Facial Implants

Part 1: Midface Implants

In the third edition of this chapter, a lot is the same and a lot has changed. Two of the most impactful factors are the popularity and expanding techniques of injectable fillers and the progress of digital technology for custom implants. Over the past 5 years, I have personally seen injectable fillers gain popularity and usage in areas previously treated by facial implants. This includes chin, cheek, and mandibular angle augmentation. Not only have fillers added a viable (but temporary) option for facial profile augmentation, but they opened the doors to more types of specialists and injectors. With continued development of filler technology, I would expect this area to expand. The advantages include a fast, minimally invasive chairside procedure with virtually no downtime as well as reversibility. Implants are in effect “silicon fillers,” so injectable fillers will continue in popularity ( Fig. 7.1 ).

Although CT-generated implants have been an option for almost 40 years, this technology has significantly changed as well. When I performed my first custom implant in the 1980s, the process included obtaining a CT scan to fabricate a custom plastic model of the facial skeleton (or segment). Once the surgeon obtained the model, a trial implant was fabricated with molded polymer clay that was then fabricated into an actual implant. Contemporary technology has dispensed the need for the CT-generated model and polymer clay. Facial implants can now be made directly from a CT scan. Although stock, off-the-shelf implants are useful for most situations, they cannot match the accuracy of a computer-generated implant. The difference is buying clothes “off the rack” versus having a custom tailor. In the not too distant future, I believe that in-office CT scanners will generate custom implants on a three-dimensional (3D) printer in the surgeon’s office. That implant will be sterilized and ready for custom placement for a precision fit.

Midfacial aging changes are outlined in the “Facial Aging” chapter in this text and play a dramatic role in aging and related rejuvenation. It is also important for the reader to realize that contemporary cosmetic facial surgery includes volume restoration of some type. “Old-fashioned” facelifts and related surgical procedures often looked so unnatural because surgeons were stretching old skin over a skeletonized face. They made patients look “tighter, but not younger.” Contemporary cosmetic facial rejuvenation includes additive rejuvenation as opposed to only subtractive surgical procedures.

Treatment options for midfacial rejuvenation include lifting procedures, injectable fillers, autologous fat injection, orthognathic skeletal surgery, and facial implants. Each treatment option carries advantages and disadvantages, but midface implants are an optimum choice in the average patient for numerous reasons. Injectable fillers are temporary, and fat or permanent fillers will move with sagging soft tissues with aging. Lifting procedures will eventually relapse. Facial implants are unique because they become part of the facial skeleton (when fixated) and provide a 3D augmentation, they are permanent, and they are reversible. “Permanent but reversible” may sound like an oxymoron, but the fact is that when placed in the subperiosteal plane and anchored to the facial skeleton with screw fixation, there is nowhere for them go. They will not descend or displace with the rest of the soft tissues of the aging face; hence they are permanent. Silicone implants are also reversible and can easily be removed or replaced because they become surrounded with a well-defined tissue capsule, and removal generally only takes minutes. There are very few mainline cosmetic procedures that can boast being permanent and removable!

Facial implants come in a vast array of shapes, sizes, and materials that make them suitable for almost every patient in a stock off-the-shelf configuration. They can also be fabricated with computer-assisted design/computer-assisted manufacturing (CAD-CAM) technology for custom applications, which will be discussed later in this chapter.

Numerous materials exist for implants that are approved by the US Food and Drug Administration (FDA). The most commonly used materials are silicone rubber, expanded polytetrafluoroethylene (ePTFE; Gore-Tex), and porous polyethylene. They are all biocompatible, and although any implant can be successful when properly integrated, each material has advantages and disadvantages ( Table 7.1 ).

Many surgeons utilize porous polyethylene implants, but these can have significant drawbacks. Being rigid, they do not conform to underlying bony anatomy like flexible implants. Because they are rigid and porous, they can be difficult to trim or drill and frequently break or fragment. When placing flexible implants, smaller incisions can be utilized, and the implants can be twisted and bent to facilitate insertion. A rigid implant requires a larger incision or a two-piece configuration that is inserted one side at a time and joined in the middle. Most of these drawbacks are noncritical, but the biggest drawback to porous polyethylene implants is their difficulty of removal. The porous nature of the material induces extreme tissue integration. This can be a positive influence in terms of stabilizing the implant when the implant never needs removal or adjustment, but it presents extreme difficulties when attempting removal. Implant removal can be very traumatic and frequently disrupts muscle and other soft tissue that become attached to the implant surface. This can also damage surrounding nerves that become entrapped in the tissue mass. These implants can become so adherent that they fragment upon removal, leaving remnant tiny pieces that are difficult to completely debride or remove. I know surgeons who are very satisfied with this material and say they never take them out. If someone places a few implants, their success rate may be high with rare removal, but extremely busy implant surgeons will have to service their own implants from time to time as well as service complications from other surgeons. Having removed scores of porous polythene implants, I can testify to the difficult and destructive nature of removal. Silicone rubber implants remain the easiest implants to remove because of their well-developed, dense, thick, fibrous capsules.

Early facial implants were crude and nonanatomic. The earliest ones had to be hand-carved tableside. The last part of the 20th century brought a refinement of both implant form and placement. Contemporary midface implants are anatomic in that they are specifically constructed with anatomic shape, and the underside is anatomic in the sense that it is fabricated to conform to the underlying bony anatomy. Modern silicone implants are available in many sizes and shapes and have different indications dependent on the aesthetic need. These anatomic implants have also given way to more conservative surgical approaches that, again, are designed to provide targeted, precise, and natural-appearing augmentation specific to various regions of the face. About 20% of my facelift patients request cheek or chin implants, and in reality 80% could have used them but did not choose the option. From time to time I will provide cheek or chin implants free of charge if the patient cannot afford them because they improve the results so dramatically that the marketing effort offsets my cost. Contemporary surgeons understand the importance of volume replacement as part of comprehensive rejuvenation, and facial implants are an excellent addition to any facial rejuvenation procedure.

Implant Selection

The greatest challenge for the novice implant surgeon is understanding what implants to use and where to put them. Although this is related to personal preference and experience, I use three main configurations for midface implants that are effective for almost all cosmetic patients.

The main contributor to midface volume is the malar fat pads. They lie in the cheek with the base on the nasolabial fold and the apex on the malar region ( Fig. 7.2 ). The malar fat pads provide volume across the entire midface and with age become atrophic and ptotic. The basis of implant selection lies in the recognition of where the aging changes have occurred and which implant would best restore youthful volume to that area. As patients age, they lose volume in the midface region. Volume loss can occur in the infraorbital region, the malar/submalar region, and the zygomatic region (see Fig. 7.2 ).

The submalar area includes the hollow area of the infraorbital, anterolateral maxillary, and canine fossa regions. If the surgeon pays close attention, they will notice that loss of facial volume represents early aging change (late third, early fourth decade) that is apparent in virtually all patients regardless of gender. I tell my patients that anyone over 35 years of age is a candidate for some type of midface augmentation. Because the midface is subject to early volume loss, implant rejuvenation is technically reinflation.

Most patients and many aesthetic practitioners are unaware of this midfacial volume loss after the third decade. If the surgeon hands the patient a mirror and asks them to smile, the ptotic tissues are elevated which produces a more youthful look. This simulation will cause many patients to comment, “This is how I looked when I was younger.” If you hold the elevated tissues in place with your thumb and index finger and ask the patient to relax their smile, the midface volume quickly drops to its aged position lower in the face when the fingers are relaxed. In essence, the youthful cheek fat later becomes the jowls with aging. The most efficient means of pointing out midfacial volume loss and the result that cheek implants would have is to recline the patient in the examination chair. This will “reposition” the aging and ptotic tissues to a more youthful position and can be used to illustrate aging and improvement and serve as a “surgical prediction” ( Fig. 7.3 ). It is common for patients to bring photos to a consultation showing their youth; 100% of the time one of the biggest changes is midface deflation.

Midface Diagnosis and Implant Selection

The most common midfacial aging change in younger patients is volume loss in the submalar region. It is not uncommon for these patients to have a deflated submalar region, but adequate and well-defined zygomatic and malar aesthetics. Despite having lost submalar volume, they have adequately projected cheekbones. My best implant choice for treating this area is the Submalar implant (Implantech Inc., Ventura, CA). The Implantech line of implants also comes in a configuration known as Conform with cross-hatched rows in the silicone to allow for more surface area to bind when healing. I do not use these and prefer the Binder submalar II model. I use this implant in about 98% of my patients as it is very versatile for younger and older female and male patients. My most commonly utilized configuration is the Binder Submalar II silicone implant ( Fig. 7.4 ). This is a general-duty midface implant and can be utilized in all age groups. The small size is rarely used as it is very small. I think the name Submalar is somewhat inaccurate as the implant sits on the maxilla and zygoma and tapers out over the zygomatic arch. I think zygomaxillary implant would be a more accurate description. The vertical length of the implant does provide some submalar augmentation and support.

Although I will describe other types of implant configurations, I have mentioned that I use the Submalar implant almost exclusively. I can use different sizes of the implant and adjust the augmentation result by how the implant is vertically and horizontally positioned. For patients who require more infraorbital augmentation, I position the implant more medially, whereas I place it more laterally for a more lateral fill. In addition, I may use an extra-large size and trim it in various dimensions to further customize the result.

The second type of common facial aesthetic deficiency is apparent in patients who have adequate submalar and anterior maxillary fill but have deficient malar regions. These patients usually have hypoplasia of the zygomaticomalar regions or simply desire a more defined or chiseled appearance (“higher cheekbones”). I treat these patients with the Terino Malar Shell implant (Implantech), which I rarely use (see Fig. 7.4 ). The isolated high cheekbone look was popular several decades ago with the “waif” look, but contemporary patients generally seek a more balanced appearance. It would also be unusual to only treat the lateral midface with fillers as most patients desire and require balance from the nasal to temporal regions.

The third type of common midfacial aging change is seen in patients with deficiency across the entire midface and require a more comprehensive augmentation. These patients benefit from both anterior maxillary fill and malar (high-cheekbone) augmentation. These patients usually have lost volume in both areas or have underdeveloped skeletal anatomy. Such patients are well suited for treatment with the Combined Submalar Shell implant (see Fig. 7.4 ). This implant is designed to augment the submalar, zygomatic, and malar regions. It is actually a combination of submalar and malar configurations in a single implant. This configuration tends to run large, and generally a small to medium implant is adequate for the average patient. The larger the implant footprint, the larger the surgery and recovery. For decades, I have successfully treated virtually all forms of midface deficiency with the three aforementioned implants. Again, the Submalar configuration is 98% of cheek implants I place. Fig. 7.5 shows the common types of midfacial deficiency, and Fig. 7.6 shows the approximate skeletal positioning of the described implants.

Preoperative Planning

Before surgical placement, the practitioner and the patient must decide on the area(s) to be enhanced and the size and configuration of the implant. This can be difficult for the novice surgeon. Beginning with easier and more straightforward cases can assist the surgeon with the learning curve. Younger patients with basic Submalar implants are a good starting point. Additionally, patients can “test-drive” implants by performing midface filler to see how they like the changes before proceeding to a surgical option. This is becoming a popular option and sometimes an alternative. Over time, many patients will switch from filler injections to silicone implants because of the cost savings and the “one-and-done” ideology. After a while, many patients become tired of shelling out several thousand dollars and getting needled for temporary results. It is important to point out that even with cheek implants, some patients may request or require filler injections. I explain to patients that the implant will serve as a permanent base and is the equivalent of several syringes of filler. Some implant patients may want further augmentation and can have filler injections. Other patients may want to “pop” or highlight certain regions of the cheek to customize their appearance.

It is important to note, discuss, and document existing asymmetries with the patient before surgery. It is common for patients to have one side of the cheeks or midface larger than the other. For example, a medium implant can be placed on one side and a large implant placed on the other side in extreme cases. Most frequently, the degree of asymmetry is such that it does not alter the final result when using the same implant on both sides. To illustrate the difference in symmetry, I keep a photo of me in each consult room that shows my normal portrait and a mirrored image of the right and left halves of my face ( Fig. 7.7 ). The difference is remarkable, and I explain to the patient that the average person has similar asymmetry. Numerous times over the years, I have had to construct a similar image of a patient to show them their asymmetry.

During preoperative evaluation, it is also important to evaluate the patient’s oral health. Placing implants in the presence of dental or periodontal disease can severely compromise the case and result in infection. Patients with oral disease must be treated to achieve a normal state of oral health before implant placement. All implant patients require a panoramic radiograph or CT scan to rule out any osseous or dental or sinus pathology as well as other abnormalities.

The preoperative consent process should discuss the common sequelae and complications experienced with midface implants. The midface is a vascular region, and significant swelling can occur and take up to several weeks to resolve. In some cases, the swelling can last longer, and the patient must understand that it may take 6 weeks to begin to see the true level of augmentation. All patients will experience temporary paresthesia in the distribution of the infraorbital nerves, but permanent numbness is rare. The surgical site and some implant configurations are in close proximity to the infraorbital nerve, and the surgeon must continually be vigilant of protection. Oral animation will be temporarily affected as a result of disruption of lip elevators and orbicularis oris muscles. Patients must be made aware that smiling and puckering and possibly speech may be temporarily affected. This dysanimation usually resolves in the first several weeks. Infection is rare. The possibility of overcorrection, undercorrection, and asymmetry must also be discussed. Fortunately, it is very easy to remove or exchange midface implants, and this is a comforting point for prospective patients.

The surgeon must also ascertain the motivation for patients requesting cheek implants. Patients with volume loss or developmental deficiencies are usually reasonable in expectations. I avoid patients (especially young males) who desire a “sculpted” or “chiseled” look or those who desire a celebrity appearance or “want to be a model.” This group of patients, in my experience, have unrealistic expectations as well as body-dysmorphic tendencies. The patient must understand exactly what cheek implants will and will not do. For instance, sometimes cheek implants can improve the nasolabial fold or tear trough, but it is not something that is necessarily repeatable in all patients. Also, many patients think that an implant will “lift” their jowls or neck. I explain to these patients that implants project and do not lift. I compare them with breast implants that project the breasts but do not lift the abdomen.

During the consent process, the patient is given prescriptions for a cephalosporin antibiotic, analgesic medications, and possibly prednisone if larger implants are used, which require more dissection and will result in more postoperative edema. Patients are told to expect the average recovery to be 10–12 days. They should also be informed that implants are foreign bodies that the patient will initially “feel,” but the body will quickly accommodate.

Size selection is more of an art than a science, and accuracy accompanies experience. In the entire experience of cosmetic facial surgery, nothing looks more unnatural than overdone cheeks or browlifts.

Surgical Placement

The surgical armamentarium is relatively simple for midface implant placement and does not require highly specialized instruments ( Fig. 7.8 ). A Molt #9 periosteal elevator; long, thin-tipped tonsil hemostats; an Aufricht nasal retractor (fiber-optic is preferable); and a Minnesota cheek retractor are useful instruments.

Placement of midfacial implants is a simple and straightforward surgical procedure for surgeons with maxillofacial experience and is easily learned by others. With experience, actual placement can be performed in less than 10 minutes per side. The implants are always placed in the subperiosteal plane, and this must remain an axiom of placement. With the exception of the infraorbital neurovascular bundle, there is little vulnerable anatomy in the midface region when dissecting in the subperiosteal plane. Midface implants can be placed with local anesthesia, although intravenous sedation or general anesthesia is always performed in my accredited office surgery center. The implants can be placed as a solitary cosmetic procedure or concomitantly with other aesthetic procedures.

The procedure is begun by injecting about 5 mL of 2% lidocaine, 1:100,000 epinephrine transcutaneously, targeting the subperiosteal plane along the region to be dissected. Because many surgeons outline the implant on the cheek, the marked area serves as a template for local injection, and the anesthetic is injected 1 cm past all margins. This usually includes the anterior maxilla region, the malar region, and the anterior zygomatic arch region. Additionally, approximately 3 mL of the same anesthetic is infiltrated in the soft-tissue planes in the mouth above the canine tooth, primarily to reduce incisional bleeding ( Fig. 7.9 ). The surgeon should not use excessive volumes of anesthetic solution as it distorts the cheeks and confounds the ability to judge the implant size and intraoperative result.

A 1-cm horizontal incision is made approximately 10–15 mm above the canine tooth. Using a radiofrequency or electrosurgery microneedle to incise the mucosa and soft tissues is hemostatic, and the incision is immediately carried to the periosteal level of the canine fossa region ( Fig. 7.10 ). Alternately, a vertical mucosal incision can be used, but this approach provides less visual and working access compared with a horizontal entry. It is very common to see bleeding from the vascular-rich mucosa, and this is immediately cauterized with a small bipolar forceps to prevent bleeding throughout the case. The oral mucosa is very pliable, and even with a small incision, the surgical site can be well visualized when retracted. The incision continues to the periosteum and the entire dissection must remain subperiosteal. A Molt #9 periosteal elevator is used to begin the subperiosteal dissection.

When beginning the subperiosteal dissection, it is not necessary to dissect medially to the piriform (also spelled pyriform ) aperture (nasal region), because no part of the implant lies in this region in the average patient. The subperiosteal dissection is begun in the anterior maxillary region, and the initial dissection vector is superior, hence it is important to protect the infraorbital neurovascular bundle ( Fig. 7.11 ). The infraorbital nerve lies approximately 5 to 8 mm inferior to the infraorbital rim in line with the medial limbus ( Fig. 7.12 ). The implants are configured to lie inferior to the infraorbital nerve, and therefore aggressive infraorbital dissection is not necessary. On occasion, the surgeon may encounter a perforation in the antral wall. This may be from previous sinus or dental procedures. In some cases, the thin anterior sinus wall may perforate from dissection. There is no need to abort the implant placement because of an old or new perforation. The implant generally covers the hole; even if it does not, healing seems to progress normally. In these cases (or all cheek implant cases for that matter), patients should not blow their nose because this can produce air emphysema in the facial tissues. Likewise, some patients may possess plates or hardware from pervious trauma or surgical procedures. Placing implants over such hardware is not problematic.

After the anterior maxilla is dissected, the periosteal elevator is angled, and the remainder of the dissection is primarily in an oblique vector ( Fig. 7.13 ). All of the common implants extend over the lateral maxilla and zygomatic regions and taper out to a thin tail. This oblique vector of dissection is carried out over the malar region and extends over the medial portion of the zygomatic arch. It is extremely important to remember that the implant pocket should be just slightly larger than the intended implant. A grossly larger pocket only serves to encourage mobility and dead space for potential hematoma or seroma formation. This is even more important if screw fixation is not being used so the smaller pocket will retain the implant and reduce mobility.

For small or medium Submalar implants, minor zygomatic dissection is required, but for combined Submalar and malar shell implants, more aggressive malar and zygomatic dissection is necessary. These larger implants also require more aggressive inferolateral dissection. It is not uncommon to encounter the origin of the masseteric tendon (or muscle) while dissecting in the area ( Fig. 7.14 ). There is no need to violate or dissect this tendon or muscle because the silicone implant can safely lie over these soft-tissue structures without a problem and frequently do with the larger-style implants. If adequate dissection is not performed over the masseteric tendon, it can create an obstruction and not allow the implant to sit passively. For smaller implants such as the medium Submalar, the extended dissection over the masseteric tendon is usually not necessary.

After the superior and superolateral dissection, a final sweeping maneuver is made with the periosteal elevator ( Fig. 7.15 ). This assists in developing the full pocket for implant placement. It is imperative that the subperiosteal dissection is totally free from adhesions that would impede passive implant placement. The surgeon can also use the fingertip to stretch the underside of the cheek for increased freedom. Care must be taken to not overstretch the area because this could possibly damage the facial nerve branches. One of my personal means of deciding if adequate dissection is achieved is the ability to place the working-end Minnesota retractor fully inside the lateral dissection pocket ( Fig. 7.16 ).

After the implant pocket is dissected, the area is checked for hemostasis. Some cases can present bleeding from areas that are difficult to visualize or access. It is imperative that bleeding is controlled before proceeding to implant placement and closure. In cases in which the bleeding source is not apparent, the pocket can be packed with gauze packed with hydrogen peroxide. This assists with hemostasis, and the peroxide bubbles away the blood and clears the surgical field. Alternately, the wound can be packed with hemostatic gauze such as Combat gauze.

The pocket is then irrigated with antibiotic solution. This is made by opening two 150-mg clindamycin capsules and mixing the powder with 60 mL of sterile saline (see Fig. 7.16 ). At this point, implant sizers can be placed to give the surgeon an idea of the ideal size ( Fig. 7.17 ). This is only an approximation as the pocket is dilated from dissection and the tissues have been injected with local anesthesia, so accuracy of sizing is compromised. When the sizer is placed, the lips are grasped and pulled down to better show the implant profile. Insertion of sizers and the final implant is assisted by the Aufricht or Minnesota retractor and a long, thin tonsil clamp to guide the pliable implant into the restricted pocket.

When the sizers are placed, the entire surgical team examines the patient from different angles until the proper size is determined. Experienced staff are very helpful in these decisions, but obviously the final result rests on the expertise of the surgeon. The pocket is again irrigated with the antibiotic solution using a Monoject syringe. When the final implant is agreed upon, it is removed from its sterile packaging and placed in the antibiotic solution. It is important not to contaminate the actual implant with surgical debris, paper, gauze tags, or glove powder. The Implantech implants are labeled with the size and correct configuration. ML would be medium left, LR would be large right, and so on. The implant is grasped with the curved tonsil clamp so the tail can be stabilized and placed into the pocket. If the pocket is correct for the implant, the prosthesis will lie passively and self-seat ( Fig. 7.18 ). An anatomic implant is fabricated on a model of the human skeleton, so the underside of the implant “automatically” seats and fits in the right zone in most patients. The concavity of the underside of the implant sits over the convexity of the maxillomalar area. It is imperative that when the thin tail is inserted on the leading edge of the implant that it does not fold over or under ( Fig. 7.19 ). If this happens, a permanent lump will be visible and palpable.

When the implant is successfully positioned, the soft tissues are manipulated to check that the dissected pocket and implant size are compatible. The cheeks are distorted with local anesthesia, edema, and dissection, which can obscure correct sizing. Pulling the cheeks posteriorly with the surgeon’s open hand, the face is compressed to give a better idea of proper size. If the implant is extruded or grossly malpositioned during manipulation, then the implant must be trimmed or the pocket expanded. One of the biggest advantages of silicone implants is their ability to be trimmed and customized.

Although the implants are anatomic, they will float several millimeters in all directions and must have their position finalized before fixation. This can require the attention of the surgeon and an experienced surgical assistant as the final position is obviously critical. Placing a 1.5-inch 25-guage needle through the skin to hold the implant in place will allow the surgeon to place fixation screws without the implant slipping around within the dissection pocket ( Fig. 7.20 ).

When the implant is positioned to the surgeon’s liking, it can be fixated. Many surgeons are not proponents of fixation, and frequently there are no problems encountered if the pocket is small and the implant is conforming. I always fixate 100% of my implants. I routinely see cheek implant complications from other surgeons, and the most common problem remains implant migration. I most commonly use two 2.0-mm titanium self-drilling screws to fixate the implant, and I have never experienced a case of implant migration. I also use screw fixation on all chin and mandibular angle implants. Surgeons without experience in the maxillofacial region may be intimidated by placing fixation screws. Screw placement is a simple procedure, and surgical screw fixation kits can be obtained on a consignment basis by most major fixation companies. The 1.8- or 2.0-mm titanium screws are self-drilling and are simply placed in the same manner as woodworking screws.

The self-drilling screw allows easy seating of the screw without the need to predrill a screw hole. The two best regions to place a fixation screw are in the thick bone of the lateral piriform aperture or the thick buttress bone in the lateral maxilla ( Fig. 7.21 ). Occasionally a screw may be placed through the maxilla and perforate the maxillary sinus. Although I try to avoid placing screws in the sinus, it is a common procedure in orbital trauma, maxillary osteotomy, and sinus surgery. Screws in the sinus are not in themselves problematic, but they could increase the possibility of a sinus infection. Additionally, the thin bone of the anterior maxillary sinus is less dense to retain a screw. Fig. 7.21 shows typical screw fixation of cheek implants.

In most cases a single screw is effective, but the second (lateral) screw prevents rotation and also can conform the flexible implant to the curvature of the posterior zygomaticomaxillary anatomy. It is important not to overtighten the screw. If this occurs, it can sink into the soft implant, and the implant can “pop off” the screw and become displaced. The head of the screw should lie flush with the implant surface. It is also important to avoid the tooth roots when placing fixation screws. It is a good idea to instruct the patient to inform their dentist that they are having fixation screws so they are not misunderstood. When dental radiographs are taken, the angle of the radiograph may be tilted, which can make the screw appear to penetrate the tooth root, when it is actually an illusion. I have seen this happen several times when a patient had a dental or tooth infection and the dentist thought the screw was perforating the tooth root. A better-positioned radiograph will show the true level of placement. After the implant is fixated, all borders are inspected to ensure that they are free and unfolded. Special care must be focused on the superior border of the implant to make ensure that it does not impinge on the infraorbital nerve. It is not common for the border to be in contact with the nerve; in these cases, a small crescent of the implant is removed with a scalpel to relieve the impingement and allow space between the nerve and implant ( Fig. 7.22 ). Edentulous patients have maxillary resorption and low infraorbital nerves relative to the atrophic alveolar ridge, and they may require significant implant relief. Also, cheek implants may not be possible in some edentulous patients as the implant may protrude into the maxillary sulcus and interfere with the denture fit.

Some surgeons advocate the use of transcutaneous bolster sutures. I have never used these and do not feel that they are necessary; in fact I feel they would distract the implant from the bone instead of fixate it. In addition, this is an unpleasant experience for the patient; no one appreciates stitches protruding through their cheek for 1 week. After placing many hundreds of cheeks implants, I can attest that this type of fixation is not necessary.

It is important to confirm that both implants are placed in the symmetrically correct position. This can be estimated by observing the position of the implant relative to the teeth, piriform aperture, or infraorbital foramina. Indexing the implants to fixed symmetric structures allows more predictable accuracy. Technically the placement of cheek implants is more of an art than a science. It is a “blind” procedure in terms that the surgeon places the implants and does his or her best to put them in the same spot on each side. Because the entire implant and surgical site cannot be visualized through the small incision, the final position is an educated guess, which is the art of implant placement. With experience, most surgeons gain his skill to enable accuracy and symmetry. When I place the first implant to the desired position, I note fixed landmarks so it can be duplicated on the contralateral side. To determine the medial/lateral position, I use a straight edge to index the medial edge of the implant to an imaginary line extending over the teeth. Assuming that the patient has a normal compliment of teeth that are in normal position, a vertical line is dropped from the medial edge of the secured implant, with the goal of positioning the contralateral implant in the same position. The medial edge of the average cheek implant will fall in line between the canine tooth and the first or second premolar ( Fig. 7.23 ). It does not matter where the imaginary line falls, as long as the first implant is in proper position and the contralateral side is duplicated. To determine the superior/inferior position of the implants, the infraorbital foramen serves as a guide. I place the first implant, and when I am happy with the finalized position, I measure the distance from the infraorbital foramen. When I place the contralateral implant, I place it the same distance inferior to the foramen as the first side (see Fig. 7.23 ). In the average case, the superior edge of the Submalar implant is close to (or covers) the infraorbital foramen. If the implant is impinging on the nerve a notch is cut out at the contact point to prevent contact with the neurovascular bundle. It is important to discuss symmetry in the preoperative phase. I explain to the patient that the implants are the exact same size and that the reason for subtle differences can be the patient’s symmetry of their hard and soft tissues. Similar to breast surgery, the patients must understand that the implants are sisters, not twins.

In the final check, it is important to verify correct placement. Three regions are routinely examined. The first region to check is the lateral implant tail. As stated earlier, it is important to ensure that the distal tail or portion of the implant is passive and not folded. The second region to check is the orbital rims. The inferior and lateral orbital rims are palpated to ensure that the implant does not extend beyond them as it will be noticeable and possibly uncomfortable for the patient. The third region is checked by placing the index finger in the posterior maxillary sulcus. On occasion, the implant edge may be palpated, but it should not extend excessively into the sulcus as the patient will feel it; also, it is probably not in correct position if it is this low.

After the appropriate position is confirmed, a final antibiotic irrigation is performed and hemostasis confirmed. The incision is closed with interrupted 4-0 gut suture ( Fig. 7.24 ). A watertight running suture is not used as is discourages drainage, which could lead to a hematoma or seroma. At the end of the procedure, a gauze pack is placed between each cheek, and the tail is left out of the mouth to prevent swallowing or aspiration. The gauze serves to compress the intraoral region and absorb drainage. I do not use any type of external compression dressing with cheek implants.

Postoperative Care

Postoperative care includes analgesics, antibiotics, and a 5-day course of prednisone (60 mg per day). The patient is instructed to refrain from the Valsalva maneuver, gum chewing, nose blowing, and significant talking or animation for the first several days. Patients are asked to follow a liquid diet for the first 24 hours and soft foods for the first week. A chlorhexidine mouthwash is prescribed for gentle rinsing for the first 10 days. A child-size toothbrush is used for tooth brushing. Ice packs are used for the first several days. The amount of swelling can be quite variable. Whereas some patients look great at 3 days, others may have significant swelling for several weeks. No immediate follow-up care is required, as the sutures are resorbable. The patient is seen the following morning for a postoperative examination. Soft swelling is normal, and placing the index finger along the upper teeth should yield soft pliable tissue. In the case of hard swelling, a seroma or hematoma must be ruled out. In the case of a seroma or hematoma, the incision line is opened and the fluid or clot is evacuated with suction. Paresthesia can be unilateral or bilateral (most commonly) and can persist from weeks to months but is rarely permanent. Patients will have a component of reduced animation, particularly smiling and puckering, for the first several weeks, but this resolves quickly with healing.

Case Presentations

Figs. 7.25–7.29 show before and after images of midface implant cases.

Sequelae and Complications

Complications after facelift surgery include the following:

• Bleeding/hematoma/seroma

• Infection

• Dysfunctional animation

• Overcorrection/undercorrection

• Asymmetry/malposition

• Extended or permanent paresthesia

• Bone resorption

• Hardware issues

Unlike facelift and blepharoplasty, significant complications are rare with midface implants. Significant edema can occur in the early postoperative period, especially if large implants are used or when implants are placed concomitantly with other cosmetic facial procedures. Minor fluid accumulations will usually resorb spontaneously, but warrant aspiration if large enough. Severe swelling may indicate hematoma or seroma formation, and if the surgeon feels that there is significant fluid buildup, it must be drained as soon as it is recognized ( Fig. 7.30 ). This can usually be done under local anesthesia by opening the incision and suctioning the blood or clot from under or around the implant, without compromising the result. Screw-retained implants will not be disturbed with drainage or evacuation, but unretained implants can displace. There are many reasons why implant fixation is advantageous. An extremely large hematoma or a continued bleeding source may require implant removal and exploration for a floating unretained implant. The disfiguring swelling and the patient discomfort and angst will immediately improve with suction evacuation. When an early seroma or hematoma is evacuated, it generally does not recur. This probably is related to the pressure from the hematoma compressing localized tissues, which aids in hemostasis. Occasionally subconjunctival or periorbital ecchymosis is seen, but this remains an uncommon finding.

Infection has been an uncommon experience, and I may see a case every 1 or 2 years. It usually manifests in the first 1 or 2 weeks after surgery. Infection generally presents as one side failing to heal. The patient may experience pain, increased swelling, periorbital edema, and purulent drainage with a bad taste in the mouth ( Figs. 7.31 and 7.32 ) The incision site will frequently fail to heal and close, and it remains inflamed ( Fig. 7.33 ). It is possible to treat minor infections and salvage the implant with open incision and drainage, irrigation, and systemic antibiotics, especially if it is screw-retained. The immobility of screw-retained implants assists in healing. In my experience, attempting to salvage a mobile, nonfixated implant is futile and should not be attempted in the face of infection or major hematoma. Regardless of whether or not it is fixated, resistant infections warrant implant removal, and the implant can be replaced after healing. Because the explanted site will have scar tissue and remnant implant capsule, the clinical appearance is sometimes not as dramatic compared with the other side as one would think. On occasion, I have taken out a single implant and not replaced it, without any noticeable cosmetic deficit. The deficient side is noticeable in most cases, and the most patients will desire replacement of the implant.

During the consent process, the patient must be warned that they will experience compromised animation when smiling and puckering for the first 1 to 2 weeks after facial implant surgery. The initial implant dissection disrupts the orbicularis oris and lip elevator musculature, which heals uneventfully with the return of normal animation. Occasionally, return of normal animation can take longer and improves as edema resolves. Patients must be made aware of the decreased animation before surgery so they do not perceive it as a complication. Facial nerve damage is very rare but can occur ( Fig. 7.34 ). In the several cases I have seen, zygomatic and/or buccal branch unilateral orbicularis and/or lip elevator weakness was probably a result of neuropraxia edema or intraoperative manipulation.

Aging face patients can be easier to manage postoperatively as implants are more frequently placed in conjunction with a facelift or other procedures. Also, it may be that they are simply more patient. Younger patients, however, sometimes begin evaluating their result immediately. I actually had a patient once tell me in the recovery room that their implants were crooked! Younger patients may have higher or unrealistic expectations of their anticipated result and begin looking in the mirror immediately. They must understand that healing takes time and that it takes 6–12 weeks for the true result to become evident. Astute surgeons will cover such information several times in the preoperative period. The most commonly encountered problems relate to implant position and symmetry and are frequently operator dependent. There is no exact science to placing cheek implants (indexing steps were previously outlined). As computer technology and custom implants evolve, there will undoubtedly be means for precision placement and symmetry. But for now, even in the most carefully planned cases, it is possible to have a preexisting asymmetry in the patient’s anatomy that can cause a disharmony from one side to the other. All of this must be covered in the informed consent process. It is not uncommon for one side to look considerably different from the other, and the patient must understand that many or most of the initial asymmetries will disappear with edema resolution.

Over the years, I have had numerous patients who felt that the augmentation was too drastic and wanted the implants removed within the first several weeks of placement. My staff and I were able to reassure them and wait out the edema instead of removing the implants. Most often, these patients were very happy when the swelling resolved and the true effect of the implants was apparent. I always encourage patients to wait at least 6 weeks to appreciate the true healed result. I have experienced several cases in which patients developed psychological ideation that they no longer could mentally tolerate a “foreign material” in their body despite an excellent cosmetic result and requested removal. One of the greatest attributes of silicone implants is their easy removal or replacement because they have a dense fibrous connective tissue capsule that forms around the implant, like a sock on a foot. This capsule is what stabilizes the implants but also makes their removal easy. When removing a healed implant, the surgeon must only locate the white fibrous capsule. Once located, the capsule is incised, and the implant can be very easily removed. Obviously, removing screw-retained implants requires removal of the screws, which is also as easy as placing them.

I have had existing implant patients request smaller implants, larger implants, or a totally different implant configuration. When replacing a larger implant with a smaller implant, the surgery is straightforward because no additional dissection is required, and the recovery is simpler. When exchanging a smaller implant with a larger one, additional dissection is required. The recovery time will be somewhat increased, but it is still usually shorter than the original placement.

Implant malposition most frequently occurs in nonfixated implants, although it is possible (rarely) for a fixated implant to rotate on a screw (if only a single retention screw was used), or in rare cases dislodge from the screw. The Valsalva maneuver, talking, excessive chewing, gum chewing, excessive animation, sleeping on one’s side, and smoking are all activities that should be minimized for the first postoperative week. Some asymmetry probably occurs with all implant cases, and small differences usually go unnoticed and blend with the subtle asymmetries of nature. I have seen CT scans of patients who look totally symmetric clinically, but the implants are in very different positions on the scan. Larger asymmetries may be very clinically evident and warrant correction. When this occurs, the patient must decide which side they prefer, and the contralateral implant is then repositioned to match. I have had patients with an implant higher or lower than the other, and they are generally very specific about which one they want repositioned. Fig. 7.35 shows a patient with the right cheek implant placed more inferiorly than the left. The right side was repositioned superiorly, and the patient was happy. If a frank preoperative asymmetry is apparent, then this can be compensated for by placing a larger or smaller implant on one side to compensate for the asymmetry. I have done this several times, where I placed a large implant on one side and a medium one on the other side.

There has been some attention to titanium mesh implants and other biomaterials that have an extremely porous and honeycombed network. Although these implants are quite light, their removal or replacement would be extremely difficult.

Implant malposition can be multidimensional. Fig. 7.36 shows two separate patients with a palpable “springy” prominence over the zygomatic arch region because the implant tail folded under the implant body during placement, as discussed earlier in this chapter. The implant was removed, and the tail was successfully repositioned in both cases.

Figs. 7.37 and 7.38 show patients whose implant was either placed improperly or migrated superiorly, causing the implant border to became palpable at the orbital rim. The affected implant was removed and successfully repositioned.

As stated earlier in this chapter, cheek implant margins must not overextend into the maxillary vestibule. Fig. 7.39 shows a patient from another state who presented with overextended, malpositioned cheek implants protruding into the maxillary vestibule.

In some cases, implant placement can have minor asymmetries that do not warrant replacement. In addition, some cases of acceptable implant results may be improved by fine-tuning with injectable fillers. I have done this to fill in gaps and depressions, feather out the augmentation, or to simply enhance the postimplant result. I usually do this with reversible fillers first to ensure that the patient is happy and then commonly use a permanent filler such as silicone oil in cases in which I am sure that the permanent result will be acceptable.

Some patients have extremely thin “potato chip” bone on the maxillary sinus, and this can be easily perforated or fractured during routine dissection ( Fig. 7.40 ). This is most often seen with novice surgeons but can occur with any surgeon if the bone is thin. If a moderate perforation occurs during implant dissection, the procedure can continue and the implant can lie over the perforation. The surgeon must take care not to allow debris to fall into the sinus through the perforation. Because patients are already on antibiotics from the implant procedure, no other coverage is necessary unless the patient become symptomatic with sinus-related problems.

From time to time, patients will complain of pain or other problems without a clinical presentation. This can be a result of the implant contacting the infraorbital nerve, unspecified inflammation, inflammation or infection involving a fixation screw, sinus or dental-related problems, or sometimes for no apparent reason. Exploring the implant site, removing the implant, cleansing the pocket to remove any inflammatory tissue or debris, and antibiotic lavage can be performed. The existing implant can be disinfected and replaced, or a new implant can be placed. In most cases, the fixation screws can be replaced in their same holes. Although not a cure all for implant problems, I have done this numerous times to alleviate subclinical problems such as pain or swelling.

Custom cheek implants are an option for patients who desire them. These implants can be fabricated directly from a cone-beam CT scan. I have performed several custom cheek implants but did not really see a huge advantage because the sizes and shapes of available stock implants are so diverse that they can achieve almost any configuration. Custom cheek implants are advantageous in cases with unusual anatomy or as reconstructive options that are status postsurgery or posttrauma. These are discussed in detail later in this chapter.

Part II: Chin Implants

Chin implant surgery is a relatively simple procedure with a very high impact on appearance and patient satisfaction. The chin, like the nose, is a very important aesthetic pillar and is frequently satirized in caricatures: a strong chin is synonymous with macho, bravado, and masculinity, whereas a recessive chin is more synonymous with a repressed, wimpy, or introverted person. It is pretty amazing how several millimeters of augmentation can truly change the look (and confidence) of a patient. Like cheek implants, chin implants have a moderate learning curve and are permanent, but they can be exchanged for a different size or shape and easily removed if desired.

Like all surgical procedures, an accurate diagnosis is paramount to proper treatment. Although many individuals have a recessive chin profile, there are other considerations in the diagnosis and treatment of microgenia (small chin). Occlusion must be checked, and patients with a deficient chin caused by mandibular retrognathia with malocclusion should be referred to an orthodontist or an oral and maxillofacial surgeon to consider orthognathic surgery to advance the mandible as a whole. By moving the maxilla and/or mandible, the entire lower jaw is frequently anteriorly positioned, which will many times normalize the profile while at the same time correct the malocclusion. Patients with severe malocclusions must be given the option for functional correction. Without treatment, they can experience future problems with oral function, temporomandibular joint (TMJ) disease, and dental restorations. Orthognathic surgery almost always requires orthodontics, and the entire process can take a number of years to complete. It is best performed in the teenage years but also can be performed on adult patients. In short, it is a significant time and financial commitment. Insurance coverage has also changed and may not cover orthognathic procedures that were commonly covered by insurance in the past. For this reason, even patients with malocclusions frequently opt for isolated chin augmentation, putting aesthetics ahead of function. Some patients with malocclusions may not see the benefit in a hospital procedure to advance their jaw and are only interested in cosmetic treatment, not occlusal normalization. Again, when in doubt, the patient deserves the benefit of referral.

All surgeons must approach all surgeries with a 3D diagnosis and treatment. Simple skeletal microgenia may only require horizontal augmentation, but many patients also require vertical chin augmentation. One of the main diagnostic pitfalls involved with chin implants is the failure to diagnose vertical deficiency of the lower third of the face. This results in placing a chin implant in a patient who diagnostically requires a genioplasty. Unfortunately, this is a common occurrence.

The face is classically divided into three relatively equal vertical thirds. The upper third is measured from the hairline (trichion) to the glabella, the middle third is measured from the glabella to the subnasion, and the lower third is measured from the subnasion to the menton ( Fig. 7.41 ). The goal of the surgeon is to balance the lower facial third with the rest of the face. This must be considered in three dimensions.

When considering the relationship of the chin harmony to the rest of the face, many factors come into play. I personally feel that profile enhancement in never a “one look fits all” type of situation. Many types of standardized cephalometric and soft tissue measurements and computerized programs are available to determine optimum chin projection. Although these are helpful, the astute surgeon will realize that many other influences contribute, including the shape of the neck, cheeks, and nose. A “boilerplate” approach may simply not look natural on some patients. The best surgeons realize the variability in faces and proportions and with experience can usually determine “what looks natural.” Reidel’s plane is a commonly used analysis that involves placing a straight line through the most protrusive portions of the upper lip and lower lip (labrale superiorus and labrale inferiorus) that intersects the soft tissue pogonion. An ideal position is when this line touches both lips and the tip of the chin ( Fig. 7.42 ). If the chin is posterior to the line, the patient is recessive; if the chin is anterior to the line, the patient has chin excess. Fig. 7.42 shows another simple soft tissue measurement. The Gonzalez-Ulloa analysis (also called zero meridian ) has a horizontal line representing the Frankfort horizontal plane and a vertical line that intersects the horizontal line at a 90-degree angle through the soft tissue nasion. In an ideal profile, the line should intersect the most anterior soft tissue projection of the chin (soft tissue pogonion). Like the Reidel plane, a deficient chin will follow posterior to the Gonzalez-Ulloa line, and a horizontally excessive chin would fall anterior to the line. With either of these analyses, surgical augmentations or advancements can be estimated. If a patient with a deficient chin has a vertical line that lies in front of the chin by 8 mm, then the surgeon can estimate an 8-mm implant projection or osteotomy advancement. Again, these are estimates and not absolute measurements or analyses as soft tissue movements are not necessarily 1:1 with implants or genioplasty.

Many patients exhibit a shortened lower facial third, which is referred to as short face syndrome . The manifestations of a foreshortened lower facial third include a recessive chin and an exaggerated mentolabial fold. The normal S -curve that exists below the lower lip and above the chin becomes collapsed in these patients causing the lip to roll outward ( Fig. 7.43 ). A chin implant is not the solution for this type of problem because it would accentuate the mentolabial fold and worsen the problem. Unfortunately, many surgeons do not realize this, and it is not uncommon to see a patient with a deep mentolabial fold and a chin that juts forward as a ledge (see Fig. 7.43 ).

For patients with lower-third vertical height deficiency, the proper treatment is to lengthen the chin. Many of these patients also have a recessive chin, so the actual augmentation requires an increase in vertical and horizontal dimensions. In some cases, a chin implant can be used to increase the lower facial height. To do this, the implant must be placed below the mandibular border, which in effect will lengthen the chin. The problem with this treatment is that there will be a palpable ridge under the chin that represents the bottom of the extended implant and may be bothersome to the patient. The mandibular glove configuration of chin implants is made to cradle the anterior inferior border of the mandible and provide several millimeters of vertical lengthening. In addition, there are very large implants (Implantech Vertical Lengthening Chin implant) that have a major extension below the mandibular border and provide a significant increase in vertical height. The concept is good in theory, but I have only placed several of these vertical chin implants, and I do not believe enough sizes are available. They only come in small, medium, and large and are too bulky for the patients when I have attempted to use them. This implant will be shown later in this chapter. Again, in most cases, a chin implant is not the appropriate treatment for a short lower facial third.

Besides a deep mentolabial fold with accompanying retrogenia, other factors can favor genioplasty over chin implants. A guide to determine whether a patient is best suited for genioplasty instead of an implant is based on the relative position of the upper and lower lip. A vertical line is drawn from the most anterior portion of the upper lip (labrale superiorus), and another vertical line is drawn from the most anterior portion of the lower lip (labrale inferiorus) ( Fig. 7.44 ). Patients who have their lower lip posterior to a vertical line from the upper lip are frequently poor candidates for chin implants as bringing the chin forward with a posterior sitting lip would deepen the mentolabial fold. These patients would benefit from simultaneous vertical and horizontal movement (i.e. advancing and lengthening the chin). Patients with vertical (and horizontal) deficiency are best treated by a lengthening and advancement genioplasty. As mentioned, a deep mentolabial fold most often precludes a chin implant as it would be accentuated.

Chin Implant Surgical Approaches

Chin implants can be inserted from an intraoral route through the mouth or extraorally from the submental area. Arguments exist between various practitioners regarding which route is best, and it boils down to surgeon preference. I use intraoral placement if I am not performing any open surgery in the submental region (e.g., platysmaplasty or submentoplasty) because it prevents a visible scar. When placing a chin implant from a submental approach, there is a natural desire to make as small of an incision as possible as it will be visible. In my opinion, this limits visibility and can hinder access for multiple screw fixation. Therefore I prefer an intraoral approach for an isolated chin procedure. If I am performing platysmaplasty and already have a submental incision, it makes sense to place the implant through this route. In placing hundreds of implants over the past three decades, I have seen no greater incidence of infection from the intraoral route, and I have a lot of experience with both. The intraoral route does provide more disruption of the mentalis muscle and probably has a slightly longer recovery, but in my experience both approaches are equally effective. If I am placing a chin implant with a facelift, then I place it through a submental approach. If I am performing a chin implant as a single procedure, I use and intraoral incision.

Intraoral chin implant and genioplasty approaches are exactly the same, but a chin implant can be placed through a much smaller incision, whereas a genioplasty requires more working room.

The intraoral incision design is a “trapdoor” outline that should extend a minimum of 15 mm anterior from the anterior mandibular sulcus. Failure to extend the incision far enough anteriorly from the sulcus will create a trench or scarring at the junction of the gingiva and mucosa that can become a bothersome and a unhygienic food trap ( Fig. 7.45 ).

I prefer CO ₂ laser or radiofrequency microneedling for this incision and dissection as they provide incision with simultaneous hemostasis. The dissection continues through oral mucosa and the orbicularis oris muscle. The labial branches of the mental nerve are usually encountered in the lateral portions of the incision and preserved ( Fig. 7.46 ).

After the mucosa and orbicularis layer are incised, the instrument is angled posterior to the mandible to avoid perforating the lip ( Fig. 7.47 ). This is an important concept for the novice surgeon to remember. To reiterate, the initial incision is made through mucosa and muscle and then directed posteriorly and inferiorly through deeper soft tissue to bone.

The dissection proceeds in a posterior and inferior direction and the deeper layers are visualized. The paired mentalis muscle and central fat pad lying between them is shown in Fig. 7.48 . The paired mentalis muscles usually blend into the soft tissues and are incised as a single deep plane unit, but they can be better identified with soft tissue dissection using gauze over a finger.

The mentalis muscles are transected and the dissection continues through periosteum to the anterior mandible ( Figs. 7.49 and 7.50 ). There are no significant neurovascular structures in the mandibular midline. Depending on the configuration of the intended implant, the inferior border may require dissection. This is not done with sliding genioplasty as it could decrease vascular supply to the segment. If the surgeon desires to use a glove-type implant or place a silicone implant slightly below the inferior border, minor dissection can be performed under the anterior mandibular border ( Fig. 7.51 )

After the periosteum is located, dissection is performed superiorly to the level of the sulcus and inferiorly to the mandibular border. At this point, the periosteal elevator is used to begin lateral subperiosteal dissection along the inferior mandibular border to the second molar region. The mental foramina (and accompanying neurovascular bundles) lie approximately 12–15 mm superior to the inferior mandibular border ( Fig. 7.52 ). This means that the surgeon generally has 12–15 mm of space between the bottom of the jaw and the nerve. The width of a Molt # 9 periosteal elevator is 9 mm and if positioned at the inferior border of the mandible, the dissection will almost always remain inferior to the mental neurovascular bundle. This same relationship is not necessarily true in patients without teeth as the alveolar ridge undergoes significant resorption that can alter the normal anatomy.

Dissection with a lighted Aufricht retractor is the most accurate means of safely avoiding the mental neurovascular bundle as the retraction and illumination facilitate locating and working around the nerve. As the lateral dissection is performed, it is important not to dissect the periosteum below the inferior border of the mandible as this creates extra space below the border and can allow the chin implant wings to extend below the border, which can result in a palpable and visible projection. In most cases, it is preferable for the dissection to stop at the inferior border of the mandible all the way around the dissection. With all implants, regardless of location, the goal is to keep the dissection pocket as small as possible to contain the implant and prevent malposition or unwanted extension, movement, rotation, and dead space. In some advanced applications or with customized chin implants, the dissection may violate the inferior mandibular border, but with normal stock implants it is important to keep the inferior border intact to contain the implant and prevent dead space, which can fill with blood or serum.

At this point, the pocket is irrigated with antibiotic solution, as described earlier in this chapter, and all bleeding is controlled. I routinely use implant “sizers,” which are the same dimensions as the actual implants ( Fig. 7.53 ). Busy implant surgeons have specific sizers for all common types of implants. Generally, the surgeon has an idea preoperatively of what type of configuration is best suited for the patient. The sizers are used to decide which size or configuration looks best. From experience, I can generally predict what I think will be the optimum implant for a given patient. If I am thinking about using a large extended anatomic chin implant, then I will also try in medium and extra-large sizers to give me a better idea of what looks best on the patient. Likewise, I may try in several sizes of another style implant to see not only what different sizes look like, but how a different implant configuration looks on the patient. Although sizers are a useful tool, the surgeon must remember that the patient is sedated so the mandibular position may not be accurate, and local anesthesia and soft tissue dissection skews the actual result. Again, the sizers are only a guide. When a sizer is placed through the intraoral incision, the surgeon should occlude the upper and lower teeth and pull the lip superior and posterior. This provides a more accurate approximation of the actual clinical result. It is important to ensure that the implant is sitting in the proper midline relationship when making these evaluations. Using a sizer from the external submental transcutaneous approach is more accurate as less tissue dissection is performed relative to the intraoral approach, and what you see is closer to what you get.

Once the proper implant size and configuration is decided, the actual corresponding silicone implant is removed from the sterile pack and placed in antibiotic solution. It is important to refrain from contaminating the implant with glove powder or surgical debris. The implant is always placed on a solid surface and never on paper or other material that could adhere. The implant is then placed into the incision. One of the main advantages of using silicone is its flexible nature. A small incision is possible as one side of the implant may be inserted into the pocket while bending the implant ends together ( Fig. 7.54 ). Being able to bend and fold the implants are one of the huge advantages of silicone material. When using rigid-type implant materials, it is much more difficult to insert implants in small pockets. It is important not to fold the implant tail under the implant body when inserting.

Being able to easily customize implants by trimming is another huge advantage of silicone material. Although many of the stock “off-the-shelf” implants work fine out of the box, experienced implant surgeons frequently customize implants to better fit the patient ( Fig. 7.55 ). My most common trimming procedure is reducing the length of implant tails on females. Many females have very petite, tapering chins, and standard implant tails can make the result too bulky.

I sometimes trim the central portion of the implant to shorten the superior portion. This reduces the vertical length of the implant and provides a lower point of projection. This is useful for patients in whom a taller central portion of the implant would overly plump the mentolabial fold.

Positioning the implant is of utmost importance, and many forms of malposition can occur. Absolute positioning is easier with the intraoral approach as visualization of the implant and pocket are much better than with a transcutaneous submental approach. As previously stated, when surgeons use the submental approach, there is a significant effort to keep the incision small for minimal scarring. The problem is that small incisions provide less access and visualization of the surgical field. Because the intraoral incision is hidden, it can be larger to enable better vision and access. The best-fitting implants adapt intimately to the mandibular anatomy. Silicone also has the advantage of flexing around anatomy that rigid materials do not. The implant must be correctly positioned in all three dimensions, and failure to do so can produce a noticeable asymmetry. First and foremost, all chin implants should lie on the lower, thicker central mandibular bone (menton). This bone has a thick cortex and is resistant to resorption. A common mistake occurs when the surgeon places the implant more superiorly on the mandibular instead of overlying the thick cortical bone. In this case, the implant sits on the more cancellous alveolar bone around or over the tooth roots and is more prone to bone resorption ( Fig. 7.56 ).

As positioning steps continue, it is imperative that the implant tails lie below the mental foramen and neurovascular bundle ( Fig. 7.57 ). It is also important that the implant tails are not so close to the nerve that oral function causes the tails to impinge on the nerve. If this occurs, the patient may report pain or a shock or electric sensation. If the mandibular anatomy or implant configuration is such that the tails contact the nerve, then the tails must be trimmed or secured inferiorly with screws. The best way to view the foramen and implant tail relationship is with a lighted Aufricht retractor.

The implant must be centered to the midline of the patient, and it can be very obvious if it is not (see Fig. 7.57 ). In a normal and symmetric patient, the skeletal, dental, and soft tissue midlines all coincide. In a symmetric patient, the space between the upper central incisors and lower central incisors are in a straight line with the chin. It is not uncommon, however, to have various asymmetries of these relationships. The patient’s midline should be marked with a surgical marker in the upright position before anesthesia to help center the midline. If the patient has midline discrepancies, then the compensated position should be marked (i.e., midline off 4 mm to the right). The final solution is to be able to aesthetically center the implant. The implants have a midline index mark that is most commonly aligned between the upper and lower incisors in the symmetric patient ( Fig. 7.58 ). If the midline is not marked or the marks are lost, the surgeon must approximate the best position to center the implant to the patient’s anatomy. The final indexing requires the surgeon to consider how the implant body sits on the mandible relative to the tails, including vertical position and pitch and yaw ( Fig. 7.59 ).

When all of the aforementioned indexing is completed and the nerve is free of obstruction, the implant is fixated. I fixate each and every implant I place whether it is a chin, cheek, or mandibular angle. As discussed earlier in this chapter, many surgeons do not employ screw fixation for implants. As I see implant complications from other surgeons from all around the United States, I can attest that it is not uncommon for nonfixated implants to migrate. A well-placed implant in a tight pocket may do well and not migrate, but oral function and bone changes can affect position. Although a nonfixated implant may not migrate, a fixated implant cannot migrate in normal circumstances. Screw fixation not only prevents migration, but also discourages micromovement, which is a force that encourages underlying bone resorption.

I routinely place a 10- to 12-mm screw in the mandibular midline and a second screw several centimeters lateral ( Figs. 7.60–7.61 ). The first group maintains the implant in position, and the second screw retains the implant and prevents it from rotating. Placing a single screw may work most of the time, but it does not prevent rotation. On occasion, the implant tails will not sit in their desired position and may be displaced superiorly or inferiorly. A screw can be placed through each tail to hold it in position if needed. When placing screws, it is important to understand the position of the inferior alveolar nerve and tooth roots and to ensure that these structures are not inadvertently damaged by the screws. Some surgeons use suture fixation instead of screws. Although this is probably better than no fixation at all, I have repositioned suture-retained implants from other surgeons that became displaced from the sutures pulling through the tissue or breaking.

When the surgeon is satisfied with the total positioning of the implant, the surgical site is checked for hemostasis and irrigated with antibiotic solution. When using the intraoral approach, it is absolutely paramount to reattach the transected mentalis muscles. If this is not done properly, lip incompetence can occur. The mentalis muscles are integral for normal lip function, and it is difficult to correct this situation at a later date. The mentalis muscle stumps are generally very vascular and easy to identify and resuture ( Fig. 7.62 ).

The orbicularis oris muscle is generally not sutured, and the final mucosal closure is performed with 4-0 gut interrupted sutures ( Fig. 7.63 ). Interrupted sutures are used intentionally as a running suture can produce a watertight closure and prevent passive drainage and encourage hematoma or seroma. A Velcro head wrap can be placed to compress the surgical site and is the option of the surgeon.

Simplified Intraoral Approach

Although the previously described intraoral approach to silicone chin implants is my most common technique, an implant can be placed with a less invasive vertical incision. This approach does not violate the mentalis muscles and therefore heals faster, but the drawback is substantially less intraoperative visualization.

A vertical incision is made in the midline of the lip through the mucosa and orbicularis oris muscle. The mentalis muscles are identified, and the tissues lying between the paired mentalis muscle are incised to bone ( Fig. 7.64 ). The mentalis muscles are retracted laterally, and the periosteal elevator is used to tunnel to the second molar region on each side. The implant is then inserted through the gap between the mentalis muscles ( Fig. 7.65 ). After successful placement and indexing, the mentalis muscle bellies are sutured in the midline, and the mucosal incision is then closed ( Fig. 7.66 ).

Submental Transcutaneous Chin Implant Approach

As stated earlier, I prefer the intraoral approach for isolated chin implant surgery but utilize the transcutaneous submental approach when I am doing a facelift, platysmaplasty, or submentoplasty because the incision is already defined. The submental incision is marked preoperatively with the patient upright and before any local anesthesia is injected. Because this will be a visible incision, optimizing the position is important as a crooked or misplaced incision is very obvious in this area ( Fig. 7.67 ). Many textbooks describe placing the implant through a small incision in the submental crease. This works well for many patients, however, if a large chin implant is to be used, it can protrude significantly, and a normal submental crease incision may end up on the chin instead of under it when the skin is redraped. In such a case, a more posterior incision is used to compensate.

I generally place the average submental incision several millimeters inferior to the submental crease with any surgery in this region. This is especially important in older patients who may have a ptotic or “witch’s” chin, and placing the incision in that submental crease can amplify the deformity. This is discussed in depth in Chapter 3 .

After the skin is prepped, 5 mL of 2% lidocaine with 1:100,000 epinephrine is injected in multiple planes to the periosteal level, and several milliliters at the soft tissue incision site. A 2- to 3-cm incision is made through the skin and subcutaneous plane with a scalpel. The best way to make a straight incision in this area is to make a V with the fingers (like a peace sign) and spread the skin taut ( Fig. 7.68 ). Experienced chin implant surgeons can place a silicone implant through a very small incision. Although this may be an attribute for a small scar, it severely limits vision. Also, in my opinion, increasing the incision by 5 mm or so can allow superior direct vision, which is important for mental nerve visualization and screw fixation.

After the scalpel incision, radiofrequency microneedling or cautery is used to dissect immediately to the subperiosteal level and expose the mandible ( Fig. 7.69 ). The midline of the submental region is a very safe region, and no major nerves or vessels are endangered. It is imperative to continue all dissection in the subperiosteal plane. In patients with chin ptosis (witch’s chin) or when using a larger implant, the surgeon can use facelift scissors to dissect superiorly in the subcutaneous plane only to undermine and free up the deep “trench.”

The subperiosteal dissection is continued superiorly so all tissues are freed to the level of the mandibular sulcus. This can be confirmed and assisted by undermining the midline dissection with the surgeon’s index finger. Using a periosteal elevator, the subperiosteal dissection is continued laterally on both sides ( Fig. 7.70 ). The lateral dissection is made with caution to avoid the mental nerve. I prefer to dissect to the mental foramen and actually visualize the neurovascular bundle. The mental nerve lies approximately 12–15 mm above the inferior border of the mandible, and its presence must be anticipated. As stated earlier, a Molt # 9 periosteal elevator is an excellent instrument to use. It is efficient, and the width of the spoon tip is narrow enough to allow dissection under the mental foramen without disrupting the nerve. If the operator keeps the dissecting edge of the periosteal elevator on the inferior border of the mandible, the mental nerve is generally well protected as shown in Fig. 7.52 . Fig. 7.71 shows an Aufricht retractor and the right mental nerve emerging from the foramen into the soft tissues.

The dissection is made posteriorly as far as necessary to accommodate the implant tails of the specific implant style used. This is usually in the area of the first or second molar. The dissection pocket should be only slightly larger than the implant to prevent movement. After the pocket is dissected, an implant “try-in” sizer can be utilized if desired ( Fig. 7.72 ). These sizers are available for most common implant configurations through the manufacturer.

Once the desired implant is chosen, optional trimming may be done depending on the size of the implant and patient. The dissection pocket is irrigated with antibiotic solution, and one side of the implant is inserted into the incision. Because silicone implants are very flexible, it is not difficult to fold the implant in the center to insert the other side through the small incision as shown with the sizer in Fig. 7.72 . It is imperative that the implant is in the proper midline position and that the implant tails are not folded under the implant body. These style implants have a blue midline mark in the center, and this should be aligned with the patient’s midline (see Fig. 7.58 ).

As stated earlier, I perform screw fixation on all implants. Self-drilling screws are not generally used on the thick mandibular cortex. This requires a drill to first make the hole, and the screw is then inserted. A single screw is used to stabilize the implant in the midline ( Fig. 7.73 ). If the implant has a tendency to rotate, a second screw can be placed to further stabilize the implant. From time to time, a third screw can be placed. This is generally a result of the implant not intimately fitting to the mandible or when the tails must be moved down and stabilized so as not to impinge on the mental nerve. I most frequently place a midline screw and a lateral antirotation screw.

After the implant is placed and fixated, I perform a final inspection for hemostasis, symmetry, and to view the implant tails in relation to the mental nerve. If the implant tails are contacting the mental nerve, they must be trimmed, relieved or fixated inferiorly to prevent future problems ( Fig. 7.74 ). Finally, the incision is closed in layers. The periosteal or deep layer can be closed if it is identified and thick enough to hold a stitch. The remaining soft tissue closure is completed with 4-0 gut suture for subcutaneous closure, and the skin is closed with 6-0 nylon suture or 5-0 gut suture ( Fig. 7.75 ).

Since the last edition of this textbook, a new type of implant has become available. Implantech’s Vertical Lengthening Chin implant is a new type of implant designed by plastic surgeon Dr. Barry Eppley ( Fig. 7.76 ). The design of this implant is unique in that it sits on the inferior border of the mandible and provides not only projection but vertical lengthening. The purpose of the implant is to be able to substitute an implant procedure instead of an advancement and lengthening genioplasty. The concept is excellent, and I have placed several of these implants; however, I think further work must be done to implement more delicate styles of this implant, especially for female patients.

Figs. 7.77–7.82 show before and after photos of selected chin implant cases. Some of these patients have also had concomitant cosmetic facial procedures, but the chin improvement of the case is obvious.

Genioplasty

Joe Niamtu, III

With Commentary by Brian Farrell and Peter Dennis

Genioplasty (also called geniotomy ) literally means “changing the chin” and can be used to advance a chin, set back a chin, lengthen a chin, correct a chin asymmetry, or a combination of these. For chin reduction, it is the best and most controlled option. For simple chin advancement, I always use implants. My main reason for performing a genioplasty is to lengthen (and frequently simultaneously advance) the chin. This was well-explained in the early part of this chapter. Fig. 7.83 shows what patients see and request when a vertical chin deficiency exists; this is important as it shows patients who are not candidates for chin implants (see Fig. 7.44 ).

A genioplasty is indicated to correct skeletal chin deformities including mild retrognathia, microgenia, microgenia, and genial asymmetry. Additionally, a primary or secondary benefit can be enlargement of the posterior airway space for treatment of obstructive sleep apnea. Contraindications include retrognathia with normal genial development, severely distorted anatomy, abnormally low mental nerve foramen positioning, and a short mandibular symphysis.

The approach for sliding genioplasty is exactly the same as described for the intraoral placement of chin implants previously discussed. Excessive dissection or stripping of anterior and inferior soft tissues is avoided with genioplasty as it is the soft tissue that nourishes the osteotomized segment.

When all subperiosteal dissection is completed, the osteotomy cut is planned. Some surgeons utilize angled and other geometric bone incisions, but I most often perform a horizontal cut with tapering ends that thin out to the mandibular border and run under the mental nerves ( Fig. 7.84 ). This bone incision is made using a reciprocating, oscillating, or sagittal microsaw ( Fig. 7.85 ). The vertical midline is marked first (see Fig. 7.84 ) for future reference, and a true horizontal line is scored with the saw inferior to the mandibular teeth. The cut will follow the mandibular occlusal plane (see Fig. 7.84 ), assuming it is normal and horizontal. Otherwise, it must follow the patient’s horizontal plane. I prefer to initially score an intended horizontal cut with tapering edges before actually making the final cut. This allows me to ensure that my symmetry is normal. After scoring, the preferred saw is used to complete the bony cuts (see Fig. 7.85 ).

This osteotomy should be placed at least 5 mm inferior to the visualized mental foramen and dental apices. We also prefer to carry the horizontal osteotomy as far back as possible in a linear fashion beyond the mental foramen. A narrow osteotomy may result in a pointed-chin appearance. Ideally, this osteotomy is placed at the same level on the buccal and lingual cortices to prevent an increase or decrease in vertical height of the chin as it is advanced. Once the surgeon is content with the height and symmetry of the planned osteotomy, it is carried from lateral to medial on each side, standing the saw perpendicular as the osteotomy progresses. This minimizes lingual bleeding as the tip of a reciprocating saw blade is not end cutting. We find that the area most frequently incompletely cut is the inferior border at the lateralmost aspect of the osteotomy. Once the bilateral osteotomies are complete and met in the midline, the genial segment should easily separate with light pressure on an osteotome. If this does not occur, we recommend assessing osteotomies to prevent an undesired fracture rather than applying more pressure with the osteotome. The optimum to achieve hemostasis of any sublingual bleeding is after the osteotomy and before fixation. Cautery or packing with a hemostatic agent is usually effective. An expanding hematoma in this area may compromise the airway. It is imperative to achieve hemostasis throughout the entire procedure, but especially before the fixation phase which obstructs access to the sublingual region.

The bone and saw blade are irrigated with saline to prevent burning, and the surgical team must be protected with face shields and appropriate personal protective equipment as the vibrating saw throws significant irrigation and bone debris in an aerosol.

Once the segment is down-fractured, the sublingual area is checked for bleeding, and hemostasis is performed with bipolar cautery. This area is extremely vascular, and gross hemorrhage can occur if the sublingual vessels are lacerated. The region can also be packed with hemostatic gauze to control bleeding if necessary. Great care is taken to not disrupt the sublingual soft tissues and muscular attachments (geniohyoid and genioglossus) to the osteotomized segment as this is important blood supply.

Once the osteotomy is complete, the segment can be stabilized with a towel clamp or wire. A drill or fissure bur can be used to make a perforation in the midline buccal cortex of the free segment. A 26-gauge wire is then passed and used to control and position the free segment ( Fig. 7.86 ). Alternatively, a temporary fixation screw may be placed in the midline of the inferior segment to be used as a positioning aid when grasped with large needle holders or wire twisters. Positioning of the osteotomy is verified by inspecting the step in the osteotomy for visual symmetry along the lateral “wings” and palpating along the inferior border. A caliper may be used to measure the advancement of osteomomy. Asymmetric changes may be incorporated based on preoperative planning. Once satisfied with positioning, fixation may either be achieved by plates or positional screws. Most hardware vendors have prebent plates to achieve predictable advancements (e.g., 8-mm, 10-mm, 12-mm). These are useful plates for pure advancement but must be modified for advancement with vertical increase. To use this type of plate with vertical lengthening, the plate is bent inferiorly to create a gap. This works adequately but is problematic because the inferior bending reduces the amount of horizontal advancement. If a 14-mm plate is used and bent down 5 mm, the advancement will not be 14 mm ( Fig. 7.87 ).

If the genioplasty only requires advancement, transosseous screws or simple plating is used to stabilize the segments. The bone plate is usually placed on the inferior segment and then positioned on the superior segment respecting the previously marked midline. When the predetermined vertical and horizontal measurements are achieved, the superior plate screws are placed ( Fig. 7.88 ). A sliding genioplasty can also be used to treat macrogenia or man­dibular prognathia, but this is seen in a much smaller segment of the population. The osteotomy procedure is the same, however the distal segment is repositioned posteriorly. Doing this can cause the wings to protrude and be visible or palpable and they will eventually recontour but can also be reduced during the procedure. The patient should be warned about this preoperatively as well. There are many other genioplasty techniques used to treat a plethora of situations such as mandibular asymmetry and vertical reduction, or widening or reducing the width of the actual chin. Deep discussion of these topics is beyond the scope of this chapter.

In patients with large movements or thick bone or in larger patients, additional stabilization may be needed to prevent inferior segment mobility (see Fig. 7.87 ).

As stated earlier, I do not usually graft intrasegmental gaps less than 1 cm. Some surgeons routinely use autologous, homologous, or synthetic grafts to fill all gaps. In my experience, most gaps less than 1 cm will fill with bone over time if the segment is totally stabilized. In cases with a larger space between the osteotomized segments, a spacer graft can be used ( Fig. 7.89 ).

If there are any sharp, protruding, or asymmetric projections on the osteotomized segments, they are smoothed with a rasp. After the plate is secured, the area is copiously irrigated with antibiotic solution, and the wound is closed in the same manner as described earlier for intraoral chin implants. Similarly, care must be exercised to reapproximate the mentalis muscles.

Sometimes genioplasty may not provide the amount of desired advancement as this is limited by the anterior-posterior thickness of the inferior segment and the limitations of the soft tissues and sublingual musculature. In some cases, a silicone chin implant may be stacked on a genioplasty to provide extra projection ( Fig. 7.90 ). I have performed this dual treatment numerous times. This is especially useful for large advancements in which using the implant does not require such a long advancement of the osteotomized segment. In other words, the surgeon can perform a 12-mm advancement by moving the bone 7 mm and adding a 5 mm chin implant. Another application for simultaneous genioplasty with a silicone implant is the patient with an extremely deep mentolabial fold. If the advancement and lengthening does not improve the mentolabial fold, a silicone implant can be placed over the deficient region to provide support and augmentation of the deep fold (see Fig. 7.90 ).