Facelift

11.6 Facelift


The extended SMAS technique in facial rejuvenation




Introduction


Surgical rejuvenation of the aging face has evolved into one of the most frequently performed surgical procedures in the United States. Facelifting, initially performed as a skin tightening procedure since the early 1900s, has technically matured during the last quarter of a century. This evolution is directly related to the scientific investigation of facial soft tissue anatomy, resulting in a better understanding of the facial anatomic changes which occur with aging. Over the last 30 years, a plethora of procedures have evolved which utilize a variety of technical approaches, having as a common goal the reconstruction of aging-related anatomic changes.


Both the public’s perception as well as the aesthetic concepts in facelifting have similarly evolved over time. Initially, both patients and surgeons focused solely on the laxity which occurs with facial aging, attempting to tighten what was loose rather than shape the face. Hence the term “facelift” (as opposed to “facialplasty”), a mechanical term implying a procedure, the goal of which is to lift what has fallen. Unfortunately, this mechanical approach to facial rejuvenation often produced a tight-appearing, operated look, the stigma of the “wind-tunnel appearance” so often associated with surgical rejuvenation of the aging face. Nonetheless, based on a better understanding of facial soft tissue anatomy and the anatomic changes which occur in aging, facelifting has developed into both a reconstructive procedure (whose goal is to reconstruct the anatomic changes which occur in aging) as well as a more artistically defined technique, which attempts to enhance facial appearance while minimizing signs that a surgical procedure, has been performed.


There are many treatment goals in facelifting besides simply correcting the hallmarks of the aging face, including improvement of the nasolabial folds, facial jowling and correction of obliquity of cervical contour. As important as the mechanical aspects of tightening a loose, aged face, are the aesthetic concepts of improving facial shape and bringing out the beauty in the face which existed during youth. To these goals, the surgeon attempting facial rejuvenation must have a thorough understanding of facial soft tissue anatomy, comprehend the anatomic changes which occur in aging which produce a change in facial shape, and understand the ideal facial shape which can be obtained for a particular patient. Artistic design of surgical access incisions to minimize scar perceptibility, as well as prevent hairline distortion, is also key in preventing surgical stigmata.


The evolution of aging in the human face is complex and multifactorial. Problems that the plastic surgeon confronts in midface rejuvenation include: (1) the dermal component of aging related to intrinsic and extrinsic skin changes (dermal elastosis); (2) facial fat descent; (3) facial deflation, which tends to be regionally specific; (4) radial expansion as facial fat becomes situated centrifugally away from the facial skeleton; and (5) the degree of skeletal support of the soft tissue which influences both loss of volumetric highlights, as well as the descent of facial fat.14 All of these factors influence facial shape changes with aging. Individual patients will exhibit various degrees of these problems at the time they request surgery, and each component of the aging face should be addressed according to individual patient needs.


Evaluation of patient photographs taken during youth and middle age are helpful in determining how a specific patient has aged. Young photographs will usually demonstrate the location of the volumetric highlights present in youth, or serve to document areas which have deflated over time, delineating both the position and vector of facial fat descent. These factors illustrate patient-specific changes in facial shape from youth to middle age, as well as clarifying the possibilities of methods which facial fat repositioning can improve and restore shape. From my perspective, the restoration of facial shape is a more worthy aesthetic goal than attempting to tighten a loose face.



Anatomic considerations


The anatomic basis that allows rhytidectomy to be performed safely is that the facial soft tissue is arranged as a series of concentric layers. This concentric arrangement allows dissection within one anatomic plane to proceed completely separate from structures lying within another anatomic plane. The layers of the face are the: (1) skin; (2) subcutaneous fat; (3) SMAS (superficial facial fascia); (4) mimetic muscles; (5) parotidomasseteric fascia (deep facial fascia); and (6) plane of the facial nerve, parotid duct, buccal fat pad, and facial artery and vein. (This information is thoroughly reviewed in Chapter 6.)


In an overview of the architectural arrangement of the facial soft tissue, the essential point is that there is a superficial component of the facial soft tissue which is defined by the superficial facial fascia and includes the SMAS and those anatomic components which move facial skin (including superficially situated mimetic muscle invested by SMAS, the subcutaneous fat, and skin). This is in contrast to the deeper component of the facial soft tissue, which is defined by the deep facial fascia and those structures related to the deep fascia (including the relatively fixed structures of the face, such as the parotid gland, masseter muscle, periosteum of the facial bones, and facial nerve branches). As the human face ages, many of the stigmata which are typically seen in aging relate to a change in the anatomic relationship which occurs between the superficial and deep facial fascia. With aging, facial fat descends in the plane between superficial and deep facial fascia, and the radial expansion of the superficial soft tissue away from the facial skeleton occurs within this plane. In the author’s opinion, these anatomic changes justify repositioning facial fat through subSMAS dissection to restore facial shape.5,6



Retaining ligaments


The communication between the superficial and deep facial fascia occurs at the level of the retaining ligaments which are discussed in Chapter 11.1. These structures fixate facial soft tissue in normal anatomic position, resisting gravitational forces.1,7 In the evolution of midface aging, the zygomatic and masseteric cutaneous ligaments bear particular attention. The zygomatic ligaments originate from the periosteum of the malar region. Their function is to fixate the malar pad to the underlying zygomatic eminence in the youthful face.


Support of the soft tissues of the medial cheek is provided from a series of fibrous bands that extend along the entire anterior border of the masseter muscle. These are the “masseteric cutaneous ligaments”, and are identified superiorly in the malar area where they mingle with the zygomatic ligaments and extend along the anterior border of the masseter as far inferiorly as the mandibular border. These fibers represent a coalescence between the superficial and deep fascia, extending from the masseter muscle vertically to insert into the overlying dermis. These masseteric ligaments support the soft tissues of the medial cheek superiorly above the mandibular border in youth.


The surgical significance of the retaining ligaments is that they represent the anatomic communication between superficial and deep facial fascia. As this support system becomes attenuated, facial shape changes. The position of the retaining ligaments also dictates the degree of dissection required in a facelift. To adequately mobilize the skin flap, the dissection needs to be carried at least to the peripheral extent of the retaining ligament system, specifically dissecting the skin flap into the malar region, as well as past the anterior border of the masseter. Similarly, the location and restrictiveness of the retaining ligaments dictates the degree of SMAS elevation required to adequately release the superficial fascia. In general, this requires the surgeon to extend the SMAS dissection into the malar region, releasing the superficial fascia from the restraint of the zygomatic ligaments, the upper masseteric ligaments, as well as medial to the anterior border of the parotid.



Aesthetic analysis and treatment planning


As the human face ages, facial shape changes, morphologic facial changes are multifactorial. Some of these changes are straightforward to address, while others remain difficult technical challenges. A paradox has always been that facial anatomy (in terms of basic soft tissue architecture) is essentially unchanged from youth to middle-age, but facial appearance changes greatly over time and is patient specific. Although each face ages differently, there are common themes noted in all aging faces.




Volume loss and facial deflation


Youthful faces are full of well supported facial fat. Over time, deflation occurs, and tends to be most apparent in regions of the face with a high density of retaining ligaments. For this reason, the areas which are noted to be volumetrically full in youth (malar, preparotid, lateral and infraorbital rim, lateral chin) become volumetrically deflated over time. With deflation, soft tissue becomes less supported and therefore appears lax. Youthful faces have a smooth blending of contour between the aesthetic subunits of the face. Middle-aged faces, secondary to both deflation and facial fat descent, develop lines of demarcation between one region of the face and another, which is intuitively identified as old. An accurate aesthetic treatment plan to improve facial shape requires repositioning descended soft tissue into areas of facial deflation to improve shape, not only by restoring volume to the position noted in youth, but also serving to blunt the lines of demarcation between aesthetic subunits. Volumetric augmentation through autologous fat injection or other injectable soft tissue fillers are ancillary agents, which can be useful in augmenting areas of deflation.


Deflation in the aging face is a complex process which tends to be regional and age-specific. Key elements in understanding how deflation occurs have been enlightened following an elucidation of the compartmentalization of subcutaneous fat within the cheek as defined by Rohrich and Pessa.8 What these investigators realized was that the cheek subcutaneous fat, rather than being homogeneous, is compartmentalized, with each facial fat compartment surrounded by specific septal membranes and with each compartment having an independent perforator blood supply. Aesthetically, the significance of compartmentalization of facial fat is that deflation tends to occur within a specific region of the cheek, explaining why the entire cheek does not deflate homogeneously (Fig. 11.6.1).



At the risk of over-simplification, one key to understanding facial deflation is the recognition of the location of zygomaticus major muscle, which traverses from the malar eminence to the oral commissure. Deflation of the cheek lateral to the zygomaticus major muscle tends to occur independently from deflation in the malar region, medial to the zygomaticus major. For many patients, lateral cheek deflation develops at an earlier age than malar pad deflation, and is often noted in patients in their forties. Medial cheek and malar pad deflation tend to occur later in life and is responsible not only for the loss of volumetric support within the anterior cheek, but also leads to the development of what has been termed the infraorbital V-deformity. Deflation in this region results in an apparent increase in the vertical length of the lower lid, as the lid–cheek junction visually descends inferiorly into the poorly supported anterior cheek (Fig. 11.6.2).


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Fig. 11.6.2 (A,B) Preoperative appearance of a 59-year-old male following a 90 pound weight loss from a gastric bypass procedure. Notice the significant areas of facial deflation along the infraorbital rim, lateral orbital rim and malar region. Also note the apparent length of the lower lid as the infraorbital V-deformity develops in association with malar pad deflation. Note also the radial expansion of skin and fat lateral to the nasolabial fold, most marked on the right side. Not only does malar fat deflate and descend, but attenuation of the retinacular connections between skin, fat and deep facial fascia lateral to the nasolabial line allows centrifugal prolapse of soft tissue which accentuates nasolabial prominence. (C,D) Postoperative result. The areas of deflation along the infraorbital rim, lateral orbital rim, and malar region are improved as facial fat has been repositioned into these regions. The nasolabial folds are somewhat improved following malar pad repositioning, but correction is incomplete, especially on the right. Malar pad elevation helps to flatten the prominent nasolabial fold, and improve the infraorbital V-deformity, but does little to correct radial expansion, with the skin lateral to the nasolabial line remaining prolapsed from its attachments to the facial skeleton.


Rights were not granted to include this figure in electronic media. Please refer to the printed book.


(From Stuzin JM. Restoring facial shape in facelifting: The role of skeletal support in facial analysis and midface soft-tissue repositioning. Plast Reconstr Surg 2007;119:362.)


An interesting region of deflation develops in some patients in the submalar region lateral to the oral commissure. In these patients, deflation can result in accentuation of the submalar concavity, which can become more obvious following the vertical soft tissue shifts associated with facelifting procedures. An accentuation of submalar depression lateral to the oral commissure can result in the development of what has been termed “joker lines” or cross-cheek depressions, which are a typical stigmata that a patient has undergone a facelift. Avoidance of vertical soft tissue repositioning in conjunction with volume addition in the submalar recess lateral to the oral commissure is useful in preventing the accentuation of postoperative cross-cheek depressions (Fig. 11.6.3).9




Radial expansion


Not all facial aging is vertical and a major challenge in facial rejuvenation is the radial expansion of facial soft tissue which occurs along specific areas of the midface. In youth, the skin and underlying subcutaneous fat are densely attached to the deep facial fascia by retinacular fibers which transverse between skin, subcutaneous fat, superficial fascia and insert into the deep fascia and facial musculature. Over time, with prolonged animation such as smiling, the skin along the nasolabial line is forced deep to the subcutaneous fat, positioned lateral to the nasolabial fold, attenuating these retinacular attachments. Prolonged animation therefore forces the skin and fat lateral to the nasolabial fold to expand radially and prolapse outward from the facial skeleton, accounting for much of the nasolabial fold prominence in the aging face. Radial expansion lateral to the oral commissure and marionette line similarly accounts for the prominence of the jowl in many middle-aged patients, making the older face appear square in shape and bottom heavy.4,10


Radial expansion is technically difficult to correct, as there are few surgical solutions to re-establish the retinacular attachments between skin, subcutaneous fat and deep fascia. Nonetheless, repositioning of facial fat through some form of support to the superficial fascia will not only reposition fat vertically, but will also provide some degree of internal repositioning such that the superficial facial soft tissues lie closer to the facial skeleton. As the soft tissues become situated closer to the underlying deeper structures of the face, facial morphology tends to be restored to a more youthful configuration. Because of the technical difficulty to completely treat radial expansion in many faces, incomplete correction of both the jowl and nasolabial fold resulting in under-correction can be noted postoperatively despite heroic efforts at repositioning descended facial fat.



Role of skeletal support in formulating a surgical treatment plan


Facial shape and contour is intuitively evaluated when analyzing a patient for facial rejuvenation. Often the two-dimensional considerations seen in photographs are the easiest aspects of aging to identify, and such factors as nasolabial fold depth, jowl prominence, and cervical contour become the primary objectives to improve appearance in the middle-aged face. While these factors are certainly important considerations in treatment planning, the more subtle three-dimensional qualities of facial shape are equally important to evaluate, and are greatly influenced by underlying skeletal support.


In evaluating facial shape during preoperative analysis, there follow some of the major factors which are helpful to consider.4



Facial width, bizygomatic diameter, and malar volume


The emphasis in facelifting over the last 30 years has focused on malar pad elevation.2,1119 While malar pad elevation and restoration of malar highlights is an important factor in improving facial shape, it needs to be patient-specific. Many patients present preoperatively with wide faces, strong malar eminences and large malar volume, with little evidence of malar fat descent. In these individuals it is necessary to evaluate preoperatively the degree of malar pad elevation required to improve facial shape. While limited degrees of malar pad elevation can be helpful in patients who present with wide bizygomatic diameters, in general, if the malar volume is significantly enhanced in these types of individuals, the aesthetic effect is to make a wide face appear even wider on the front view postoperatively. In patients with adequate facial width, the author tends to limit both SMAS release and malar pad elevation to the lateral aspect of the zygomatic eminence such that bizygomatic diameter is not increased postoperatively (Fig. 11.6.4).





Convexity of the malar region juxtaposed to the concavity of the submalar region


In youth, facial fat is situated overlying the malar and preparotid region. This malar fullness is juxtaposed to a concavity within the submalar region overlying the buccinator. As patients age, the relationship between the malar and submalar regions changes and with it, facial shape changes. As facial fat descends and facial deflation occurs, there is less volume overlying the malar eminence and an associated increase in fullness resulting from radial expansion within the submalar region. As the aesthetic relationship between the malar and submalar region becomes modified with time, there is a loss of the angular, tapered configuration in shape noted in youth, and middle-aged faces often appear oval. With greater facial fat descent, and an increase in submalar fullness, older faces appear square.


Preoperatively, an evaluation of the relationship between the malar and submalar region on front view is an essential component of aesthetic treatment planning. For many patients, a restoration in this relationship by increasing malar highlights and malar volume, in association with a restoration of concavity in the submalar region through repositioning fat internally overlying the buccinator muscle becomes a central component in improving facial shape (Figs 11.6.6, 11.6.7).


Feb 21, 2016 | Posted by in General Surgery | Comments Off on Facelift
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