A custom implant is the most assured method for creating almost any form of skull augmentation. This becomes an absolutely essential approach when the skull surface area coverage of the implant is substantial. (aka a large custom skull implant)
With large custom skull implants there are two considerations of great relevance that does not exist to such a significant degree in smaller implants. The first is an obvious one as the incision to place it will need to be bigger. The second one is not so obvious…large skull implants that extend below the equator of the skull can not be manufactured in one piece. They must be made in two pieces and assembled together during surgery.
In most cases the most aesthetically important half of a large custom skull implant is the front piece. This is because it usually extends onto the forehead where placement of the implant edges is of paramount importance. The front half is positioned and then screwed into place at multiple locations.
Putting the back piece is straightforward as it now must fit into the geometric split line of the back end of the front piece. While it could be screwed into place, it is just as effective to place a running suture between the two implant pieces. A 2-0 vicryl suture works just fine and creates a very tight fit along the entire seam of the implant edges. While this is a reservable suture it probably may never completely resorb being partially in the implant or if it does it will take a very long time. By that time natural encapsulation of the implant will be all the fixation needed.
Dr. Barry Eppley