Mental fat compartment (chin): anatomy
Quick facts
- Definition
- Superficial fat of the chin, between the skin and the mentalis muscle.
- Boundaries
- Labiomental fold (above) and mandibular ligament (lateral).
- Lateral neighbor
- Jowl compartment, separated by the prejowl sulcus.
- Relevance in HOF
- Gives the chin its contour and explains the prejowl sulcus and the descent of the jowl.
The chin compartment is the superficial fat of the chin, located between the skin and the mentalis muscle. It gives volume and contour to the area and extends from the labiomental fold, just below the lower lip, to the base of the chin. It is part of the map of the superficial facial compartments.
Where does it end?
Laterally, the compartment is bounded by the mandibular ligament, a structure that anchors the skin to the bone. On the other side of the ligament is the jowl compartment, the pouch that drops over the jawline. Where the two meet, they form the prejowl sulcus, the depression beside the chin.
| Structure | Role |
|---|---|
| Chin compartment | Forms the chin |
| Mandibular ligament | Anchors the skin to the bone and marks the boundary |
| Jowl | Fat that drops over the jaw |
| Prejowl sulcus | Depression between the chin and the jowl |
Why does planning depend on this?
With age, the chin loses projection, the jowl descends and the prejowl sulcus deepens. A complaint of a "sagging chin" or "marionette lines" may come from volume, from the descent of the jowl or from the action of muscles such as the mentalis and the depressor anguli oris. Telling the origin apart avoids results that look artificial, such as a chin that is too large.
In Harmy
Harmy's Chin point lets you simulate volume in the chin, and the Jawline point simulates the line of the jaw. The projection is illustrative and does not show compartments.
Frequently asked questions
What is the chin compartment?
It is the superficial fat of the chin, located above the mentalis muscle. It gives the chin its shape and is separated from the jowl by a ligament.
Why does the jowl appear with age?
The fat lateral to the chin drops over the jaw, while the mandibular ligament holds the tissue at one point. The groove between the two is the prejowl sulcus.