The deep plane facelift surgeon must develop asense of spatial awareness and navigation within the intricate anatomy of the face and neck, and this requires an understanding of 3-dimensional layering and depth. Simplistically, one can separate the face into 5 layers based on depth and into lateral and anterior components based on function.
A vertical line drawn from the lateral orbital rim through the mandible demarcates the anterior (mobile) component from the lateral (immobile) component of the face; this correlates with the line of underlying retaining ligaments that connect the overlying skin to the bone and/or deep fascial layers.1–11 The lateral face is relatively immobile because the structures in this region are designed for mastication requiring much less emphasis on precise movement, whereas the anterior face requires significant mobility to facilitate communication and expression.
Layers 1 through 3 of the mid and lower face consist of the skin (epidermis and dermis), the subcutaneous layer (subcutaneous fat and the retinacular cutis), and the superficial musculoaponeurotic system (SMAS), which together work as a composite flap to move over the deep fascia of layer 5.1,7 Layer 3 is continuous over the entire face with the main focus of facelift surgery, the SMAS, covering the portion of the mid and lower face.1,5–7,9,10,15–19 These layers are considered safe for dissection because the complexity and potential danger arises in sub-SMAS territory.
Layer 4 of the anterior face contains the retaining ligaments, deep fat compartments, and facial soft tissue spaces that help orchestrate movement,whereas layer 4 of the lateral face serves primarily as a region of fusion.1–5 Layer 5 consists of either periosteum positioned over bony locations or deep fasciawhen covering muscles that overlie the bone (Figs. 1–3).
A comprehensive understanding of how aging impacts facial anatomy is crucial for proper patient assessment and preoperative planning, including but not limited to, changes to skin quality and composition, the loss of adiposity, volumetric deflation, tissue descent, and changes to the facial skeleton. 20 Patient assessment should include an analysis of the patient’s skin quality, including Fitzpatrick skin type, their facial shape, and the presence or absence of asymmetries.7,20 Evaluation of the midcheek includes the degree of segmentation of the malar, nasolabial, and lid cheek segments, noting evidence of malar pad descent with malar volume depletion and fullness of the submalar region. 9–15,21 Other findings to look for are skin redundancy, nasolabial fold prominence, marionette lines, and evident jowling.
The contour of the jawline and neck should also be evaluated making note of platysma laxity, the presence of vertical banding, or submental and submandibular fat prominence. Although understanding the nuances of the aging face is vital, the patient assessment should first and foremost be guided by identifying the patient’s main concerns and addressing features they find most bothersome. It is crucial that the facelift surgeon practices a patient-centered approach in which surgical plans are individualized based on his or her expertise and the patient’s expectations. 20 Patient planning includes more than facial analysis, but it also requires comprehensive evaluation of the patient’s medical history, medication list, anesthesia history, as well as a psychosocial evaluation.