Korea facial contouring for a slimmer lower face follows two broad routes: non-surgical treatment that reduces muscle or fat, and mandible reduction surgery that removes bone. Which one fits depends on what makes the jaw look wide. A bulky masseter muscle often softens over several weeks after botulinum toxin injections, which wear off and need repeating. Soft fullness along the jaw line may respond to fat reduction. A broad or flaring jaw bone changes only with surgery under general anesthesia, which brings months of swelling and a real risk of nerve injury. The sections below explain how to tell the causes apart and what two recent papers report.
Guide
Muscle, fat or bone: what makes the lower face look wide
Three different tissues can widen the lower face, and many people have a mix. The masseter, the chewing muscle over the jaw angle, bulges forward when the teeth are clenched. Fat sits in front of and under the jaw line and feels soft when pinched. Bone sets the outline underneath both, and its width and angle show clearly on an X-ray or CT scan.
A clench test at consultation gives a first hint: if the jaw corner hardens and pushes out, muscle is part of the picture. A scan then shows how much of the width is skeletal.
Guide
The non-surgical route: masseter toxin and fat reduction
Botulinum toxin injected into the masseter relaxes the muscle, which then shrinks with less use. The slimming appears over several weeks, and the muscle regains bulk if injections stop, so most people repeat them every few months. Common effects are bruising and a tired feeling when chewing hard food. Less often the toxin spreads to nearby muscles and changes the smile until it wears off.
Fat along the jaw line can be reduced with fat-dissolving injections or a minor suction procedure, which this site covers on its liposuction guide. Neither injection route makes the bone any narrower or shortens a long chin.
Guide
The surgical route: what mandible reduction removes
Facial bone surgery in Korea for the lower face usually trims the jaw angle and the body of the mandible, sometimes with a narrowing cut at the chin. Surgeons work through incisions inside the mouth after planning on a CT scan, so skin scars are usually avoided.
In a 2018 study in the Journal of Craniofacial Surgery, Kim and colleagues randomly assigned 14 patients with a prominent jaw angle and chin to conventional mandibuloplasty with narrowing genioplasty or to a one-piece cut from the angle to the front of the chin, planned on a 3D-printed model. Mean bone removed per side was 41.8 cc with the one-piece method and 36.5 cc with the conventional one, and the one-piece operation was shorter, about 71 versus 105 minutes. A visible step in the bone line, called a secondary angle, was linked to dissatisfaction. The group was small, so treat the results as a guide.
Guide
Who fits which route
Many plans start with the least invasive step and reassess once the muscle has relaxed.
| What the exam shows | Likely cause | Route usually discussed | Trade-off |
|---|---|---|---|
| Jaw corner bulges on clenching, bone normal on scan | Masseter muscle | Toxin injections | Temporary; repeat sessions needed |
| Soft fullness under the jaw line | Fat | Fat reduction | Modest change; skin laxity may show |
| Wide or flaring angles on scan | Bone | Angle and body reduction | General anesthesia, long swelling, nerve risk |
| Wide angles plus a long or broad chin | Bone of the whole lower jaw | Reduction with narrowing genioplasty or a one-piece cut | Longer operation, chin and lip numbness |
| Muscle bulk and wide bone together | Mixed | Toxin first, then reassess bone | Staged plan; takes more time |
Guide
Risks of the bone route, stated plainly
Facial contour surgery in Korea carries the same risks as anywhere. The inferior alveolar nerve runs through the jaw and exits near the chin, so lower lip and chin numbness is the complication visitors ask about most. It often improves over months, but it can last. Bleeding from vessels near the angle, uneven sides, a secondary angle, sagging soft tissue after bone removal and infection inside the mouth are also possible. Removed bone cannot be replaced.
Rarer problems exist too. In a 2025 case report in the Journal of Craniofacial Surgery, Kim and colleagues described a 27-year-old woman who developed itchy red papules on the chin one year after angle-body reduction, in an area that had lost sensation, which they attributed to autonomic nerve injury. The lesions cleared on their own but left scarring and contour irregularities.
Evidence
Research behind this page
- Autonomic Denervative Dermatitis in the Chin Area Following MandibuloplastyJournal of Craniofacial Surgery · 2025 · doi:10.1097/scs.0000000000011603
Case report of a rare chin skin condition linked to autonomic nerve injury that appeared one year after angle-body reduction mandibuloplasty.
- One-Piece Mandibuloplasty Compared to Conventional Mandibuloplasty With Narrowing GenioplastyJournal of Craniofacial Surgery · 2018 · doi:10.1097/scs.0000000000004458
In 14 randomized patients, one-piece mandibuloplasty removed slightly more bone per side and took less operating time than the conventional method with narrowing genioplasty.
FAQ
Questions about V-line surgery in Gangnam
Can masseter toxin injections replace jaw bone surgery?
Toxin can replace surgery only when the width comes mainly from muscle rather than bone. Injections relax and gradually shrink the masseter, which softens a square look at the jaw corners. They do not narrow the bone, shorten the chin or change the jaw line seen on a scan. If a CT scan shows wide or flaring bone, toxin may soften the outline slightly, but the skeletal shape stays the same.
How soon does the jaw look slimmer after toxin injections?
The change usually appears gradually over several weeks rather than in the first days. The toxin relaxes the masseter, and the muscle then loses bulk because it is used less. Most people repeat injections every few months to keep the effect, since the muscle slowly regains strength. Photos taken from the same angle judge the change more fairly than a mirror.
Is facial contouring in Korea reversible?
Bone reduction is not reversible, because the removed bone cannot be put back. Revision surgery can smooth an uneven line or a step in the jaw, but it cannot rebuild lost width without implants or grafts. Toxin effects, by contrast, fade if injections stop. This difference is a strong reason to confirm the cause of the width on a scan before choosing a surgical plan.
What do surgeons check before facial bone surgery in Korea?
Surgeons usually take a CT scan, photographs and measurements of the face, and check the bite and the position of the nerve canal in the jaw. Blood tests and an anesthesia review are standard before general anesthesia. Facial contouring Korea clinics also assess the muscle and soft tissue, since removing bone under thick or loose tissue may not give the expected change. Ask to see the scan and the planned cut lines.
Does lower-face contouring leave visible scars?
Jaw angle, body and chin reduction are usually done through incisions inside the mouth, so there is normally no visible facial scar. The inside wounds need careful hygiene, gargling and a soft diet while they heal. Some techniques add a small skin opening for instruments, which leaves a tiny mark. Ask the surgeon where every incision will be placed and how the mouth should be cleaned afterward.