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The fasciae of the face: An anatomic and histologic analysis
Dermatologic surgery The fasciae of the face: An anatomic and histologic analysis Leonard M. Dzubow, M.D. Philadelphia, PA The face has two distinct fascial components-a superficial layer and a deep layer. The anatomy of the fasciae in relation to surgically significant vessels, nerves, and muscles is examined with anatomic and histologic specimens. (J AM ACAD DERMATOL 14:502-507, 1986.)
The anatomy of the fascial components of the face is often perceived as perplexing and complex. This is partially due to confusing and occasionally conflicting terminology. The superficial fascia overlying the temporal region, for example, has been variously classified as superficial temporal fascia, I galea, 2 and a superior extension of the superficial musculoaponeurotic system (SMAS). 3 The fibrous component of the superficial fascia overlying the parotid gland, often referred to as SMAS, has recently been claimed to be the true parotid fascia. 4 The purpose of this article is to simplify classification by using strict anatomic terminology. An understanding of the relationship of the fascia to surgically important vessels and nerves will be emphasized by anatomic illustrations and histopathologic cross sections. FASCIAL ORGANIZATION
Fasciae are noncontractile connective tissue elements that organize and stabilize muscles, nerves, and vessels. The face proper has two distinct fasciae-superficial and deep5 (Fig. 1). The superficial fascia of the face is a structurally distinct layer underlying the dermis. It consists of a variable blend of fatty and fibrous tissue, depending on the specific site. The fibrous component of the superficial fascia takes origin from the dermis, From the Department of Dermatology, University of Pennsylvania School of Medicine. Reprint requests to: Dr. Leonard M. Dzubow, Department of Dermatology, University of Pennsylvania, University Hospital, 2 Maloney Bldg., 3600 Spruce St., Philadelphia, PA 19104.
502
where it arises as a reticulated septal network permeating the panniculus. A distinct fibrous layer, if present, lies on the deep surface of the subdermal fat and is a condensation of the fibrous septae into a continuous sheet (Fig. 2). The fibrous layer is the stabilizing envelope of the muscles of facial expression. It splits into two lamellae and encloses each facial muscle with an individual superficial and deep muscular fascia. Superficial facial vessels and sensory nerves normally run within the fibrous component of the superficial fascia. If the fascia has bifurcated around a muscle, these structures normally sit on the external surface of the muscle within the superficial muscular fascia. Branches of the facial nerve enter the muscle from the undersurface within the deep component of the muscular fascia. The superficial fascia is separated from the deep fascia by either a layer of fat or loose areolar tissue. In the face, deep fascia includes temporalis fascia, parotid-masseteric fascia, investing fascia of the neck, periosteum, perichondrium, and orbital septum. These structures all exist at the same plane of dissection. REGIONAL FASCIAL ANATOMY
Scalp. The superficial fascia of the scalp consists of a thick, fatty layer whose septae condense inferiorly into a strong, inelastic fibrous sheath, the galea. The major branches of the supraorbital, superficial temporal, and occipital vessels, as well as the sensory nerves, run within the superficial fascia, mostly at the fat-galeal junction. Loose
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Fig. 1. Superficial fascia represented by galea and fibrofatty layer enveloping facial musculature. Deep fascia is shown as a continuity from pericranium,'teinporal fascia, parotidmassenteric fascia to the investing layer of cervical fascia. (From Gray H: Anatomy of the human body, ed. 30. Edited by C. D. Clemente. Philadelphia, 1985, Lea & Febiger.)
areolar tissue separates the superficial fascia from the underlying deep fascia, the periosteum. Forehead. The fatty component of the superficial fascia of the forehead is normally thin. The fibrous component of the superficial fascia of the scalp (the galea) splits on the forehead to enclose
the frontalis muscle. The deep surface of the frontalis has a dense fibrous, muscular fascia, whereas the superficial muscle fascia is delicate and transparent. The fascia envelops the muscle and anchors the two bellies of the frontalis together. Often there is a decrease in or an absence of muscular
504
Dzubow
Fig. 2. Photomicrograph from forehead, Ilhowing fine and thick septae (S) from the panniculus condensing superior to the frontalis muscle (M) to form the superficial (f) and deep (F) muscular fasciae.
in the midline of the forehead. One then finds primarily fibrous fascia above the glabella and minimal frontalis muscle. The supraorbital and supratrochlear nerves and vessels, having ascended from their foramina! travel cephalically external to the muscle in the fatty-fibrous superficial fascia (Fig. 3). The temporal or frontal branches of the facial nerve enter the muscle on the deep side. They lie within the fibrous component of the superficial fascia temporally. As this fascia bifurcates to envelop the frontalis muscle, the nerves travel within the lower component, which becomes the deep muscular fascia (Fig. 4.). The deep fascia of the forehead, the periosteum, is separated from the superficial fascia by loose areolar tissue. Eyelids. There is no fatty component of the superficial fascia of the lids. The fibrous component envelops the orbicularis muscle, with the thick component again on the deep surface of the muscle. The deep fascia is the orbital septum, a
Journal of the American Academy of Dermatology
Fig. 3. Photomicrograph from lateral aspect of forehead; Note major sensory neural bundle (N) enclosed within fascial components above frontalis muscle (M). Dermis (D) is above, and thick subfrontalis fascia (F) is below. .
fiber~
fascial layer continuous with the orbital periosteum. The superficial and deep fascia are connected by loose areolar tissue. Temple. The fatty component of the superficial fascia of the temple is normally ample. Its septae condense inferiorly to form a distinct fibrous component grossly visible as a white membrane. The thin, variably present temporoparietalis muscle· is enveloped by this fascia, as are the small auricular muscles. The superficial temporal vessels and their branches lie within the fatty-fibrous junction (Fig. 5). The auriculotemporal nerve, a sensory nerve, also ascends within this plane. The frontal branch of the facial nerve, as it travels toward the frontalis muscle, is found within the fibrous component of the superficial fascia (Fig. 5). The deep fascia of the temporal region is called the temporalis fascia: It is separated from the superficial fascia by loose fatty-areolar tissue. The temporalis fascia consists of two layers, a delicate superficial membrane and
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Fig. 5. Fresh cadaver dissection demonstrating branches of superficial temporal artery (A) and frontal branch of facial nerve (N) within superficial fascia (F) of temple. Fig. 4. Photomicrograph from temple-forehead junction. Note large frontal branch of facial nerve (N) entering muscle (M) from below within deep muscular fascia. Dermis (D) is above.
a thick, dense, deep fibrous sheath. The deeper sheath directly overlies the temporalis muscle (Fig. 6) . . Cheek. Laterally, the superficial fascia of the cheek consists of a thick, fatty layer and a welldefined white, fibrous layer (Figs. 7 and 8). Medially, the fibrous sheath attenuates and envelops the facial musculature responsible for mouth and lip motion. This fibrous layer has been termed the superficial musculoaponeurotic system, or SMAS, 6 and is used surgically to facilitate rhytidectomies by tightening and suspending facial muscles and attached tissues. The effect of this procedure is based on the unifying nature of the fascia on the muscles. Tension applied to any portion of the fascia is relayed to the muscles and interconnected skin through the muscular fasciae. This allows tightening of the entire face by fascial plication or imbrication. 7 The deep fascia of the cheek is a thin, transparent fibrous layer overlying the parotid gland and masseter muscle (Fig. 7).
Fig: 6. Fresh cadaver dissection demonstrating temporal fascia (T) in same plane as periosteum (P) .of frontal bone. Note thick, fibrous fascia (/), part of the superficial fascia, underlying frontalis musck, (demonstrated by scalpel). Nose is to right, ear to left.
506
Journal of the American Academy of Dermatology
Dzubow
Fig. 7. Fresh cadaver dissection showing superficial fascia, or SMAS (8), elevated from glistening deep fascia that overlies parotid gland (P) and masseter muscle (M). Forceps demonstrates Stenson's duct (s).
The parotid-masseteric fascia is separated from the overlying superficial fascia by a fatty-areolar layer. The branches of the facial nerve, after exiting the parotid gland, run for a short distance within the deep fascia before ascending to enter the fibrous component of the superficial fascia or the deep component of the muscular fascia. Neck. The fibrous component of the superficial fascia envelops the platysma muscle to form its superficial and deep muscular fasciae. The investing layer of the deep cervical fascia lies deep to the superficial fascia and is separated from it by a loose areolar layer. The marginal mandibular branch of the facial nerve runs within the deep muscular fascia of the platysma before reaching the deep surface of the depressor musculature of the lips. SUMMARY
Fig. 8. Photomicrograph from lateral aspect of the
cheek, demonstrating superficial, fascial layer, or SMAS (S), above and deep fascia (p) overlying parotid gland (P) below. Dennis (D) is separated from fibrous component of SMAS by a fatty layer.
The superficial fascia is a consistent and continuous layer throughout the body. In the face, it envelops the muscles of expression and forms a stable conduit for superficial vessels and nerves. It consists of three layers of variable thickness: a superficial fatty panniculus, a deeper fibrous sheath, and a still deeper fatty panniculus. In areas where muscle fibers are absent or sparse, such as
Volume 14 Number 3 March, 1986
Fasciae offace
the scalp, temple, and lateral cheek, the fibrous components form a well-defined membrane. This component bifurcates over and under facial musculature to enclose each muscle in a fascial compartment. The result is an interconnecting link between muscles. Teleologically, this linkage allows a multitude of complex, coordinated facial movements. The concept of the SMAS is based on this interconnection. However, since an aponeurosis is anatomically a flattened tendon, connecting a muscle to bone, this term is inaccurate. The organization is truly a musculofascial system. Deep fascia is separated from the superficial fascia by a well-defined plane termed a fascial cleft. The deep fascia covers temporalis and masseter muscle, superficial neck musculature (including platysma), the parotid gland, bone, and cartilage. It would be advantageous for surgeons to employ accepted anatomic terminology and to aban-
507
don inaccurate nomenclature. The superficial fascia is truly a universal phenomenon over the entire body surface and can be best understood as a unified whole, rather than as regional variations. REFERENCES I. Grabski Wl, Salasche S1: Management of temporal nerve injuries. 1 Dermatol Surg Oncolll:145-151, 1985. 2. Riefkohl R: The forehead-brow lift. Ann Plast Surg 8:5563, 1982. 3. Liebman EP, Webster RC, Berger AS, Della Vecchia M: The frontalis nerve in the temporal brow lift. Arch Otolaryngol 108:232-235, 1982. 4. lost G, Levet Y: Parotid fascia and face lifting: A critical evaluation of the SMAS concept. Plast Reconstr Surg 74:42-51, 1984. 5. Clemente CD, editor: Gray's anatomy of the human body, ed. 30. Philadelphia, 1985, Lea & Febiger. 6. Mitz V, Peyronie M: The superficial musculoaponeurotic system (SMAS) in the parotid and cheek area. Plast Reconstr Surg 27:544-548, 1961. 7. Webster RC, Smith RC, Karolow WW, et al: Comparison of SMAS plication with SMAS imbrication in face lifting. Laryngoscope 92:901-912, 1982.
ABSTRACTS A placebo-controlled comparative study of sustained-release brompheniramine maleate against c1emastine fumarate in the treatment of chronic urticaria Jolliffe DS, Sim-Davis D, Templeton JS: Curr Med Res Opin 9:394-399, 1985 This study of the treatment of urticaria in twenty-four patients illustrates the usual difficulties in assessing the results fairly yet in a convincing manner. The antihistamines were preferred over the placebo, but only moderately. Four people seemingly had important adverse effects from the placebo. These studies are expensive and have many shortcomings, but they are necessary for planning rational therapy. Large samples may compensate for lack of good control and for imagination. P. C. Anderson, M.D.
The levels of androgen in serum in female acne patients Schmidt JB, Spona J: Endocrinol Exp (Bratisl)
19:17-23, 1985
Do female acne patients have abnormally high androgens? In nineteen of twenty-six studied here some excess was found, and the fact was deemed to be clinically useful. P. C. Anderson, M.D.
Fatty acid composition of plasma lipids in acrodermatitis enteropathica before and after zinc supplementation Koletzko B, Bretschneider A, Bremer HI: Eur J Pediatr 143:310-314, 1985 Not surprisingly, persons who are severely zinc-deficient have many secondary biochemical defects, several due to the diarrhea. Suggestions are offered that might improve therapy. P. C. Anderson, M.D.
Etretinate therapy in children with severe keratinization defects Traupe H, Happle R: Eur J Pediatr 143:166-169,
1985 Oriented to the safe treatment of children with etretinate, this review of lengthy European experience is timely now that the drug is finally approved by the Food and Drug Administration (FDA) for use in the United States. Juvenile pityriasis rubra pilaris is discussed. P. C. Anderson, M.D.
The anatomy of the fascial components of the face is often perceived as perplexing and complex. This is partially due to confusing and occasionally conflicting terminology. The superficial fascia overlying the temporal region, for example, has been variously classified as superficial temporal fascia, I galea, 2 and a superior extension of the superficial musculoaponeurotic system (SMAS). 3 The fibrous component of the superficial fascia overlying the parotid gland, often referred to as SMAS, has recently been claimed to be the true parotid fascia. 4 The purpose of this article is to simplify classification by using strict anatomic terminology. An understanding of the relationship of the fascia to surgically important vessels and nerves will be emphasized by anatomic illustrations and histopathologic cross sections. FASCIAL ORGANIZATION
Fasciae are noncontractile connective tissue elements that organize and stabilize muscles, nerves, and vessels. The face proper has two distinct fasciae-superficial and deep5 (Fig. 1). The superficial fascia of the face is a structurally distinct layer underlying the dermis. It consists of a variable blend of fatty and fibrous tissue, depending on the specific site. The fibrous component of the superficial fascia takes origin from the dermis, From the Department of Dermatology, University of Pennsylvania School of Medicine. Reprint requests to: Dr. Leonard M. Dzubow, Department of Dermatology, University of Pennsylvania, University Hospital, 2 Maloney Bldg., 3600 Spruce St., Philadelphia, PA 19104.
502
where it arises as a reticulated septal network permeating the panniculus. A distinct fibrous layer, if present, lies on the deep surface of the subdermal fat and is a condensation of the fibrous septae into a continuous sheet (Fig. 2). The fibrous layer is the stabilizing envelope of the muscles of facial expression. It splits into two lamellae and encloses each facial muscle with an individual superficial and deep muscular fascia. Superficial facial vessels and sensory nerves normally run within the fibrous component of the superficial fascia. If the fascia has bifurcated around a muscle, these structures normally sit on the external surface of the muscle within the superficial muscular fascia. Branches of the facial nerve enter the muscle from the undersurface within the deep component of the muscular fascia. The superficial fascia is separated from the deep fascia by either a layer of fat or loose areolar tissue. In the face, deep fascia includes temporalis fascia, parotid-masseteric fascia, investing fascia of the neck, periosteum, perichondrium, and orbital septum. These structures all exist at the same plane of dissection. REGIONAL FASCIAL ANATOMY
Scalp. The superficial fascia of the scalp consists of a thick, fatty layer whose septae condense inferiorly into a strong, inelastic fibrous sheath, the galea. The major branches of the supraorbital, superficial temporal, and occipital vessels, as well as the sensory nerves, run within the superficial fascia, mostly at the fat-galeal junction. Loose
Volume 14 Number 3 March, 1986
Fasciae offace
503
Fig. 1. Superficial fascia represented by galea and fibrofatty layer enveloping facial musculature. Deep fascia is shown as a continuity from pericranium,'teinporal fascia, parotidmassenteric fascia to the investing layer of cervical fascia. (From Gray H: Anatomy of the human body, ed. 30. Edited by C. D. Clemente. Philadelphia, 1985, Lea & Febiger.)
areolar tissue separates the superficial fascia from the underlying deep fascia, the periosteum. Forehead. The fatty component of the superficial fascia of the forehead is normally thin. The fibrous component of the superficial fascia of the scalp (the galea) splits on the forehead to enclose
the frontalis muscle. The deep surface of the frontalis has a dense fibrous, muscular fascia, whereas the superficial muscle fascia is delicate and transparent. The fascia envelops the muscle and anchors the two bellies of the frontalis together. Often there is a decrease in or an absence of muscular
504
Dzubow
Fig. 2. Photomicrograph from forehead, Ilhowing fine and thick septae (S) from the panniculus condensing superior to the frontalis muscle (M) to form the superficial (f) and deep (F) muscular fasciae.
in the midline of the forehead. One then finds primarily fibrous fascia above the glabella and minimal frontalis muscle. The supraorbital and supratrochlear nerves and vessels, having ascended from their foramina! travel cephalically external to the muscle in the fatty-fibrous superficial fascia (Fig. 3). The temporal or frontal branches of the facial nerve enter the muscle on the deep side. They lie within the fibrous component of the superficial fascia temporally. As this fascia bifurcates to envelop the frontalis muscle, the nerves travel within the lower component, which becomes the deep muscular fascia (Fig. 4.). The deep fascia of the forehead, the periosteum, is separated from the superficial fascia by loose areolar tissue. Eyelids. There is no fatty component of the superficial fascia of the lids. The fibrous component envelops the orbicularis muscle, with the thick component again on the deep surface of the muscle. The deep fascia is the orbital septum, a
Journal of the American Academy of Dermatology
Fig. 3. Photomicrograph from lateral aspect of forehead; Note major sensory neural bundle (N) enclosed within fascial components above frontalis muscle (M). Dermis (D) is above, and thick subfrontalis fascia (F) is below. .
fiber~
fascial layer continuous with the orbital periosteum. The superficial and deep fascia are connected by loose areolar tissue. Temple. The fatty component of the superficial fascia of the temple is normally ample. Its septae condense inferiorly to form a distinct fibrous component grossly visible as a white membrane. The thin, variably present temporoparietalis muscle· is enveloped by this fascia, as are the small auricular muscles. The superficial temporal vessels and their branches lie within the fatty-fibrous junction (Fig. 5). The auriculotemporal nerve, a sensory nerve, also ascends within this plane. The frontal branch of the facial nerve, as it travels toward the frontalis muscle, is found within the fibrous component of the superficial fascia (Fig. 5). The deep fascia of the temporal region is called the temporalis fascia: It is separated from the superficial fascia by loose fatty-areolar tissue. The temporalis fascia consists of two layers, a delicate superficial membrane and
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Fasciae offace
505
Fig. 5. Fresh cadaver dissection demonstrating branches of superficial temporal artery (A) and frontal branch of facial nerve (N) within superficial fascia (F) of temple. Fig. 4. Photomicrograph from temple-forehead junction. Note large frontal branch of facial nerve (N) entering muscle (M) from below within deep muscular fascia. Dermis (D) is above.
a thick, dense, deep fibrous sheath. The deeper sheath directly overlies the temporalis muscle (Fig. 6) . . Cheek. Laterally, the superficial fascia of the cheek consists of a thick, fatty layer and a welldefined white, fibrous layer (Figs. 7 and 8). Medially, the fibrous sheath attenuates and envelops the facial musculature responsible for mouth and lip motion. This fibrous layer has been termed the superficial musculoaponeurotic system, or SMAS, 6 and is used surgically to facilitate rhytidectomies by tightening and suspending facial muscles and attached tissues. The effect of this procedure is based on the unifying nature of the fascia on the muscles. Tension applied to any portion of the fascia is relayed to the muscles and interconnected skin through the muscular fasciae. This allows tightening of the entire face by fascial plication or imbrication. 7 The deep fascia of the cheek is a thin, transparent fibrous layer overlying the parotid gland and masseter muscle (Fig. 7).
Fig: 6. Fresh cadaver dissection demonstrating temporal fascia (T) in same plane as periosteum (P) .of frontal bone. Note thick, fibrous fascia (/), part of the superficial fascia, underlying frontalis musck, (demonstrated by scalpel). Nose is to right, ear to left.
506
Journal of the American Academy of Dermatology
Dzubow
Fig. 7. Fresh cadaver dissection showing superficial fascia, or SMAS (8), elevated from glistening deep fascia that overlies parotid gland (P) and masseter muscle (M). Forceps demonstrates Stenson's duct (s).
The parotid-masseteric fascia is separated from the overlying superficial fascia by a fatty-areolar layer. The branches of the facial nerve, after exiting the parotid gland, run for a short distance within the deep fascia before ascending to enter the fibrous component of the superficial fascia or the deep component of the muscular fascia. Neck. The fibrous component of the superficial fascia envelops the platysma muscle to form its superficial and deep muscular fasciae. The investing layer of the deep cervical fascia lies deep to the superficial fascia and is separated from it by a loose areolar layer. The marginal mandibular branch of the facial nerve runs within the deep muscular fascia of the platysma before reaching the deep surface of the depressor musculature of the lips. SUMMARY
Fig. 8. Photomicrograph from lateral aspect of the
cheek, demonstrating superficial, fascial layer, or SMAS (S), above and deep fascia (p) overlying parotid gland (P) below. Dennis (D) is separated from fibrous component of SMAS by a fatty layer.
The superficial fascia is a consistent and continuous layer throughout the body. In the face, it envelops the muscles of expression and forms a stable conduit for superficial vessels and nerves. It consists of three layers of variable thickness: a superficial fatty panniculus, a deeper fibrous sheath, and a still deeper fatty panniculus. In areas where muscle fibers are absent or sparse, such as
Volume 14 Number 3 March, 1986
Fasciae offace
the scalp, temple, and lateral cheek, the fibrous components form a well-defined membrane. This component bifurcates over and under facial musculature to enclose each muscle in a fascial compartment. The result is an interconnecting link between muscles. Teleologically, this linkage allows a multitude of complex, coordinated facial movements. The concept of the SMAS is based on this interconnection. However, since an aponeurosis is anatomically a flattened tendon, connecting a muscle to bone, this term is inaccurate. The organization is truly a musculofascial system. Deep fascia is separated from the superficial fascia by a well-defined plane termed a fascial cleft. The deep fascia covers temporalis and masseter muscle, superficial neck musculature (including platysma), the parotid gland, bone, and cartilage. It would be advantageous for surgeons to employ accepted anatomic terminology and to aban-
507
don inaccurate nomenclature. The superficial fascia is truly a universal phenomenon over the entire body surface and can be best understood as a unified whole, rather than as regional variations. REFERENCES I. Grabski Wl, Salasche S1: Management of temporal nerve injuries. 1 Dermatol Surg Oncolll:145-151, 1985. 2. Riefkohl R: The forehead-brow lift. Ann Plast Surg 8:5563, 1982. 3. Liebman EP, Webster RC, Berger AS, Della Vecchia M: The frontalis nerve in the temporal brow lift. Arch Otolaryngol 108:232-235, 1982. 4. lost G, Levet Y: Parotid fascia and face lifting: A critical evaluation of the SMAS concept. Plast Reconstr Surg 74:42-51, 1984. 5. Clemente CD, editor: Gray's anatomy of the human body, ed. 30. Philadelphia, 1985, Lea & Febiger. 6. Mitz V, Peyronie M: The superficial musculoaponeurotic system (SMAS) in the parotid and cheek area. Plast Reconstr Surg 27:544-548, 1961. 7. Webster RC, Smith RC, Karolow WW, et al: Comparison of SMAS plication with SMAS imbrication in face lifting. Laryngoscope 92:901-912, 1982.
ABSTRACTS A placebo-controlled comparative study of sustained-release brompheniramine maleate against c1emastine fumarate in the treatment of chronic urticaria Jolliffe DS, Sim-Davis D, Templeton JS: Curr Med Res Opin 9:394-399, 1985 This study of the treatment of urticaria in twenty-four patients illustrates the usual difficulties in assessing the results fairly yet in a convincing manner. The antihistamines were preferred over the placebo, but only moderately. Four people seemingly had important adverse effects from the placebo. These studies are expensive and have many shortcomings, but they are necessary for planning rational therapy. Large samples may compensate for lack of good control and for imagination. P. C. Anderson, M.D.
The levels of androgen in serum in female acne patients Schmidt JB, Spona J: Endocrinol Exp (Bratisl)
19:17-23, 1985
Do female acne patients have abnormally high androgens? In nineteen of twenty-six studied here some excess was found, and the fact was deemed to be clinically useful. P. C. Anderson, M.D.
Fatty acid composition of plasma lipids in acrodermatitis enteropathica before and after zinc supplementation Koletzko B, Bretschneider A, Bremer HI: Eur J Pediatr 143:310-314, 1985 Not surprisingly, persons who are severely zinc-deficient have many secondary biochemical defects, several due to the diarrhea. Suggestions are offered that might improve therapy. P. C. Anderson, M.D.
Etretinate therapy in children with severe keratinization defects Traupe H, Happle R: Eur J Pediatr 143:166-169,
1985 Oriented to the safe treatment of children with etretinate, this review of lengthy European experience is timely now that the drug is finally approved by the Food and Drug Administration (FDA) for use in the United States. Juvenile pityriasis rubra pilaris is discussed. P. C. Anderson, M.D.