Overview
The superficial surface of the superficial musculoaponeurotic system (SMAS) provides a strategic dissection plane for facial surgery. This superficial musculoaponeurotic plane (SMAP) includes the superficial face of the SMAS/platysma and related surfaces, the superficial temporal fascia, the frontalis, the superficial surface of the facial mimetic muscles, and the superficial cervical fascia over the sternocleidomastoid and posterior triangle.
This article describes a technique of cervicofacial rhytidectomy that employs the SMAP for dissection and flap development. Use of the SMAP gives the surgeon flexibility of design and of flap movement (SMAP flap). Extensive shifting of the facial skin with the full thickness of its fascial-fatty layer allows dramatic improvement of severe gravitational effects. This technique is particularly suitable for patients with advanced aging changes. [1, 2, 3]
The surgeon evaluates the physical properties of the skin of the patient's face and neck, pulling it in various directions, noting extensibility and secondary effects on facial features. The surgeon observes the direction and magnitude of movement that give the best contours. In effect, the facelift is rehearsed. On the basis of these findings, the surgeon plots a detailed pattern for skin excisions. The pattern is recorded by direct measurement and by photographs for reference in the operating room and for future comparisons.
For facelifts on the SMAP, a patterned skin excision provides precision for advancement and closure of the facial flaps. The extended SMAP continues beyond the borders of the SMAS/platysma layer to include the surface of the superficial temporal fascia, orbicularis oculi, frontalis, and superficial cervical fascia. A subcutaneous forehead lift, a facelift, and a platysma myorrhaphy can be performed on the same plane with complete flexibility of access and of flap movement.
History of the procedure
When Tessier observed the clinical entity of an SMAS of the face, he motivated Mitz and Peyronie to carry out analysis in the anatomy laboratory. [4] Their findings stimulated surgeons to rethink facial dissection planes. The choices now include planes that are within the subcutaneous layer (eg, standard facelift plane, intrasubcutaneous plane), supraplatysmal planes (eg, SMAP), sub-SMAS planes, subplatysmal planes, preperiosteal planes, subperiosteal planes, and any combination.
In 1963, Limberg published drawings of a facelift in which a typical pattern of skin excision had been rendered as a geometric figure. When the defect was closed, the triangle and trapezoids collapsed into a linear closure, and a convincing lift of the dependent facial skin was illustrated. Limberg's drawings were based on geometry without regard to biomechanics, but they were a prototype for precision in planning.
In 1987, the author reported the use of manual rehearsal of the facelift plan incorporating biomechanical evaluation and plotting the pattern for skin excision with the aid of anthropometric landmarks.
Incidental to illustrations of retaining ligaments of the cheek, in 1989, the author showed the SMAP and subsequently presented a video demonstration of the SMAP flap.
Indications
The superficial musculoaponeurotic plane (SMAP) is a utility plane that is excellent for facial rhytidectomy, [5] parotidectomy, [6] placement of free flaps in facial volume defects, and development of local flaps to repair defects from facial tumors. Familiarity with this plane and its anatomic variations is helpful in addressing facial trauma.
The SMAP is useful in any patient who has mature aging changes. This plane can be used in its entirety for correcting the forehead, face, and neck; if a patient desires a brow lift that avoids a hairline incision, an endoscopic brow lift on a deeper plane can be a complementary step.
Previous facial surgery is not a contraindication. For the most part, the SMAP is undisturbed when different dissection planes have been used for the primary lift. When the SMAP was previously used, the repeat SMAP dissection has proven to be different but generally no more difficult than the first dissection. The surgeon must identify, record, and discuss with the patient facial asymmetry, facial nerve weakness, facial nerve synkinesis, or other physical features that may be erroneously attributed to the secondary procedure. Such findings demand special vigilance during the secondary dissection.
The technique of patterned skin excision is useful in facelifts in which skin closure plays an important role in the lifting force. It is particularly useful when the skin sags severely, necessitating a more extensive soft tissue resection than usual. Patterned skin excisions are also useful for small secondary lifting procedures.
These strategies provide predictability, reproducibility, and flexibility with minimum complications.
Contraindications
Currently, with endoscopic and short-incision techniques, patients who have mild aging changes of the mid face but youthful lower face and neck areas gain satisfactory improvement. These patients are not candidates for a superficial musculoaponeurotic system (SMAS) facelift.
Anesthesia
Because the operating time is lengthy, local anesthesia with monitored anesthesia care is uniformly chosen.
Technique
The superficial surface of the SMAS provides a strategic dissection plane for facial surgery. This superficial musculoaponeurotic plane (SMAP) includes the superficial face of the platysma/superficial musculoaponeurotic system (SMAS) and related surfaces, the superficial temporal fascia, the frontalis, the superficial surface of the facial mimetic muscles, and the superficial cervical fascia over the sternocleidomastoid and posterior triangle. Dissection on this plane liberates a thick flap of skin that includes the cheek mass, malar crescent, and fascial-fatty layer (ie, all soft tissue from the areolar surface of the SMAS to the epidermis). The SMAP flap transmits its lift by the force generated from direct edge-to-edge closure of the patterned excision. Additional lift results from emulating the zygomatic ligaments with sutures and by shortening the zygomaticus major muscle by plication.
The facial integument is disengaged from all practicable restraints so that maximum flap advancement results from minimal force and the surgeon gains wide latitude in repositioning dependent soft tissues.
In this discussion, the SMAS is assumed to be a musculoaponeurotic layer devoid of attached fat and to be a continuous part of the platysma. The fibrous part of the SMAS is a fascial area corresponding clinically (intraoperatively) to a segment of parotideomasseteric fascia. This segment of fascia is a link between the SMAS/platysma and the periauricular dermis through many telae subcutaneae and is thus termed the platysma-auricular fascia (PAF). Anterior to the ear, this fascial sheet becomes the SMAS; anteroinferiorly, the PAF becomes platysma. The superficial surface of the SMAS/platysma is a starting point for a dissection plane that is readily extended over the surface of the orbicularis oculi, the superficial temporal fascia, the frontalis muscle, and the superficial cervical fascia.
When the SMAP is part of the surgical strategy, the pattern of the skin excision is particularly important to the effectiveness of a facelift. Once the facial integument has been released from its retaining ligaments [7] and fusion planes, the force generated in the approximation of the edges of the excisional defect is an important determinant of the new facial contours. An overestimate of the amount of skin to be excised could cause excess tension with vascular compromise, and an underestimate could cause an ineffective operation. For this reason, the design is subjected to careful intraoperative scrutiny so that the pattern can be corrected.
Approach
The 2 basic maneuvers that are central to a facelift performed on the SMAP are (1) release of restraints to cephalad movement of the ptotic facial tissues and (2) cephalad advancement and anchorage of the ptotic facial tissues in a natural position that effaces the ptotic changes. This cephalad movement is achieved by 3 surgical steps.
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Closure of the patterned skin excision: The excess skin that is to be excised incidental to the facelift is plotted as a systematically designed pattern. This skin pattern is designed to transmit optimum tension to the lax skin of the face and neck so that, as the skin is closed, sagging and laxity are effaced. The inclusion of the full thickness of the subcutaneous fascial-fatty tissue in the cheek flap provides strength and circulatory reliability.
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Plication of the zygomaticus major muscle: The muscle belly of the zygomaticus major is shortened by folding it at its origin. This provides extra support to the ptotic modiolus labii and surrounding structures.
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Modiolar support sutures: The zygomatic ligaments are transected to release restraints to cephalad movement of the cheek flaps. Each zygomatic ligament is figuratively reconstructed with nonabsorbable 4-0 Prolene, elevating the modiolar peninsula to the region of the stump of the zygomatic ligament or to a lower point on the masseteric fascia.
Anatomy
The superficial musculoaponeurotic plane (SMAP) is a cleavage plane that separates the fascial-fatty layer of skin from the surface of the superficial muscle layer of the face and neck. In many areas, identification of this potential space is obvious. In other areas, retaining ligaments, fascial fusion planes, ambiguous pathways, anatomic variations, and anomalies obscure the cleft. [8]
Foremost on the surgeon's mind is the position of the facial nerve and its branches. The facial nerve is protected by (1) blunt dissection underneath the SMAS superficial to the fascia overlying the masseter in which the facial nerves exist, (2) dissecting on structures that cover the facial nerve with certainty, (3) identifying the nerve branches and dissecting over them or beside them, or (4) dissecting in areas that are out of the region of the facial nerve. Familiarity with sensory nerves that occasionally mimic the facial nerve is important, as is knowledge of the supporting structures that must be separated or detached for surgical exposure.
For more information about the relevant anatomy, see Facelift Anatomy and Facial Nerve Anatomy.
Anthropometric landmarks
Before surgery, with the patient seated, the surgeon manually rehearses the operative steps. The patient's face is upright, aligned with gravity, simulating the natural position from which the result will be viewed. The surgeon grasps the skin and lifts it upward, proceeding from point to point, to determine the tension needed to achieve the surgical goals. The surgeon mentally compares this to the level of tension that may distort the facial features or that risks skin loss by exceeding the blanching tension.
A series of anthropometric points aids in accurate placement and recording of the landmarks (see Anthropometric points below). Primary points are marked along the frontal and temporal hairline, around the base of the ear, and along the postauricular and mastoid hairline. The facial skin incision line is plotted by connecting these points. The surgeon then judges how much excess skin is present below each primary point. The amount of excess at each site is marked with a secondary point. Posteriorly, where the skin adheres tightly to the sternomastoid muscle, this judgment is made indirectly. The surgeon grasps the lax skin anterior to the border of the sternomastoid muscle to determine the amount of excessive skin. A corresponding secondary point is then placed so the distance between the primary and secondary point equals the amount of skin excess.
When the series of secondary points is complete, the points are connected, rendering the proposed line of excision of excess skin. Between the incision line and the excision line lies the tentative patterned skin excision.
A series of chords is then marked, indicating the lines for pilot cuts. These chords simply connect each primary point with its fellow secondary point. The pilot cuts are incised, and, with staples, the primary points are approximated to the secondary points in a trial closure. The resultant distribution and magnitude of skin tension from the trial closure is studied. Excess laxity is corrected by extending the length of the pilot cut and restapling the primary point to the new secondary point. Excess tension is released by reducing the length of the pilot cut by a partial closure with carefully placed sutures.
With experience, the surgeon can plan patterned skin excisions that need minimal adjustment.
Plotting a patterned skin excision for the ptotic mid face and nasolabial fold
The region of the patterned skin excision that most influences the mid face and nasolabial fold is the transverse part of the temporal hairline temporozygomatic limbs. Often, chords at least 3 cm long are incorporated in this part of the pattern to bring about optimal change.
In the author's experience, the lift is more effective when the closure line is nearer to the target tissue because less force is dissipated in stretching the intervening skin. An incision at the temporal hairline is 5 cm closer to the nasolabial target area than a coronal in-scalp incision. Thus, a hairline incision is the author's usual approach. (This point is discussed in great detail with the patient before surgery.)
A transverse facial incision, ie, a subciliary eyelid incision that extends laterally all the way to the temporal hairline, is even closer to the nasolabial/midfacial target area. In a well-chosen patient, this incision provides wide flexibility for removal of excess skin and sets the stage for a completely controlled correction of the nasolabial fold. This incision is reserved for patients with exceptionally severe aging changes who are willing to accept a fine scar line in a visible site.
The patient performs the presurgical wash and shampoo before arriving for markings. The facial markings are plotted the afternoon before surgery. With the patient seated, the surgeon rehearses the operative steps manually. The patient holds his or her head in a natural upright position. The surgeon grasps the skin and elevates it, proceeding from point to point, to determine the levels of tension necessary to achieve the goals. The surgeon avoids a level of tension that distorts the facial features or risks skin loss.
The proposed incision lines are marked with a gentian violet marking pen. The chords, excision lines, and anatomic features are marked with a red extra fine–point Sharpie marker. Once the plan is finalized, the red lines are reinforced with gentian violet. The dimensions of the limbs and chords are recorded on a diagram. These figures are transferred to a printed table that is sterilized (as is the diagram) for recording intraoperative adjustments.
Anthropometric points
A series of anthropometric points aids in accurate placement and recording of the landmarks. The main incision line is laid out by connecting the anthropometric points referred to as primary points. The segments between these points are primary limbs. The main excision line is laid out with a series of secondary points and secondary limbs. Additional points and lines are placed simply for anatomic reference.
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Primary points: Primary points are marked along the lower temporal hairline, around the base of the ear, and along the postauricular and mastoid hairline. If an open brow lift is planned, the upper temporal and frontal areas are included. Some of these points are classic anthropometric points, and others have been developed specifically for planning facial surgery.
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Primary limbs: The line connecting any 2 adjacent primary points is recorded as a primary limb. The main incision line is the sum of the primary limbs.
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Secondary points: The surgeon judges how much excess skin can be gathered manually below each primary point. He marks the amount of excess at each site with a secondary point placed below the primary point. Posteriorly, where the skin adheres tightly to the sternomastoid muscle, this judgment is made indirectly. The surgeon grasps the lax cervical skin anterior to the border of the sternomastoid muscle to determine the amount of skin redundancy. The secondary point is marked at a distance from the primary point that corresponds to the excess cervical skin. Around the ear, a periauricular incision line is plotted, which usually includes a tragal flap.
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Chords: Each chord is a line that connects a primary point to a secondary point. The chords indicate the breadth of the segment of skin that is to be excised. In the operating room, each chord is the site of a pilot cut.
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Secondary limbs: Most of the proposed line of excision is a sum of the series of secondary limbs that connect the secondary points. In addition, a cutout for the earlobe is plotted to include the chord of the otobasion inferius. The outline of a tragal camouflage flap is drawn, as is the outline of a flap to fit into the glabrous patch of skin between the crus of the helix and the posterior temporal hairline (ie, preauricular camouflage flap).
Patterned skin excision
The incision line and the excision line form the perimeter of the pattern for the proposed skin excision.
Choice of incisions at the hairline
If dissection is performed on the SMAP, the lift is more effective with a line of closure nearer to the target tissue because less force is dissipated in strain (stretch) of the intervening skin. An incision at the temporal hairline is 5 cm closer to the nasolabial, jowl, or cervical target areas than a coronal in-scalp incision. Thus, a hairline incision with a periauricular component is biomechanically a more effective approach.
Markings of anatomic features
See the list below:
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Zygomatic ligament: The zygomatic ligament is found 42-45 mm anterior to the crease of the tragus at the inferior border of the zygomatic arch. It usually consists of several flat horizontal rows of stout, flat, ligamentous fibers that originate from a 4- to 5-mm patch of zygomatic periosteum and extend to the dermis, passing through all intervening structures. This ligament must be divided to free the SMAP for cephalic movement. The estimated position of the zygomatic ligament is marked with gentian violet.
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Zygomaticus major muscle: The position of the zygomaticus major muscle is marked out from the zygoma to the modiolus. The origin is immediately anterior to the zygomatic ligament. It is marked as a fanlike series of fibers converging on the modiolus labii.
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Masseteric ligaments: The location of the masseteric ligaments is too variable for preoperative estimation. They are found in varying number and size in a vertical patch extending from the anterior border of the masseter between the zygomatic arch and Bichat fat pad.
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Mandibular ligament: The mandibular ligaments are similar in structure to the zygomatic ligaments. They are somewhat smaller and are located 3-4 mm above the mandibular margin and 40-45 mm from the midline of the chin. The estimated positions are marked with gentian violet.
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Modiolar peninsula
The modiolar peninsula is an area lateral to the corner of the mouth that is excluded from dissection. It is a mobile 4 X 4-cm full-thickness section of the cheek. The inferior border of this patch is just above the mandibular ligament; the medial border is at the anguli oris. The modiolar peninsula is in a highly mobile area of the masticatory part of the face; dissection is unnecessary. The intact peninsula is more efficient in transmitting forces to the lower face and it captures extra blood supply from the facial and labial vessels.
The superolateral portion of this peninsula is often within 2.5-3.5 cm of the site of origin of the zygomatic ligament. Midface support is provided by suturing connective tissue of the deeper layers of the superolateral corner of the peninsula to the area of the attachment of the zygomatic ligament or to the masseteric aponeurosis below it. If intraoperatively it appears that these sutures may compress branches of the facial nerve, they are omitted.
Limit lines
Limit lines are marked out to plot where dissection along the SMAP terminates. The boundaries of the SMAP usually include the lateral and inferior part of the orbicularis oculi and the upper two thirds of the zygomaticus major; the limit line skirts the outline of the modiolar peninsula and includes the area of the detached mandibular ligament. The dissection plane crosses the midline of the submandibular area. The inferior limit line extends from the occipital point to the prominence of the cricoid cartilage. The dissection plane crosses the midline of the neck and submandibular areas.
External jugular vein and facial artery
The external jugular vein is compressed below the level of the inferior limit line, and its outline is marked on the skin. The mandibular margin is palpated just in front of the level of the anterior border of the masseter; the pulsation of the facial artery is identified and its site is marked.
Transverse temporal incision
In patients with profound laxity of facial and cervical skin, a transverse incision crossing the temple from the lateral canthal area to the temporal hairline is even closer to the target tissue than a hairline incision and allows for excision of excess skin that cannot be removed by other means. In a well-chosen patient, this incision provides for transmission of an effective lifting force to pendulous submental-anterior cervical skin and for dramatic improvement of festooned cheeks and jowls. This incision is reserved for patients with exceptionally severe gravitational changes who are willing to accept an inconspicuous scar in a conspicuous site. Extra time is needed for plotting the pattern for this excision because more secondary changes must be accounted for. Extra time is also needed in the operating room.
Protection of the markings
Facial markings are protected with a head wrap, which is worn overnight.
Preparation of the operating room
The SMAP facelift is performed with the patient under local anesthesia; sedation and monitoring are performed by an anesthesiologist.
A coaxial headlamp and high-power loupes (4.5X with an 11.5" working distance) provide for anatomic control.
The operating table is padded and contoured in consultation with the patient and staff to eliminate pressure points and to provide complete comfort during the extended local anesthesia. Intravenous access is gained, and Kefzol or a similar intraoperative antibiotic is administered.
Before formal preparation of the patient, the area of skin that has been marked for incisions is infiltrated with 0.5% Xylocaine with epinephrine 1:400,000. It is prepared with Betadine and the incision lines (primary limbs) are scored with a No. 10 blade deep enough for clear visibility during surgery. The excision lines are scored just deep enough to ensure visibility but not to leave scars on skin that may not be excised. The chords are scored with appropriate variation in depth. Tiny x 's are made with No. 15c blades at the intersection of each chord and incision line or excision line. Methylene blue tattoos are an alternate to the x 's, but they tend to disappear.
The nasal oxygen cannula is secured with sutures.
The patient's face, neck, and base of neck are prepared widely with Betadine, the hair is saturated with diluted Hibiclens, and sterile drapes are placed.
The right side of the face and neck is infiltrated with buffered 0.5% Xylocaine with epinephrine 1:400,000. Nerve blocks are placed with 0.25% Marcaine with epinephrine 1:200,000.
Points of entry to the SMAP
Incisions are made and the dissection plane is developed central-ward using points of entry in the temporal area, anterior auricular area, and mastoid area.
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Temporal incision: A temporal incision opens the path to the temporozygomatic zone of dissection (TZ). The temporal skin edge is elevated and the plane of the superficial temporal fascia is located. It is verified by observing the lobular fatty surface of the subcutaneous layer as it peels away from the thin whitish superficial temporal fascia. The peripheral fibers of the orbicularis oculi are sought so the plane can be correctly directed onto the superficial surface of the muscle.
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Anterior auricular incision (including earlobe): This incision opens the path to the parotideomasseteric dissection zone (PM). Around the earlobe, scissors-spreading dissection is carried through the subcutaneous fat to locate the PAF, which provides a safe pathway to the SMAS-platysma, with which it is continuous.
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Mastoid incision: The mastoid incision opens the path to the mastoid-cervical dissection zone (MC). Postauricular skin is elevated to expose the cervical fascia overlying the aponeurotic fibers of origin of the sternocleidomastoid and the fascial floor of the posterior triangle.
Once the TZ, PM, and MC zones have been exposed, they converge anteriorly on the buccal-mandibular dissection zone (BM) and submental-cervical dissection zone (SC).
Elevation of the cervicofacial flap from the SMAP and the extended SMAP
The deep surface of the fascial-fatty layer of the cervicofacial flap is separated from the superficial surface of the SMAP. The surface of this plane is the bare musculofibrous face of the SMAS. The exposed surface of the flap is a multilobular plane of fat interlaced with connective tissue fibers. No part of this dissection plane penetrates through either the fascial-fatty or the SMAS/platysma layer.
As previoiusly mentioned, the extended SMAP continues beyond the borders of the SMAS/platysma layer to include the surface of the superficial temporal fascia, orbicularis oculi, frontalis, and superficial cervical fascia. A subcutaneous forehead lift, a facelift, and a platysma myorrhaphy can be performed on the same plane with complete flexibility of access and of flap movement. No membranous/mesenteric attachments are present, and no change in plane is needed during dissection.
Release of ligamentous restraints to the superficial musculoaponeurotic flap
In the course of the dissection, the zygomatic ligament, mandibular ligament, masseteric cutaneous ligaments, and other restraints to free cephalic movement of the flap are separated.
Dissection sequence
Most of the dissection of the SMAP is performed with a scissors-spreading maneuver. Sharply pointed scissors are used for insinuation between the adherent structures. With gentle dissection, areolar and muscular barriers are separated without injuring nerve branches or arteries.
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Temporozygomatic dissection: After entering the SMAP in the temporal area, the superficial temporal fascia is exposed. The superficial temporal vein is sought just anterior to the tragus and the crus of the helix; it is identified and protected. The flap is elevated anteriorly, seeking the edge of the orbicularis oculi. The peripheral extent of the orbicularis oculi is variable and the edge of the orbicularis adheres more to the subcutaneous fat than to its underlying fascia. The vigilant surgeon finds the muscle edge and proceeds with dissection on the anterior face of the muscle. If the plane is inadvertently directed beneath the muscle, the dark shadow of the muscle rather than translucent lobules of fat is observed on the undersurface of the flap and the path is corrected. Frequently, a muscle bundle diverges downward and forward from the orbicularis oculi, heading toward the modiolus. This muscle surface provides a safe dissection path.
Parotid and zygomatic arch
The tragus and zygomatic arch are reference features for this area. The course of the temporal branch of the facial nerve, where it crosses the arch a fingerbreadth in front of the tragus, is remembered. The continuing course of the rami to the frontalis and orbicularis is kept in mind. The TZ dissection is continued in the posterior cheek. The fascial-fatty layers are less defined just cephalad to the parotid. If the parotid is small, the area of exposure of the branches of the facial nerve is increased. If the parotid is particularly large, care is taken to avoid an inadvertent plane beneath the upper pole of the gland.
The zygomatic branches of the facial nerve are identified as they pass just below and parallel to the lower border of the zygomatic arch en route to the zygomaticus major. Frequently, a large sensory branch mimics a zygomatic motor branch. It emerges from the anterior edge of the parotid with the main zygomatic motor branches, but it diverges outward, passing to the soft tissues of the cheek. Its terminal branches divide and disperse as they merge into the subcutaneous tissue. If this sensory branch is traced posteriorly into the parotid, it is indistinguishable from a zygomatic motor branch. If the nerve is traced and divided distally, it serves the purpose of establishing identity.
Zygomatic ligament
At the lower border of the zygomatic arch, deep to the level of the inferior-oblique bundle of orbicularis, the firm attachment of the zygomatic ligament can be palpated about 42-45 mm anterior to the base of the tragus. With scissors-spreading dissection, the ligamentous fibers are exposed and separated. The zygomatic branches of the facial nerve that intermingle with the ligamentous strands are identified and protected. The superficial branch of the transverse facial artery that accompanies the fibers is coagulated with a bipolar cautery. All strands of the ligament are transected. The location of the stump is marked because it is helpful in locating the zygomaticus major muscle and for choosing a site for the modiolus suspension suture.
The posterior and central dissection of the PM and the MC of the SMAP are completed to free the SMAP flap for the anterior dissection of the TZ.
Zygomaticus major muscle
Of the radially oriented muscles of oral expression, the zygomaticus major is the best developed, strongest, and most consistent in morphology. Its origin passes just anterior to the zygomatic ligament. Zygomatic branches of the facial nerve cross the outer face of the origin of the zygomaticus major (often under cover of the orbicularis oculi) and several more branches pass forward beneath the muscle. These are visualized and protected. The muscle belly of the zygomaticus major courses obliquely downward from its origin on the zygomatic body to its insertion in the modiolus labii. The muscle belly is often encased in its own fat compartment. This compartment is opened with gentle scissors-spreading dissection.
To verify the identification of the zygomaticus major, the belly is grasped with forceps and gently retracted upward. The zygomaticus major unequivocally elevates the modiolus labii and related structures. If this movement is not elicited, a further search is carried out. The upper two thirds of the zygomaticus are freed of all direct and indirect connections to the skin that might cause dimpling when the muscle is plicated.
Preplacement of plication sutures for the zygomaticus major muscle
Currently the author plicates the zygomaticus major muscle by suturing selected points of the posterior and anterior borders of the muscle belly to the fibers of the zygomatic origin of the muscle. A small white aponeurotic patch is found on the deep surface of the muscle origin where it joins the zygomatic periosteum, cephalad to the inferior border of the zygomatic arch.
The anchoring bite of the posterior plication suture (4-0 Prolene, RB-1 needle) is placed through this aponeurotic patch and the plicating bite is placed through the posterior edge of the belly, 15-18 mm below the border of the arch. A surgeon's throw is tightened to view the effectiveness of the plication and to identify any dimpling and the need for further dissection. If the suture placement is satisfactory, it is clamped and left untied. An anterior suture is similarly preplaced; tying occurs after completion of the platysma myorrhaphy.
Support sutures for the modiolar peninsula
A patch of masseteric aponeurosis below the stump of the zygomatic ligament is chosen as the anchorage site for a modiolar support suture. The aponeurotic fibers are usually covered by a layer of translucent yellowish fatty-areolar tissue. Rami of the zygomatic branch of the facial nerve pass through this areolar tissue, parallel to the zygomatic arch. With gentle dissection, an aperture is made through the areolar layer exposing the shiny white fibers of the masseteric aponeurosis. Zygomatic nerve branches are gently pushed cephalad so the suture does not compress them. A 4-0 Prolene suture with an RB-1 taper needle is placed through the masseteric aponeurosis and is then passed through the retinacular connective tissue and fat of the superoposterior part of the modiolar peninsula.
With a surgeon's throw, the suture is tested for effectiveness and unnatural dimpling. The suture is replaced if needed. The strands are then loosened and clamped; they are tied later.
If the distance from the zygomatic arch to the modiolar peninsula is too great for an anchorage suture, a lower point on the masseteric fascia is selected or the suture is omitted.
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Parotideomasseteric dissection
The anterior auricular entry incision is developed and carried around the earlobe. With scissors-spreading dissection, periauricular telae subcutanea are identified. These whitish strands of connective tissue pass from the PAF to the periauricular dermis. The attachments are often very firm and may be distributed widely. The telae pass through a layer of yellow fat lobules. Because the telae are continuous with the PAF, the 2 structures are occasionally indistinguishable and care is exercised in developing the plane.
Clinically, the PAF represents a section of the parotideomasseteric fascia. If dissection is carried through the PAF by spreading the fascial fibers, the capsule of the parotid gland is exposed. The surface of the PAF diverges peripherally from the earlobe and from the lower anterior part of the auricle. It is usually a fascial sheet that can be followed directly forward until it continues as SMAS or obliquely downward until it continues as platysma. Terminal fibers of the great auricular nerve and sensory branches of the cervical plexus pass over, under, or within the fibrous layers of the PAF. Dissection continues forward on the SMAS until the pulsations of the facial artery are seen, and the SMAS is followed to the buccomandibular area.
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Mastoid-cervical dissection
The superficial cervical fascia and the sternomastoid muscle belly are exposed through the mastoid entry incision. As the postauricular-mastoid flap is developed, the surgeon protects the lesser occipital nerve where it runs along the posterior border of the sternomastoid muscle. The fascial floor of the posterior triangle is exposed anteriorly but not disturbed. In a small slender woman, the accessory nerve is at risk in an imprecise dissection.
The main trunk of the great auricular nerve is seen where it passes vertically from the posterior border of the sternocleidomastoid muscle to distribute terminal branches in the periauricular area. The great auricular nerve is covered by adherent subcutaneous tissue and firm superficial cervical fascia. As the nerve is exposed and dissection proceeds forward, a few millimeters beyond it a tangle of whitish fascial fibers heralds the muscle fibers of the posterior border of the platysma. If the undersurface of the flap appears fascial or muscular rather than fatty, then the surface of the platysma is sought on a more superficial level. When the platysma muscle is identified and followed 4-8 mm further, the bluish bulge of the external jugular vein is seen beneath the muscle fibers.
In patients in whom the platysma auricular fascia is not well developed and doubt exists as to the identity of the muscular SMAS, the platysma can be located by the following sequence: sternomastoid muscle to great auricular nerve to border of platysma, then proceeding to the SMAS from the platysma. The external jugular vein is variable and occasionally lies more posteriorly, outside the cover of the platysma.
Dissection is continued forward on the platysma toward the SC region. A number of neurosensory-vascular bundles are isolated, coagulated, and divided.
Dissection is then continued cephalad over the mandibular margin. Precision is exercised in separating the fatty lobular surface of the flap from the musculoareolar layer of the SMAP. Muscle bundles of the platysma are seen to terminate in skin insertions in the area of the mandibular margin. The sheet of muscle becomes thin and delicate as platysma merges into SMAS. Marginal mandibular and buccal filaments of the facial nerve that pass beneath the SMAS are close to the surface and are occasionally visible through the muscle. A sensory ansa is occasionally observed within the superficial layers of the SMAS overlying the posterior-inferior surface of the masseter. Several nerve fibers ramify from a single branch that originates from an anterior cervical sensory nerve. These sensory rami are less than one half the diameter of the motor rami that lie deep to them on the surface of the masseter.
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Buccal-mandibular dissection
Anteriorly, the planes of the TZ and PM areas converge on the BM area. Between the lower part of the zygomaticus major and a line just above the mandibular ligament lies the modiolar peninsula, which is left undissected. This peninsula retains direct attachments between the SMA tissues and the most mobile area of the cheek. The buccal fat pad lies within its capsule at the superior margin of the peninsula and is usually not disturbed. Organized muscular SMAS fibers are not observed in the region above the peninsula. Below this peninsula, dissection continues forward on the SMAP.
Neurosensory-vascular bundles are isolated, coagulated, and divided. The mandibular ligaments are identified. Accompanying vessels are coagulated near the skin to avoid injury to motor branches beneath the thin SMAS. The mandibular ligaments are divided near their skin insertions. Dissection proceeds over the mandibular margin on the SMAS where the muscle continues as platysma in the SC.
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Submental-cervical dissection
Release of the mandibular ligaments gives access to the submental area and to the superior and anterior areas of the platysma. Dissection continues forward on the platysma to the free anterior border of the muscle. The anterior edge of the platysma is freed from its underlying fascial attachments to provide a free border for myorrhaphy sutures. The fascial-fatty layer of the SMAP flap is elevated from the superficial cervical fascia of the midcervical area. Interplatysmal fat is elevated from the fascia and retained on the flap for trimming. If significant subplatysmal fat beyond the interplatysmal area is present, a submental counterincision is placed to address it.
A stay suture of 4-0 chromic catgut is placed through the free border of the platysma at the level of the cricoid notch. The suture is clamped and set aside until needed for the anterior platysma myorrhaphy.
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Incisions and dissection of the opposite side of the face and neck
The incisions and dissection of the opposite side of the face and neck are performed with the same technique.
Suction drains are placed on both sides.
Anterior myorrhaphy of the platysma muscles
The chromic catgut stay suture from the right platysma is passed under the flap across the midline to the left side of the flap. The 2 stay sutures are tied together, approximating the 2 muscles at the midline. Secure closure is gained from the upper end of the gap to the mid level of the thyroid cartilage.
Plication of the zygomaticus major muscles
The 2 plication sutures of the right zygomaticus major are carefully tightened, avoiding strangulation of muscle tissue. The sutures are tied. The left zygomaticus major is similarly plicated.
Modiolar support sutures
The modiolar support sutures are tied in the same manner as the zygomaticus major plication sutures. Mild dimpling of the skin disappears within a few days. Moderate dimpling is evaluated to ascertain whether the site would appear to be a natural dimple if a permanent depression existed. If dimpling is marked, the sutures are removed and replaced or are omitted.
Placement of pilot cuts and trial sutures
The chords are cut as marked at 3 key sites on the right side. For example, the temporozygomatic chord, the preauricular (PrA) chord, and the mastoid (Ms) chord are cut. Inverted simple 5-0 Monocryl sutures are placed at each of the 3 sites. Matching sites are cut and sutured on the left side.
If the closure tension is correct, these trial sutures are left in place. If the tension is excessive, the tight sutures are removed and replaced. A few millimeters of the pilot cut are closed, diminishing the length of the pilot cut and reducing the skin tension.
If facial laxity has not been corrected sufficiently, any suture with insufficient tension is removed and the pilot cut is lengthened. A new suture is placed and the tension is reevaluated. These steps are continued until the tension and contours of the skin appear correct.
Once the tension feels correct and the contours look good, all the remaining chords are cut on both left and right sides and the points are approximated with pilot sutures.
The tension on the skin of the face and neck is again evaluated. At this point, adjustments in tension are still possible; the expense at most is a short inconspicuous scar at a point at which a pilot cut has been shortened.
Adjustment to the length of any chord is indicated on the sterile diagram and table for intraoperative and postoperative reference.
Removal of excess skin
After a final assessment of skin tension and contours, the overlapping skin tabs are marked for excision. The marks indicate the original secondary limbs or the adjusted secondary limbs; adjustments of positions of the secondary limbs correspond to adjustments to the chords.
Tragal camouflage flaps and preauricular camouflage flaps
Once the skin is in final position, the exact size and shape of these flaps can be determined. A final outline is drawn to match the site of placement. The tragal flap is thinned so that the subcutaneous fat is 1 mm thick. The preauricular flap is thinned to 3-4 mm. A recipient site 1 mm deep is marked and cut in the tragus. A recipient site 3-4 mm deep is marked and cut in the glabrous preauricular patch. These flaps are positioned with inverted interrupted 6-0 Monocryl sutures.
Final skin closure and dressings
Incisions of the anterior border of the ear and hairline are closed with running 6-0 Prolene sutures (P-1 needles). Incisions of the posterior border of the ear, posterior hairline, and scalp are closed with a running 3-0 Prolene suture (PS-5 needle) in the intrascalp part of the incision; this suture is converted to a running subcuticular suture along the hairline and posterior border of the ear. Behind the ear, a simple running suture tends to leave suture marks. The suture is knotted with a conspicuous loop at each end for easy retrieval. Steri-Strips are placed on the periauricular wounds. Antibiotic ointment is lightly coated on the hairline wounds.
A layer of shaped polyurethane foam padding is placed against the cheek and neck and a knitted gauze head wrap is applied.
Postoperative details
The drains and head wrap are removed on the first postoperative day and the patient showers the first postoperative evening. Anterior sutures are removed on approximately the fifth day and posterior sutures are removed on approximately the eighth day. Usually, little analgesia is needed.
Follow-up
Dressings and drains are removed on the first postoperative day and a light wrap-around dressing is applied. The patient removes the head dressing that night, takes a shower, and gently shampoos. The patient returns for removal of the anterior auricular and facial sutures on the fifth postoperative day and then returns on the eighth day for removal of all posterior sutures. Activity is increased daily. The patient is monitored with weekly visits for 5 weeks, then monthly visits for 3 months, then annual visits.
Outcome and Prognosis
Patients are virtually uniformly satisfied with this procedure. The need for revisions and touchups is uncommon. The need for future repeat procedures is a function of the continuing aging process.
A cadaveric study by Rao et al comparing skin-only, SMAS plication, and extended SMAS facelifts reported that lifting along the horizontal and vertical vectors was significantly greater for the SMAS operations than for the skin-only surgery. Indeed, no appreciable vertical elevation was seen with the skin-only procedures. For all three methods, the greatest horizontal lift was achieved in the lower face, the aggregate lifts for this region being 0.72 cm, 1.27 cm, and 1.28 cm for the skin-only, SMAS plication, and extended SMAS lifts, respectively. [9]
Complications
Transient facial neurapraxias of 1 or occasionally 2 facial nerve branches are noted in approximately 5% of the author's patients because of dissection directly over the branches. Most of the time, this finding is so subtle that the patient does not notice it until it is called to his or her attention. Almost all return in 3-4 weeks. One outlier was a weak orbicularis that required 3 months to regain full return of function. Permanent motor nerve injury has not occurred.
No hematoma has occurred in this series. One significant skin slough occurred in the temporal area of a woman who claimed to be a former smoker; later, she was discovered to have smoked throughout the perioperative period. The defect was corrected and no permanent esthetic defect resulted. One patient developed a fever on the first postoperative day and proved to have atelectasis, which cleared promptly with treatment. In one of the first patients who had a zygomaticus major plication, a dimple of the cheek occurred.
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Extended superficial musculoaponeurotic system (SMAS) facelift. Superficial musculoaponeurotic plane (SMAP) and SMAP flap. SMAP flap dissection complete. Note extended SMAP with continuity between frontalis, SMAS, cervical platysma, and sternocleidomastoid. With help of retractor, submental fat is visible.
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Extended superficial musculoaponeurotic system (SMAS) facelift. Superficial musculoaponeurotic plane (SMAP) flap in place. Dissection area includes zygomaticus major (ZMM), mandibular ligament (ML), and zygomatic ligament (ZL). Dissection area outlined by gentian violet limit line. A peninsula is left attached to capture vasculature in the buccal area. Excision lines, incision lines, and chords have been scored as guides for excision and closure.
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Extended superficial musculoaponeurotic system (SMAS) facelift. Aponeurotic component and muscular component of SMAS. The SMAS is exposed and marked with gentian violet. Musc = muscular component; Apon = aponeurotic component.
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Extended superficial musculoaponeurotic system (SMAS) facelift. Telae subcutanea and platysma-auricular fascia (PAF). Scissors are tunneled beneath the telae subcutanea in preparation for transecting them. They hold the skin to the underlying PAF. The PAF is visible as a shiny white structure between the tips of the scissors blades. The PAF also forms part of the aponeurotic area of the SMAS.
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Extended superficial musculoaponeurotic system (SMAS) facelift. Muscular component of SMAS. The delicacy and pliability of the muscular SMAS is demonstrated by picking it up and folding it with Castroviejo forceps. The muscle is so thin that fibers of the masseter and branches of the facial nerve can be visualized through its semitranslucency.
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Extended superficial musculoaponeurotic system (SMAS) facelift. Left: Markings for extended SMAS face/forehead lift. Right: Postoperative lateral view.
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Before extended sub-SMAS face lift. Photograph demonstrates SMAS redundancy resulting in jowling and neck platysmal weakening.
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Result after extended SMAS face lift with correction of cervicofacial ptosis. This patient also underwent an upper and lower blepharoplasty and endoscopic midface and browlift.