Anatomy of the Facial Glideplanes, Deep Plane Spaces and Ligaments: Implications for Surgical and Non-Surgical Lifting Procedures.

BACKGROUND: The soft tissue glideplanes of the face are functionally important and have a role in facial rejuvenation surgery. The aim of this study was to improve our understanding of soft tissue mobility of the face and its impact on the redraping of tissues involved in facelifting. The consequences of "no-release" and "extensive-release" lifting were analyzed to explain the difference in efficacy and potential longevity between these two contrasting philosophies. MATERIALS METHODS: Preliminary dissections and macro sectioning were followed by a definitive series of standardized layered dissections on fifty cadaver heads, along with histology, sheet plastination, and mechanical testing. RESULTS: The previously described spaces are potential surgical dissection planes deep to the superficial fascia layer. The classically described retaining ligaments are local reinforcements of a system of small retaining fibers (retinacula cutis and deep retinacula fibers) which provide support of the soft tissues of the face and neck against gravitational sagging while allowing certain mobility. This mobility is utilized when mobile tissues are lifted without surgical release. However, the process of dragging up these fibers results in a loss of their previous, anti-gravitational, supportive orientation. CONCLUSION: No-release lifting techniques, such as thread lifts and minimal-invasive facelifts, tighten "tissue laxity" with a change of the gravity-opposing tissue architecture, placing the weight of the flap solely on the fixation, which limits longevity of the lift. The alternative, to perform a full release with redraping, enables reattachment of the flap to a higher position, with preservation of the original deep fascial architecture with its antigravity orientation and natural mobility, conceivably improving the longevity of the lift.

Lifting the Anterior Midcheek and Nasolabial Fold: Introduction to the Melo Fat Pad Anatomy and Its Role in Longevity and Recurrence.

BACKGROUND: A limitation of current facelift techniques is the early postoperative reappearance of anterior midcheek laxity associated with recurrence of the nasolabial fold (NLF). OBJECTIVES: This study was undertaken to examine the regional anatomy of the anterior midcheek and NLF with a focus on explaining the early recurrence phenomenon and to explore the possibility of alternative surgical methods that prolong NLF correction. METHODS: Fifty cadaver heads were studied (16 embalmed, 34 fresh; mean age, 75 years). Following preliminary dissections and macrosectioning, a series of standardized layered dissections were performed, complemented by histology, sheet plastination, and microcomputed tomography. Mechanical testing of the melo fat pad (MFP) and skin was performed to gain insight on which structure is responsible for transmission of the lifting tension in a composite facelift procedure. RESULTS: Anatomic dissections, sheet plastination, and microcomputed tomography demonstrated the 3-dimensional architecture and borders of the MFP. Histology of a lifted midcheek demonstrated that a composite MFP lift causes a change in connective tissue organization from a hanging-down pattern into a pulled-upward pattern, suggesting traction on the skin. Mechanical testing confirmed that, in a composite lift, despite the sutures being placed directly into the deep aspect of the MFP, the lifting tension distal to the suture is transmitted through the skin and not through the MFP. CONCLUSIONS: The usual method of performing a composite midcheek lift results in the skin, and not the MFP itself, bearing the load of the nondissected tissues distal to the lifting suture. For this reason, early recurrence of the NLF occurs following skin relaxation in the postoperative period. Accordingly, specific surgical procedures for remodeling the MFP should be explored, possibly in combination with volume restoration of the fat and bone, for more lasting improvement of the NLF.

The Functional Anatomy and Innervation of the Platysma is Segmental: Implications for Lower Lip Dysfunction, Recurrent Platysmal Bands, and Surgical Rejuvenation.

BACKGROUND: Despite the central role of the platysma in face and neck rejuvenation, much confusion exists regarding its surgical anatomy. OBJECTIVES: This study was undertaken to clarify the regional anatomy of the platysma and its innervation pattern and to explain clinical phenomena, such as the origin of platysmal bands and their recurrence, and the etiology of lower lip dysfunction after neck lift procedures. METHODS: Fifty-five cadaver heads were studied (16 embalmed, 39 fresh, mean age 75 years). Following preliminary dissections and macro-sectioning, a series of standardized layered dissections were performed, complemented by histology and sheet plastination. RESULTS: In addition to its origin and insertion, the platysma is attached to the skin and deep fascia across its entire superficial and deep surfaces. This composite system explains the age-related formation of static platysmal bands, recurrent platysmal bands after complete platysma transection, and recurrent anterior neck laxity after no-release lifting. The facial part of the platysma is primarily innervated by the marginal mandibular branch of the facial nerve, whereas the submandibular platysma is innervated by the "first" cervical branches, which terminate at the mandibular origin of the depressor labii inferioris. This pattern has implications for postoperative dysfunction of the lower lip, including pseudoparalysis, and potential targeted surgical denervation. CONCLUSIONS: This anatomical study, comprised of layered dissections, large histology, and sheet plastination, fully describes the anatomy of the platysma including its bony, fascial, and dermal attachments, as well as its segmental innervation including its nerve danger zones. It provides a sound anatomical basis for the further development of surgical techniques to rejuvenate the neck with prevention of recurrent platysmal banding.

"The Deep Fascia of the Head and Neck Revisited: Relationship with the Facial Nerve and Implications for Rhytidectomy".

INTRODUCTION: The deep fascia is important in facelift surgery as it is relied on for protection of the facial nerve during surgical dissection. Lack of consistency with the term may be due to the term deep fascia having two different meanings. It is a specific type of connective tissue, classically, thin, fibrous and flat. Whereas, in the description of the layers of the face and neck, the deep fascia layer includes all the connective tissue deep to the superficial fascia layer. This cadaver study was undertaken to clarify the layered anatomy of the face and neck and its relationship with the facial nerve branches. MATERIALS METHODS: Preliminary dissections and macro sectioning, followed by a conclusive series of standardized layered dissections, histology and sheet plastination, was performed on fifty cadaver heads. RESULTS: The deep fascia is thin in convex areas of the face and neck, while thicker in concave areas, it being interspersed with deep fat. The facial nerve branches, after emerging from the parotid gland, are embedded within the deep fascia, not deep to it. They transition from deep within the deep fascia at specific locations to course in the most superficial part of the deep fascia where they underlie their target superficial fascia muscles and are at risk from deep plane facelift dissection. CONCLUSION: The deep fascia layer is a multilamellar fibrofatty layer of variable thickness, which includes the deep fat in which the facial nerve branches are embedded. In deep plane facelift surgery, dissection must be performed in the most superficial level of this deep fascia layer. LEVEL OF EVIDENCE: No level of evidence is needed for Cadaver Study Articles.

The Superficial Musculo-Aponeurotic System (SMAS): Does it Really Exist as an Anatomic Entity?

INTRODUCTION: The exact anatomic entity behind the term superficial musculoaponeurotic system (SMAS) remains poorly understood. The different interpretations of the term SMAS by anatomists, surgeons and histologists have caused confusion. This study aims to provide clarity regarding this term and the relevant anatomy. MATERIALS METHODS: A literature review was conducted to uncover the variety of descriptions of the term SMAS. A feasibility study, followed by a conclusive series of standardized layered dissections, complemented by histology and sheet plastination was performed on fifty cadaver heads (16 embalmed, 34 fresh, mean age 75 years). RESULTS: Most literature considers the SMAS as layer 3, i.e., a musculoaponeurotic layer that separates the subcutaneous fat of the superficial fascia from the deep fat of the deep fascia. Our dissections, histology and sheet plastination demonstrated that a layer 3 is present only where there are flat mimetic muscles and platysma-auricular fascia over the posterior part of the parotid gland as the evolutionary remnant of the platysma, but not between the flat mimetic muscles. Here, the subcutaneous fat is in direct contact with the deep fat without the interposition of a musculo-aponeurotic layer 3. CONCLUSION: Due to the absence of a distinct and complete layer 3 connecting the flat mimetic muscles, we conclude that the SMAS as originally concepted does not exist as a specific anatomical entity. In retrospect, the surgically created compound layered flap composed of a variable thickness of subcutaneous fat, mimetic muscles (platysma, orbicularis oculi, …), and a thin layer of deep fascia, is what is known as the "SMAS". LEVEL OF EVIDENCE: No level of evidence is needed for Cadaver Study Articles.

Enhanced study of facial soft tissues using a novel large scale histology technique.

The safety and effectiveness of facial cosmetic surgery procedures are dependent on detailed 3D understanding of the complex surgical anatomy of the face. Traditional, small sample size anatomical dissection studies have limitations in providing definitive clarification of the fascial layers of the face, and especially in their relationship with the facial nerve, and their reaction to surgical manipulation. The objective study of large tissue areas is required to effectively demonstrate the broader architecture. Conventional histology techniques were modified to handle extraordinarily large tissue samples to fulfill this requirement. Full-thickness soft tissue samples (skin to bone) of maximum length 18 cm, width 4 cm, and tissue thickness 1 cm, were harvested from 20 hemifaces of 15 fresh human cadavers (mean age at death = 81 years). After fixation, the samples were processed with an automated processor using paraffin wax for 156 h, sectioned at 30 µm, collected on gelatin-chromium-coated glass slides, stained with a Masson's Trichrome technique and photographed. Using this technique, excellent visualization was obtained of the fascial connective tissue and its relationship with the facial mimetic muscles, muscles of mastication and salivary glands in 73 large histological slides. The resulting slides improved the study of the platysma and superficial musculo-aponeurotic system (SMAS), the spaces and ligaments, the malar fat pad, and the facial nerve in relations to the deep fascia. Additionally, surgically induced changes in the soft-tissue organization were successfully visualized. This technique enables improved insight into the broad structural architecture and histomorphology of large-scale facial tissues.

The Surgical Anatomy of the Jowl and the Mandibular Ligament Reassessed.

INTRODUCTION: A visible jowl is a reason patients consider lower facial rejuvenation surgery. The anatomical changes that lead to formation of the jowl remain unclear. The aim of this study was to elucidate the anatomy of the jowl, the mandibular ligament and the labiomandibular crease, and their relationship with the marginal mandibular branch of the facial nerve. MATERIALS AND METHODS: Forty-nine cadaver heads were studied (16 embalmed, 33 fresh, mean age 75 years). Following preliminary dissections and macro-sectioning, a series of standardized layered dissections were performed, complemented by histology, sheet plastination and micro-CT. RESULTS: The jowl forms in the subcutaneous layer where it overlies the posterior part of the mandibular ligament. The mandibular ligament proper exists only in the deep, sub-platysma plane, formed by the combined muscular attachment to the mandible of the specific lower lip depressor muscles and the platysma. The mandibular ligament does not have a definitive subcutaneous component. The labiomandibular crease inferior to the oral commissure marks the posterior extent of the fixed dermal attachment of depressor anguli oris. CONCLUSION: Jowls develop as a consequence of aging changes on the functional adaptions of the mouth in humans. To accommodate wide jaw opening with a narrowed commissure requires hypermobility of the tissues overlying the mandible immediately lateral to the level of the oral commissure. This hypermobility over the mandibular attachment of the lower lip depressor muscles occurs entirely in the subcutaneous layer to allow the mandible to move largely independent from the skin. The short, elastic subcutaneous connective tissue, which allows this exceptional mobility without laxity in youth, lengthens with aging, resulting in laxity. The development of subcutaneous and dermal redundancy constitutes the jowl in this location. 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 ."

Inverted-V Deformity: An Anatomic Study.

BACKGROUND: The inverted-V deformity is an unwanted aesthetic consequence of dorsal hump resection. Despite their attachment to the nasal bones, the upper lateral cartilages (ULCs) can separate from the nasal bones, creating a step-off after cartilaginous dorsal hump removal. OBJECTIVES: The mechanism of how the ULCs can separate from the nasal bones despite their attachment was studied to improve understanding of the inverted-V complication and its prevention. METHODS: A dorsal hump resection (bony and cartilaginous) was performed on 12 fresh cadavers to observe the effect on the ULCs. As a secondary study, the effect of different preventative maneuvers was investigated. RESULTS: Cartilaginous dorsal resection destroys the spreader mechanism of the T-frame and impacts the stabilization of the ULCs, resulting in them becoming free-floating. This causes them to migrate in a posterior, medial, and cranial direction relative to the nasal bones. The dynamic attachment of the ULCs to the nasal bones is key in this mechanism and allows actual separation of the ULCs from the nasal bones to result in the inverted-V deformity. Caudal traction to the ULCs re-tensions these attachments, pulling the ULCs against the nasal bones again. CONCLUSIONS: This anatomic dissection study has established that the connection between the nasal dorsum and ULCs is not a static fusion but is dynamic. This attachment can be used in primary rhinoplasty to prevent inverted-V deformity by applying caudal traction to the ULCs when reconstructing the dorsum which will tension the ULCs toward the nasal bones.

Aesthetic Enhancement of the Brow using Hydroxyapatite.

BACKGROUND: An aesthetically pleasing appearance of the 'eyes' usually includes good projection of the outer brow. Weak bony projection of the superolateral periorbital region tends to be not only less attractive, but also predisposes to hooding over the temporal part of the upper lid. Congenital lack of skeletal volume is exacerbated by ageing due to lipoatrophy and soft tissue laxity. The rationale and technique for performing skeletal augmentation of the superolateral orbital rim is described, along with long-term results from a series of cases. MATERIAL AND METHODS: A series of patients having augmentation of the superolateral orbital rim, using the technique described, were evaluated. A forehead crease incision was used, then a precise subperiosteal pocket developed in the lateral brow region between the supraorbital foramen and the superior temporal septum. The hydroxyapatite granule mixture was incrementally placed using modified syringes. The patients were followed to assess the long-term results. RESULTS: Two hundred and fifty patients, 80% women, mean age = 53 years [range 23-78] underwent supraorbital rim augmentation using subperiosteal hydroxyapatite granules, during a 12-year period, commencing in 2007. The mean follow-up was 41 months (range 1-12 years). The mean volume used for augmentation was 1.0 mL per side (range 0.4-2.3 mL). Projection of the upper lateral periorbital prominence was effectively increased, resulting in enhancement of the brow position and shape. Twenty-seven patients (11%) had an undercorrection, requiring additional volume augmentation, all during the first three years of the experience. Twelve patients (5%) required correction of contour irregularities. There were no infections and no long-term complications. Resorption of the hydroxyapatite volume over time was not noted. CONCLUSION: The aesthetic significance of superolateral orbital rim projection is introduced. Patients who have a degree of skeletal deficiency of the zygomatic process of the frontal bone should be considered for hydroxyapatite augmentation of the bone as a complement to upper lid blepharoplasty and brow elevation. This procedure should be considered in the spectrum of upper periorbital aesthetic procedures. 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 .