Malar and Submalar Implants Treatment & Management

Silastic implants remain one of the most common materials used for malar and submalar augmentation. Silastic implants possess many characteristics of the ideal facial implant, including ease of placement and the ability to be readily exchangeable, malleable, conformable, nonimmunogenic and noncarcinogenic, resistant to infection, and easily tailored by the surgeon. Recently designed facial implants have been very successful, based in part on their anatomic conformability to the facial skeleton. The projecting contour of the bone is accommodated by the posterior surface of the implant as it molds over the surface.

In addition, the larger surface area of the implants allows them to fit the facial contour more effectively and minimizes malposition, migration, and displacement. Solid silastic implants prevent actual tissue ingrowth, and a resultant dense fibrous capsule forms around the implant. Some surgeons prefer to fixate the implants into position with the use of titanium screws or nonresorbable sutures, thus securing the implant in position and minimizing the complication of implant migration.

More recently, expanded polytetrafluoroethylene (ePTFE) has been used for facial augmentation; the advantages of ePTFE include rapid stabilization and limited capsule formation. A basic science study demonstrated less capsule formation and increased neovascularization with ePTFE reinforced with fluorinated ethylene propylene when compared with silicone implants.

Additionally, high-density porous polyethylene (Medpor) has gained popularity in facial augmentation. However, a considerable ingrowth of fibrous tissue results, which makes the removal of the implant challenging.

A prospective study by Khiabani et al indicated that mild to moderate malar depression can be successfully corrected with buccal fat pad pedicle flaps. In the study, 13 patients underwent the procedure either for aesthetic purposes or in response to imprecisely reduced zygomaticomaxillary complex fractures. At 1-year follow-up, resorption averaged 0.376 mm. No major complications, such as massive hematoma, asymmetry, intense pain, parotid duct injury, or prolonged bruising, were found in association with the procedure. ^[15]

Prior to performing augmentation procedures for facial rejuvenation, the surgeon should critically analyze youthful faces. Youthful qualities include full cheeks with smooth, symmetric contours. Actual measurements of facial proportion are not usually performed prior to the placement of malar and submalar implants. Instead, the facial plastic surgeon should develop a sense of aesthetic facial proportion and consider the patient's requests. The patient is evaluated in at least 6 views, including frontal, right/left lateral, right/left oblique, and basal views.

The surgeon may find analysis of the frontal view with the patient smiling and in repose helpful. Photographic documentation of all these views is recommended. The malar eminence is evaluated in context of other facial features, including overall facial shape, contour and strength of the mandible, and size and shape of the nose. The surgeon should carefully analyze and identify patterns of midface deficiency so as to choose the most appropriate implant that yields the best surgical result. Any facial asymmetries should be brought to the patient's attention and documented.

The surgeon should assess both the underlying skeletal support and the character of the overlying skin and soft tissue. The thickness and quality of soft tissue influences implant size and positioning. The size, shape, and position of the implant to be placed can change the facial contour in a precise and controlled way. Customized implants based on a sculpted moulage or 3-dimensional CT scan are available.

Detailed preoperative counseling allows the surgeon and the patient to discuss the desired changes and those that are possible. Computer imaging provides a useful tool for communication between the patient and surgeon. Care must be taken to ensure that the images produced are not construed as a guaranteed result. In addition, asking the patient to provide photographs of him or herself at a younger age or photos of people (eg, actors, models) with the desired facial contour may reveal patient expectations and uncover unrealistic ones. Careful documentation and frank discussion are critical components of the preoperative workup. The implant to be placed is chosen based on patient's anatomy and the result desired.

Once the appropriate implant is chosen, it is placed on the skin overlying the malar-submalar area, and the surgeon subjectively determines the proper positioning. Then, the edges of the prosthesis are outlined on the skin. The procedure can be completed with the patient under general anesthesia or local anesthesia with sedation. Perioperative antibiotics are recommended.

Soft tissue elevation is facilitated by infiltrating a diluted local anesthetic agent to create a hydrodissected plane. Excellent hemostasis is required to provide accurate visualization and proper implant placement.

Several approaches may be used to place a malar-submalar implant, including intraoral, subciliary, rhytidectomy, and transconjunctival approaches. The following describes a technique for intraoral placement of malar and/or submalar implants, which is the most common approach.

Make a 1-cm diagonal incision in the gingivobuccal sulcus mucosa with electrocautery on the cutting setting. Dissect down to the periosteum and maintain hemostasis with monopolar cautery. Incise the periosteum of the malar eminence and elevate it with a wide periosteal elevator. Elevation proceeds in a superolateral direction. Use short, firm, controlled pushes to elevate the periosteum. Keep the location of the infraorbital nerve in mind to avoid nerve injury. Dissection in the subperiosteal plane protects the facial nerve branches from injury.

The surgeon's free hand constantly palpates as the internal dissection is completed. Place a sizer in the created pocket. Sizers of different shapes and positions are used to determine the optimal placement for the actual implant. Pocket size should accommodate passive placement of the implant because a pocket that is too small pushes the implant in the opposite direction, leading to possible extrusion. Binder et al report that 4 mm of projection is the most commonly used thickness of malar implant. ^[16] Irrigate the pocket and soak the implant in antibiotic solution of bacitracin and gentamicin; a no-touch technique is used. If transcutaneous fixation is desired, pass a long Keith needle suture through the most lateral aspect of the implant and then transcutaneously through the hairline. Then, gently tie the suture over a dental roll bolster.

The senior author prefers fixation of the implant with a single 6-mm titanium screw to prevent migration of the implant; place a single screw at the inferomedial extent of the implant to prevent migration. Not all authors agree on the need for fixation, and several recent articles emphasize creation of a precise pocket over suture fixation. A long, nonserrated clamp can be used to assist in positioning and can be retracted without difficulty. Manipulate the implant into position and pass a periosteal elevator anterior and posterior to the implant to ensure that no folding has occurred. Inspect and simultaneously palpate the implants from the head of the bed to check for symmetry.

For the submalar or combined malar-submalar implant, create a pocket by elevating the soft tissue that overlies the masseter muscle. The tendons of masseter are characteristically glistening white and should be maintained intact to provide support for the implant. Place the submalar implant below the zygoma and zygomatic arch, overlying the masseter tendon, or position it more superiorly over bone. The incision is closed in 2 layers using 3-0 chromic for muscle and 2-0 chromic for mucosa.

Some authors suggest placing elastic tape or stretch bandages over the implant site to maintain compression during the immediate postoperative period. The patient should maintain head elevation for 24-48 hours, and ice packs or cold compresses should be applied for the first 24 hours. Antibiotics are continued for 5 days. Caution the patient to consume a soft diet for the first week to avoid unnecessary motion and strain around the implant site.

The surgeon should evaluate the patient within the first 12-24 hours to check for any facial asymmetry that may develop secondary to hematoma or seroma. If placed for fixation, bolsters and sutures can be removed on the third postoperative day.

Given the safety and simplicity of malar-submalar augmentation, complications occur infrequently. Complications that occur in the placement of malar and submalar implants are largely dependent on technique and selection. Complications include implants that are malpositioned, asymmetrical, or inappropriately sized. Improper positioning of the implant is the most common complication, followed by improper implant size. When asymmetry or malposition occurs, removal of the implant, replacement of the implant, and subperiosteal mid-face resuspension is advocated. ^[17]

In addition, the implant may become exposed or extruded. The patient may develop a hematoma or seroma, which may require only surgical drainage, or the patient may develop an infection around the implant, which may require its removal. After resolution of the process, an implant may be reinserted in 6-8 weeks. Problems with local tissue reactions and capsule formation causing abnormal ridging and projections may also necessitate removal. Reimplantation should be avoided in these situations. ^[18]

Nerve injury is usually transient if the infraorbital nerve is stretched during the dissection. Numbness may last 2-6 months. Facial nerve injury is rare and transient. Paresthesias may persist if the implant impinges on a nerve. Persistent cheek pain may cause some patients to demand removal of the implants. Transverse mucosal/muscular incisions that divide the zygomaticus muscles may cause transient or even permanent partial muscle weakness. The patient's smile may be altered as normal lip elevation is inhibited.

Placement of malar-submalar implants via a subciliary or transconjunctival approach may be complicated by lower eyelid malposition or ectropion.

Unlike the findings of bone erosion associated with silastic chin implants, malar and submalar implants maintain facial contour without compromise to the underlying skeleton.

A retrospective study by D’Agostino et al of 42 patients with 116 zygomatic implants found, at 5-year follow-up, that the severe complication rate for these implants was lower than for other treatments for extreme upper jaw atrophy. There was an assessment of one zygomatic bone fracture, with sinusitis reported in eight patients and oro-antral communications found in two. As measured using preoperative and postoperative Lund-Mackay scores, sinonasal disease underwent a statistically significant increase. Mucositis was associated with 21 implants, and gingival recession with eight implants. ^[19]

Alloplastic facial augmentation produces permanent and effective 3-dimensional changes that result in a more youthful-appearing midface. Silastic implants have demonstrated consistent results and remain the implant of choice for the senior author. In 2003, a prospective multicenter study was conducted to evaluate the safety and efficacy of subcutaneous augmentation material (SAM) preformed facial implants for malar augmentation. One implant became infected and required removal. The infection rate (3.8%) was consistent with that previously reported in the literature. No implant migration was reported. The aesthetic results of the implants were evaluated by a panel of facial plastic surgeons and demonstrated a satisfactory-to-good aesthetic result. Results from studies that evaluated the efficacy and safety of ePTFE in the malar region have demonstrated similar results. ^[20]

Yaremchuk performed a retrospective study of malar augmentation with porous polyethylene (Medpor); his long-term results demonstrated no evidence of late complications. ^[21] A later study by Deshpande and Munoli concluded that high-density porous polyethylene implants are an alternative to autogenous grafts for facial skeletal augmentation. They had good long-term results and a low incidence of complications, provided vascular soft tissue cover was adequate. ^[22]

Malar and submalar augmentation with alloplastic implants can be used to enhance and restore facial harmony and balance. Defects that have developed as a result of aging or trauma as well as congenital defects may be addressed. Strong skeletal contours enhance beauty. Redraping, reshaping, and redistributing the soft tissue over a strong facial skeleton enhance restoration and rejuvenation of the face. Successful malar and submalar augmentation results from proper patient and implant selection as well as appropriate facial analysis and surgical technique. Alloplastic facial augmentation produces reliable, durable, predictable results with little morbidity and high patient satisfaction.