A slimmer jaw comes down to addressing one or more of three things: muscle bulk, fat, or bone structure. Most people with a wide or square jaw have enlarged masseter muscles (the muscles you clench when you chew), excess fat around the lower face, or a naturally wide jawbone. The right approach depends on which factor is driving the width, and some options are temporary while others are permanent.
Figure Out What’s Making Your Jaw Wide
Before choosing any method, it helps to understand what you’re working with. The masseter muscle sits at the angle of your jaw on both sides. If you clench your teeth and feel a firm bulge at the back of your jaw, you likely have some degree of masseter hypertrophy. This is common in people who grind their teeth, chew gum frequently, or simply have naturally thick jaw muscles.
If the width is softer and more about fullness in the cheeks or under the chin, subcutaneous fat is the main contributor. And in some cases, the mandibular bone itself is broad. A doctor can distinguish between these by palpating the muscle while you clench, then again while your mouth is relaxed. When the muscle is relaxed, irregularities at the jaw angle can mimic bone enlargement, so imaging like a CT scan is sometimes used to get a clear picture.
Masseter Botox: The Most Popular Non-Surgical Option
Injecting a neurotoxin into the masseter muscle is the most common cosmetic approach to jaw slimming. It works by partially relaxing the muscle, which causes it to gradually shrink over time, the same way any muscle loses mass when you stop using it. Most patients receive 20 to 30 units per side, totaling 40 to 60 units.
The timeline is slower than typical Botox for wrinkles. You may notice the muscle feels softer within one to two weeks, but visible slimming of the jawline takes longer. The muscle gradually shrinks over 8 to 12 weeks, with peak results around the three-month mark. That’s when you’ll see the most difference in photos and your side profile.
Results typically last four to six months before the muscle begins rebuilding. Most people return for repeat treatments, and over time the muscle can stay smaller with less frequent sessions. Cost ranges from $300 to $800 or more per treatment, depending on location and the number of units used. Insurance does not cover cosmetic jaw slimming, though it may cover masseter Botox when prescribed for teeth grinding.
Reducing Fat Around the Jaw and Chin
If fullness under the chin or along the jawline is your main concern, fat reduction procedures target that tissue directly. There are two main options: injectable fat dissolvers and liposuction.
Injectable treatments use a compound that breaks down fat cells beneath the chin. The standard course involves two to three sessions, though some people need four. Swelling, bruising, pain, and numbness are the most commonly reported side effects, and recovery can be uncomfortable. A large analysis of patient reviews found that people who had injectable fat reduction tended to focus on post-procedure difficulties, while those who had submental liposuction were more likely to express satisfaction. Liposuction removes fat through a single small incision under the chin and generally produces more dramatic, one-session results, though it requires local or general anesthesia.
Buccal Fat Removal: A Permanent Trade-Off
Buccal fat pads sit in the lower cheeks and contribute to a round or full face shape. Removing them creates a more sculpted, contoured look. The procedure is done through small incisions inside the mouth, so there are no visible scars.
The important caveat is aging. Everyone naturally loses fat and muscle volume in the face over time, and skin begins to loosen. People who have buccal fat removed in their twenties or thirties sometimes find that their faces look gaunt or older than expected a decade or two later. Johns Hopkins Medicine notes that retaining some buccal fat helps preserve a smoother, more youthful appearance as you age. If too much is removed, the effect intensifies over time rather than fading. This is a permanent procedure, so it requires careful consideration of your facial structure and long-term goals.
Jaw Surgery for Bone Structure
When the jawbone itself is wide, no amount of muscle relaxation or fat removal will change the underlying frame. Mandibular angle reduction, sometimes called V-line surgery, involves shaving or cutting the bone at the jaw angle to create a narrower, more tapered shape. This is a significant surgical procedure typically performed under general anesthesia.
Initial bone healing takes about six weeks, with full healing up to 12 weeks. Risks include blood loss, infection, nerve injury, jaw joint pain, problems with bite alignment, and in rare cases the jaw returning toward its original position or needing additional surgery. Recovery involves a period of swelling, pain, and difficulty eating. This option is most common in East Asian cosmetic surgery markets and is generally considered a last resort for people whose bone structure is the primary concern.
Dermal Fillers for Jawline Contouring
Fillers don’t make the jaw smaller, but they can reshape its appearance. Strategic placement along the jawline or chin can create a more defined, angular look that gives the illusion of a slimmer face. This works best for people whose jawline is soft or poorly defined rather than genuinely wide.
Jawline filler typically costs $1,200 to $4,000 or more per session, with most people needing two to six syringes at $600 to $1,500 each. Results last 12 to 18 months depending on the product used. The procedure takes under an hour, and swelling and bruising are the main side effects.
What About Facial Exercises and Gua Sha?
Facial exercises are widely promoted online, but the evidence is thin. A study published in JAMA Dermatology found that a 20-week facial exercise program improved mid-face and lower face fullness, likely through muscle hypertrophy. That’s the opposite of slimming. For the jawline specifically, the study found no statistically significant change. Exercises that target the masseter would, if anything, build the muscle and make the jaw wider.
“Mewing,” the practice of pressing the tongue against the roof of the mouth to reshape the jaw, has no clinical evidence supporting structural changes in adults whose bones have finished growing.
Gua sha and facial massage can temporarily reduce puffiness by encouraging lymphatic fluid to drain. The gentle downward strokes move fluid that pools in the face overnight, which is why many people notice their face looks slightly slimmer after a session. The effect is real but short-lived, typically lasting a few hours. It won’t change muscle size, fat deposits, or bone structure, but it can make a noticeable difference for photos or events.
Choosing the Right Approach
The best option depends entirely on what’s creating the width. If you clench and feel a prominent muscle, masseter Botox is the lowest-risk starting point with reversible results. If you carry extra fat under the chin or in the lower face, liposuction or injectable fat dissolvers address that directly. If your bone structure is the issue, surgery is the only option that changes it.
Many people benefit from combining approaches. Masseter Botox paired with jawline filler, for example, can slim the muscle while sharpening the chin and jaw angle. Starting with the least invasive option lets you see how much change you actually need before committing to anything permanent.