Background: The normal rounder shape of the skull can be altered for a wide variety of reasons. One of the most common reasons for skull deformation is congenital or genetic. Usually this affects one or several of the cranial sutures creating a variety of fairly classic skull shape deformations. But there are a whole host of other skull deformities that are not so easily explainable as that of craniosynostosis.
The skull is prone to a variety of indentations, raised areas and other contour deformities that defy an exact explanation as to why they are there. Such is the case of the bilateral occipital skull indentation deformity. I have seen this specific type of skull contour deformity several times and have no explanation for its presence. It is as if the back of the head was placed in a vise during development creating two symmetric flat spots. It is the symmetry of the flat spots that defies a specific developmental explanation.
For men that shave their heads or who have significant hair loss, a smooth skull contour takes on great significance. An otherwise known skull shape or contour issue is acceptable when one has hair or wears a hair piece. But once the scalp is clearly seen the shape of the skull takes on great significance.
Case Study: This 62 year old man wanted to improve the shape of his skull by getting rid of the two (technically three) flat spots on the back of his head. (two larger bilateral ones and one smaller central one) He had always worn a hairpiece so they were historically hidden. But he decided to get rid of his hairpiece which exposed these skull contour concerns. Using a 3D CT scan a custom skull implant was made to cover all three occipital skull areas with a single piece silicone implant.
Under general anesthesia the custom skull implant was placed through a high occipital incision of 9 cms in length. By folding the sides of the implant underneath the central part, the large custom skull implant was able to be inserted through the much smaller incisional width and unrolled once under the scalp. The skull implant fit perfectly aided by the location of the negative impressions of the occipital skull indents on the concave inner surface of the implant.
At just one week after surgery at the time of scalp suture removal, the elimination of the skull dents by the implant could be immediately seen. A custom skull implant is the best method for reshaping the skull of various larger contour depressions. By covering a broader surface area the implant covers the depressions and blends into the surrounding skull bone surfaces smoothly. Because the skull implant does not need to be that thick, it can be inserted through a relatively small incision and does not exceed the ability of the scalp to adequately stretch to accomodate it.
Highlights:
1) Bilateral dents or indentations in the skull are usually formed by their natural development whose origins are unclear.
2) Bilateral occipital dents are rare and are best treated by an overall augmentation of the back of the head.
3) A custom skull implant for coverage the deformed portion of the occipital skull can be made from a 3D CT scan.
Dr. Barry Eppley
Indianapolis, Indiana