21.4Surgical Procedure

Implant placement, in experienced hands, is relatively simple and should take about 10 min per side. As with all aesthetic and reconstructive procedures, there are technical nuances that can significantly impact the final surgical outcome.

While cheek implants can be placed with local anesthesia alone, the author’s preference is the addition of intravenous sedation, as cheek implants are commonly inserted as a part of more involved cosmetic facial procedures. Local anesthesia is infiltrated intraorally in the subperiosteal plane with 2% lidocaine with 1:100,000 epinephrine. Infiltration proceeds

Fig. 21.9 A 10 mm incision is made about 10–12 mm above the gingival margin of the canine tooth just beneath the maxillary sulcus to the level of the periosteum. (Photo courtesy Joe Niamtu III)

over the maxilla from the infraorbital rim to the root of the teeth, and from the pyriform aperture to the zygomatic region. Percutaneous infiltration follows over the lateral malar region and tapers over the zygomatic arch.

The incision for cheek implant placement is made into the sulcus above the canine tooth about 10–12 mm above the gingival margin. The mucosa in this region is extensile and easily stretches so there is no need to make a large incision. A 10 mm incision is made with a scalpel, cautery, or radiowave electrode (Fig. 21.9). The subperiosteal plane is immediately identified. It is imperative that the incision and dissection remain subperiosteal as this is the plane in which the implants are placed. A periosteal elevator is used to elevate the periosteum and identify the infraorbital nerve, the only anatomic landmark of concern in the field of dissection. As tissue is elevated, the attachments of some of the lip elevator muscles are stripped from their osseous origins. They reattach as a consequence of normal healing.

The confines of the dissection are dictated by the size and shape of the implant placed. The dissection pocket should be slightly larger than the size of the implant and requires dissection that tapers over the zygomatic arch (Fig. 21.10). A larger pocket serves no purpose and may increase edema, potential hematoma formation, and excessive implant mobility. Larger implants, with larger dissections, will portend longer recoveries with more postoperative swelling and bruising. There is no need to dissect superior to the infraorbital rim or medially to the pyriform aperture as most implants are placed inferior and lateral to these landmarks. Most implants do not encroach on the infraorbital nerve, but occasionally, if this is an issue, the implant is trimmed to accommodate the nerve. This is more common in patients who use dentures as they can have significant bone resorption

Fig. 21.10 The implant dissection pocket should be just slightly larger than the actual implant. More generous dissection serves no purpose and can encourage displacement and seroma. This image shows an outline in blue of the size of the dissection pocket in relation to the implant. (Photo courtesy Joe Niamtu III)

and the nerve is more easily encountered due to a vertically shortened maxilla.

With larger implants, that require more lateral and inferior dissection, the surgeon will encounter the masseter tendon where the muscle originates on the zygoma. There is no reason to violate this structure. The soft tissue is dissected off the tendon and muscle to accommodate the implant. There is no consequence of the implant lying partially on the masseter tendon or muscle in this area (Fig. 21.11).

When the implant pocket dissection is complete, an implant sizer may be utilized to evaluate the potential aesthetic outcome. These devices are silicone analogues of the actual implants and can be “tried in” to evaluate the appearance of a given implant size or shape. For novice surgeons, this can be a valuable tool. Even with sizers, it can be difficult to estimate the final surgical result on the operating room table, due to gravity and tissue swelling. Accurate judging of implant size and shape is an acquired ability that comes with experience.

It is always better to err on the side of placement of a smaller implant. The most common implant I place in women (90% of my cases) is a medium Binder Type II submalar implant (Implantech, Inc., Ventura, CA). The smaller submalar

Fig. 21.11 The masseter tendon is frequently visible during midface implant dissection and no release of this structure is necessary. The implant periphery can lie over the tendon and related muscle without

consequence. (a) An anatomic representation of the masseter tendon; (b) intraoperative view of the masseter tendon. (Photos courtesy Joe Niamtu III. Reprinted from Niamtu [13], with permission from Elsevier)

implant is typically inadequate for most patients. The large submalar implant is appropriate for bigger (taller) patients and those with significant volume deficit. The combined submalar shell implant is a very large implant, and even a medium size frequently requires trimming. In general, dissection for malar shell or combined submalar shell implants is more extensive to accommodate for the larger size or more superiolateral augmentation.

Midface implants are available in two configurations. The standard configuration has a smooth and more rigid posterior surface. A variation, known as the Conform Implant, provides increased implant flexibility and surface area by employing numerous flexible feet that protrude on the underside of the implant. The author’s preference is to use the standard implant as its rigidity makes it easier to place through the tunnel. Implantech also makes implants that are coated with an ePTFE material, but I do not see an advantage in this addition over solid silicone.

The surgeon must strike a balance between the size of the implant and the size of the dissection pocket as the implant needs to sit passively in the pocket. Most contemporary facial implants are anatomic in form which means they have been made to conform to underlying normal anatomic contours. As a result, they will frequently fall into place and stabilize over the underlying bony contours.

After the implant is placed in the final pocket, the cheeks and upper lip are manipulated externally to simulate facial animation. If these maneuvers extrude the implant, then the pocket is poorly sized and a correction of one or both is necessary. A well-placed implant is one that passively sits on top of the maxilla and is not easily displaced from the incision pocket.

Once the correct implant placement is confirmed, the pocket is irrigated with antibiotic solution and the implant is

secured with a single fixation screw. Many surgeons omit this step, but the author feels this is an extremely important step. After placing hundreds of implants, the author has never seen migration or significant underlying bone resorption with a stabilized implant. A single 6-mm self-drilling screw (eliminates the need for drills) is placed through the thinner periphery of the implant over the dense zygomatic buttress potion of bone (Fig. 21.12).

As stated, some surgeons believe fixation is not necessary. When patients begin early postoperative facial animation, an unsecured implant can become displaced. Empirically, a secured implant is less likely to migrate, cause bone resorption, or become infected. Many surgeons fabricate a complex bolster system to stabilize the implant where fixation sutures are placed intraorally, through the implant and exit the cheek where they are secured around a cotton roll or bolster. While this may stabilize the implant in some vectors, it may pull the implant away from bone, creating a potential space, and allowing the formation of a seroma, hematoma, and predisposing to infection. Once the implant becomes encapsulated, the chance of migration is less likely, but stabilizing the implant until that point is prudent.

The fixation screw should not be placed over the thinner antral bone at the canine fossa. When placing screws in the anterior sinus wall, the operator must not exert excessive pressure or the entire screw can be pushed into the maxillary sinus. If a sinus perforation occurs, the implant can still be placed. In the author’s experience, numerous implants have been placed over antral perforations from previous sinus or maxillofacial surgery without consequence. Before the implant is screwed into final position, the operator must assure that the implants on both sides are in a similar and suitable position. This is more art than science, as it is difficult to accurately index the implants to fixed structures.

Fig. 21.13 Indexing the medial border of the implants to the first or second premolar region can assist in positional harmony and symmetry. (Photo courtesy Joe Niamtu III. Reprinted from Niamtu [13], with permission from Elsevier)

One means of identifying symmetry is to observe the medial edge of the submalar implant, as it typically is in vertical alignment with the first or second premolar teeth (Fig. 21.13). Another means of approximate alignment is to trace the implant in its approximated position on the face

Fig. 21.14 Preoperative tracings can be referenced intraoperatively to assist the surgeon in symmetric implant placement. (Photo courtesy Joe Niamtu III. Reprinted from Niamtu [13], with permission from Elsevier)

preoperatively and use those marks to index the intraoperative position (Fig. 21.14). Prior to the fixation, the surgeon should make sure that the implant edge or tail is not folded on itself. Since many of the implant configurations have a thinner leading edge or periphery, it is possible to roll the thin edge under the implant body during placement (Fig. 21.15). If this happens, a palpable and visible prominence will appear. Direct observation or running a periosteal elevator under the implant is the best means of confirming proper placement.

After the implants have been properly placed, indexed, and secured, the wound can be closed. Antibiotic solution should be irrigated again prior to closure. The wound is closed in a single layer by taking big “bites” with a 4–0 chromic gut suture (Fig. 21.16). Facial dressing is not required.