Filling the prejowl sulcus involves injecting a dermal filler into the shallow depression that forms on either side of the chin along the jawline, restoring volume that bone resorption and soft-tissue descent have taken away. The technique is one of the more anatomy-sensitive procedures in non-surgical facial rejuvenation, because the target zone sits close to the facial artery and demands precise product placement to avoid a lumpy or asymmetric result. Getting it right requires understanding not just where to inject, but how deep, with what device, and in what order relative to the surrounding jawline.
What Creates the Prejowl Sulcus
The prejowl sulcus is not a crease you develop from a particular facial expression. It is a structural gap that appears as the mandible loses bone over time. The chin projection itself tends to shrink, and the bone on either side of the chin recedes faster than the central mentum, leaving a groove that runs along the front of the jawline. A review in Facial Plastic Surgery describes this as the formation of an “anterior mandibular groove” driven by age-related bone resorption of the mandible.1PubMed. Chin and prejowl augmentation in the management of the aging jawline The soft tissue above the bone then loses its scaffolding, and gravity pulls the cheek pad downward, which is why the sulcus often appears alongside early jowling.
Not everyone develops it at the same pace. Bone loss and ligament loosening can cause the sulcus and marionette lines to show up earlier in people who start with a smaller lower-facial skeleton. An Indian expert consensus panel noted that this earlier onset is common among Indians due to a relatively smaller lower-facial framework.2PubMed Central. Consensus Recommendations for Treatment Strategies in Indians Using Botulinum Toxin and Hyaluronic Acid Fillers Similarly, jowling and loss of jawline definition are described as hallmarks of aging in patients of East Asian descent, where mandibular recession tends to be pronounced.3Dermatologic Surgery. Assessing the Lower Face: Lips, Chin, and Jawline Congenital chin retrusion, where the chin is set further back than average from birth, can also create a prejowl appearance in younger adults who have not yet experienced significant age-related bone loss.
Assessing the Jawline Before Treatment
Before any filler is placed, the injector needs to grade the severity of the volume loss. Eyeballing it is not enough, especially for tracking results over time or across sessions. Validated photonumeric scales have been developed specifically for this purpose. One widely used tool is the Merz Jawline Assessment Scale, a five-point grading system that rates loss of jawline volume and contour. In its validation study, the scale showed near-perfect agreement when the same rater scored a patient on two separate occasions three weeks apart.4Journal of Drugs in Dermatology. Development and Validation of a Photonumeric Scale for Evaluation of Jawline Contour
A separate set of five-point scales has been validated for assessing chin projection and jawline sagging independently, which helps distinguish between someone whose chin is retruded and someone whose jowls are the primary problem. The distinction matters because the two issues respond to different injection strategies.5Journal of Cosmetic Dermatology. Validated 5‐point photonumeric scales for the assessment of the jowls and chin A broader set of photonumeric scales used in facial aesthetics has also demonstrated that a one-point shift on these scales represents a clinically meaningful change, giving injectors a concrete threshold for “did this treatment actually make a visible difference.”6Aesthetic Surgery Journal Open Forum. Validating a Series of Photonumeric Rating Scales for Use in Facial Aesthetics Using Statistical Analysis of Intra- and Inter-rater Reliability
In practice, these scales help an injector decide whether filler alone will produce a noticeable result or whether the severity warrants a surgical approach. A mild sulcus with intact skin quality is an ideal filler candidate. A deep sulcus paired with heavy jowling and significant skin laxity may need more than volume replacement can offer.
Cannula Versus Needle
Two tools exist for placing filler in the prejowl area: a sharp needle and a blunt-tipped cannula. Both can deliver product to the correct depth, but they behave very differently once they are under the skin. A cadaver study comparing the two found that when a cannula was used, the filler stayed confined to the deep tissue planes where it was intended to go. With a sharp needle, even when the tip was placed directly against the bone, the product migrated backward along the needle track during injection, ending up scattered across multiple tissue layers from the periosteum up to more superficial skin.7Aesthetic Surgery Journal. Cannula Versus Sharp Needle for Placement of Soft Tissue Fillers: An Observational Cadaver Study
That upward migration has practical consequences. Filler deposited too superficially can cause visible lumps or a palpable ridge under the skin. In the prejowl region, where the skin is relatively thin and closely draped over the bone, even small amounts of misplaced product can be noticeable. The same cadaver study also found that sharp-needle injection resulted in intra-arterial placement in some cases, even when the injector kept the needle tip on the periosteum throughout. The cannula technique did not produce intra-arterial injection in any case.
This does not mean sharp needles are never appropriate. Some injectors prefer a needle for deep bolus deposits directly on the periosteum, where the firmness of the bone provides tactile feedback. A cannula works well for fanning product along a broader area of the sulcus from a single entry point, reducing the number of skin punctures. Many experienced practitioners use both in the same session: a needle for precise supraperiosteal boluses and a cannula for smoothing and blending.
Placement Strategy and Treatment Sequencing
Where you place filler in the prejowl sulcus matters as much as what you fill it with. The deepest layer, right on top of the bone, is the primary target. Supraperiosteal injection provides structural support in the area where bone has receded, essentially rebuilding the scaffolding that has been lost. This is where firm, high-G-prime fillers do their best work, resisting the downward force of the overlying tissue.
A common mistake is treating the sulcus itself in isolation without addressing the surrounding jawline. In older patients, the visible groove often results as much from volume loss in the lateral mid-face and lower cheek as from localized prejowl bone resorption. The Indian expert consensus group recommended that when jowls and marionette lines are present, the lateral mid-face and lower-face volume deficit should be corrected first, followed by filling of the sulcus itself.8PubMed Central. Consensus Recommendations for Treatment Strategies in Indians Using Botulinum Toxin and Hyaluronic Acid Fillers Restoring lateral volume lifts some of the tissue that is dragging into the jowl area, reducing the depth of the prejowl groove before you ever touch it directly. This sequencing can mean less filler is needed in the sulcus itself, which reduces the risk of overcorrection and keeps the chin looking natural.
When treating the sulcus directly, small aliquots placed along the groove in a linear threading or serial puncture pattern tend to produce the smoothest results. Injecting a single large bolus in the center of the sulcus risks creating a visible mound. The goal is a gradual, even fill that transitions smoothly into the chin centrally and into the body of the mandible laterally.
Choosing a Filler Product
Three broad categories of filler are used in the prejowl area, and each brings different trade-offs in longevity, reversibility, and tissue behavior.
- Hyaluronic acid (HA): The most commonly used filler type overall. For the prejowl sulcus, a firm, cohesive HA product is typically chosen because the area needs structural support rather than soft-tissue draping. HA is reversible with hyaluronidase, which makes it the safest option for less experienced injectors and for patients who want an adjustable result. A randomized trial of Restylane Defyne for chin augmentation found that satisfaction scores roughly doubled at 12 weeks compared to baseline, and roughly two-thirds to three-quarters of patients still reported satisfaction at 48 weeks.9PubMed Central. A Randomized Trial to Assess Effectiveness and Safety of a Hyaluronic Acid Filler for Chin Augmentation and Correction of Chin Retrusion
- Calcium hydroxyapatite (CaHA): A biostimulatory filler that provides immediate volume and then promotes new collagen growth in the treated area. One technique using CaHA targets deep facial augmentation to restructure retaining ligaments, combined with a diluted form for more superficial enhancement.10Aesthetic Plastic Surgery. An Innovative Treatment Using Calcium Hydroxyapatite for Non-Surgical Facial Rejuvenation: The Vectorial-Lift Technique CaHA is not reversible with an enzyme the way HA is, which makes precision in placement more important.
- Polymethylmethacrylate (PMMA): A permanent, biostimulatory filler. In a 24-month prospective study of PMMA-collagen gel specifically for the prejowl sulcus, jawline severity scores improved from about 2.4 at baseline to 1.5 by 52 weeks, with progressive improvement over time indicating ongoing collagen stimulation. At 104 weeks, 100 percent of patients were rated as at least “improved” and all reported being at least “somewhat satisfied.”11Aesthetic Surgery Journal Open Forum. Safety and Efficacy of Polymethylmethacrylate-Collagen Gel Filler for Correction of the Pre-jowl Sulcus: A 24-month Prospective Study The durability is appealing, but permanence is a double-edged sword: if the result is uneven or the patient’s anatomy continues to change with aging, correction is far more difficult than with a resorbable product.
For most first-time prejowl patients, HA is the default choice. The reversibility provides a safety margin, and the longevity of firm HA products in a deep, low-movement zone like the prejowl area is generally better than in high-mobility areas like the lips. Biostimulatory fillers are usually reserved for patients with a longer treatment history who want to reduce the frequency of repeat injections.
Safety and the Facial Artery
The prejowl region sits uncomfortably close to the facial artery, which crosses the inferior border of the mandible on its way from the neck to the side of the nose. At the lower border of the jawbone, the artery’s external diameter averages about 1.9 mm with an internal diameter of about 1.2 mm.12Plastic and Reconstructive Surgery. External and Internal Diameters of the Facial Artery Relevant to Intravascular Filler Injection That is wide enough for a needle or cannula tip to enter, and inadvertent intravascular injection is the most feared complication in any lower-face filler procedure. Vascular compromise can lead to tissue death if blood supply is blocked.
The path the facial artery takes is not identical from person to person. It can sit more medially or laterally along the mandible, and its branches vary. Because of this anatomical unpredictability, the standard safety approach includes aspirating before injection when using a needle, injecting slowly with low pressure, and using small volumes per bolus. Blunt cannulas reduce the risk of vessel puncture, as discussed earlier, but do not eliminate it entirely in areas where the artery sits superficially.
Complications from filler injections are broadly grouped by timing. Early complications include bruising, swelling, and vascular events. Late complications include nodules, which can stem from product migration, biofilm formation, or an inflammatory reaction. Having hyaluronidase available is considered mandatory when injecting HA products, because it can dissolve the filler rapidly if a vascular event is suspected.13PubMed Central. Practical Approach and Safety of Hyaluronic Acid Fillers This reversibility advantage does not apply to CaHA or PMMA, which is one reason HA remains the first-line choice in high-risk zones.
How Gender Shapes the Approach
Men and women tend to seek filler in different parts of the face. A comparison study found that men were more likely to receive jawline fillers, while women were more likely to receive lip and perioral fillers.14PubMed. Comparison of injectable filler locations in men and women: An age-matched case analysis This tracks with the aesthetic goals each group typically brings to the consultation: men often want a more defined, angular jawline, while women tend to prioritize softness and proportion in the lower face.
These different goals change the injection strategy in the prejowl area. For a male patient, the injector may place filler more laterally along the mandible to widen and square the jawline, using the prejowl correction as part of a broader angular-jawline build. For a female patient, the focus is usually on smoothing the transition between chin and jaw, restoring a gentle curve rather than a sharp angle. The volume of product also tends to differ: men generally tolerate and benefit from larger volumes in the jawline because their baseline bone structure and soft-tissue envelope are larger.
Ethnic Variation in Lower-Face Aging
The underlying bone structure and soft-tissue thickness of the lower face vary across ethnic groups, and these differences influence both when the prejowl sulcus appears and how it should be treated. As noted above, the mandible can recede on either side of the chin with age, forming grooves and a visible sulcus. In patients of East Asian descent, this mandibular recession combined with jowling is described as a hallmark of lower-face aging.15Dermatologic Surgery. Assessing the Lower Face: Lips, Chin, and Jawline The same source notes that bone loss, ligament laxity, and congenital chin retrusion can all cause the sulcus and marionette lines to form at a younger age.
Treatment planning should account for these differences rather than applying a one-size-fits-all template. In patients with a smaller lower-facial skeleton, less filler may be needed to make a visible difference, but the structural deficit may also be more pronounced, requiring deep periosteal support rather than superficial smoothing alone. The Indian consensus panel’s recommendation to address lateral volume loss before filling the sulcus directly reflects this reality: in populations where the overall lower-facial framework is smaller, the gravitational descent from the mid-face has a proportionally larger effect on the jawline contour.16PubMed Central. Consensus Recommendations for Treatment Strategies in Indians Using Botulinum Toxin and Hyaluronic Acid Fillers
When Filler Is Not Enough
Non-surgical prejowl correction works well within a certain range of severity. For mild to moderate sulcus depth with reasonable skin quality, filler can produce a natural-looking improvement that lasts anywhere from several months to a couple of years depending on the product. But fillers have limits. They add volume; they do not lift sagging skin or tighten lax ligaments. In a patient with significant jowling, heavy skin laxity, and deep prejowl grooves, piling filler into the sulcus to match the surrounding tissue level can lead to an overfilled, heavy lower face that looks worse in motion than at rest.
Surgical options for the prejowl area include alloplastic chin implants that extend laterally along the mandible, specifically designed to fill the prejowl groove with a permanent solid implant. Facelift procedures address the skin and soft-tissue laxity that fillers cannot correct. Some patients benefit from a combination: a surgical procedure to manage the laxity and repositioning, with filler used for fine-tuning residual volume deficits afterward. A recent review in Facial Plastic Surgery summarized the relationship plainly: non-surgical treatments cannot replace surgical interventions, but they often provide effective temporary solutions for patients seeking low-downtime alternatives.17PubMed. Nonsurgical Chin and Prejowl Modification
The honest conversation between injector and patient, then, is not just about technique but about candidacy. A well-placed syringe of HA filler in a mild prejowl sulcus can take years off the jawline with virtually no recovery time. Trying to achieve the same thing in a severe case with three syringes and a prayer is where outcomes start to disappoint. Knowing where filler stops being the right tool is as important as knowing how to use it.