Skull implants today can be designed to cover any surface area of the skull that needs to be augmented. Utilizing the patient’s 3D CT scan, its design and size is only limited by the limitations imposed by the elasticity of the scalp. (how much can the scalp stretch to accommodate what lies underneath it)
Typically skull implants that cover larger surface areas of the skull have more projection (thickness) as well in an effort to make he overall skull larger. In most of these cases a first stage scalp expander is needed to be able to accommodate the large skull implant secondarily.
But is some cases of near total skull coverage the goal is not to make it appreciably bigger but to make it smoother with a more modest augmentative effect. Such a larger but thinner skull implant can be placed without the need for prior scalp expansion. It can be seen that such a skull implant provides coverage over the entire bony surface areas from the brow bones back to the nuchal ridge in the back of the head.
The insertion of a thinner custom skull implant design requites two specific needs. A subtotal coronal scalp incision is needed halfway between the front and back to be able to do adequate subperiosteal dissection. Secondly the durometer or stiffness of the implant material must be greater to ensure that the its thinner edges do not inadvertently roll up during placement.
Such total coverage skull implants are for patients that have an unevenness or a skull surface irregularities, some modest frontal or occipital asymmetries or a top of the head that has a peak or depression and lacks a more pleasing convex contour. They are one of the least requested custom skull implant design due to their large surface area coverage but in the properly selected patient can be very effective.
Dr. Barry Eppley