A sliding genioplasty is a very versatile chin reshaping procedure that has been used for decades. In elective chin augmentations it is the alternative option to the use of a chin implant. Although chin implants are by far more commonly done in a ratio of at least 20:1 if not greater. While chin implants are a simpler procedure they are not appealing to everyone nor are they always the best choice for every type of chin deficiency.
A sliding genioplasty is usually best done for younger patients who have significant chin deficiencies. There also is a much higher tendency to them at the time of orthognathic surgery when other facial bones are being manipulated as well. In larger chin deficiences moving of the bone has less potential for any long-term problems than does an implant.
The limits of how far forward a sliding genioplasty can move the chin horizontally is a function of the thickness of the chin bone. It is important to maintain some bone contact between the upper and lower chin segments, meaning the back edge of the downfractured chin segment should at least touch the front edge of the chin bone above it. (and be stabilized by plate fixation)
But in some larger chin deficiencies even maximal forward chin bone movement may still leave one with less than an ideal profile change. In these circumstances, whether recognized during the initial sliding genioplasty or afterwards, the solution can be a chin implant. A chin implant can be placed on the front edge of the sliding genioplasty to gain an additional 3 to 5mms of horizontal chin projection. An extended anatomic chin implant is used so that its wings cover the step off area on the back side of the osteotome line. It is critically important that the chin implant is secured by screw fixation to the sliding genioplasty segment.
While chin implants and sliding genioplasties are traditionally thought of as being mutually exclusive, they do not have to be. In need of extreme amounts of chin projection, the combination of a sliding genioplasty with a chin implant overlay can be a useful chin augmentation strategy.
Chin augmentation using synthetic materials is both the most historic facial implant procedure and still the most commonly done. This is evidenced in that chin implants have the largest number of styles and sizes commercially available of any facial implant manufactured today. Chin implants are inserted by incisions either from the inside of the mouth mucosa or through the skin under the chin. There are advocates for either approach but successful chin augmentation results can be obtained either way with good attention to their unique technical details.
The placement of chin implants is most commonly done from a submental skin incision. It has the advantages of more limited disruption of the mentalis muscle of the chin, less risk of lower lip numbness and a more assured and sustained placement of the implant on the lowest portion of the chin bone. (where it belongs for its maximal effect) Understandably some patients are concerned about the final appearance of the submental scar. This concern is most significant in patients of intermediate skin pigments.
I have seen many submental chin implant scars and there are often much larger (longer) than they need to be. The use of silicone chin implants, even the longer anatomic or winged ones, allows for the implant to be inserted in a folded fashion, one half at a time. This enables a remarkably small incision to be used despite the length of the chin implant.
The key is to develop the subperiosteal tunnels along the sides of the chin bone in largely a blinded fashion. Once the incision is made down to the bone, small elevators are used to made the subperiosteal tunnels along the inferior border of the mandible. It is important to make these tunnels longer than the wings of the implant on each side. By so doing half of the implant can be inserted and slide past its midline to one side. This will allow the opposite wing to be folded and inserted easily and then slide back to the midline.
Once the implant is in the tunnels it can be slide back into the midline and secured by whatever fixation method one desires. (in this case of a vertical lengthening chin implant a 1.5mm screw was used)
Minimal incision chin augmentation can be very effectively done through a submental skin incision using preformed silicone implants.
Synthetic implants are involved in some of the most common procedures performed in plastic surgery. From the skull down to the calfs, implants allow an instantaneous augmentation effect to be achieved of a variety of sizes and shapes. While rivaled more recently in some procedures by fat injection grafting, implants offers a permanent volume/augmentation effect that is simpler to achieve. (out of a box so to speak)
While implants offer many benefits, they also have their own set of potential complications. Infections, malposition and size issues are amongst the most common no matter where in the face and body an implant may be placed. These are obvious complications that occur in the short-term, within weeks or months after surgery.
But longer term changes which sometimes lead to complications with implants come about from a less obvious source. When a synthetic implant is placed in the body, the implant itself can never change as they are made of materials that do not degrade or change. (e.g., silicone) Rather the body must adapt to it and respond based on the pressure caused by the implant’s volume. Thus tissues change around the implant and these changes are almost always that atrophy. Surrounding tissues thin to varying degrees based on implant size and body location.
One of the classic examples of this response is that of the chin implant. Often erroneously referred to as ‘erosion’ (which suggests an inflammatory reaction which it is not) some chin implants can be seen on x-rays of being partially inside the bone. This is a benign but natural process of implant settling. As a response to the pressure of the chin implant, which causes its aesthetic effect by pushing off the underly bone on the soft tissues of the chin, the bone responds to this pressure over time by resorbing under the implant. This allows the chin implant to imprint into the bone. Once a ‘pressure release’ is obtained no further settling into the bone occurs. Interestingly it does not occur in all chin implants and rarely if ever occurs in any other type of facial implant.
An often recognized example but one that is far more common is that of breast implants. The pressure release phenomenon occurs through the dual effect of overlying breast tissue thinning and underlying rib deformation. Every plastic surgeon has seen it in some women who undergo breast implant replacements. When the existing breast implant is removed, the remaining breast mound will look sunken in and deformed. This is one reason some women over time feel that their breast implants no longer look as big. The breast implant has never changed in volume but the surrounding breast tissue has become less and the implant may have settled down into the ribs more.
While this tissue response to chin and breast implants rarely causes any problems, such a response on the nose can be very problematic. Rhinoplasty that uses large implants for nasal augmentation is well known to cause thinning of the overlying soft tissues which is very thin. This can lead to implant exposure and infection.
Tissue atrophy and thinning occurs to some degree around every augmentative implant placed in the body. It usually does not cause any long-term problems but is one compelling reason to avoid very large implants at any face or body location.
Chin augmentation can be done by a variety of surgical methods including a chin implant and a sliding genioplasty. Each of these aesthetic chin techniques has a role to play and they have their own advantages and disadvantages. But both have the same limitation…a limit to how much the chin can be horizontally projected. Chin implants are not made with standard thicknesses that are greater than 10 to 12mms. A sliding genioplasty can only be moved as far as the thickness of the bone will allow which can vary between 10mm to 16mms.
The horizontal movements provided by standard chin implants and sliding genioplasties are sufficient for the vast majority of patients with chin/jaw deficiencies. But they can be inadequate for the few patients that have horizontal chin projection deficiencies that exceed 15mm and may be as significant as 25mms.
Combining a sliding genioplasty with an implant is a novel method to achieve larger amounts of chin projection that I have done for years. Through an intraoral approach, which is needed for a sliding genioplasty, the implant is placed on the chin bone just one would normally do. It does need to be secured into placed by screw fixation otherwise it would easily become displaced. A chin implant with long wings also has the advantage of covering over the bony step-off that often occurs at the back end of the osteotomy.
Very large chin deficiences can be managed by the creation of a custom implant but combining an implant and a sliding geniplasty may be sufficient in some of these cases. In my experience there has been no higher infection risk when placing an implant on top of a sliding genioplasty than when using a chin implant alone.
Chin augmentation is one of the most commonly performed aesthetic facial surgeries and has a long history in plastic surgery. Other than rhinoplasty, in which it is often concurrently performed, it is the most frequently changed facial skeletal structure for cosmetic enhancement. While historically done with bone and cartilage, it is almost always done today by a large collection of preformed synthetic implants that offer a wide range of three-dimensional changes of horizontal projection, width and vertical length.
While chin augmentation is often perceived as a simple and straightforward procedure, both by surgeons and patients alike, there are numerous issues that must be considered for a successful result.
Chin Augmentation is a Three-Dimensional Facial Enhancement. While the historic assessment of chin deficiency, and the success of chin augmentation, has been based on the amount of horizontal augmentation, this dimensional consideration alone is inadequate. Adequate chin augmentation should take into consideration its width as well as its height or vertical length. These dimensions can be almost as important as horizontal projection when one is viewed or seeing themselves in the frontal and oblique facial views. Many of these dimensions can be changed by contemporary chin implant designs.
The Shape of the Chin Is Different in Men and Women. The shape of the face has some very gender specific differences and the chin is no exception. Men want a stronger chin that can aesthetically have more projection and width. (squareness) Conversely, a woman’s chin can be a little bit weaker (less projection) and should have more of a triangular shape, it should also not be too vertically long. The most frequent aesthetic chin augmentation ‘complication‘ is a chin augmentation result in a women that looks too big, often being too wide.
The Chin Is Connected to the Rest of the Jawline. Deficiencies in the chin almost always reflect other jawline issues since the chin is just an extension of the total mandibular bone and its growth and development. For these reason, short chins will almost always have a high jaw angle. For men this may mean that they may aesthetically benefit by the placement of jaw angle implants with their chin augmentation to really given them a much better shaped overall jawline.
The Path of Chin Implant Insertion Can Affect The Results. Chin implants can be inserted through either inside the mouth or from under the chin. While patients understandably are focused on avoiding a scar under the chin, the intraoral route is associated with a far greater risk of complications and poor implant positioning not to mention recovery…all due to disruption of the insertion of the mentalis muscle. It actually takes much greater technical skill to get a good chin augmentation result when done from the ‘scarless’ method of chin implant placement.
Not All Chin Implants Come Preformed Out Of A Box. While there is a wide variety of styles and sizes of chin implant available today, a performed implant may still not be the most ideal for some patients. If the jawline/chin has asymmetry or the amount of chin augmentation is extreme and may require an extended chin implant, a custom designed chin implant can be the much better way to go. While it does add cost, an unhappy result or revisional surgery may end up costing more later.
Chin augmentation is the original facial implant procedure and is still the most commonly one performed today. Several different materials of chin implants are available and a wide variety of styles and sizes exist from different manufacturers. Despite the apparent diversity of chin implant options, it is generally viewed as a ‘very simple and safe’ aesthetic facial operation.
But despite this seemingly simplicity, complications from chin implants are not rare. Infection, implant asymmetry/displacement and aesthetic dissatisfaction do occur and are probably more common than plastic surgeons care to know. Part of this is due to the fact that a synthetic material implanted anywhere in the body always has some risk and another reason for complications is also due to surgical technique.
While the chin bone has few vital structures around it, there is the mental nerves to the periphery and the mentalis muscle which drapes directly over the front part of the bone. To clarify the important anatomy that is involved in the placement of chin implants, an article was published in the April 2013 issue of the journal of Plastic and Reconstructive Surgery entitled ‘The Safe Zone for Placement of Chin Implants’. Using fresh cadaver dissections, the location of the exit from the bone of the mental nerves was consistently around 1.5 cms above the lower border of the jaw and located between the first and second premolar (bicuspid) teeth. The origin of the mentalis muscle was at the base of the anterior mandibular sulcus at the incisor roots (the level of the outer labiomental sulcus) and descends downward to insert into the chin soft tissue pad in a fan-shaped manner.
While this article provides no new anatomic information that hasn’t been known for some time, it helps the novice plastic surgeon be aware of the subperiosteal location in which to stay when placing chin implants. (below the muscular origin of the muscle and the mental nerves) Its relevance to the patient is in several issues to ponder when undergoing chin implant augmentation.
While some patients like to avoid a submental scar in placing the implant, one is at greater risk of mentalis muscle problems going from inside the mouth if the muscle is not put back together properly. The submental incisional approach is probably ‘safer’ in many cases and in most surgical hands. In addition, while a 1.5 cm pathway below the mental nerves is fairly generous for the wings of most chin implants, large implants and even custom jawline implants that are bigger are at greater risk of injuring the nerve during dissection and/or have an implant impinge on it afterwards causing lip and chin numbness/pain.
‘All societies in history were and are preoccupied with facial beauty’
‘ Facial balance and symmetry are the key features to attractiveness’
‘All people regardless of race, class or age share a similar sense of what is attractive’
‘Square jawed males are viewed as more masculine, gain higher ranks in the military and have earlier and more frequent sex’
‘ A square chin and jawline frames the lower face, making it more symmetrical and defined’
‘Defined jaw points and angles are more attractive in both men and women’
These are just a few of the well known facial facts of beauty that are often quoted and specifically address the merits of a strong and well defined jawline. While some have it naturally, the vast majority of us don’t and must seek a surgical solution. While there are a variety of facial implants for jawline enhancement, there are numerous misconceptions about how they work and how a better jawline is achieved.
‘The jawline consists of three parts, the chin, body and angles, all which can be implanted although not equally effectively or in all dimensions’
The most well known jawline implant is that of the chin. It is the most frequently done of all facial implants and has been surgically implanted for over fifty years. While the styles and size of chin implants have improved dramatically over this time, chin augmentation only affects the front 1/3 of the jawline. While one could argue that this is the most important part of the jawline and has its U-shape provides very visible forward projection, a chin implant provides no change for the posterior 2/3s of the jawline.(body and angles) Even today’s extended anatomic designs rarely provide any augmentation to the body even though the tail of the implants may lay upon it. Today’s chin implants, while providing projection and even square shapes through increased width, can not provide vertical lengthening…an overlooked feature of chin implant designs.
Three-dimensional chin reshaping can be done by a sliding genioplasty which can add vertical lengthening as well as horizontal projection. In extreme chin deficiencies, an osteotomy can be combined with an implant in front of it for a few more millimeters of projection or the implant can serve to fill in the notching that often occurs in the bone in the prejowl area.
Jaw angle implants are the least performed augmentations of any of the facial prominences. (chin, cheek, nose and jaw angles) While jaw angle implant designs have been around for nearly fifteen years, they have not garnered great use because their surgical implantation is more difficult and aesthetic interest is more recent. Current jaw angle implants produce mainly lateral augmentation (width) which actually is indicated for only the minority of patients seeking jaw angle enhancement. For someone with a favorably low jaw angle point, width alone may produce a satisfactory enhancement.
Jaw angle deficiencies, however, almost always are the result of a high jaw angle which by definition implies a vertical deficiency as well. Getting current implant designs low enough is difficult if the surgeon does not do adequate soft tissue release and the implant does not have a design that can engage the lower border of the jaw angle for positional security. Jaw angle implant designs that provide both horizontal and vertical augmentation (inferolateral) are most useful to a larger number of patients, particularly men, who seek a more defined and prominent jaw angle area.
While chin implants augment the anterior two-thirds and jaw angle implants enhance the posterior two-thirds of the jawline, the missing area is the middle or the body of the jawline. Sandwiched between the chin and the jaw angle, the body area has not specific implant for it. There is no ‘connector’ implant between the two. For those seeking a perfectly straight line back from the chin to the jaw angle point, this may be an aesthetic problem. While chin implants have extensions that go back and jaw angle implants have a forward reaching design, the two only connect over the body by overlapping their feathered edges if done together. This is why many jawline enhancement patients may have a visible step-off or break in their new surgically created jawline. For some combined chin and jaw angle patients, this body discrepancy is minimal and not an aesthetic issue.
The body gap becomes most manifest when the jawline deficiency has a vertical deficiency component to it, areas that are not optimally augmented with current chin and jaw angle implant designs. When a perfectly straight and well defined jawline is desired, a custom two-piece implant is ideally needed that augments the entire jawline from front to back in a perfectly smooth fashion. These are particularly effective when the lower jaw is vertically short and the implant can be made to extend the entire lower border of the jaw. These ‘wrap-around’ jawline implants can produce some dramatic jawline changes.
The most unique jawline problem that can only be addressed by custom implants is when the entire jawline is vertically deficient, creating a small lower face. This almost always is associated with a lot of overbite of the anterior teeth, indicating that the lower jaw is small and fits partially inside the upper jaw. This creates an overclosing of the lower jaw making it too short vertically. Making a custom implant that fits only on the lower border of the jaw and lengthening it from front to back is the only effective solution.
Jawline enhancement must be assessed carefully in every patient to get the right jawline implant(s) design and size. For many patients, a chin implant may only be needed. For others seeking a three-point prominence change, off-the-shelf chin and jaw angle implants will suffice. Improving implant designs and sizes will make using this implants even more effective in the near future. For those seeking a completely new jawline with existing front to back deficiencies, wrap around jawline implants are designed and custom made for each patient’s specific jaw anatomy.
Background: A strong jawline is perceived as a sign of masculinity and is a commonly desired feature of some men. Using implants is the only way to create a well-defined jawline through the triple approach of chin and jaw angle implants. While these implants are available in different materials from various manufacturers, their most important feature is the style and size that they offer. Picking these implant features for any male patient is a lot more art that it is science.
When picking implants for any facial area, it is important to take into account their facial shape and the overlying soft tissue thickness. Thick faces blunt the effects of implants and may simultaneously benefit from some defatting procedures as well. Thinner faces have less overlying soft tissue and the effects of implants can more easily be seen. These facial characteristics are particularly important at the jawline which is essentially a transition point between the face and the neck. Augmenting the front (chin) and the back part (jaw angles) of the U-shaped jawline can change its appearance dramatically.
The thin face and jawline has the benefit of being more easily skeletonized by implants. But implant size must be tempered lest their effects become too pronounced or big. The lower face must not overpower the upper face by being too wide or extending beyond the upper zygomatic width. It must also not become too square in appearance and still maintain some element of being thin and somewhat narrow, just with a more defined jawline.
Case Study: This 45 year-old male felt that his entire jawline was weak. He had a chin implant placed four years ago and, while it provided some benefit, it was still not satisfactory. As part of the discussion about how to improve his chin, his highly angled jaw angle area was pointed out and it was agreed that jaw angle implants would be beneficial as well. He remembered that his prior chin implant was of mersilene mesh composition and that it was ‘large’ according to his original surgeon.
A square silicone chin was chosen to replace his existing chin implant. At least 9mms of additional horizontal augmentation was needed with a more square frontal shape. Silicone jaw angle implants that dropped the angle border down was also chosen but with a width that was not more than 7mms, keeping in line with the rest of the width of his face. The implants would have some overlap across the body of the mandible but with no augmentation effect in this area, which is common.
During surgery, the chin was approached through his existing submental scar. The mersilene mesh implant was heavily ingrown with tissue and was near the dermis of the skin. Removing it was felt to leave too little soft tissue between the skin and any new implant. It was elected to leave it in place and place the new square silicone implant between the underside of the mesh implant and the bone. The wings of the square chin implant went well beyond that of the mesh implant and had no problem providing a more square shape effect. The jaw angle implants were placed through an intraoral incision behind the molars. Dissection released muscular attachments off the angle and the inferior border so the jaw angle implants could be placed low enough. They dropped the border 5mms and had 7mms width. A single screw secured them in place to keep them low and to the back of the angle.
He had some moderate facial swelling, but like in all thin faces, it resolved fairly quickly within three weeks after surgery. He had a much improved jawline with better definition but a jawline width that stayed in line with his upper facial width.
1) Jawline enhancement in men is most commonly performed by a combination of off-the-shelf chin and jaw angle implants.
2) The style and size of chin and jaw angle implants must be chosen carefully and with an appreciation of the patient’s natural anatomy and soft tissue thickness.
3) In the thin male face, jawline implants should not be too wide or over-sized as small implant can produce dramatic effects.
Synthetic implants have a wide variety of uses throughout the body, usually creating an aesthetic augmentation of a deficient or missing body part. The vast majority of face and body implants are composed of silicone due to its biocompatibility, low cost and ease of insertion. Besides breast implants, every other silicone implant is composed of a non-liquid composition with various degrees of firmmess/softness known as a durometer level.
Unknown to many, solid and saline-filled implants exist for the testicles. Outside of the Urologic surgery and sexual medicine worlds, this may seem to be a strange place for an implant. But loss of one testicle due to surgery or a birth defect is not rare and can be very bothersome to some men. As a result, testicular implants in various forms have been implanted for over fifty years.
A new version of a testicular implant was reported in the October 2012 issue of the Journal of Sexual Medicine. Out of Mexico, a case was reported in which a 45 year-old man had his right testicle implanted/reconstructed with a chin implant. The patient was born with only a testicular remnant on the right side and a normal-sized left testicle. The smaller testicle was initially removed and replaced but apparently had a residual size mismatch. In a subsequent surgery, the right testicular implant was revised by adding to it a silicone chin implant to make a better size match to the opposite side. He went on to heal without complications and a satisfactory result.
While using a chin implant for aid in testicular augmentation is unusual and at the least entertaining, it is the simple application of implant materials science. Most testicular and chin implants are made of exactly the same silicone material with very similar durometers. The only real difference is in their shapes, the testicular implant is oblong (egg-shaped) and the chin implant is shaped more like a horseshoe that is thicker in the middle. To make a smaller testicular implant bigger, a chin implant can have its wings removed and the residual crescent-shaped middle portion fit onto the testicular implant by suturing it to it.
The only real perplexing part of the story is why not just use a larger testicular implant? Silicone testicles come in a variety of sizes. Ordering a new larger one would seem the more logical approach…unless one didn’t have it or want to order a new one and used what was lying and available…a chin implant. A one-piece implant is always better than a two-piece composite which can eventually separate due to the shearing stresses in a highly mobile area like the scrotum.
The fastest growing cosmetic plastic surgery operation in 2011 was…chin augmentation. Done primarily with an implant, enhancing one’s profile by improving the projection of the chin increased over 70% last year. The rise in chin augmentation has been linked to the increasing use of Skype and FaceTime, applications where you are forced to look at yourself while talking to others. The distortion of webcams rarely improves one’s appearance and often makes the face look fatter. More likely the increase is due to new chin implant sizes and styles and the growing number of different types of facelifts which are often combined with chin implants to create a more defined and smoother jawline and neck angle.
Dr. Barry Eppley is an extensively trained plastic and cosmetic surgeon with more than 20 years of surgical experience. He is both a licensed physician and dentist as well as double board-certified in both Plastic and Reconstructive Surgery and Oral and Maxillofacial Surgery. This training allows him to perform the most complex surgical procedures from cosmetic changes to the face and body to craniofacial surgery. Dr. Eppley has made extensive contributions to plastic surgery starting with the development of several advanced surgical techniques. He is a revered author, lecturer and educator in the field of plastic and cosmetic surgery.