SMAS: the superficial musculoaponeurotic system

SMAS stands for superficial musculoaponeurotic system. It is a continuous fibromuscular layer that wraps and connects the muscles of facial expression, between the subcutaneous fat and the deeper structures. It continues with the platysma in the neck and with the superficial temporal fascia on the side of the head.

The face is usually described in layers: skin, subcutaneous fat, SMAS, spaces and deep fat and, finally, periosteum and bone. The SMAS works as a network that transmits muscle contraction to the skin, and for that reason it takes direct part in facial expression.

Why does the SMAS matter in facial harmonization?

With aging, the SMAS loses firmness. Together with the loosening of the retaining ligaments and the loss of volume in the fat pads, this contributes to the descent of tissues and to the loss of definition in the lower contour.

The SMAS is a central reference in facelift surgery. In facial harmonization, it helps explain the logic of support procedures, such as thread lifts, and to separate what lies above and below this layer, since vessels and nerve branches follow different paths at each plane.

What precautions does this layer involve?

Branches of the facial nerve run beneath the SMAS for much of their course, and vessels change depth across the face. Knowing the layers is part of the safety of any injectable or thread procedure. The indication, technique and plan are defined by the qualified professional, according to the rules of their professional board in Brazil.

In Harmy

Harmy does not simulate layers: the projection shows the visual effect of the volume marked in areas such as Cheekbone and Jawline, to support the conversation about the plan.

Also called: superficial musculoaponeurotic system.