Cheek implants, medically known as malar augmentation, involve the surgical placement of a solid device to enhance the contours and projection of the midface. Individuals often seek this procedure to restore volume lost with age or to achieve greater facial definition. The devices are crafted from synthetic, non-biological materials, which must be selected for their biocompatibility and long-term durability within the body. Understanding the specific composition of these medical devices is a primary step in learning about this form of permanent facial contouring.
Primary Materials Used in Cheek Augmentation
Permanent cheek implants are manufactured from one of three primary medical-grade polymers, each offering distinct characteristics for facial augmentation. Solid silicone is a widely used elastomer that is inert and non-reactive within the body. This material’s smooth, non-porous surface prevents tissue ingrowth, which makes it easier for a surgeon to remove or adjust the implant if necessary. Silicone implants are favored for their relative pliability and are available in a vast array of pre-formed shapes and sizes.
Porous polyethylene, often referred to by the brand name Medpor, is a high-density, rigid material. This material has a highly interconnected porous structure with pore sizes typically ranging from 100 to 200 micrometers. This porosity facilitates the integration of the patient’s own fibrovascular tissue. The ingrowth of tissue firmly anchors the implant to the surrounding bone and soft tissue, significantly reducing the chance of migration.
The third material is expanded polytetrafluoroethylene (ePTFE), a softer and more flexible polymer. This material is known for its microporous structure, consisting of nodes connected by fine fibrils, which allows for some degree of controlled tissue integration. The partial ingrowth of soft tissue into ePTFE provides stability without the same level of firm adherence seen with porous polyethylene. This material is widely recognized in medicine for its use in permanent surgical applications due to its inert nature.
Structural Properties and Tissue Interaction
The fundamental difference in materials lies in their surface structure, which dictates how the body interacts with the foreign object. Non-porous implants, such as solid silicone, cause the body to form a thin layer of scar tissue, called a fibrous capsule, around the entire device. This encapsulation keeps the implant separate from the surrounding tissues, allowing for relative ease of removal. However, this lack of integration can also make them more prone to shifting from their original placement over time.
Porous materials like high-density polyethylene and ePTFE are designed to encourage tissue integration. The interconnected pores allow blood vessels and connective tissue to grow directly into the implant structure. This direct tissue ingrowth provides superior long-term stability and minimizes the formation of a restrictive fibrous capsule. However, this strong biological fixation means that porous implants are significantly more challenging to remove or revise if a patient desires a change in the future.
The physical hardness or flexibility of the polymer plays a substantial role in the long-term outcome and feel of the implant. Polyethylene is rigid, providing a firm, stable contour that closely mimics bone structure. Silicone is softer and more pliable, which can feel more natural to the touch but may be slightly more palpable beneath thin skin. ePTFE generally falls between the two, offering a soft, flexible feel while providing structural support.
Customization and Anatomical Placement Types
Manufacturers produce cheek implants in numerous pre-formed sizes to accommodate anatomical variations and aesthetic goals. For a precise fit, the surgeon may intraoperatively carve or trim a pre-formed implant, particularly those made of silicone or porous polyethylene, to better match the patient’s underlying bone structure. For complex reconstructions or highly individualized cosmetic enhancements, implants can be custom-made using three-dimensional computed tomography scans of the patient’s face.
The specific placement of the implant material is categorized based on the region of the cheekbone being augmented.
Malar Implants
Malar implants are placed directly over the cheekbone (zygoma) to increase the outward projection of the high cheek prominence.
Submalar Implants
Submalar implants are positioned below the cheekbone to fill in the hollow or sunken appearance of the mid-cheek region.
Combination Implants
Combination implants are an extended design intended to augment both the malar and submalar areas simultaneously, providing a more comprehensive contouring effect.
The choice of material is influenced by the intended anatomical location and the desired level of projection and definition. For instance, the firm structure of porous polyethylene is preferred for high-projection malar augmentation where a strong, bone-like contour is needed. Conversely, softer materials like ePTFE may be chosen for submalar augmentation to provide a subtle, flexible volume enhancement in the soft tissue areas. The final implant selection is a careful balance between the material’s properties, the surgical site, and the patient’s specific aesthetic goals.