Facial asymmetry is not all that uncommon and can occur for a variety of reasons and in different degrees of expression. But the most common reason for facial asymmetry is developmental that becomes apparent as facial growth completes by late teenage years. In the majority of developmental facial asymmetry cases, the abnormal side is positioned lower. It is very rare to have the normal side be the ‘low’ side and the abnormal side be the ‘high’ side.
One of the most conspicuous features of many facial asymmetry cases is the lower jawline. The affected jawline hangs lower and is obviously different than the other side since it is an edge or profile facial feature. X-rays will show that the jawline is usually vertically longer and even the intraosseous inferior alveolar nerve canal and tooth root positions are lower than the other side. This may be associated with a cant to the occlusal plane.
Correcting the ‘hanging’ lower jawline is often one of the important procedures that are needed for improved facial symmetry. The simplest and very accurate way to determine how much of the lower end of the jawline that needs to be removed is to take measurements on a panorex x-ray. This tomoraphic films lays out the 3D image of the lower jaw in a 2D fashion.Tracings will show how much lower the affected side is and where the nerve lies so a safe ostectomy line can be made.
The best and most accurate method to perform an inferior border reduction of the lower jaw (inferior jawline shave) is from a submental approach. While many patients would prefer an intraoral approach, this makes it very difficult (if not impossible) to make an accurate line of reduction and also places the mental nerve at risk of injury. While the submental incision creates a small fine line scar, it offers a bone cut that can be made with a direct line of sight back to the jaw angle.
The submental incision best protects the inferior alveolar nerve in the bone as well as the external mental nerve exit into the soft tissues. With a long saw blade on a sagittal saw the desired amount of inferior border bone can be removed in two or three pieces that best matches what has been presurgically outlined on the x-ray.
Facial asymmetry is common and it is often said that everyone has some degree of it. While this is true, more significant facial asymmetries are not common and are a source of frequent patient self-esteem issues. In significant facial asymmetries the entire face is affected from the brow down to the jawline. The affected side is almost always lower as if it is pulled downward. It is extremely rare to ever see a facial asymmetry where the affected side is higher rather than lower than the normal side
The most significant component of facial asymmetry is often around the eye area. This is usually manifest by a difference in the horizontal level of the pupils. The eyeball sits lower as the orbital floor is located more inferior than the opposite normal side. But the orbital floor is not the culprit but a symptom of the overall facial asymmetry. The entire orbitozygomatic bony complex is situated lower. This is seen by the presence of a smaller and less projected cheek and greater soft tissue fullness below the cheek.
In correcting the orbital or midfacial component of facial asymmetry, orbital floor and cheek augmentation are the two skeletal components of the problem that needs to be addressed. There are a variety of materials and methods to this type of skeletal augmentation and all can be successful when done well.
The more recent availability and use of 3D CT scan imaging and computer designing, however, brings greater precision to the level of the surgical result obtainable for orbito-zygomatic reconstruction in facial asymmetry. Comparing the lower side to the higher normal side allows for an implant that can create a bony augmentation that matches to the other side with millimeter precision. In addition a total one-piece implant can be made that augments all outer areas of the bone including the infraorbital and lateral orbital rim. This would be the most accurate method of implant reconstruction available.
A custom orbitozygomatic implant is placed through a lower blepharoplasty incision. This is a subciliary incision with a small lateral canthal extension. A skin-muscle flap is raised down to the bone where subperiosteal undermining is done to placed the implant. It is important on closure that the orbicularis muscle suspension is done as well as closing the deeper tissue layer over the lateral orbital rim.
It is important to recognize that a custom orbitozygomatic implant provides bone correction but the overlying soft tissues of the eye must often be addressed as well. These could include lateral canthoplasty for outer corner of the eye correction as well as potential upper eyelid ptosis repair. As the eyeball is lifted a ptosis may be created as the upper eyelid position will not have changed. This eyelid correction should be corrected secondarily three months later when all the swelling has resolved and the tissues have stabilized.
Background: Facial asymmetry can occur from a wide variety of bone and soft tissue deficiencies or even, more uncommonly, overgrowths. (hypertrophy) One of the most common components of facial asymmetry occurs in the jawline of the lower face. Growth abnormalities emanate from the rami of the mandible, the meeting point of the vertical and horizontal bony limbs of the lower jaw.
Developmental or growth abnormalities always alter the rami or jaw angle shape in a variety of dimensions. Given that the jaw angle actually has four dimensions (height, length, width and degree of angulation) even subtle changes in development can create visible facial changes. These would be seen in the amount of flaring of the jaw angles, evenness of the jawline as it comes forward and the centric position of the chin as seen from the direct frontal view.
In correction of lower facial asymmetry, the first decision is whether the chin has a midline position. If so then correction can focus on the jaw angle region exclusively. If not then the treatment plan must incorporate a combined jawline approach that augments the chin back to the jaw angle area.
Case Study: This 35 year-old female presented with concerns about asymmetry of her face. She felt that the left side of lower jaw was not the same size as her right side. It was flatter and did not have as sharp a jawline or angle shape. The remainder of her face was symmetric and without concerns.
Under general anesthesia, a width only (3mm) jaw angle implant was placed through an intraoral retromandibular incision. It was situated only over the bone with the intent of adding a small amount of jaw angle width and definition.
The usual significant jaw swelling occurred that was largely gone by three weeks after surgery. By six weeks after surgery the full result was seen with nearly symmetric jaw angle prominences and a significant improvement in her facial asymmetry.
In using a jaw angle implant for correction of a lower facial asymmetry, it is unusual that only width expansion is needed without some vertical component. As most jaw angle deficiencies involve a component of retraction (vertical shortening) as well as lack of width development.
1) Jaw asymmetries frequently originate from the rami or angle regions and can affect both the vertical and horizontal dimensions of the lower third of the face.
2) Jaw angle augmentation is a frequent need for correction of lower third facial asymmetry.
3) Jaw angle implants are put in through an intraoral incision and different styles and sizes allow for either width expansion, vertical lengthening or both.
Facial attractiveness is highly influenced by the symmetry of its composite parts. It is well known and studied from the scientific analysis of beauty that the more two facial halfs (one half and its mirror image) are, the more attractive one is perceived to be. This is true whether it is of the male or female gender. While one does need to have a face that is perfectly symmetric to be perceived as attractive, the closer the better.
Interestingly, many faces have some degree of facial asymmetry and in many cases this is just viewed as having a little character. In fact some would say that a little asymmetry is even more attractive than perfect symmetry. But there is a limit as to when the asymmetry crosses the line and becomes less attractive rather than more. Quantitatively measuring how much facial asymmetry is unacceptable is scientifically impossible but it becomes a problem when a person thinks that it is so.
There many causes of facial asymmetry from birth defects, like hemifacial microsomia and hemifacial hyperytrophy, induced by traumatic injuries to one’s natural genetic-driven facial development. It can come in very severe degrees of asymmetry, usually from birth defects, to more milder forms. Almost always facial asymmetry affects more than one part of the face and at multiple tissue levels. (skin down to bone) It is far more common that the asymmetry is caused by underdevelopment or tissue loss than it is from overgrowth or too much tissue.
The various problems in facial asymmetry are numerous and can include such presentations as chin/jawline deviation, vertical facial shortening, cheek flattening, orbital floor/eyeball inferior isplacement, eyebrow lowering, forehead and brow bone protrusion or retrusions and nasal root and tip deviations. Due to the constellation of facial problems and tissue deformities, facial asymmetry surgery (FAS) requires a number of techniques borrowed from the plastic surgery fields of aesthetic, maxillofacial and craniofacial surgery. In many ways, FAS is very similar to facial feminization surgery which also requires a broad knowledge of plastic surgery techniques to achieve an overall facial change.
Facial asymmetry surgery (FAS) can include changes from the top of the skull down to the below the jawline and everything in between. It encompasses the following procedures; skull reshaping/cranioplasty, forehead/brow augmentation/reduction, temporal line augmentation/reduction, browlift, orbital rim reshaping, orbital floor/rim augmentation, eyelid canthal tendon adjustments, cheek augmentation/reduction, rhinoplasty, buccal lipectomies/perioral mound liposuction, soft tissue fat injections, lip land corner of mouth lifts, chin reshaping with osteotomies/ostectomies and implants, jawline/jaw angle reduction and narrowing, jawline implant augmentation, submental and neck liposuction, face and necklifts and ear reshaping.
Treatment planning for FAS requires a physical examination, facial photographs and computer imaging. A 3D CT scan is the radiographic assessment of choice if needed. From these one can determine what exact procedure(s) would be beneficial and which ones provide the greatest degree of facial asymmetry improvement. It is always a good idea in treatment planning to generate a list of the problems in order of importance to the patient. Then the procedures for correction can be chosen and the patient can invest their efforts wisely to get the most change with the minimum number of procedures. In most cases, all selected procedures are done during a single stage operation.
All FAS procedures are done under general anesthesia and certain patients will require an overnite stay in the facility based on the number of facial procedures performed and whether they are traveling alone or with someone. Each FAS procedure has its own unique methods of being performed, many involve bone or implants whole others are done by more traditional aesthetic surgery techniques such as soft tissue suspension or fat removal or injection augmentation. Based on the number of facial procedures done, one should expect a moderate amount of facial swelling and even some bruising. Total resolution of swelling and bruising for public passability is two to three weeks.
Risks and complications from any FAS are based on each individual procedure but remember those risks are additive. The biggest overall issue to understand is that FAS is about lessening the degree of asymmetry and perfect facial symmetry is usually not possible. In many patients, it may take more than one surgery to get the best result possible.
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.