Subplatysmal Fat: the Deep Double Chin
- Muscle
- Highlighted area
Quick facts
- Definition
- Fat located beneath the platysma muscle, in the submental and central region of the neck.
- Location
- Between the medial edges of the two platysmas, over the digastric and mylohyoid muscles.
- Difference from pre-platysmal fat
- Pre-platysmal fat lies between the skin and the platysma; subplatysmal fat lies below the muscle.
- How to assess
- Palpation with the platysma relaxed and then contracted; imaging when in doubt.
- Relevance in HOF
- It explains the double chin that does not improve with superficial fat treatments and changes the indication.
Subplatysmal fat is the fat located beneath the platysma, the thin muscle that covers the front of the neck. It occupies the submental and central region, between the medial edges of the two platysmas and over the muscles of the floor of the mouth. It is what people informally call the deep double chin. The distinction matters because most non-surgical treatments for a double chin act on the fat above the muscle, not the fat below it.
What are the layers of a double chin?
Fullness under the chin rarely has a single cause. The assessment separates the layers, from the skin inward:
| Layer | What it contains | Usual response to treatment |
|---|---|---|
| Skin | Quality, laxity and excess | Laxity does not improve with fat reduction |
| Pre-platysmal (subcutaneous) fat | Fat between the skin and the muscle | Target of superficial fat treatments |
| Platysma | Muscle and its bands | Bands and muscle laxity, topics for toxin and surgery |
| Subplatysmal fat | Central fat beneath the muscle | Generally a surgical approach |
| Submandibular glands and digastrics | Deep structures that can create volume | Not targets of an injectable aesthetic procedure |
Beyond the layers, the skeleton matters: a recessed chin, a low hyoid bone and a short mandible leave the cervicomental angle more open even with little fat.
How do you tell subplatysmal fat apart in the assessment?
- Relaxed pinch: with the neck in a neutral position, pinch the skin and the fat under the chin.
- Pinch with the platysma contracted: ask the patient to tense the neck, pulling the corners of the mouth down. Fat that can still be pinched lies above the muscle; firm, central volume that remains beneath the contracted muscle suggests a subplatysmal component.
- Profile: assess the definition of the jawline and of the angle between chin and neck.
- Imaging: ultrasound or other tests help when palpation is not conclusive.
The full walkthrough is in double chin: assessment.
Why does it matter in HOF?
When the double chin is mostly subplatysmal, superficial fat treatments, such as those described in enzymatic double chin lipolysis, tend to bring little change and may even leave the skin looser over volume that remains. In those cases, referral for a surgical assessment is usually the most honest course. When the problem is lack of chin projection, support of the chin can improve the profile, at the professional's discretion.
Also called: central subplatysmal fat, interplatysmal fat, deep double chin, subplatysmal fat.
Frequently asked questions
Does enzymatic double chin lipolysis remove the fat beneath the platysma?
Generally, no. Injectable treatments and submental liposuction act on the fat above the platysma. Subplatysmal fat lies below the muscle and, when it is the main cause of the double chin, usually calls for a surgical assessment.
How can you tell whether a double chin is subplatysmal fat?
On palpation, fat above the platysma can be pinched even with the muscle contracted. Volume that remains beneath the contracted muscle, firm and central, suggests a subplatysmal component. Imaging helps when in doubt.