Implants provide a wide array of options for facial augmentation. While initially only a chin implant was available forty years ago, today there are over fifty different styles and shapes that are available in more than one material composition. From the chin to the forehead, the options for bony enhancement now cover such obscure areas as the tear trough, paranasal and geniomandibular areas. Such facial implants play a very valuable role in aesthetic facial augmentation whether it is the younger patient seeking a structural facial change or the older patient in which an implant complements soft tissue lifting procedures.
Despite the tremendous diversity of facial implants, off-the-shelf styles and sizes can not fill all patient aesthetic needs. There are certain types of aesthetic problems in which stock implants are inadequate such as facial asymmetries, congenital and traumatic deformities and failed results using commercially-available implants. While stock facial implants, particularly those composed of silicone, are easy to intraoperatively shape and ‘customize’, the judgment of how they are to be shaped is still a matter of artistic adaptation.
The use of custom facial implants offers real advantages in challenging cases of facial augmentation. I classify custom facial implants into four types; 1) intraoperative modification of stock implants, 2) preoperative stock implant modification on a standard anatomic model, 3) preoperative stock implant modification on a patient-specific anatomic model, and 4) fabrication of an implant on a patient-specific anatomic model. Type #1 and #2 custom facial implant approaches have been done for decades and may even be questionable as to whether they are truly custom implants. Types #3 and #4 are a truly custom implant approach.
The basis of a truly custom facial implant approach is a patient-specific anatomic model. This requires the patient to first receive a 3-D facial CT scan based on a 1mm slice-taken protocol. These images are then sent to a manufacturer of craniofacial models. The manufacturer that I use is Medical Modeling (Golden, CO) although there are others. The model can be made in either an Osteoview style (opaque) or a Clearview style. (clear acrylic) In the Clearview style, teeth, nerves, plates and screws and other implants can be colorized (red) so they stand out from the clear bone structures. The Osteoview is satisfactory if a custom implant is needed and the patient has not had prior surgery. The Clearview model is preferred when prior bone or implant work has been done and the bony anatomy has been altered.
Off of these models, the custom facial implants are made. While most patients think that there is a computer program that makes the implants, and this certainly exists, the cost and availability of this technology makes it currently not practical in aesthetic facial surgery applications. Custom implant designs and prototypes are made by hand. I mold, shape and carved them out of clay or silicone elastomer which air dries to a hard set. If needed, they are further shaped and contoured by diamond wheels on a small hand drill. Finally they are covered by a lacquer which dries to a clear coat.
As part of this process, I often share images with patients of their implants in the fabrication process by e-mail or they may come in to see and handle the implant prototypes. It is important in the custom implant fabrication process for patients to participate in the decision process about the design. Once the design is agreed upon, the implant(s) are sent to a manufacturer for fabrication. Most custom implants can only be made from silicone. For many custom facial implants this is the best material because their differing shapes and sizes may make them difficult to place. Flexibility and lack of frictional resistance on insertion are important implant insertion properties in any facial implant but is of critical importance in many custom designs. Besides the obvious benefit of creating an implant design that is as accurately accurate and symmetric as possible, the custom design process can also add features that make them able to be more effectively secured to the bone by screw fixation.
From the time that a 3-D anatomic model is obtained, a three week period is usually needed from design until the sterilized implants are returned from the manufacturer and ready for surgery. Depending upon the number of implants, the cost of custom designed facial implants can be from $5500 to $7,000 in addition to other surgical costs.
Dr. Barry Eppley
Indianapolis, Indiana