BIOANATOMY AND BIOMECHANICS
The cheek extends medially from the nasolabial fold and nasofacial sulcus laterally to the preauricular sulcus. Superomedially, the cheek ends at the infraorbital crease and laterally at the zygomatic arch. The inferolateral border is the margin of the mandible. The cheek is a convex structure in youth and often develops an inferolateral concavity with age consequent to volume loss. The skin is generally nonsebaceous. In men, the lateral and inferior cheek bares dense terminal hair. In youth, the medial border of the cheek with the upper lip lateral subunit is indistinct, but with age a visible nasolabial fold develops. The nasofacial sulcus is a concave deflection which defines the shape of the nose, and ablation of which leads to asymmetry.
The cheek is not the structure of greatest cosmetic significance on the face and a simple scar on the cheek is not indicative of disfigurement. Nonetheless, large complex scars on the cheek can be very distracting. Grafts are, with few exceptions, unaesthetic and unacceptable. Fortunately, large reconstructions can often be accomplished while maintaining aesthetic goals. Repairs that are designed to avoid the medial cheek are more aesthetically pleasing on frontal view. Because repairs on the cheek are often not anchored by deep restraint, horizontal and vertical tension vectors can be transmitted to free margins. It is important to direct tensions horizontally to avoid lower lid ectropion and to maintain the positions of the infraorbital crease, the alar crease, and the nasolabial fold.
The subcutaneous fatty tissue of the cheek is deep and extensive. Laterally, the fibrous septae of the fat intermingle with the superficial musculoaponeurotic system (SMAS) as it extends inferiorly from the temple. Medially, the SMAS is much deeper, wrapping the underlying facial musculature. The fat of the medial cheek is particularly thick, thus providing a very mobile base for reconstruction. The superficial fat lobules of the cheek are dense and richly vascularized, especially in middle-aged to older patients with rosacea. The deeper fat lobules are elongated, much larger, and supplied by larger, less-frequent vessels. For this reason, it is far easier to undermine somewhat more deeply within the subcutaneous tissue of the cheek. The laxity available on the cheek is highly variable. Some older patients have loose, redundant skin and even extensive wounds can easily be closed with minimal undermining. In some middle-aged patients with thick, fibrous, highly vascularized cheeks, all reconstructions can be challenging.
The vascular supply of the cheek is highly redundant with multiple perforators and branches from the infraorbital artery, facial artery, and superficial temporal artery.
Neurovascular structures lie deeply in the cheek. The facial artery courses along and usually just lateral to the nasolabial fold. The infraorbital artery emerges deeply from the infraorbital foramen and branches extensively within the deep subcutaneous fat. Laterally, the origin of the superficial temporal artery is deep to the SMAS. The zygomatic and buccal branches of the ...