The Surface-Volume Coefficient of the Superficial and Deep Facial Fat Compartments: A Cadaveric Three-Dimensional Volumetric Analysis

Abstract

Background: Soft-tissue filler injections for the treatment of facial aging can result in different skin surface effects depending on the targeted facial fat compartment and fascial plane. This work investigates the tissue response of defined amounts of soft-tissue filler material injected into superficial and deep facial fat compartments by means of the calculation of the surface-volume coefficient. Methods: Four fresh frozen cephalic specimens obtained from human donors (three female and one male; mean age, 74.96 ± 22.6 years; mean body mass index, 21.82 ± 6.3 kg/m2) were studied. The superficial and deep lateral forehead compartments, deep temporal fat pad, sub–orbicularis oculi fat compartment, and deep medial cheek fat compartment were injected with aliquots of 0.1 cc of contrast-enhanced material and scanned using three-dimensional surface imaging, resulting in a total of 226 injection and scanning procedures. Results: The sub–orbicularis oculi fat compartment revealed the highest correlation coefficient (r p = 0.992; p < 0.001) and the highest surface-volume coefficient (0.94). The compartment with the lowest tissue response was the deep medial cheek fat compartment (r p = 0.745; p < 0.001; surface-volume coefficient = 0.29), followed by the deep lateral forehead compartment (r p = 0.814; p < 0.001; surface-volume coefficient = 0.68), superficial lateral forehead compartment (r p = 0.824; p < 0.001; surface-volume coefficient = 0.74), and deep temporal fat pad (r p = 0.947; p < 0.001; overall surface-volume coefficient = 0.64). Conclusions: These results, confirmatory in their nature to current injection strategies, provide evidence for the validity and reliability of the surface-volume coefficient. Injection procedures should be targeted in terms of facial fat compartments and fascial planes for a desired aesthetic outcome, as each fat compartment and fascial plane has unique tissue responses to injected soft-tissue fillers.

The Influence of the Insertion Angle on Middle and Lower Face Tissue-Mechanics When Treating the Nasolabial Folds with Facial Suspension Threads—An Experimental Split-Face Cadaveric Study

“…This model was chosen in the past to describe the facial fat compartments, [34][35][36] facial danger zones, the pathophysiology behind injection-related visual compromises, 37,38 and when establishing the surfacevolume-coefficient, a novel parameter to describe soft tissue filler effectiveness. 29,32 However, the present study is the first to investigate the biomechanical effects of facial suspension threads in a cadaveric model. Future studies will need to validate the findings presented herein in a clinical setting.…”

“…Despite failing to reach statistical significance, volume reduction was greater for the PCL suspension threads at the nasolabial and at the labiomandibular sulcus but not when measured along the A strength of the present study is that study outcomes were objectively assessed using 3D surface scanning, which identifies skin movement and surface-volume projection changes between two 3D images. [26][27][28][29][30][31][32] Measurements were conducted using an objective mathematic algorithm, eliminating observer bias. Calculations yielded changes in skin displacement in a 2D Cartesian coordinate system (x-and y-values; representative for vertical lifting (y-value) and horizontal lifting (x-value) given in mm) and changes in surface volume (given in mL).…”

Three-dimensional surface imaging in breast cancer: a new tool for clinical studies?

“…The volumetric measurement capabilities of the Artec Eva scanner were previously examined in a cadaveric model, where predefined amounts of injected volume were analysed in various facial regions [20,21]. The imaging device was found to provide highly accurate results, even when dealing with as little as milliltres of injected volume.…”

“…The mobile Artec Eva 3D surface scanner (Artec 3D Inc., Luxembourg) is an affordable device that combines the latter two technologies. Its ability to create both, spatially highly accurate and textured 3D models with little effort, has already been successfully used in other clinical studies [20][21][22][23]. 3DSI allows to reproducibly assess changes in breast volume and appearance due to edema, fibrosis or erythema.…”

Influence of needle size and injection angle on the distribution pattern of facial soft tissue fillers

“…Soft tissue filler injections are performed using either sharp‐tip needles or blunt‐tip cannulas . Previous studies have shown that injecting with a needle oriented perpendicular to (in contact with) the bony surface distributes the filler material into all fascial planes, whereas injecting with a cannula parallel to the bone surface positions product solely in the targeted plane .…”