Background: Observation suggests that the subcutaneous fat of the face is partitioned as distinct anatomical compartments.
Methods: Thirty hemifacial cadaver dissections were performed after methylene blue had been injected into specified regions. Initial work focused on the nasolabial fat. Dye was allowed to set for a minimum of 24 hours to achieve consistent diffusion. Dissection was performed in the cadaver laboratory using microscopic and loupe magnification.
Results: The subcutaneous fat of the face is partitioned into multiple, independent anatomical compartments. The nasolabial fold is a discrete unit with distinct anatomical boundaries. What has been referred to as malar fat is composed of three separate compartments: medial, middle, and lateral temporal-cheek fat. The forehead is similarly composed of three anatomical units including central, middle, and lateral temporal-cheek fat. Orbital fat is noted in three compartments determined by septal borders. Jowl fat is the most inferior of the subcutaneous fat compartments. Some of the structures referred to as "retaining ligaments" are formed simply by fusion points of abutting septal barriers of these compartments.
Conclusions: The subcutaneous fat of the face is partitioned into discrete anatomic compartments. Facial aging is, in part, characterized by how these compartments change with age. The concept of separate compartments of fat suggests that the face does not age as a confluent or composite mass. Shearing between adjacent compartments may be an additional factor in the etiology of soft-tissue malposition. Knowledge of this anatomy will lead to better understanding and greater precision in the preoperative analysis and surgical treatment of the aging face.