Over the years, it has often been women seeking out procedures that could deliver aesthetic corrections. However, the demographics of people seeking out such procedures has dramatically shifted in recent years: men have now begun to increasingly seek appearance-altering work, particularly in respect to facial rejuvenation. This includes mid-face filler treatments, lip fillers, and chin and jawline contouring. This article is intended to outline the anatomical differences between the female and male jawline, as well as the best approach for contouring the male jawline.
It should come as no surprise that as with any procedure, a comprehensive understanding of the anatomy of the area of interest is vital in the initial steps when approaching the patient.
The mandibular symphysis is the result of fusion of both left and right mandibles which establishes the foundation of the jawline. The area consists of a curved tooth-bearing body that extends from the midline symphysis with the mental protuberance inferiorly, and to the ramus laterally. The laterally positioned rami has two superior processes: coronoid process, where the temporal muscles are attached, and the neck and condyle process, which has an articular surface that forms the mandibular part of the temporomandibular joint. Between these two processes is the mandibular notch. A major muscle of mastication, the masseter muscle is attached to the surface of the ramus of the mandible and is the main component that shapes the lateral jawline. They are the fleshy parts that are palpated during examination, and they undergo extensive atrophy with aging.
There are also several muscles that originate or attach at the body of the mandible the mentalis, and part of the orbicularis oris muscle originates from the incisive fossa, which is below the incisor teeth. The depressor anguli oris and depressor labii inferioris muscles attach to the oblique line superiorly while the plastysma muscle attaches inferiorly.
The inferior alveolar branches of the mandibular branch of the trigeminal nerve passes through two crucial foraminae on both sides. The nerves enter the mandible via the mandibular foramen in the ramus that is located behind the deep surface of the lateral pterygoid muscle to the deep surface of the masseter muscle.
The nerves continue along the mandibular canal inside the body of the mandible and branch out to supply sensation to the teeth. They exit from the mandible as the mental nerve via the mental foramen to supply sensation to the chin and low lip. Lateral to the mental tubercles is the mental foramen. This has important clinical implications because the location and direction of these nerves must be considered when choosing the appropriate injection technique to minimize risk of damage to these structures.
Both the superficial fat pads and salivary glands relates to another vital clinical point. The parotid gland is located superficially to the ramus and masseter muscle, and it has varying sizes between individuals. It can even extend posteriorly to the deep surface of the ramus. It has the parotid duct, which courses through the buccinators muscle to open into the vestibule of the mouth at the second maxillary molar. The gland is also supplied by the trunk and main branches of the facial nerve. The superficial lamina of the deep cervical fascia rests superficially on the gland, and posteriorly, the greater auricular nerve lies closely.
The lateral temporal cheek fat pads also lie superficial to the parotid gland, while the middle cheek fat pads are positioned anteriorly, and the superior and inferior mandibular fat pads lie further anteriorly over the anterolateral surface of the body of the mandible. All these fat pads are separated by numerous septae, and it is these septae that contributes to the signs of aging as seen in the lower face. The mandibular septum is particularly important, as it is what separates the jowl fat pad from the neck fat. It adheres to the anterior surface of the body of the mandible and the mandibular cutaneous ligament that tethers the skin anterior to the jowl fat pads and the jowl fat pads to the bone anteriorly. This results in the groove seen anterior to the jowl with descent of the fat pads due to aging.
Both the risorius and zygomaticus major muscle, along with the facial artery branch of the external carotid artery, lies superficial over the surface of the mandible in the plane deep to the platysma. They are crossed superficially by the branches of the facial nerve that run a superomedially tortuous route over the face and is also deep to the superficial fat pads of the face. You can easily palpate the point at which it crosses the border of the mandible. This point should be noted and marked before any injection procedures to avoid damage or an intravascular injection.
Take note of the marginal mandibular branch of the facial nerve that is also in close proximity. It runs deep to the platysma and the depressor anguli oris muscles. It extends across the border of the mandible from the neck at about 3cm anterior to the angle of the mandible. It always lies superficially to the facial artery and the anterior facial vein. It supplies the motor innervation to the depressor labii inferioris and mentalis and depressor anguli oris while communicating with the inferior alveolar nerve.
Male vs female jaws
During prepubescent years, both sexes’ appearances resemble each other due to the lack of testosterone in male youth. Once a sufficient elevation of testosterone occurs during puberty in males, secondary male characteristics start to develop. In particular, the jawline starts to develop to become much larger and stronger, and the mandibular angle and ramus of the mandible starts to have greater delineation. Muscle bulk surrounding these tissues increase to accommodate the changes. The male chin becomes wider and squarer compared to the female. Keep these masculine features in mind when performing facial rejuvenation in the male patient to avoid implementing the same technique as you would in a female patient.
With age, the lower face undergoes further changes in both men and women, including the loss of volume, descent of the jowl fat pads, mandibular septum dehiscence, descent of mandibular fat pads into the neck, mandibular bone resorption, and increased skin laxity. The pulling force from gravity and the platysma muscle further accelerate these age-related changes.
There are two areas that needs to be addressed when treating the male jawline. The first is to augment any anatomical deficit so that the contours are consistent with the surrounding facial tissue. The second stage is to replace the volume lost through aging. Jawline enhancement can result in a significant departure from the old appearance if done correctly. Injectable dermal fillers are used to accentuate a more V-shaped face in women, while they are used to create a defined, masculine, and a more rectangular chin in males.
Creating the ideal jawline for male patients
Focus your treatment technique in augmenting or adding volume to areas where there has been volume loss as a result of aging. Volume can also be added to areas where it is needed. For chin projection, there are various lines of projection that you can use as a guide. For example, the ideal chin is the one that is able to reach a continuous imaginary line in the sagittal plane from the menton to the most anterior projecting part of the lips. On the same note, there was a study in 2016 that reported the ideal male jawline should have the following features:
- 130° angle in profile view;
- Intergonial width with close approximation to facial width;
- Vertical position in frontal view at the oral commissure or not below the lower lip;
- Jawline slope in the frontal face view that is nearly parallel to (maximum 15° downward deviation from) an imaginary line extending from the lateral canthus of the eye to the nasal alae;
- Inferior margin should be blunt and should be visible from the earlobe to chin. Ascending ramus slope should be between 65°-75° in relation to the Frankfort horizontal line;
- Curvature in the oblique view.
Patient selection is an important process that helps determine the likelihood of a successful outcome. Male patients that seek treatment for their jawline tend to be more body image conscious, so it is advisable screen them for body dysmorphia. To ensure better patient satisfaction, make sure you explain and elaborate thoroughly the limits of the treatment plan. Answer any questions they have diligently.
The jawline can be an area of continuous refinement. This should be conveyed to the patient so that they can anticipate any needs for further correction in the later stages of the treatment. Also inform them that the procedure is a gradual process and that any correction of asymmetry cannot be guaranteed. Likewise, any demands from the patient for specific improvements in specific areas can only be presented back to them as a possibility.
Once you have determined the proportions and angles needed for correction on the patient, the next step will be to decide on the techniques and products that you will use. The central tenet in this aesthetic correction is a combined approach. Combining injectable dermal fillers and skin surface treatments have generally been more fruitful approaches. Younger patients on the other hand that require volume augmentation require less product.
Opt for a higher gauge cosmetic filler for male jawlines because this area is much more likely to undergo deforming forces during its residence under the skin, particularly in the masseteric area. Juvederm Voluma provides a high gauge and a tangible solution for overcorrection via its reversibility that makes it suitable for deep contouring purposes. Other known brands such as Restylane Lyft and Teosyal RHA 4 are excellent choices that provide similar advantages. Collagen-stimulating dermal fillers have fallen out of favor due to their lack of reversibility in the serious event of intravascular injection that results in vascular compromise.
Injection techniques would depend on your preference, but again, a combination of both needle and cannula techniques should be used for this area. However, sensitive areas that are in close proximity to the facial artery should be done using a cannula instead. To avoid the incidence of overfilling, space the treatment procedures over a few sessions to achieve a gradual effect on the treated area.
Using a needle, introduce a deep intramuscular bolus of cosmetic filler near the periosteum region at the angle of the mandible. Use two 1ml syringes to deposit aliquots in the range of 0.3 to 0.5ml per side in two to three points. After that, deposit 0.1 to 0.2ml of bolus filler into the anterior portion of the mandibular retaining ligament to correct defects. This technique may be applicable to a broad range of patients, but always note that there is a great degree of variability among patients that you should account for in your approach.
Proceed with a deep bolus injection into the surface of the mental process using 0.1 to 0.2ml of cosmetic filler to begin squaring the chin. There are times where you can use a cannula along the more superficial subcutaneous plane for cosmetic filler deposition around the mandible, but the feasibility of this technique varies with patients. As mentioned earlier, this is the area of the marginal mandibular branch of the facial nerve and facial vessels, so take extreme caution to avoid these important structures. Neurotoxins such as botulinum toxin A can be used in this area if there is drooping of the jowl fat pads. To determine drooping, ask the patient to grimace, and when the platysma is fully contracted, mark the bands; the strongest ones tend to be the ones posterior to the mandibular retaining ligament.
When injecting, follow the bands and make sure that the most superior injection point is 1cm below the jawline to avoid any spread of the injection material to the depressor muscles of the mouth. 20 units to 25 units of botulinum toxin A is recommended for this area. Continue with a small dose of toxin into the mentalis to also improve the chin area. Skin and SMA’s laxity in older patients benefit more when combined with adjunctive treatment, such as energy-based treatments like HIFU and radiofrequency (ablative and non-ablative).
Male patients seeking an aesthetic procedure for the jawline should be a major point of consideration for the practitioner. The knowledge required in respect to the anatomical details needed to perform the appropriate procedures have been highlighted in this article. Important structures have also been outlined for your consideration when injecting in those specific areas. As with any aesthetic procedures, view the patient as a whole and determine if treating only the jawline may benefit them. More often than not, a number of different treatment techniques are needed for the optimal cosmetic result.