Background: The following study was undertaken to address the following questions: (1) Why do soft tissues over the mandibular body appear to be tethered to the jaw, restricting inferior descent? (2) Why does characteristic surface anatomy appear as it does? (3) What is the anatomical basis of jowl fat?
Methods: Sixteen hemifacial cadaver dissections were performed after injecting methylene blue into subcutaneous regions around the mandibular body. Dissection was performed using loupe magnification.
Results: Discrete compartments of subcutaneous fat were identified. Two subcutaneous compartments above the mandibular border make up the substance of the jowl fat: A superior compartment and an inferior compartment. A subcutaneous fat compartment below the mandibular border was identified. Buccal fat is distinct from jowl fat. Jowl fat is separated from the submandibular fat by a septum. This septum is adherent to the mandibular body. Fibers from the platysma interdigitate with the mandibular septum and both adhere to the anterior border of the mandible.
Conclusions: There are distinct overlapping subcutaneous fat compartments above and below the mandibular border that define jowl fat. Buccal fat is anatomically independent from the jowl fat. The mandibular septum, separating jowl from neck fat, travels across and is adherent to the anterior surface of the body of the mandible. The mandibular septum tethers skin to the border of the mandible. This anatomical relationship is similar to the temporal septa and cheek septa and further suggests that facial rejuvenation should be performed in a site-specific manner.