Use midface implants to restore youth and avoid the “skeleton” look
Over the past few decades, there has been a paradigm shift in the approach to treating facial aging. This philosophical recalibration has consisted of a departure from older “subtractive” facial-surgery techniques to newer “restorative” procedures that evoke more appealing and natural-looking results.
Older facial-rejuvenation methods consisted primarily of removing—subtracting—skin and fat and pulling tissues tight. In many instances, this often led to a skeletonized and more aged, “operated-on” appearance. We now recognize that it is not only the skin that needs to be addressed to correct the signs of facial aging, but also facial soft tissues—subcutaneous tissue and fat—and facial bones that lose vital volume and projection as an individual ages.
The major architectural promontories of the facial skeleton, including the malar–midface region, nose, and chin, provide the structural foundation for facial beauty. The overall harmony of the face is largely determined by the balance, size, shape, and position of these fundamental structures.
An aesthetic surgeon may be able to add implants to the facial skeleton to accentuate the areas of the cheekbone and achieve midfacial restoration. These skeletal augmentations redrape and tighten facial skin and reorchestrate the elements of facial balance and proportion for an improved aesthetic result.
Depending on the individual’s specific aesthetic requirements, implant procedures can be performed alone or in combination with other facial plastic surgery procedures to provide a more healthy and youthful appearance. Implant-placement surgeries are performed with hidden or invisible incisions so that no scars are evident and the results are immediately apparent.
Implant Selection
Proper selection of implants requires a working knowledge of the general size, thickness, and material composition of the implant types available. Alloplastic facial implants offer the surgeon many advantages over autogenous tissue, including ready availability of material and simplicity of the surgical procedure. The surgeon must be careful to select the proper implant characteristics for the desired aesthetic result, because each synthetic material has unique properties. With all implant types and materials, careful surgical technique is essential to minimize the risk of complications.
In the past, a wide range of substances were used for soft-tissue and bone augmentation, including autogenous materials such as iliac and rib-bone grafts and nasal cartilage. Various alloplastic materials, including ivory, acrylics, and precious metals, were also used, but they are now solely of historical interest. Advancements in biomaterial science have promoted the use of novel, alloplastic implant materials for facial-skeletal augmentation.
Several general features contribute to an implant’s biocompatibility. The ideal implant consists of materials that do not elicit a chronic inflammatory response or foreign-body reaction, and are nonimmunogenic, noncarcinogenic, and inert toward body fluids. Implant materials must not biodegrade, and they must be malleable enough to sustain their shape and position over time.
Many materials are used for alloplastic implants, including solid silicone elastomers, expanded polytetrafluoroethylene (ePTFE), high-density porous polyethylenes, poly(methyl methacrylate), nylon mesh, bioglass, alumina ceramics, and hydroxyapatite (calcium phosphate) materials. Currently, the most commonly used materials are solid silicone and ePTFE. Both have performed well in terms of low infection incidence and low tendency toward bony resorption when they are positioned in the correct dissection plane.
Improved understanding of the biology of tissue–implant interfaces has spurred the development of bioactive implants, which permit the biological bonding of tissue to implant. This bonding permits natural tissue regeneration, as opposed to chronic foreign-body or inflammatory reactions.
Evolving material technologies have led to the creation of better implants. However, the ideal alloplastic material has yet to be formulated. Plastic surgeons are still being challenged to develop safe and effective materials for facial contouring and restoration. But the most significant burden remains accurate facial analysis, assessment, and planning to achieve a good surgical outcome.
Assessing the Midface
Surgical technique affects both the short-term and long-lasting outcomes of facial skeletal augmentation. General surgical principles related to implantation technique, such as avoiding contaminated fields, using perioperative antibiotics, and meticulous intraoperative handling of the implant materials, are vital to the success and safety of the operation. Careful preoperative assessment of the recipient site should determine whether adequate vascularity and soft-tissue coverage are present.
Prominent malar eminences are a canon of beauty in many cultures, conveying the youthful appearance of facial fullness. A flat, hypoplastic malar area can make the face appear tired and contributes to a prematurely aged countenance.
This tired, sunken look can be secondary to midface hypoplasia or atrophy and ptosis of the soft tissues. But it can also be accentuated by an overresected facelift procedure. The goal of midface augmentation is to restore the appearance of youth and beauty by enhancing structure and facial contour.
Most patients are unaware of the contribution the midface provides to overall facial harmony. They focus instead on the nose, eyes, or lax facial skin. The plastic surgeon can educate patients by illustrating how malar augmentation can restore a youthful and balanced facial contour.
In patients who lack bony substructure, rhytidectomy alone may not provide sufficient rejuvenation. Volume restoration by means of midface augmentation in conjunction with a facelift can provide the scaffolding for the optimal redraping of facial tissues to achieve a more successful rejuvenation. Malar implantation can enhance rhytidectomy or rhinoplasty results by further improving facial balance and harmony.
The majority of malar augmentations are performed on an elective basis. General indications for malar augmentation include post–tumor-resection and posttraumatic deformities, congenital deformities, an aged face with atrophy and ptosis of soft tissues, an unbalanced aesthetic facial triangle, a very round full face or a very long narrow face, and midface hypoplasia. Patients may present with changes associated with aging, such as hollowing of the cheeks and ptosis of the midfacial soft tissue.
Malar implants can augment cheek hollows and grooves associated with inferior displacement of the malar fat pad and soft tissues secondary to volume depletion of aging. Patients with midface hypoplasia gain aesthetic benefit from enhanced facial volume. Patients with mild hemifacial microsomia may also show improvement.
Patients not in any of these categories may request facial augmentation to produce a dramatic high and sharp cheek contour. Flat, thin, and round faces all benefit from malar augmentation, because it balances the face to create a more aesthetically appealing appearance.
Facial evaluation that incorporates photographic documentation is a critical component of patient selection for malar augmentation. Several techniques for facial-measurement analysis of the malar region are available. However, the exact location for augmenting the malar eminence is not universally agreed upon, because the type of malar deficiency varies from patient to patient.
Surgical Technique
After the measurements have been made and the implant size has been determined, the patient is ready to undergo the procedure. The most common technique used is the intraoral approach, in which no external incisions are made on the face.
The patient is marked to determine where the implants will be placed. The specific anesthetic solution used is not critical, but it must contain epinephrine. After the anesthetic is infiltrated on both sides, a 1.5-cm sublabial incision is made in the vertical direction through all layers down to the bone. Horizontal incisions for the approach are not advisable.
Once this incision has been made, a periosteal elevator is used to dissect the periosteum off the bone. Many authors favor the use of fixation to help secure the implant, but I prefer to use precise subperiosteal pockets for implant placement. Therefore, wide undermining is not required, but careful, deliberate creation of pockets allows for precise localization of the implant. The infraorbital nerve is not compromised during the dissection.
Depending on the type of implant used, the lateral dissection may be extended to the zygomatic arch. Submalar implants or combined implants necessitate a more inferior dissection from the arch over the masseter muscle. The correct plane of dissection is over the glistening white fibers of the muscle.
Prior to implant placement, an antibiotic solution is used to irrigate the cavity. A 4-0 chromic suture is passed through the lateral edge of the implant. With the use of an Aufricht retractor, the lateral extent of the pocket is identified and the same suture is passed though to the skin surface. With a gentle amount of tension, the implant is inserted into the pocket. The assistant gently pulls on the suture while the surgeon guides from medial to lateral direction. The suture is then gently tied over a bolster.
The incisions are meticulously closed in two layers. Attention to detail during the closure cannot be overemphasized: Any saliva that penetrates the wound cavity can lead to infection. Over the next 24 to 48 hours, the pocket will “shrink-wrap” around the implant, thereby holding it in its correct position. By the time the sutured bolsters are removed at 5 days postprocedure, the correctly placed implant should be firmly healing into place.
I have described the intraoral route, but other approaches may be preferred by other surgeons. The subciliary approach, through a lower-blepharoplasty incision, may be used to place smaller implants, especially those used to augment the nasojugal fold. During facelift surgery, penetration can also be made via the subcutaneous musculoaponeurotic system (SMAS) and then carried down to the bone. A subperiosteal pocket can be formed from lateral to medial. This technique limits the access for implant positioning.
Complications
The complications of using implants for facial augmentation include infection, extrusion, malposition, bleeding, persistent edema, abnormal prominence, seroma, displacement, and nerve damage. Most of these complications are the result of technical error; they are not caused by the implant material used.
Implant extrusion should not occur if the implants were not forced into the pockets. There should be no folding or spring in the implant after placement.
Impaired nerve function, which is usually temporary, is caused by trauma to the tissues overlying the dissection. Bone erosion beneath the implant can occur, and it is more commonly seen in mandibular implants than malar implants. However, there have been no reports of clinical significance when the implant has been placed in the correct position.
Disfigurement is a risk following a failed implant. This can occur as capsule formation, contracture, or scarring. The failed implant must be removed along with any capsule that has developed. The wound must be debrided in case of infection. Implant replacement following a failed implant is not recommended.
Summing Up
The role of skeletal changes in facial aging has brought to light the importance of volume restoration in modern facial rejuvenation. Many patients seek surgery to improve the appearance and balance of facial features to restore a youthful visage.
Performing a detailed, complete facial analysis and setting appropriate expectations are vital for all patients who undergo aesthetic surgery. Alloplastic facial implants offer the aesthetic or reconstructive surgeon many advantages over autogenous tissue, including availability of allograft materials and simplification of the surgical procedure.
With all implant types and materials, careful surgical technique is crucial for minimizing the risks of complications, including extrusion and infection. Cheek implants can serve to effectively and aesthetically replace lost midface volume with relative simplicity and low morbidity. In properly selected patients, alloplastic mid-facial implantation can yield highly satisfying results and may complement other facial plastic surgical procedures. PSP
Benjamin A. Bassichis, MD, FACS, is a double board-certified facial plastic and reconstructive surgeon and director of the Advanced Facial Plastic Surgery Center in Dallas. He is also a clinical assistant professor at the University of Texas-Southwestern Medical Center in Dallas. He can be reached at (972) 774-1777 or via his Web site, www.advancedfacialplastic.com.
Recommended Reading
Eppley BL. Alloplastic implantation. Plast Reconstr Surg. 1999;104: 1761–1783.
Friedman CD. Future directions in alloplastic materials for facial skeletal augmentation. Facial Plast Surg Clin North Am. 2002;10: 175–180.
Friedman CD, Constantino PD. Alloplastic materials for facial skeletal augmentation. Facial Plast Surg Clin North Am. 2002;10:325–333.
Terino EO. Facial contouring with alloplastic implants: Aesthetic surgery that creates three dimensions. Facial Plast Surg Clin North Am. 1999;7: 55–83.
