A custom skull implant design based on the patient’s 3D CT scan is the best method for almost any aesthetic skull augmentation. As long as the volume of the skull implant does not exceed the ability of the scalp to stretch to accommodate it any shape or size implants can be designed. This makes many aesthetic skull shape abnormalities that were previously untreatable very much treatable.
In designing a custom skull implant the first step is to establish what is known as its footprint. This is the perimeter of the implant’s surface area coverage on the skull. Regardless of the various thicknesses of the final implant design, it must always taper down to as thin an edge as possible around its perimeter. A smooth transition of the implant onto the bone is important to avoid the risk of postoperative visible edging of the implant seen on the exterior of the scalp. This is critically important on the exposed forehead and, in particular, in any male with very short hair or a shaved head.
Most aesthetic skull implants are made of solid silicone which offers the elastic deformation property to be able to be inserted through small scalp incisions. Because such implants are fabricated from a mold it is important to always be vigilant of their edges in skull implants. While the scalp may offer a thick tissue cover, implant edges of even 1mm may become visible. Knowing this I always check the implant’s edge and if there are any concerns about whether they have adequate thickness intraoperative modification is done using a scalpel blade.
The key to thinning the skull implant edge is a hard flat surface for the implant to rest on and be stabilized and a #10 scalpel blade. Working at an angle that parallels the slope of the implant’s curvature, thin slices of material are taken along the implant’s edge. To do so effectively and smoothly on a less than absolutely rigid material is a learned skill that requires patience and good visualization using loupe magnification.
The high risk patient for edge visualization in custom skull implants is the shaved head male. With light reflecting off of a very smooth scalp surface the slightest thickened edge of an implant can become somewhat visible. Intraoperative implant edge inspection, and modification if necessary, is the best method to assure this aesthetic liability does not occur.
Dr. Barry Eppley
Indianapolis, Indiana