The midface is the central third of the human face, a complex anatomical region that serves as the foundation for facial structure and appearance. It occupies the area between the upper face (forehead and eyes) and the lower face (mouth and jawline). This central positioning makes the midface integral to the structural support of the eyes and the functional roles of breathing and eating. Understanding this region involves recognizing its boundaries, structures, and how it changes over a lifetime.
Defining the Midface Boundaries
The midface is defined as the area extending vertically from the lower eyelids down to the upper lip. The upper border is the lower orbital rim, the bony edge beneath the eye socket, extending across the bridge of the nose to the medial canthus (inner corner of the eye). Laterally, the midface includes the prominent cheekbones, or zygomatic arches.
The lower boundary is marked by a line extending from the earlobe (tragus) to the corner of the mouth, continuing along the nasolabial fold towards the nose. This region includes the cheeks, the nose, and the upper jaw structure. The midface is sometimes divided into the anterior midcheek and the lateral cheek, focusing on the central, projecting portion of the face.
Critical Structures of the Midface
The core of the midface is its bony framework, which provides support for the overlying soft tissues. The primary skeletal components are the maxilla (the upper jaw bone) and the zygomatic bones (cheekbones). The maxilla forms the floor of the orbit and the lateral walls of the nasal cavity, while the zygoma forms the lateral and inferior orbital rim.
Overlaying this bone structure are layers of soft tissue, including muscles, ligaments, and distinct fat compartments. Muscles of facial expression, such as the zygomaticus major and minor, originate here and are responsible for movements like smiling. The fat is organized into superficial and deep compartments, separated by the Superficial Musculoaponeurotic System (SMAS).
The deep fat compartments, including the suborbicularis oculi fat (SOOF), lie against the facial skeleton. Superficial fat compartments, like the malar fat pad, are closer to the skin. Ligaments, such as the orbitomalar and zygomatic ligaments, anchor the soft tissues to the underlying bone. This layered arrangement is responsible for the contour and mobility of the cheeks and lower eyelids.
Essential Functional Roles
Beyond its role in appearance, the midface performs several foundational biological functions. The bony structure of the maxilla and zygoma offers protection to the eyes by forming the lower and lateral support for the orbital socket. This skeletal buttress helps shield the contents of the orbit from external impact.
The midface also houses the nasal cavity and the maxillary sinuses, which are integral to respiration and air conditioning. The sinuses are air-filled spaces within the maxilla that help humidify and warm inhaled air, while also contributing to voice resonance. The upper jaw’s positioning is also fundamental for mastication (chewing), as the maxilla contains the upper teeth. Proper alignment between the upper and lower teeth is necessary for effective eating.
Aesthetic Impact and Age-Related Changes
The midface is often the first region to show visible signs of aging, driven by changes in all its structural layers. A significant factor is bone resorption, where the maxilla loses density and volume, particularly around the orbital rim. This loss of skeletal support causes the overlying soft tissues to sag and flatten.
Fat atrophy (volume loss) is another major contributor, affecting both the superficial and deep fat compartments of the cheeks. The deep fat compartments, which sit against the bone, show volume loss, reducing the outward projection of the cheek. The resulting descent and flattening of the soft tissues leads to the formation of noticeable features like tear troughs (hollows under the eyes) and deepened nasolabial folds (creases running from the nose to the corners of the mouth).