Historical background

Recently, the public demand and expectations for aesthetic facial surgery in both males and females has increased dramatically. This has challenged surgeons and scientists to develop more natural and longer lasting enhancements that are safe, ethical, and scientifically tested. Today’s augmentation technology far exceeds earlier fads such as the well publicized 1970s silicone injections to accentuate “cheekbones” and facial contours which resulted in horrific complications.

Among the first materials used successfully were non-reactive metals such as stainless steel and Vitallium. The past four decades of scientific research in solid-state synthesis, material sciences and facial contour aesthetic theory has yielded a new applied clinical science with an armament of tools that reliably have produced more reproducible surgical techniques.

Recent history has seen the introduction of silicone rubber (Silastic), Proplast I and II, Mersilene, Teflon, Dacron, Gore-Tex, acrylic, methymethacrylate, polyethylene, and hydroxylapatite among others. This chapter will endeavor to describe the facial architectural concepts and applied surgical techniques that are employed by Drs E.O. Terino and M.C. Edwards of the Plastic Surgery Institute of Southern California, to alloplastically augment the entire aesthetic facial contour.

The senior author (E.O.T.) is widely recognized for his unique and bold contribution to the development of reproducible and more anatomically precise alloplastic implants for facial rejuvenation (Terino, 1992). This was a time period when the surgical community was still greatly influenced and biased toward the sole use of autologous craniofacial reconstruction techniques pioneered by the Paul Tessier (Tessier, 1971).

At the turn of century, the search for safer and more durable alloplastic materials grew out of necessity due to a need to camouflage contour defects secondary to congenital (e.g. cleft deformities) or traumatically acquired (e.g. modern warfare, automobile accidents, etc.) facial skeletal deformities.

More surprisingly, alloplastic materials have been used for centuries earlier in cosmetic and reconstructive surgery. The roots of this science find themselves first described in papyrus documents from ancient Egypt and Greece. Fascinating ancient anecdotes (before 1000 AD) including the use of sea shells hammered into the jaw to replace missing teeth (dental implants).

In the 20th century, chin alloplastic augmentation was first described in 1948 (Rubin and Walden, 1955). Gonzalez-Ulloa is credited to be among the first surgeons to describe malar augmentation with alloplastic implants (Gonzales-Ulloa, 1957). In the mid-1960s, Ulrich Hinderer developed unilateral corrective malar silicone implants (Hinderer, 1975).

Now we find ourselves, in a new era of facial augmentation that has an exciting and promising future due to an ever expanding armamentarium. The refined synergism of classical tissue transfer, injectable fillers, and alloplastic implants portends to define the next decade of advanced facial aesthetic surgery ultimately leading to the future “promised land” of true tissue engineering based on intimate knowledge of cell biology and stem cells.

The evaluation

Patient evaluation for total alloplastic facial augmentation includes the following:

Applied anatomy for total alloplastic facial augmentation

Interrelationships of the facial promontories

These are three major promontories of volume and mass. In order of importance, they are the nose, the two malar zygomatic eminences, and the chin–jaw line (Fig. 78.1). The supraorbital ridges, constitute a fourth promontory, which are of lesser significance (and will not be discussed in this chapter).

Fig. 78.1 Artist’s rendering of facial architecture illustrating major promontories of mass and volume: the nose, malar-midface and mandible jawline.

By altering the interrelationships of the three major prominentories, a surgeon can uniquely create or restore facial harmony, balance, and beauty. By mathematical law, the diminution or enhancement of any one of the three promontories directly and inversely affects the aesthetic importance of the others. Facial aesthetics is the art and science of achieving beauty by creating a balance in all three elements of facial skeletal anatomy. One important method by which the aesthetic surgeon can accomplish this balance is by properly employing alloplastic implants (Fig. 78.2). Recent advances in applied alloplastic implant technology now make it possible for the surgeon to make subtle or dramatic changes in the facial promontories with ease and predictability.

Fig. 78.2 Example of a 36-year-old male with disproportion and imbalance of malar mid face to the mandibular jaw line aesthetic segment, showing an improvement in facial harmony by augmenting the central mentum, mandibular angles, and malar region.

Over the past decades, aesthetic surgery has evolved dramatically. Surgical procedures have gone from simple skin-tightening techniques to removal or addition of subcutaneous fat, to lifting or plication of the submuscular aponeurotic system (SMAS) as well as suspension techniques of the brow and midface and more recently the introduction of a vast array of injectable fillers including autologous fat.

The restructuring of all these layers still has many limitations. Patients who display round, full, fleshy facial contours with an abundance of subcutaneous fat rarely appear beautiful by contemporary standards. Conversely, there are lean-faced individuals with a tendency to a longer facial contour with inadequate skeletal promontories in the malar or mandibular regions or both. Both extremes of these facial types, as well as innumerable patients who have combinations of volume deficiencies in varying anatomic locations can be significantly improved by rearranging the balance of their skeletal promontories with targeted alloplastic augmentation techniques. Furthermore, contour surgery of the facial skeleton should also be complemented by a wide variety of other sound coordinated facial procedures (Fig. 78.3).

Fig. 78.3 A 56-year-old female who demonstrates the significant benefits from upper midface suspension, malar-submalar augmentation, and rhytidectomy techniques.

Zonal anatomy of the malar and premandible regions

That part of the facial skeleton which, when appropriately augmented, produces an aesthetic change in the contour of midface can be called the “malar-midface space”. To determine the most aesthetic augmentation to select for that space, it is useful to partition the midface region into five distinct anatomic zones (Terino, 1992) (Fig. 78.4). By understanding these five zones and their interrelationships, the surgeon can vary cheek and/or midface shapes to accommodate each unique patient.

Fig. 78.4 Anatomic facial contour zones of the midface.

Summary of zones

Zone 1, the largest area, includes the major portion of the malar bone and the first third of the zygomatic arch. Augmentation of this entire zone produces the greatest volumetric filling of the cheek and also maximizes the projection of the maxillary eminence (Fig. 78.5).

Zone 2, the second most important site, overlies the middle third of the zygomatic arch. Enhancement of this zone along with zone 1 increases accentuation of the cheek bone laterally, giving a broader dimension to the upper third of the face, and creating a high, arched appearance. This change of contour is particularly useful for individuals with a narrow upper face or a long-face syndrome. When, however, zones 1 and 2 are augmented in excess, an abnormal and unattractive protuberance may result (Fig. 78.6).

Zone 3 is the paranasal area, which lies medial to the infraorbital foramen and nerve. A line drawn vertically down from the infraorbital foramen marks the medial extent of the usual dissection for malar augmentation. This line also represents the lateral border of zone 3. When paranasal augmentation in zone 3 occurs, medial fullness of the face is created, often in the upper nasolabial area, which can be unattractive or can produce a “chipmunk-cheek” effect. The skin and subcutaneous tissues are thin in that region; consequently, any implant placed there must be carefully sculptured and tapered. Augmentation of zone 3 is indicated for certain reconstructive purposes, following trauma or other heredity deficiencies (Fig. 78.7).

Zone 4 overlies the posterior third of the zygomatic arch. Augmentation in this area is never needed as it would produce an unnatural appearance. Moreover, dissection here may be dangerous, since it is very possible to injure the zygomaticotemporal or orbicularis oculi branches of the facial nerve, and even the capsule of the temporomandibular joint. Infrequently, deformities have been observed that resulted from operations in this area.

Zone 5, the submalar zone or “submalar triangle,” is bounded posteriorly by the tendonous surface of the masseter muscle, and anteriorly by the canine fossa region of the maxilla. The superior boundary of zone 5 is the inferior margin of the malar bone, which constitutes the first two thirds of the zygomatic arch. The medial extent of the submalar space ends at the lateral border of the nasolabial mound and sulcus. Its anterior limit is bounded by the inferomedial portion of the roof of the entire malar-midface space. It contains the overlying facial musculature, fat, skin, and subcutaneous of the midface region. The inferior limit is selected by the surgeon in the natural dissection plane that separates the masseter from the overlying facial musculature according to the desired configuration of midface fullness selected by the patient. This equates to creating certain breast shape by choosing the lower limit of the submammary sulcus.

Fig. 78.5 Malar hypoplasia and the resulting malar-midface contour from Zone 1, 2 malar volume enhancement.

Fig. 78.6 A postop appearance that is too strong and skeletal looking, due to the wrong implant size, shape and position. Postop view shows significant improvement by using a generous malar shell in zone 1 and submalar, zone 5.

Fig. 78.7 Suborbital volume deficiency and placement of tear trough implants.

In order to orchestrate aesthetic alloplastic augmentation, an understanding of facial types is necessary. Facial type 1 consists of a deficiency in the upper malar bone segment of the malar/midface. This specific contour weakness encompasses zones 1 and 2. Augmentation of zone 1 creates upper cheek fullness that pleasingly simulates bony contour. When a large implant is used to augment zone 2, as well as zone 1, widening of the upper midface occurs which shortens the appearance of a long and narrow face.

The transverse dimensions of the malar bone in the upper malar/midface measure from 4.5 to 6.5 cm from the infraorbital foramen to the posterior third of the zygomatic arch. Vertically, there is, on average, 3.0 to 4.0 cm in distance from the lateral canthus to the inferior margin of the malar bone. Over-accentuation of zone 1 in females may result in a masculine, sharp, angular, harsh or skeletal appearance.

A type 2 facial aesthetic deficiency consists of a soft tissue contour depression specifically in the lower aspect of the midfacial aesthetic unit called the submalar zone 5 (SM5) or submalar “triangle”. This deficiency resides over the masseter tendon and the canine fossa lying under the inferior border of the malar bone and zygomatic arch. A large malar shell implanted over the inferior aspect of the malar bone in zone 1 and extending into the submalar space below the border of the malar bone creates the illusion of a round, full “apple cheek” in females.

The soft tissues overlying the skeleton of the midface, malar, and submalar area undergo environmentally influenced predetermined genetic-based atrophy. A modest 3 mm or 4 mm implant thickness can augment and rejuvenate an aging face.

Augmenting the submalar region creates the youthful appearance of soft tissue fullness in the midface as well as the illusion of a larger malar bone. This is especially useful in the aging face where atrophy and the midface soft tissue descent create a more pronounced nasolabial fold. The inferior limit of the submalar space is variably created by dissecting the soft tissue roof (buccinator, zygomaticus muscles, and SMAS) from the masseter tendon. This is similar histologically to the inframammary sulcus created during breast augmentation. As the SM5 space is dissected and augmented in a more inferior direction, a larger, rounder cheek contour is produced which simulates both bony and soft tissue fullness. This type of midface contour is exemplified in the images of actresses Bo Derek and Linda Evans, or today’s Renee Zellweger and Angelina Jolie.

By definition, a comprehensive augmentation of the entire malar-midface unit may require an implant shell with maximal transverse dimensions of 5.5 cm across and 4.5 cm vertically. A type 2 face has adequate malar bone prominence, but is deficient in submalar soft tissue volume. This creates a flat, older, midface contour. This frequently occurs in the aging face of both males and females. In a young individual with strongly defined cheekbones and yet deficiencies in the midface soft tissues, a submalar augmentation produces aesthetic softness, and adds youthful fullness to the face. Some people feel strongly that a submalar implant can lift the nasolabial sulcus and give the illusion of facial tightening that will postpone the perceived need for rhytidectomy. The authors have not observed this occurrence. The authors favor volume filling of the midface just posterior to the nasolabial mound, in order to de-emphasize the appearance of fullness and simultaneously correct the soft tissue volume deficiency in the midface.

A type 3 facial aesthetic deficiency in a face consists of a very strong malar zygomatic superstructure and a very sunken submalar infrastructure. Such faces often have thin skin and subcutaneous support requiring a generous submalar augmentation with a projecting implant thickness (5–8 mm). This facial type occurs with aging, as well as from heredity (Fig. 78.8). The appearance is that of an emaciated, drawn, haggard and even sick countenance. This can result from soft tissue disease states such as Romberg’s hemi-atrophy and HIV lipodystrophy. The remedy, for any etiology, is the same: a generous volume filling of the submalar zone 5 (SM5) (Fig. 78.9).

Fig. 78.8 Submalar zone 5 is anatomically below the lower border of the malar bone. It may be volume deficient either by hereditary or from aging atrophy. An appropriate submalar implant placement provides excellent aesthetic improvement.

Fig. 78.9 Fat atrophy occurs universally with aging face. This can produce a sunken, tired, older look. When there is adequate malar bone prominence in a type 2 or type 3 face, a large malar shell placed in the submalar region (SM5) restores a youthful fullness to the face.

A type 4 facial type consists of extreme volume deficiency in both malar zones 1 and 2 and the submalar zone 5 (SM5) regions and may also include the suborbital and paranasal zone 3 areas. It is more common in men than in women. It is identified by a “flat face” appearance. It also has been described as the “polar bear” syndrome because of a suborbital skeletal deficiency, which contributes to a proptotic, bulging appearance of the globe of the eye. Due to bony deficiency of the infraorbital region, a downward or vertical descent of the lower eyelid may result in scleral show.

A comprehensive shell implant which fills the medial tear trough, the suborbital rim, and the upper malar zones, improves this aesthetic imbalance significantly. For some patients a large shell implant to fill malar zones 1 and 2 as well as submalar zone 5 is all that is necessary. Theoretically, the shell implant may also add support and elevate the eyelid into a more attractive horizontal position. However, lateral canthopexy techniques may be necessary to benefit patients with this facial type.

Type 5 aesthetic facial deficiency exists as a weakness of facial structure in the suborbital “tear trough” region. This creates a tired and “hollow” appearance around the eyes, especially in the lower orbital region. There may also be a tendency for the eyeball itself to look proptotic due to the “negative vector” orbit (Fig. 78.10).

Fig. 78.10 Before and after pictures of a patient with a type 4 face demonstrating the improvement of an extreme volume deficiency of the entire maxilla and a “negative” vector suborbital bony rim using a comprehensive extended tear trough–malar shell. This helps to correct a “flat or dish-face” appearance.

Volume deficiency in this area is especially viewed to be unattractive in females. A uniquely designed tear trough implant extends from the medial canthus to the lateral orbital malar rim, considerably improves this deficiency. Fat grafting along the inferior orbital rim has been considered by some to be advantageous but by most to be highly risky. In general, the authors’ experience is that all autologous soft tissue grafting in this region manifests unpredictable shrinkage and may produce irregularities or result in negligible improvement with added risks.

When this volume deficiency is also accompanied by significant malar-zygomatic hypoplasia the new suborbital tear trough-malar shell (SOTTM) is indicated (Fig. 78.11). Autogenous tissue transplants of fat, muscle, galea and temporalis fascia into this area by a variety of authors have been only partially successful because all autologous grafts, due to unpredictable cell death, demonstrate variable shrinkage and contour irregularities. Their success and complication rate are still debated. More recent techniques for “SOOF” infraorbital dissections which release and elevate the suborbital cheek and malar soft tissue structures beneath the orbital rim and transpose intraorbital fat exist and are more successful in correcting this deficiency but still remain dependent on the locally available tissue mass.

Fig. 78.11 The new suborbital tear trough–malar implant and the technique for insertion around the infraorbital nerve.

Tissue repositioning techniques whether “deep plane”, “FAME”, “SOMME”, or “subperiosteal” are still undergoing evaluation for their long-term persistence and reproducibility. Used in conjunction with the guaranteed permanence of alloplastic malar or suborbital augmentation, this tissue repositioning achieves optimum aesthetic appearances and reproducible surgical results.

Finally, there is the facial type 6 aesthetic deficiency in the premaxillary segment. A true premaxillary congenital deformity with dental occlusal problems and abnormal mandibular dental interrelationships can create the appearance of a significant “sunken” appearance in the paranasal, perialar region. A deficiency of either soft tissue or bone in the upper nasolabial sulci adjacent to the nostrils also produces a retrusive, unattractive perialar appearance. This is especially true when either a strong jaw line or a strong malar region or both accompany this central weakness and accentuate it by relative comparison.

Type 6 aesthetic deficiencies are extremely common in all races and are frequently overlooked by aesthetic surgeons. However, mild to moderate forms of premaxillary retrusion can have significant aesthetic improvement from alloplastic augmentation. There are several ways to do this; a silicone rubber implant has been specially designed to fit around the lower pyriform aperture. It is easily placed either directly onto the bone through intraoral or intranasal incisions. Its natural anatomic shape and posterior contour provide stability when positioned properly (Fig. 78.12).

Fig. 78.12 Example of two patients in whom premaxillary retrusive contour deformities were corrected using a peripyriform premaxillary contemporary design implant.

Zonal anatomy of the premandible

Techniques for chin augmentation have been amplified by extending the shape and size of the traditional, centrally placed implant to provide more lateral and posterior alteration of the chin contour. Oval chin implants have traditionally been placed between the mental foramen. Implants placed only into this central segment often produce an unattractive, round, central protuberance (Fig. 78.13). Moreover, displacement of the origins of the mentalis muscle by traditional chin implant surgery may result in a downward dislocation of the overlying soft-tissue mound and musculature, thereby creating the dreadful “witch’s chin” or “drooping chin” deformity. Furthermore, an adjacent soft tissue sulcus between the central chin mound and the sagging, more lateral jowl elements produce “marionette lines” or the “anterior mandibular sulcus”.

Fig. 78.13 Traditional chin implants have been placed centrally between the mental foramina. This often produces a unattractive central abnormal, rounded protuberance.

Therefore, to achieve natural chin augmentation, the “premandible space” must be taken into consideration. This region can be configured into four functional anatomic zones (Terino, 2002) (Fig. 78.14).

Fig. 78.14 There are four anatomic zones within the premandible space that can be augmented to correct specific regional contours for the lower aesthetic mandibular facial segment.

Extending the premandible space laterally into the middle half of the horizontal ramus, and the region of the oblique line, enables the surgeon to define a midlateral zone (ML) of the mandible. Augmentation of this zone, in addition to the central mentum, creates a chin-jawline that has a natural contour (Figs 78.15, 78.16). This embodies the principle of the “extended anatomic contour” implants designed by the senior author (E.O.T.). For maximal aesthetic enhancement, augmentation within the midlateral zone, and even further into the more posterior part of the mandible, creates broadening which appears to shorten the face as well as give greater definition of the mid and posterior aspects of the jaw line. The posterolateral segment of the premandibular space, overlies the posterior half of the horizontal ramus, extending back from the oblique line and including the angle of the mandible and its ascending ramus. Augmentation creates a sculptured enhancement of the posterior jaw line.

Fig. 78.15 Anatomic design implants are contoured posteriorly to securely fit the bony surface like a glove.

Fig. 78.16 Abnormal contours from traditional central implants can be corrected by using extended anatomic chin implants designed by the author.

The fourth and final premandibular zone resides beneath the inferior border of the mandible and is called the submandibular zone (Fig. 78.17). Traditional chin implants have lacked the ability to extend volume deficient mandibles in a vertical direction. The newer implants, however, have been designed to wrap around the bony margin of the mandible to increase the vertical height of the face from the lower lip to the inferior chin line, thereby augmenting the submandibular zone (Fig. 78.18).

Fig. 78.17 The submandibular implant which lengthens a face vertically by 4 mm as well as providing 4 mm of anterior–posterior projection.

Fig. 78.18 Pre- and postoperative photos of a 21-year-old Asian female who had significant aesthetic balance improvement in the lower third facial aesthetic segment from a submandibular implant.

The “marionette lines” or prejowl sulcus overlay the mental nerve where the anterior mandibular ligament restricts the downward and forward descent of the lower cheek issues during the aging process.

Technical steps of alloplastic facial augmentation

^* IMPLANTECH Corporation – Ventura, California.

When placed directly on bone, smooth silicone implants become rapidly fixed and securely surrounded by capsular fibrosis. Because this creates a space well-demarcated, they can be removed readily and exchanged when necessary or desirable. On the other hand, porous implants that permit tissue ingrowth such as high-density polyethylene, e.g. Medpor, fenestrated implants, and implants with Dacron backing have a low but consistent, predictable, and clinically significant incidence of infection (Carboni, Gasparini et al., 2002). They are also significantly more difficult to exchange or modify due to bone sequestration and other locally induced tissue interactions. Perhaps, most pertinent is the recognition that Medpor is also more likely to extrude when placed under thinner tissue coverage (Sevin, Askar et al., 2000).

By contradistinction, silastic implants can survive the onset of inflammation and even gross purulence, whereas infected porous implants may necessitate removal.

The success of recent anatomic facial implants is also, in large part, due to their conformability to the facial skeleton. Implants are being produced whose posterior aspect are accurately molded to the shape and form of the facial skeleton. The evolution of implants volumetrically to fit the dimensions of the face effectively minimizes mobility and malposition.

A second achievement has been the increased malleability and compressibility of facial implants, which enable the insertion into smaller apertures. With the currently expanding use of larger implants, these two qualities have become even more critical. Often implants of 10–20 cm² need to be placed onto the malar bone or the mandible of the facial skeleton.

Silicone rubber implants, fabricated into a suitable medium-grade consistency, make it possible to perform this procedure with ease. Finally, the ready modifiability of silicone implants works in the surgeon’s favor when a formidable barrier is encountered during the operation. Instead of enforcing a traumatic dissection upon an area of anatomy where nerve damage may be imminent, the surgeon can easily diminish the implants or alter their configuration with a scalpel without affecting the resulting contour.

Preoperative planning

Preoperative planning for all plastic and reconstructive surgery is the critically essential step for achieving successful results. For aesthetic surgery, such planning must include accurate and definitive communication with the patient, whose perceptions and expectations the surgeon must understand completely. For traditional surgery on aging patients, communication about their needs and wishes may be relatively simple. They wish to have their prior youthful contours and facial features restored as completely as possible. With the passing years, individuals accommodate to the slow, gradual changes that take place in the soft-tissue contours of their faces. The limited technical results of routine tissue repositioning and tightening techniques from traditional facial aesthetic surgery may therefore be acceptable to them, because they do produce some significant visible albeit limited postoperative improvements.

Well-established techniques for altering facial contours and facial promontories go beyond routine surgery in that they may, if desired, change a patient’s inherited anatomic configuration. Following facial implant surgery, patients experience much improved visual and perceptual images of themselves and with more permanence of contour.

Although there currently is an assortment of ever-evolving tools for measuring aesthetic skeletal parameters, precise implementation of facial form still remains challenging, even in the most experienced hands. Therefore, before the surgeon attempts an alloplastic facial contour alteration, it is imperative that he or she knows exactly what facial image the patient desires. The authors request their patients to modify photographs of themselves and bring them in, or to provide, from fashion magazines or other sources, examples of facial contours that they admire, namely, faces that they feel look similar to their own but are more attractive in the pertinent skeletal areas (Fig. 78.19). Although this process may run contrary to standard residency teaching, it creates an understanding of patients’ expectations by providing invaluable visual insights and imagery to discuss. Most patients do have very precise ideas about the images of facial contours they wish to emulate. Therefore, when they do not, it is easy to discover that their expectations cannot be met. In elective operations, surgeons must not undertake what they are not sure they can accomplish especially when the patient’s own visually described goals are poorly defined. Overall, the authors find computer imaging technology to be indispensable in this process.

Fig. 78.19 All patients wish to have youthful fullness return to their faces. This can be accomplished by alloplastic augmentation. Patients are asked to bring photographs of themselves in a more youthful time of life in order to try to recover their earlier “ideal scene”.

During patient consultations, it is important to determine the desired anatomic zones to augmentation, because, by definition, this is responsible for the patient’s postoperative appearance. Multiple consultations with the patient are important to precisely define the final desired outcome. On the morning of surgery, quality time spent in marking, measuring, and discussing surgical details with the patient is essential. Finally, by drawing the preoperative configurations of the pertinent regional and zonal anatomic landmarks on the patient’s face, the surgeon is provided with guidelines for accurately performing the intraoperative surgical dissection and implant placement (Fig. 78.20).

Fig. 78.20 Preoperative markings are made on all patients’ faces the morning of surgery to outline their zonal anatomy and bone structure.

Suggested operative techniques

With regard to operative technique, the authors offer the following suggestions:

Table 78.2 Anesthesia

Technical elements

The various routes for entering the malar space, including the submalar region, are as follows: (1) intraoral; (2) lower blepharoplasty (subciliary); (3) rhytidectomv; (4) zygomaticotemporal; and (5) transcoronal; and (5) transconjunctival. The intraoral route has been the traditional and most frequent approach to maxillary malar and midface augmentation. The authors use an incision that is L-shaped with 1 cm limbs, made through the mucosa only and in a vertically oblique direction. It is located over the anterior buttress of the maxilla, just above the canine tooth and approximately 2.5 cm medial to the orifice of Stensen’s duct.

A spatula-shaped elevator with a 1 cm wide blade is placed directly under the periosteum and under the orbicularis oris muscle in a vertical orientation at the inferior base of the maxillary buttress, in the apex of the gingival-buccal sulcus. The overlying soft tissues are swept obliquely upward over the maxillary eminence by maintaining the elevator directly on bone. The elevator should always remain on the bony margin along the inferior border of the malar eminence and zygomatic arch (Fig. 78.21).

Fig. 78.21 The intraoral approach to malar augmentation involves an oblique and a horizontal 1.5-cm incision just over the maxillary buttress and through mucosa only. The dissection is subperiosteal, through the lower border of the incision beneath the muscles and always remains on bone.

Manual palpation of the previously marked zonal design of the malar space anatomy on the skin is performed, while the underlying elevator mobilizes the tissues directly from the bone. This maneuver includes palpating the orbital rim and the upper and lower borders of the zygoma as the elevator dissects the subperiosteal space within these areas (Fig. 78.22).

Fig. 78.22 Illustration showing manual guidance of an elevator beneath the previously marked malar anatomy while creating an accurate subperiosteal space for malar shell placement.

A lighted fiberoptic Aufricht retractor confirms the anatomic dissection. Once bony margins are reached, further space expansion is performed only by means of a rounded, blunter spatula elevator. No dissection should occur into the soft tissues with a penetrating and forceful motion.

No dissection should occur directly into the area of the infraorbital nerve. When desired, the periosteum may be mobilized, both lateral and inferior to the infraorbital foramen, with a careful scraping motion until the nerve and foramen is visualized. This is indicated for placement of suborbital tear trough implants. Frequent irrigation is performed with antibiotic solution (bacitracin, 50,000 U/L or Ancef 1 g/L of normal saline).

Once the space is mobilized, the chosen implant is introduced with a long, curved, serrated clamp placed transversely across the upper end of the implant and inserted into the posterior zygomatic tunnel while two 10 inch needles swedged on a 2-0 prolene suture (Ethibond) are placed from inside to outside in the temporal region and then tied over a large bolster sponge. Should buckling of the implant occur, correct positioning can be ensured by using a Russian forceps, in combination with a spatula periosteal elevator, passed both anterior and posterior to the implant. Fiberoptic Aufricht retractors or other illuminating instruments are used to illuminate the interior of the space, reveal the internal anatomy, and confirm the correct position of the implant.

In the submalar zone, the soft tissues are swept off the shiny, white, glistening, fibrous tendon of the masseter muscle in an inferior and outward direction. This opens up the submalar space for approximately 1–2 cm, depending on the desired choice of cheek shape and the corresponding implant necessary to achieve it. When adequate anesthesia techniques are used, the intraoral approach permits excellent visualization of the skeletal anatomy and musculature. This exposure allows accurate implant placement into zones 1, 2, and 5 (SM5). It permits the surgeon to place a spatula elevator above and below the implant to make certain that its edges are not buckled or that the zygomatic extension of the implant is not curled. It is not necessary to visualize the infraorbital nerve, but it is rather easy to do so when required, or when an implant is used for the suborbital region.

Subciliary blepharoplasty approach

In the standard subciliary blepharoplasty approach, an incision is made 3 mm below the lash line, and limited in its lateral extension to avoid scars in the lateral canthal region. This approach may be used either in conjunction with routine blepharoplasty or as an independent route of entry for a malar implant. When used for implant placement alone, the incision is limited to a length of 10–15 mm. It is designed only in the middle to lateral third of the lower eyelid, in the subciliary region (Fig. 78.23). Moreover, the dissection inferiorly provides a sturdy shelf upon which the implant rests.

Fig. 78.23 A subciliary lower eyelid incision is performed using a skin muscle flap down to inferior orbital bony margin and penetrating the periosteum and SOOF layer 4 mm below the orbital rim.

Tear trough implants can be placed through an external subciliary blepharoplasty incision, a transconjunctival incision, or an intraoral route. The tear trough implant is placed after cutting out a segment, which allows it to surround the main trunk of the infraorbital nerve. If desired, it can be secured by one or two sutures to the medial orbicularis muscles or to the inferior orbital rim.

The greatest advantage of the subciliary blepharoplasty approach is the opportunity for correct positioning, because the surgeon is able to directly observe the relationship of the implant to the inferior orbital rim.

The rhytidectomy approach

Zone 1 of the malar region is a safe zone for penetration through the superficial musculo-aponeurotic system (SMAS) into the malar space. There are no named branches of the facial nerve in that region. Once the rhytidectomy flap is elevated over zones 1 and 2, the roof of the malar space can be directly penetrated through the SMAS with a small, sharp elevator onto the malar bone. This may be done either medial or lateral to the zygomaticus origins. The seventh nerve branches leading to the frontalis muscle run more proximal over the middle third of the zygomatic arch, and the motor nerve to the orbicularis oculi is more superior. By creating a transverse aperture that parallels facial nerve fibers, nerve risk is minimal. It is important to remember that dissection backward along the zygomatic arch is necessary to position a malar shell implant comfortably and correctly without a buckling of the lateral tail.

Rhytidectomy insertion offers two advantages: (1) a sterile and readily accessible entry wound; and (2) a reasonable opportunity for accurate placement with direct observation and palpation. We have not used this approach frequently.

Premandible augmentation technique

Extending a centrally placed implant into the midlateral and posterolateral zones requires only a dissection along the inferior mandibular border into the “safe zone” posterior to the mental nerve. There is a significant constriction and adherence of the tissues to the bone surrounding the mental foramen called the mandibular ligament. Once these are released, dissection of the tissues from the posterolateral zone occurs easily.

Although operations to augment the central mandible for aesthetic purposes have existed for over 50 years (Millard, 1954), and plastic surgeons have well understood the advantages of improved nasomentum profile relationships, it is only within the last 30 years that methods have been developed for augmenting the premandible by extending central chin implants over a larger surface area as well and with using anatomically designed alloplastic devices. These techniques also make it possible to alter the shape and size of the midlateral and posterior aspects of the mandible, and even to lengthen the submandibular segment vertically.

Access to the premandible space can be achieved by either the standard intraoral route or the submental route (Fig. 78.24). These authors use the submental approach exclusively for operations that require additional surgery in the submental and submandibular region, such as liposculpturing and platysmal contouring.

Fig. 78.24 Photos showing both the submental (A) and the intraoral (B) routes for insertion of extended anatomic chin implants.

In both approaches, the incisions are transverse and 2 cm long. The intraoral transverse incision is through mucosa only. The mentalis muscles are then divided vertically through their midline raphe to avoid transection of the muscle bellies and total detachment from their bony origins (Fig. 78.25). This aperture provides direct access downward onto the bony plane and eliminates the muscle weakening that occurs with customary transection methods.

Fig. 78.25 Illustration of the central subperiosteal dissection between the mental nerves down to the inferior border of the central mandible and location of an extended anatomic implant beneath the mental nerves.

By adhering to the principle of subperiosteal elevation on bone, the muscle attachments are elevated from their origins along the inferior margin of the mandible. This area does not endanger the mental nerve. The mandibular branch of facial nerve VII does, however, cross just anterior to the mid portion of the mandible in the midlateral zone. Consequently, it is important not to traumatize the tissues that overlie and constitute the roof of the premandible space in that region. The mental nerve and foramen can vary in number and location. Reported anatomic variations consist of multiple foramina existing between 1.5 and 4.5 cm from the mid line in a small percentage of individuals. The bony configuration of the foramen, however, directs the mental nerve in a superior path upward into the lower lip. Dissections that remain inferior to the foramen and along the lower border of the mandible avoid significant danger of nerve damage.

In one operation, the senior author inadvertently placed a premandible implant superior to the mental nerves bilaterally. The immediate result was compression symptoms in the form of anesthesia of the lower lip. Unfortunately, other facial procedures performed at the same time (rhytidectomy and blepharoplasty) obscured the diagnosis until the swelling had diminished. The implant was repositioned beneath the nerves on the ninth postoperative day. Replacement of an implant or repositioning can easily be done within the first 10 to 14 days. By applying the basic principles of wound healing taught during residency, the surgeon is able to re-enter the premandible or malar space to replace or reposition implants prior to the rapid increase in wound tensile strength, which occurs from 14 to 21 days after the operation.

Dysesthesias and paresthesias in small or sometimes larger areas of distribution of the mental nerve are not common following alloplastic chin and premandible augmentation. The symptoms are usually temporary and subside within 4–6 weeks.

Clinically, there appears to be a definite correlation between the occurrence of nerve symptoms and the degree of difficulty that the surgeon experiences in placing the implant. There is no correlation, however, with the size and shape of the implant. Extended alloplastic anatomic-contoured implants contain specific notches designed to avoid pressure around the mental foramen. They provide for normal variations in the location of the mental foramen, which is 8–10 mm up from the lower mandibular margin.

Additional incisions may be made posterior to the mental nerve to accurately place lateral mandibular bars and implants that extend into the midlateral and posterolateral zones. A 3 cm horizontal mucosal incision made in front of the first molar, followed by direct penetration through the muscle onto the mandibular bone, allows access to, and easy dissection of, the premandible space beneath. This aperture assists accurate placement of mandibular angle implant and also facilitates positioning the posterior extensions of other implants to augment simultaneously the central mentum and the midlateral zones anteriorly.

The authors have already stated that integrity of the mental nerve and easy positioning of the implant beneath it can be assured through fiberoptic techniques. A narrow, malleable ribbon retractor is utilized to distract the soft tissues for the placement of premandible implants into their tunnels. To position a long, extended premandible implant, a tunnel or space must be created that is longer posteriorly than the length of the implant. The implant can then be inserted from the central incision far into one side and then be folded upon itself to be introduced into the opposite mandibular tunnel. Careful palpation, lateral positioning, and observing the central marking of the implant directly over the central mental protuberance are keys to accurate placement.

Posterolateral implants are placed through a posterolateral incision. The posterolateral incision is transverse and is located approximately 1.5–2 cm anterior and adjacent to the angle of the mandible. Appropriate space for placement is created by making a direct dissection onto bone and subperiosteally beneath the masseter muscle (Fig. 78.26). A curved elevator is used to dissect around the posterior aspects of the ascending ramus in the angle region. In this way, implants designed to fit securely around the angle of the mandible can be accurately positioned (Figs 78.27, 78.28). As with all facial implant incisions, a two-layer closure of muscle and mucosa is optimal.

Fig. 78.26 Artist’s illustration, demonstrating a 3-cm intraoral incision just posterior to the molar teeth. A subperiosteal space is created, disinserting the masseter from the posterior border, and angle of the mandible, as well as its anterior horizontal margin and extending up the ascending ramus.

Fig. 78.27 Photographs of a mandibular angle implant insertion using a curved clamp and placing it in an upward and posterior position over the mandibular angle and ascending ramus.

Fig. 78.28 Examples of mandibular augmentation. Left patient, preoperative and six months postoperative mandibular angle augmentation. Right patient, preoperative and one year after placement of mandibular angle implant.

Postoperative care

Postoperative care for facial implants is straightforward and uncomplicated. Perioperative oral antibiotics are utilized. At the present time, cephalosporins are favored. Prior to the start of surgery, 1 g of Ancef is given intravenously by the anesthesiologist. 10 mg of Decadron is also given intravenously during the surgery to control postoperative edema. During the postoperative period a 5-day diminishing course of steroid in the form of a Medrol dose pack is taken orally. For the first 12 hours cold compresses are applied intermittently to the operative site either in the midface or premandible region. No bandages are used. Removal of intraoral mucosal and external subcuticular sutures is unnecessary. A soft diet is maintained for 10 days. It is highly recommended that the patient recline at a 45 degree angle and in the supine position for at least 1 week. Vigorous physical activity is not permitted for 4 weeks. After which, patients may engage in any and all types of exercise activities.

Complications

The major disadvantages of the use of alloplastic materials are several: