Layers
- Five concentric layers: skin, subcutaneous fat, superficial fascia (SMAS), mimetic muscle, deep facial fascia (parotidomasseteric), then the plane holding the facial nerve, parotid duct and buccal fat pad (PMID 1741467).
- Facial nerve branches in the cheek lie deep to the deep facial fascia (PMID 1741467).
- Mitz and Peyronie described the SMAS in the parotid and cheek area in 1976; dissection under it was safe over the parotid and dangerous anterior to it (PMID 935283).
- Mitz, 2026: fifty-year review of the SMAS and facelift evolution (PMID 42481023).
- 24 facial halves: a distinct parotid fascia separates SMAS from gland; SMAS ends within 1 cm below the zygomatic arch; histology varies by region and person (PMID 8248400).
- Large-format histology, 20 hemifaces, slides up to 18 cm long: shows SMAS, platysma, spaces, ligaments and nerve relations to deep fascia in one section (PMID 35951617).
- A deep fascia of the midface ("Chiara's fascia") forms the floor of the deep plane; found in 100 of 100 hemifaces (PMID 36261112).
- Ultrasound in 150 people: skin to superficial fascia 4.82 mm buccal, 4.25 mm premasseteric, 3.71 mm lateral neck; deeper with higher BMI, shallower with age (PMID 30882511).
Retaining ligaments
- Furnas (1989): zygomatic ligaments (McGregor's patch), mandibular ligaments, platysma-auricular ligament and anterior platysma-cutaneous ligaments; zygomatic and mandibular ligaments must be released for maximal skin movement (PMID 2909050).
- Two ligament types by origin: from bone, or from other fixed structures in the face (PMID 1741467).
- Ligaments sit in constant locations, separate spaces and compartments, and act as landmarks for nerve branches (PMID 23855010).
- 22 hemifaces: main zygomatic and upper masseteric ligaments 44.9 mm and 46.4 mm from the tragus; an upper zygomatic branch passes deep between them; danger area is just inferomedial to the upper masseteric ligament, where a zygomatic branch is 1.41 mm deep (PMID 23358020).
- Force to penetrate with a 21-G cannula: zygomatic ligament proper 9.16 N, zygomatic retaining 8.01 N, mandibular 3.64 N (PMID 40624370).
- Mandibular ligament release against fat grafting of the prejowl sulcus, 25 vs 25 patients: fat grafting with less release corrected jowls more (P = .046) (PMID 39001648).
Soft-tissue spaces
- Prezygomatic space: a glide-plane space over the zygoma; zygomatic branches run in its walls and roof, not across it (PMID 12172155).
- Premasseter space: membrane-lined space over the lower masseter; all facial nerve branches lie outside it; its expansion with age forms the jowl (PMID 18183455).
- Mendelson commentary on retaining ligament anatomy and rejuvenation (PMID 23494030).
Fat compartments
- 30 hemifaces, dye injection: subcutaneous fat is divided into separate compartments (nasolabial, medial, middle and lateral temporal-cheek, forehead, jowl) (PMID 17519724).
- Septa between compartments run from superficial fascia to dermis; face ages three-dimensionally by compartment (PMID 18454006).
- Deep medial cheek fat: volume loss produces "pseudoptosis" and a deeper nasolabial fold (PMID 18520902).
- 2019 review: compartments guide how far to dissect the skin flap and explain regional cheek deflation (PMID 31688754).
Facial nerve danger zones
- Frontal (temporal) branch variation in face lifting (Pitanguy and Ramos 1966) (PMID 5926990).
- Frontal branch runs on the undersurface of the temporoparietal fascia and is superficial over the zygomatic arch (PMID 2911626).
- Over the arch the frontal branch lies under a separate parotid-temporal fascia deep to the SMAS; high-SMAS division above the arch left it intact (PMID 20335873).
- Facial nerve injury in rhytidectomy under 1%, with spontaneous return in over 80% within 6 months (1979 data) (PMID 515227).
- 12 cadaver halves: trunk 20.1 mm deep; branches exit the parotid 9-10.6 mm deep; danger areas where branches become superficial: distal temporal, lower buccal, upper mandibular over masseter, marginal mandibular at the facial artery (PMID 2315394).
- Branch position varies in two dimensions; relation to soft-tissue planes is constant (PMID 25919245).
- Depth of marginal and cervical branches is constant and predictable in three dimensions (PMID 31881610).
- Cervical branch lies under the investing deep cervical fascia after leaving the parotid; exposed to electrocautery in midline approaches (PMID 38748536).
Platysma
- 50 cadavers: decussation 1-2 cm below the chin in 75%, at the thyroid cartilage in 15%, none in 10% (PMID 7433553).
- CT in 50 and dissection in 30: fusion suprahyoid 64%, at thyroid cartilage 20%, none 16%; a fascial adhesion zone explains paramedian bands (PMID 34529598).
- Platysma innervation is segmental: marginal mandibular branch for the facial part, first cervical branches for the submandibular part (PMID 37186556).
- Ultrasound in 80 muscles: inside a band the muscle thickens 37.9% on contraction without gliding; outside bands it glides 2.76 mm (PMID 37418617).
Skeleton
- Areas that resorb with age: maxilla including pyriform, superomedial and inferolateral orbital rim, prejowl mandible (PMID 22580543).
Glossary
- SMAS (superficial musculoaponeurotic system): superficial facial fascia that invests the platysma, orbicularis oculi and zygomaticus muscles (PMID 1741467); named by Mitz and Peyronie (PMID 935283).
- Deep plane: the plane under the SMAS whose floor is the deep fascia (PMID 36261112); term introduced by Hamra (PMID 38354840).
- Retaining ligament: fibrous band from bone or deep fascia to skin (PMID 23855010).
- McGregor's patch: the zygomatic ligament area of the cheek (PMID 2909050).
- Premasseter space: sub-SMAS space over the lower masseter (PMID 18183455).
- Prezygomatic space: space over the body of the zygoma under the orbicularis (PMID 12172155).
- Fat compartment: separate pocket of facial fat bounded by septa (PMID 17519724).
- Parotid-temporal fascia: deep fascia that covers the frontal branch over the zygomatic arch (PMID 20335873).
- Danger zone: area where a nerve branch becomes superficial to a common plane of dissection (PMID 31881610).
- Pseudoptosis: apparent sagging caused by deep fat volume loss (PMID 18520902).
Papers
| PMID | First author | Year | Journal | Title | Finding |
|---|---|---|---|---|---|
| 1741467 | Stuzin JM | 1992 | Plast Reconstr Surg | The relationship of the superficial and deep facial fascias: relevance to rhytidectomy and aging. | Five facial layers; nerve deep to deep fascia; two ligament types (landmark) |
| 935283 | Mitz V | 1976 | Plast Reconstr Surg | The superficial musculo-aponeurotic system (SMAS) in the parotid and cheek area. | First description of the SMAS (landmark) |
| 42481023 | Mitz V | 2026 | Aesthet Surg J | Fifty Years of the Superficial Musculoaponeurotic System: The Evolution of Modern Facelift Surgery. | Fifty-year review of the SMAS by Mitz |
| 8248400 | Gosain AK | 1993 | Plast Reconstr Surg | Surgical anatomy of the SMAS: a reinvestigation. | SMAS histology varies; ends below the zygomatic arch (landmark) |
| 35951617 | Minelli L | 2023 | Clin Anat | Enhanced study of facial soft tissues using a novel large scale histology technique. | Large-format histology of facial layers, 20 hemifaces |
| 36261112 | Andretto Amodeo C | 2022 | Facial Plast Surg | The Deep Fascia of the Infraorbital Region, Deep Plane, and Suprafibromuscular Facelift: New Anatomy for Safer Facelifting. | Deep fascia of the midface forms the floor of the deep plane |
| 30882511 | Casabona G | 2019 | Dermatol Surg | Influence of Age, Sex, and Body Mass Index on the Depth of the Superficial Fascia in the Face and Neck. | Ultrasound depth of superficial fascia by age, sex, BMI |
| 2909050 | Furnas DW | 1989 | Plast Reconstr Surg | The retaining ligaments of the cheek. | Retaining ligaments of the cheek described (landmark) |
| 23855010 | Alghoul M | 2013 | Aesthet Surg J | Retaining ligaments of the face: review of anatomy and clinical applications. | Review of retaining ligament anatomy (landmark) |
| 23358020 | Alghoul M | 2013 | Plast Reconstr Surg | Relationship of the zygomatic facial nerve to the retaining ligaments of the face: the Sub-SMAS danger zone. | Sub-SMAS zygomatic branch danger zone (landmark) |
| 40624370 | Hong GW | 2025 | Aesthetic Plast Surg | Quantifying the Strength of the Facial Ligaments and Its Clinical Implications. | Ligament penetration force measured |
| 39001648 | Talei B | 2024 | Aesthet Surg J | Mandibular Ligament and the Prejowl Sulcus Explained. | Prejowl sulcus: fat grafting beat mandibular ligament release |
| 12172155 | Mendelson BC | 2002 | Plast Reconstr Surg | Surgical anatomy of the midcheek and malar mounds. | Prezygomatic space described (landmark) |
| 18183455 | Mendelson BC | 2008 | Aesthetic Plast Surg | Surgical anatomy of the lower face: the premasseter space, the jowl, and the labiomandibular fold. | Premasseter space described; jowl mechanism (landmark) |
| 23494030 | Mendelson BC | 2013 | Aesthetic Plast Surg | Anatomic study of the retaining ligaments of the face and applications for facial rejuvenation. | Retaining ligaments and rejuvenation, commentary (landmark) |
| 17519724 | Rohrich RJ | 2007 | Plast Reconstr Surg | The fat compartments of the face: anatomy and clinical implications for cosmetic surgery. | Facial fat compartments described (landmark) |
| 18454006 | Rohrich RJ | 2008 | Plast Reconstr Surg | The retaining system of the face: histologic evaluation of the septal boundaries of the subcutaneous fat compartments. | Septal boundaries of fat compartments (landmark) |
| 18520902 | Rohrich RJ | 2008 | Plast Reconstr Surg | The youthful cheek and the deep medial fat compartment. | Deep medial cheek fat and pseudoptosis (landmark) |
| 31688754 | Stuzin JM | 2019 | Plast Reconstr Surg | The Facial Fat Compartments Revisited: Clinical Relevance to Subcutaneous Dissection and Facial Deflation in Face Lifting. | Fat compartments applied to flap dissection and deflation |
| 5926990 | Pitanguy I | 1966 | Plast Reconstr Surg | The frontal branch of the facial nerve: the importance of its variations in face lifting. | Frontal branch variation in face lifting (landmark) |
| 2911626 | Stuzin JM | 1989 | Plast Reconstr Surg | Anatomy of the frontal branch of the facial nerve: the significance of the temporal fat pad. | Frontal branch plane and temporal fat pad (landmark) |
| 20335873 | Trussler AP | 2010 | Plast Reconstr Surg | The frontal branch of the facial nerve across the zygomatic arch: anatomical relevance of the high-SMAS technique. | Frontal branch under parotid-temporal fascia; high-SMAS safe (landmark) |
| 515227 | Baker DC | 1979 | Plast Reconstr Surg | Avoiding facial nerve injuries in rhytidectomy. Anatomical variations and pitfalls. | Facial nerve injury in rhytidectomy: under 1%, most recover (landmark) |
| 2315394 | Rudolph R | 1990 | Plast Reconstr Surg | Depth of the facial nerve in face lift dissections. | Facial nerve depth in face lift dissection (landmark) |
| 25919245 | Roostaeian J | 2015 | Plast Reconstr Surg | Anatomical considerations to prevent facial nerve injury. | Nerve relations to soft-tissue planes are constant (landmark) |
| 31881610 | Stuzin JM | 2020 | Plast Reconstr Surg | Facial Nerve Danger Zones. | Facial nerve danger zones, 3D |
| 38748536 | Cakmak O | 2024 | Aesthet Surg J | Anatomical Insights on the Cervical Nerve for Contemporary Face and Neck Lifting: A Cadaveric Study. | Cervical branch course, 20 hemiheads |
| 7433553 | de Castro CC | 1980 | Plast Reconstr Surg | The anatomy of the platysma muscle. | Platysma decussation patterns (landmark) |
| 34529598 | Davidovic K | 2021 | Plast Reconstr Surg | Anatomy behind the Paramedian Platysmal Band: A Combined Cadaveric and Computed Tomographic Study. | Paramedian platysmal band anatomy, CT and cadaver |
| 37186556 | Minelli L | 2023 | Aesthet Surg J | The Functional Anatomy and Innervation of the Platysma is Segmental: Implications for Lower Lip Dysfunction, Recurrent Platysmal Bands, and Surgical Rejuvenation. | Platysma innervation is segmental |
| 37418617 | Calomeni M | 2024 | Aesthet Surg J | Understanding Platysma Muscle Contraction Pattern and Its Relationship to Platysmal Banding: A Real-Time Ultrasound Study. | Ultrasound of platysma band contraction |
| 22580543 | Mendelson B | 2012 | Aesthetic Plast Surg | Changes in the facial skeleton with aging: implications and clinical applications in facial rejuvenation. | Facial skeleton resorption with age (landmark) |
| 38354840 | Talei B | 2024 | Facial Plast Surg | The Detailed Anatomy of the Deep Plane of the Face and Neck with Current Nomenclature. | Deep plane anatomy and current nomenclature |
Open questions / controversies
- SMAS definition: histology varies by region and person (PMID 8248400); nomenclature for the deep plane was restated in 2024 (PMID 38354840).
- Jowl mechanism: ligament tethering (PMID 2909050) against subdermal atrophy corrected by fat (PMID 39001648).
- Retaining ligaments as separate structures or as fused compartment septa (PMID 17519724, PMID 23855010).
- Platysma band origin: muscle activity (PMID 37418617) against fascial adhesion and laxity (PMID 34529598).