effective tissue movement, and repositioning during various type of facelift procedures.

Anastomoses (Superficial Cervical Ansa) Between the Cervical Plexus and Peripheral Facial Nerve Branches: Implications for Regional Anesthesia in Carotid Endarterectomies - Anatomical Study

Purpose

Sensory innervation in the carotid triangle involves the cervical plexus, cranial nerves, and the sympathetic trunk. This innervation also applies to skin incision, including various anatomical structures with potentially different innervation, such as the skin (dermatomes), the platysma (myotomes), and the superficial layer of the cervical fascia (fasciotomes), as well as retromandibular retractor insertion (co-innervation: V, VII). The aim of this anatomical study was to develop an injection technique for carotid endarterectomies to additionally block anastomoses between the transverse cervical nerve (TCN), the cervical branch VII (CB VII), and the marginal mandibular branch VII (MMB VII). These anastomoses are also termed superficial cervical ansa (SCA).

Materials and Methods

Preparations (n=16) were performed on unembalmed donor cadavers (n=8). Subplatysmal injections (each using 5 mL of Alcian blue) were performed cranially within the carotid triangle between the anterior margin of the sternocleidomastoid muscle and the submandibular gland.

Results

Anastomoses between the TCN, CB VII, and MMB VII were stained in all preparations (n=16).

Conclusion

This anatomical study presents an ultrasound-guided subplatysmal SCA block to optimize, in addition to a cervical plexus block, the quality of anesthesia for carotid endarterectomies.

Platysmal Lineaments of the Neck With Emphasis on Endoscopic Endocrine Surgery

BACKGROUND

In endoscopic neck endocrine surgery, the subplatysmal plane is an anatomic key structure that must be identified and preserved, to progress with the dissection. We define the prevalence of platysma, in the intermediate plane of the anterior cervical region, and evaluate potential statistical correlations with clinical and pathologic variables.

MATERIALS AND METHODS

The study included patients who had thyroid surgery. Morphologies, asymmetry, and patterns of the platysma were described. The analysis of the different considered variables was quantitative and qualitative, using multiple data reports.

RESULTS

A total of 23 men and 90 women, aged 19 to 70 (median 41±19) years constituted the study cohort. Their neck circumference and height were 388.5±45 mm (334 to 479 mm) and 200±30 mm (160 to 270 mm), respectively. The hemi-platysmal muscle was bilaterally identified in 109 (96.4%). The mean platysmal thickness was 2.7±1.7 mm (range: 0.7 to 8.2 mm). The intermediate plane between the platysmal muscles was classified into 4 types, depending on the muscle features in the midline: Type A: the left and right platysmal fibers were interlaced with each other in the midline (7%); type B: the platysmal fibers were disconnected by <1 cm (27%); type C: between 1 and 3 cm (52%); and type D separated >3 cm (14%).

CONCLUSIONS

We provide descriptive characteristics of the cervical platysma. A better understanding of the anatomic variability in cervical platysma may be useful in performing a more accurate dissection in endoscopic endocrine neck surgery.

The "Segmental SMAS Model": A Didactic Concept of Face and Neck Lift Anatomy

Profound understanding of the surgical anatomy of the face and neck is the key to successful face lift surgery. The "Segmental SMAS Model" presented herein is the result of a decade-long effort in teaching fellows a logical and coherent anatomic model of face lift anatomy. The superficial musculo-aponeurotic system (SMAS) consists of segments with distinct surgical characteristics. These are determined by the presence of a deep gliding plane and/or adhesion through fibrous insertions. In this article, we define SMAS segments that are profoundly heterogeneous in their behavior and have surgical implications on the maneuvers required for a deep plane face lift. The present model introduces several novel interpretations of the surgical anatomy of the face and neck lift procedure and hopes to convey a better understanding of face lift anatomy to training surgeons.

Applied Anatomy for Botulinum Toxin Injection in Cosmetic Interventions

Purpose of Review

To provide the reader with a clear overview of facial anatomy as it relates to injection of botulinum toxin.

Recent Findings

The review suggests the presentation of multiple combinations of facial musculature, with the forehead, glabellar, and nasal base areas as particular areas of variation. Differences in musculature result in different wrinkling patterns; with age, these changes first become apparent in the upper face, particularly in the forehead and glabellar area.

Summary

Botulinum toxin is well suited to achieve the optimal outcome: it is popular, safe, and non-invasive and presents with few adverse effects. Though limited, when adverse effects do arise these are primarily related to poor injection technique, often fuelled by poor anatomical knowledge. For clinicians to achieve the best outcomes with botulinum toxin use, an understanding of the facial muscles’ anatomy, actions, and interactions is key. This paper discusses the broad and intricate detail regarding the key target muscles of botulinum toxin, based on both literature review and cadaveric dissection carried out by the authors.

Incorporating Midline Platysmaplasty with Lateral Superficial Muscular Aponeurotic System Facelifting

Management of the platysma is key to achieving an ideal neck contour during rhytidectomy. This article reviews platysmal anatomy, indications for platysmaplasty, preoperative patient assessment, surgical technique for midline platysmaplasty, postoperative management, long-term outcomes, and the senior author's experience and philosophy on midline platysmaplasty in the setting of lateral superficial muscular aponeurotic system facelifting.

Platysmaplasty: Is it Possible to Pull the Platysma Effectively in the Medial or Lateral Direction?

The aim of this study was to investigate whether it is possible to pull the platysma effectively in the medial or lateral direction (medial platysmaplasty and lateral platysmaplasty) and to explore the anatomical basis of those findings.Six hemifaces from 3 fresh cadavers were dissected. After skin removal, the platysma was pulled upward and in the medial or lateral direction with the ulnar side of the palm. Its mobility was checked. In 2 volunteers, using wooden bar, the skin overlying platysma was pulled in superomedial and superolateral direction.The platysma ran diagonally from the acromio-deltoid region to the perioral and submental area. In all hemifaces, the platysma was attached to the mandible along its course. The platysma inserted into the mandibular body. At its medial portion (approximately halfway medially from the mentum to the angle; 4-5 cm), the attachment was so firm that it could not be moved horizontally. The posterolateral portion of the platysma was indirectly attached to the mandible and movable. In cadaver, platysma did not move much when it was pulled in the medial direction. In the lateral direction, however, platysma did move well. In living body, when skin overlying platysma was pulled in superomedial direction and superolateral direction, 3 points marked on mandibular border moved about 1.5-2.0 cm and 2.0-2.5 cm respectively.It is thought that medial platysmaplasty can correct anterior neck deformities and redistribute neck skin mainly in the submental area, while that lateral platysmaplasty can pull the cheek skin in superolateral direction.

Motor cortex representation of deep and superficial neck flexor muscles in individuals with and without neck pain

Sensorimotor control of neck muscles differs between individuals with and without pain. Differences in the primary motor cortex (M1) maps of these muscles may be involved. This study compared M1 representations of deep (DNF) and superficial (SNF) neck flexor muscles between 10 individuals with neck pain (NP) and 10 painfree controls. M1 organisation was studied using transcranial magnetic stimulation (TMS) applied to a grid over the skull and surface electromyography of DNF (pharyngeal electrode) and SNF. Three-dimensional maps of M1 representation of each muscle were generated. Peaks in the SNF map that represented the sternocleidomastoid (SCM) and platysma muscles were identified. Unique centre of gravity (CoG)/map peaks were identified for the three muscles. In comparison to painfree controls, NP participants had more medial location of the CoG/peak of DNF, SCM, and platysma, greater mediolateral variation in DNF CoG (p = 0.02), fewer SNF and DNF map peaks (p = 0.01). These data show that neck flexor muscle M1 maps relate to trunk, neck, and face areas of the motor homunculus. Differences in M1 representation in NP have some similarities and some differences with observations for other musculoskeletal pain conditions. Despite the small sample size, our data did reveal differences and is comparable to other similar studies. The results of this study should be interpreted with consideration of methodological issues.

The Rejuvenating Effect and Tolerability of an Auto-Cross-Linked Hyaluronic Acid on Décolletage: A Pilot Prospective Study

BACKGROUND

A novel auto-cross-linked hyaluronic acid formulation (HA-ACP) has been proposed as a treatment for skin rejuvenation. This prospective pilot study aims to assess its tolerability and performance in the treatment of skin aging of the décolletage.

METHODS

Fifteen women (mean age 49.0 ± 8.0  (range 30-65)) who complained about the appearance of their décolletage were prospectively enrolled and treated with three sets of HA-ACP (IAL-SYSTEM ACP®) intradermal injections, administered three weeks apart. Control visits followed at 80 and 120 days from enrollment. The rejuvenating effect was assessed using the Beagley-Gibson and Fabi-Bolton scores. The investigators and the subjects also subjectively assessed skin appearance using a 1-10 scale. The rejuvenating effect and its persistence were assessed comparing the scores collected at the different experimental times by means of Wilcoxon rank tests. Adverse events and their duration were recorded and compared to those reported in the literature.

RESULTS

The HA-ACP formulation provided a significant improvement according to the Beagley-Gibson score (p < 0.005) at all time points. At the 120-day follow-up, the Fabi-Bolton score was significantly improved with respect to baseline (p < 0.05). The rejuvenating effect persisted unaltered between the 80-day and the 120-day visits. At the 120-day visit, the subjects' and investigators' subjective scores were between 8 and 10 in most cases. No unexpected adverse effects were observed. All adverse effects were well tolerated and disappeared over a short period.

CONCLUSIONS

The HA-ACP treatment under investigation is safe, well tolerated, and provides effective and long-lasting décolletage rejuvenation.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Randomized clinical trial of platysma muscle suture versus no suture for wound closure after thyroid surgery

Background

Suturing the platysma muscle during wound closure after thyroid surgery is frequently described in the literature. There is no prospective evidence to support its use or benefit. The aim of this study was to evaluate how a platysma muscle suture influences initial postoperative pain following thyroid surgery.

Methods

Patients were assigned randomly to receive a platysma suture or no platysma suture in this prospective, patient-blinded trial. The duration of follow-up was 6 months. The primary endpoint was wound-specific pain 24 h after thyroid resection. Secondary endpoints were intraoperative and perioperative analgesia requirement, postoperative pain and complications until postoperative day 14, and Patient and Observer Scar Assessment Score (POSAS) 6 months after surgery.

Results

Forty-one patients were randomized to each group. Visual analogue scale scores for wound-specific pain were lower in patients without a platysma suture 24 h after surgery (mean(s.d.) 3·15(1·46) versus 2·17(1·41) in groups with and without suture respectively; P = 0·002). There were no differences in the perioperative and postoperative need for analgesics, postoperative wound complications or cervical scar cosmesis 6 months after surgery (mean(s.d.) POSAS 23·99(9·53) versus 26·51(8·69); P = 0·148).

Conclusion

Omitting the platysma muscle suture after thyroid surgery resulted in less wound-specific pain initially, with no difference in postoperative wound complications or cosmetic results. Registration number: NCT02951000 (http://www.clinicaltrials.gov).

The human platysma contains numerous muscle spindles

The mimic muscles are usually described as containing no muscle spindles. In the present publication the human platysma was reinvestigated concerning its content of corpuscular sensors. Serial sections through the platysma of seven donors revealed numerous muscle spindles but no Pacini corpuscules. The muscle spindles were located in the cranial two-thirds of the platysma, and were evenly distributed with a tendency to have more spindles in the lateral part of the muscle. Immunohistochemical staining with S46 antibodies revealed a predominance of nuclear bag fibers. The results point to an extended function of the platysma as an afferent center of the lower face mimic muscles.