“My double chin remains no matter how much I diet,” or “I had submental liposuction and the profile still isn’t sharp” — these are some of the most common concerns we hear at AVAN TOKYO consultations. The reality is that a double chin is not caused by submental fat alone. Subcutaneous fat that runs continuously from beneath the chin into the anterior neck, laxity of the platysma muscle, deep (subplatysmal) fat, and age-related skin laxity all stack in layers to produce that profile. In this column, Dr. Moriwaki of AVAN TOKYO explains why submental liposuction alone cannot fully resolve a double chin, and outlines the combined approach required for a truly sharp jawline.

What Really Causes a Double Chin — More Than Just Submental Fat

Most people think of a double chin as “the fat below the jaw,” but anatomically that’s only one piece of the picture. From the submentum down into the anterior neck, subcutaneous fat, the platysma muscle, subplatysmal (deep) fat, and the submandibular gland all stack as layers — and each one influences the side profile. Asian patients in particular tend to have a smaller mandibular skeleton than Western populations and accumulate fat more easily in the anterior neck, which is why even modest fat volumes can produce a visible step in the jawline.

Submental Fat Comes in Two Layers

Submental fat divides into the superficial layer immediately beneath the skin and the deep (subplatysmal) layer located underneath the platysma muscle. Standard submental liposuction primarily addresses the superficial layer; safe access to the deep fat requires a surgeon who is thoroughly familiar with nerve pathways and the position of the submandibular gland. When deep fat is left untouched, the profile never becomes fully refined — and the complaint of “I had liposuction but it didn’t change as much as I expected” most often comes down to under-treatment of this deep layer.

The Submentum and Anterior Neck Form One Continuous Fat Compartment

Beneath the chin and across the front of the neck, the subcutaneous tissue is anatomically continuous. If liposuction stops at the submentum alone, the untouched fat of the anterior neck remains and creates a step-like contour just below the mandibular border. At AVAN TOKYO, when designing for the jawline we always plan a continuous resection from the mandibular border down to just above the thyroid cartilage. A beautiful profile is built as a line, not as a single point.

Platysma Laxity Creates a “Banding” Form of Loose Skin

The platysma is a thin sheet-like muscle spread across the front of the neck. With age and poor posture, it can form vertical bands (platysmal bands) that show through the skin. Even after fat removal, if platysma laxity remains, the “banded” presentation will not improve. We address this with botulinum toxin injection or, when appropriate, platysmaplasty.

Three Reasons Submental Liposuction Alone Falls Short

One of the most common consultations we receive is “I had submental liposuction at another clinic but my double chin is still there.” Broadly speaking, there are three reasons for this.

1. Anterior Neck Fat Has Been Left Behind

When only the submentum is treated, the subcutaneous fat in the anterior neck remains untouched, leaving a draping contour just below the mandibular border. Continuous design is what brings out the sharpness of the profile.

2. Deep (Subplatysmal) Fat Has Not Been Addressed

Safe access to the deep fat requires precise knowledge of the marginal mandibular branch of the facial nerve, the position of the submandibular gland, and the subplatysmal space. Less experienced surgeons stop at the superficial layer, which is why residual thickness persists.

3. Skin Tightening Has Not Been Combined

Even if fat volume is reduced, skin without sufficient elasticity will remain as laxity. Especially for patients in their 40s and beyond, combining liposuction with skin tightening modalities (HIFU, RF, Morpheus8, etc.) produces a noticeably sharper final contour.

A truly effective combined approach for a double chin

At AVAN TOKYO, we believe a fundamental improvement requires three pillars: removing fat, tightening laxity, and refining the muscular line.

• Continuous liposuction across the submentum and anterior neck (both superficial and deep layers)
• Botulinum toxin for the platysma, or platysmaplasty when indicated
• Skin tightening (HIFU, RF, Morpheus8, etc.)

This combination transforms the procedure from “fat removal” into a three-dimensional redesign of the profile, neck, and jawline. For information on safety standards in aesthetic surgery, please also refer to the Japan Society of Aesthetic Surgery.

The Most Important Step Is the Initial Diagnosis

The idea that “submental liposuction alone will eliminate a double chin” is, unfortunately, not accurate. In reality, the profile is determined by the layered interaction of four elements: bone structure (mandibular length and chin projection), fat volume and distribution (superficial and deep), platysma tension, and skin elasticity. At AVAN TOKYO, the first consultation always assesses each of these four elements individually, so we can propose only the procedures truly needed — and avoid unnecessary surgery or excessive treatment.

For more detailed articles on liposuction and breast augmentation, please visit our liposuction column index.

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Supervising Physician: Shin Moriwaki, MD

Member, Japan Society of Aesthetic Surgery (JSAS) / Member, American Academy of Aesthetic Medicine

ECFMG Certificate Holder

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📍AVAN TOKYO GINZA LIPOSUCTION CLINIC

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