The submental fat compartment of the neck.

The anatomic understanding of the superficial compartments of the head and neck are evolving. Recently, studies have shown that the superficial fat is sequestered into separate "compartments"; however, the superficial anatomy of the submental region of the neck has yet to be defined, and improved understanding of this area may lead to advances in our ability to rejuvenate the neck. This cadaveric investigation revealed that there is one superficial fat compartment in the submental region. The anterior boundary of this compartment, previously without name, has been labeled the "submental septum." The posterior boundary of the submental fat compartment is created by a septum that arises from the platysma at a point superficial to the hyoid. Because this area is over the hyoid, it has been named the "suprahyoid septum." The lateral septal boundaries have been labeled the "digastric septae."