Maintaining or acquiring good cheek structure and adequate volume is essential to not only provide support to the directly overlying soft tissue (skin, fat, muscle and ligaments) but also to the neighbouring and more distant regions of the face such as the tear trough area, nasolabial folds (“smile lines”) and even corners of the mouth.

In young patients, this is important to help maintain or achieve better facial proportionality. In older patients, good cheek structure helps reduce the formation of grooves and folds including hollowing under the eyes as well as to counteract the normal progressive descent of the soft tissue that occurs during ageing and is evident as facial sagging. Some individuals maintain a youthful appearance despite ageing, and this can often be attributed to good cheek structure.

The cheek area is composed of both the facial skeleton and overlying layers of soft tissue containing skin, fat, muscles and ligaments. The cheekbones act as a rigid support and anchor point for these soft tissues and convey shape and dimension through them to the skin surface. The overall shape and cheek profile is, therefore determined by both the bone and overlying soft tissue.

The facial soft tissue is mainly composed of fat divided into superficial and deep layers with the facial muscle layer (SMAS) in between. The superficial and deep fat are further divided into anatomical compartments. The superficial fat compartments are fairly mobile and move freely with contraction of the underlying SMAS muscle layer to permit facial expressions such as smiling. The deep compartments are more fixed in position attached by ligaments and fibrous attachments to the underlying bone and provide cushion support or buffer from the bone for the overlying SMAS layer during muscle contraction.

During the ageing process, these different fat compartments go through a complex progressive but specific pattern of volume change. Most of the fat compartments, principally the deeper ones, loose volume, whereas some of the superficial compartments gain volume. Furthermore, the ligaments and muscles that hold these compartments in place begin to weaken and loosen, leading to downward displacement and separation of the fat compartments. These changes are accompanied at the deeper level by gradual reabsorption of the mid-facial (maxillary and zygomatic) bones resulting in loss of structural support and projection with visible flattening of the cheeks. The loss of outward/side projection and hence the width of the cheekbones due to bone reabsorption effectively narrows the middle of the face relative to the upper and lower face. This, in turn, can negatively impact the proportions of the face and overall attractiveness.

As the deep fat compartments lose volume and anchoring ligaments and attachments weaken, the superficial fat compartments begin to migrate over the deep compartments and separate such that the once smooth cheek contours start to develop surface irregularities and grooves. The differential pattern of volume loss and volume gain between the deep and superficial compartments and separation and migration for the superficial compartments lead is noticeable in the mid-face as deepening of the nasolabial folds as well as marionette lines that develop from the corners of the mouth.

Modern hyaluronic acid (HA) fillers come in different densities with specific qualities that can be used to target each soft tissue layer of the face from the deep layer over the bone to the superficial layer just under or in the skin. Consequently, depending on the type of filler injected, they can be used to create lift, projection, definition and contour in the cheek and general mid-facial area.

The outer cheekbone area can be made to look more defined and, where necessary, provide better outward/sideward projection to improve the width of the midface relative to the lower and upper face. This, in turn, can improve the overall shape and proportions of the face and attractiveness as well as providing lateral soft tissue support to aid against facial sagging. This effect is further enhanced by treating the areas of volume loss just below the outer cheekbones (the sub-zygomatic region), which helps create a platform for the overlying soft tissue helping to reduce mid-face heaviness and sagging. 

Treating the front part of the cheeks under the eye area with fillers in patients who lack good forward cheek projection can help recreate the convex contour of youth and allow a smoother transition with the outer cheekbone area.

Treating both the inner and outer areas of the cheeks with cosmetic fillers can also significantly improve both neighbouring and more distant regions of the face.  Replacing lost volume in the inner or front part of the cheeks can support the area under the eyes and reduce the appearance of under-eye hollows as well as hide mild to moderate eye bags, particularly when combined with outer cheekbone injections.

Injections into the deep cheek fat compartments either side of the nose in an area called the piriform fossa, as well as the outer cheekbones, provides support for the overlying fat compartments pushing them upwards and outwards, helping to significantly reduce the nasolabial folds (“smile lines”). Injections into the piriform fossa also help lessen a ‘gummy’ or ‘snarly’ smile and can narrow the apparent width of the nose.

Finally, injecting filler in the outer cheeks can help lift the corners of the mouth when the filler is placed under one of the smile muscles (zygomaticus major) that runs from the outer cheeks to the mouth corners. The filler acts as a fulcrum for the overlying muscle giving the muscle a mechanical advantage, and hence increasing its ability to pull on the corner of the mouth. This process is an example of myomodulation i.e. the ability of fillers to improve or inhibit muscle action. It is an important mechanism by which treating one area of the face can enhance another, often more distant, area of the face.

Since the cheek structure is defined by both the bone support and overlying soft tissue, aesthetic enhancement of this area can be achieved by either augmenting the bone (with surgical cheek implants) or augmenting the soft tissue (with fat grafts or volumising fillers).

Surgical implants provide direct local enhancement of the underlying facial skeleton, which is conveyed through the overlying soft tissue to the skin surface through an expansion effect and acts as a support platform for those tissues. In contrast, fat transfer restores fat volume and fullness in the fatty layer of the face between the skin and bone.

Cosmetic cheek fillers, depending on the depth of injection and the type of filler used, can provide both structural support for the overlying soft tissue (when injected just above the bone), fullness in the mid-layer of the face (when injected at the mid-fat layer depth) and also superficial contour smoothening to correct surface irregularities such as grooves and hollows (when injected at the superficial fat layer). Both cosmetic fillers and fat can have a more diffuse area effect than surgical implants, depending on the size of the area treated and volume used.