Submandibular Gland vs. Chin Fat: 2 Checks

If you can pinch it up with the skin, it's most likely fat. If it sits deeper, off to the side just below the edge of your jawbone, and won't lift with a pinch, a salivary gland is the more likely cause. The two can look the same in a side-profile photo, but they're treated differently, so it's worth telling them apart before you book any jawline injection.

Is the Bulge Under My Jaw Fat or a Salivary Gland?

Is the Bulge Under My Jaw Fat or a Salivary Gland?

You can get a good first read with your fingers. Chin fat sits between the skin and a thin sheet of neck muscle called the platysma, so when you tense your neck and pinch, it lifts softly along with the skin. The submandibular gland lies underneath that muscle, tucked under the body of the jawbone, so it won't come up in a pinch.

Platysma: a thin, flat muscle that covers the front of the neck from the jaw down to the collarbone. You can see it as vertical cords when you clench and pull the corners of your mouth down.

Location helps, too. Fat tends to collect in the middle, right under the tip of the chin. The gland is felt off to each side, between the chin and the angle of the jaw, one on the left and one on the right. When researchers dissected 29 adult bodies, about 40% of the gland lay below the lower edge of the jawbone. That's why even a slim person can have a visible bump below the side of the jaw.

Is the Bulge Under My Jaw Fat or a Salivary Gland?

Some people have both. That's why the pinch test is only a starting point. If you're thinking about shrinking the gland, an ultrasound shows how thick it is, how far it sits from the skin, and where nearby blood vessels run. In an ultrasound study of 42 people, gland thickness and depth varied from one spot to the next.

Does the Gland Drop With Age and Blur the Jawline?

Does the Gland Drop With Age and Blur the Jawline?

The evidence points both ways. In a review of face CT scans from 100 people, older age went along with the bottom of the gland sitting farther below the jawbone, which worked out to about 0.17 mm of descent per year. Gland volume, on the other hand, didn't change with age in that group.

The 29-body dissection didn't find anatomical evidence of a drooping gland, even in the oldest specimens. So if your jawline has softened over the years, it's worth asking whether the gland has shifted down, whether the skin and muscle have loosened, or both.

If you're younger and you've lost weight but a bump below the side of the jaw is still there, the gland deserves a closer look. Repeating fat-dissolving injections won't change a bump that isn't fat.

How Do Treatments Differ for a Gland and for Fat?

How Do Treatments Differ for a Gland and for Fat?

For fat, a fat-dissolving injection goes into the fat layer above the platysma. According to the U.S. prescribing information for deoxycholic acid (Kybella), the injector should first rule out other causes of fullness under the chin, such as an enlarged thyroid or swollen neck lymph nodes. The label also says not to inject into or within 1 to 1.5 cm of salivary glands, lymph nodes, or muscles.

Deoxycholic acid: a substance also found in bile. Injected into fat, it breaks down fat cells.

A gland won't shrink with a fat injection. Instead, some doctors inject botulinum toxin into the gland itself to reduce its size. One report followed 20 people who had ultrasound-guided injections into the gland and measured the same spot every month for 6 months.

How Do Treatments Differ for a Gland and for Fat?

Width dropped the most at 2 months and was close to where it started by 6 months. It's a change that plays out over months, not a one-time fix, so plan for repeat visits if you want to keep the effect. Keep in mind that the report had no comparison group and came from a single practice, so treat the timeline as a rough guide. Individual results vary.

What's Normal After Treatment, and When Should You Call?

What's Normal After Treatment, and When Should You Call?

Mild swelling, bruising, or soreness at the injection site for a few days is something you can watch. The 20 people who had gland injections didn't report less saliva; the authors attributed that to the other salivary glands, in front of the ears and under the tongue, still doing their job.

If the toxin spreads into the swallowing muscles near the gland, swallowing can become difficult. One case report described a 37-year-old woman who had both glands injected without ultrasound guidance. She had trouble swallowing food and liquids from the next day, and full recovery took 5 months. It's rare, but contact the clinic right away if you notice any of these:

• Food or water catches when you swallow, or you often choke on liquids
• Your speech sounds different than usual
• The injection site turns red and warm, and you have a fever
• One side of your lower lip or mouth corner moves less when you smile

If you have trouble breathing, go to the nearest emergency room. With fat-dissolving injections, the drug can injure a blood vessel if it goes in by mistake, so the warning signs the FDA lists for dermal fillers are a sensible reference. Seek care right away for unusual pain or skin near the injection site turning white, gray, or blue. Go to the nearest emergency room for vision changes or signs of a stroke: sudden difficulty speaking, numbness or weakness in your face, arms, or legs, difficulty walking, face drooping, severe headache, dizziness, or confusion.

Fitting This Into a Trip to Korea

Fitting This Into a Trip to Korea

Neither treatment involves sedation, so there's no treatment-related reason to delay your flight home. A single visit won't reshape your jawline on the spot. With gland injections, the change in width builds over the first 1 to 2 months, so you'll likely see the result after you're back home rather than during your stay.

Once you're home, you can send photos to the clinic through its English contact channel. If you develop trouble swallowing, a high fever, or trouble breathing, see a local doctor or emergency service first rather than waiting for a reply.

When Should a Jaw Bulge Be Checked by a Doctor First?

Some gland swelling needs medical care before any cosmetic plan. A stone in the gland's duct can make the area under your jaw swell and hurt when you eat or drink. A gland infection can bring fever, a squeezing pain while eating, and redness over the side of the face or upper neck.

A firm, usually painless lump on one side that slowly grows is another pattern to take seriously. Salivary gland tumors are rare, but a lump under the jaw or in the neck that hasn't gone away in 2 to 3 weeks, or that's getting bigger, should be checked by a doctor. If the glands look noticeably enlarged or uneven, finding the cause comes before any injection.

Before you decide, ask, "Is the fullness under my jaw fat above the platysma, or the gland below it?" That one answer tells you which treatment even applies. If it's the gland, ask whether the plan is based on an ultrasound of its thickness and depth, and when you'll compare same-angle photos afterward. STON Clinic is in Seoul. When you reach out, include a side-profile photo with your chin slightly raised, whether the bump is on one side or both, and whether it ever swells or hurts when you eat.