Deep fat compartments of the face have been described including the ROOF and SOOF.  Other fat compartments have been investigated.  This study defines the anatomy of the deep fat of the lip.  Cadaver dissections show that there exists a sub-orbicularis fat compartment of both the upper and lower lips.

This study was performed using 10 hemifacial cadaver dissections.  All specimens were fresh.  Dye injection was used initially to identify this compartment.  After the gross anatomy was understood, macro and micro dissection was performed.  Loupe magnification aided dissection.  All studies were done in the dissection laboratory.

It was noted in all specimens that a sub-orbicularis oris fat compartment of the lip (SFL) exists.  There is both an upper as well as a lower lip compartment (Figures 1 and 2).  A lateral compartment, noted by splitting the orbicularis muscle at the commissure was likewise noted on dissection (Figure 3).  A large branch of the facial nerve, innervating the orbicularis oris, is noted to course through the lateral deep lip fat. 

The deep fat of the upper and lower lips, deep to orbicularis oris, may act as a supporting foundation. Lateral deep fat may also contribute to lip support. As is the case with SOOF, this fat may contribute to the stigmata of facial aging.  Other compartments in the peri-oral region were also noted on dissection and delineated with dye injection.  Some of these will be described.

References:

1. May JW, Feron J, Zingarelli P. Retro-orbicularis oculi fat (ROOF) resection in aesthetic blepharoplasty: A 6 year study in 63 patients. Plast Reconst Surg 86:682, 1990.
2. Aiache A, Ramirez O. The suborbicularis oculi fat pads: An anatomic and clinical study. Plast Reconst Surg 95:37, 1995