Primary and Secondary Malar Implant Surgery

During plastic surgery training, my chief warned that, too often, patients are displeased with their appearance after alloplastic malar augmentation. Dr. Hoopes facetiously said:

“Malar implant surgery is a three- part procedure.

You put them in.

You adjust them.

You take them out”

Although this statement exaggerates the frequency of patient dissatisfaction after malar augmentation, the literature does document a relatively high incidence of revisional surgery for this procedure. About 10 % of malar implants are removed or replaced because of improper implant size, shape or position. One might assume that the reoperation rate for malar implant surgery performed by surgeons less experienced than those quoted in the surgical literature may be considerably higher.

A retrospective review of patients presenting for secondary surgery documented three main reasons for patient dissatisfaction: asymmetry; displeasing contours – too wide, too large, too low or too prominent with time; and infraorbital nerve dysfunction. A retrospective review of  patients treated primarily showed that these problems can be avoided with an operative technique that employs wide subperiosteal exposure of the skeleton, precise augmentation of the deficient area to create a normal anatomy, and screw fixation of the implant. Secondary surgery consists of removal of the displeasing implants, replacement with appropriately positioned and sized implants; and resuspension of the cheek soft tissue envelope (midface lift) to mask and redistribute implant related soft tissue distortions.

The results of malar implant surgery can be unsatisfactory for not only technical, but also for conceptual reasons. A paucity of objective data has made the indications and goals of implant surgery in this area more subjective than for other areas of the facial skeleton. For example, there are no cephalometric or anthropometric analyses that describe the malar area similar to those for the chin.  Because it is difficult to define what is average or normal for the malar area, selection of implant shape, implant size and implant position can be problematic. A perceived interchangeability of facial skeletal augmentation with facial soft tissue augmentation may lead to both skeletal and soft tissue augmentations that result in unnatural contours

Several surgeons have empirically devised methods to identify an ideal area of malar prominence as a guide to malar augmentation. Their methods locate the malar prominence through a grid system based on fixed relations to various anatomic landmarks. For example, Hinderer, one of the first to advocate the use of alloplastic implants for aesthetic surgery ,divided the malar area into quadrants formed by two intersecting lines. One is drawn from the ala to the tragus and the other from the oral commissure to the lateral canthus. He advocated placing the implant in the upper outer quadrant formed by these intersecting lines. Prendergast and Schoenrockdrew a line from the oral commissure to the lateral canthus. They determined the malar prominence to be on this line at a point one third of the distance from the canthus. Silver ,Wilkinson , and Powell using different landmark based grid systems proposed more lateral points of ideal malar projection. The lack of consensus regarding the most projecting point of the malar bone by these authors bespeaks the clinician’s dilemma. It is my aesthetic judgment that many analyses place the point of maximum malar projection too lateral. This placement will increase the bizygomatic distance, already the widest part of the face, and exaggerate any midface hypoplasia (a common skeletal morphology in patients receiving malar implants). My analysis indicates that the point of maximum malar projection is most often near the intersection of a vertical line placed through the infraorbital foramen and a vertical line dropped from the lateral canthus.

As the most prominent and surgically accessible portion of the midface, many patients receive malar implants when the entire midface or another midface area is deficient. This may exaggerate the facial imbalance. For example, malar augmentation, particularly when it extends far onto the zygomatic arch, may exaggerate the appearance of prominent eyes due to midface hypoplasia. These patients are better served with augmentation of the infraorbital rim alone or, in combination with malar augmentation and other soft tissue manipulations .

Since full cheeks are associated with youth, malar augmentation is often performed to provide a youthful appearance . This may provide an aesthetic benefit if there is a relative malar hypoplasia or if the implants are of modest size and projection. This skeletal augmentation is not equivalent to a soft tissue augmentation or resuspension.  Similarly, malar implants are often advocated as a means to obliterate lower eyelid wrinkles or secondary bags. Malar augmentation has little impact on these surface irregularities. More often, they detract from periorbital aesthetics by contributing to lower lid malposition, particularly when placed through an eyelid approach.

Certain implant designs do not mimic the contours of the midface skeleton.  For example, submalar implants are designed to be placed over and below the origin of the masseter muscle -a location where there is no midface skeleton- in an attempt to provide cheek fullness. It is often performed as an adjunct to, or as an alternative to a facelift .This may result is an unnatural midface contour – one with too much lower midface fullness which detracts from malar definition and projection .

Plastic surgery’s last decade is notable for its recognition that aging is accompanied by facial soft tissue atrophy. Facial rejuvenative surgery is no longer one of simple excising and tightening. The value of soft tissue augmentation has been recognized and exploited. Free fat grafting can be an effective means of augmenting facial contour. This technique is intuitive for the restoration of soft tissue volume loss due to senile atrophy.  In my experience, fat injection has a limited role in simulating the effect of an increase in skeletal projection.  Despite the fact that the ultimate expression of skeletal or soft tissue structure is reflected on the skin’s surface, some surgeons have used this as a justification for the equivalence and interchangeability of soft and hard tissue augmentation. For example, malar skeletal implants are used to restore cheek fullness while fat grafts are used to create malar prominence. Up to a millimeter or so, the visual effect of either augmentation modality may be equivalent depending on the thickness of the overlying soft tissue envelope. However, beyond a minimal augmentation, the visual effects of these modalities are markedly different. This is easily conceptualized when envisioning large augmentations. A large implant placed on the malar bone will make the cheek project more, making the face more defined, angular, and therefore, make the face appear thinner and more skeletal. Implanting fat into the cheeks will also make the cheek project more, however the face will appear increasingly round, and therefore, less defined and less angular. These two treatment modalities can be complementary but should not be considered interchangeable.

09, October, 2015admin0 Comments

Leave Comments