Background: Of the five surfaces of the skull the most prone to irregularities and asymmetries is the back of the head. While often referred to as the occiput or occipital skull bone, anatomically it is more complex than one single bone surface. The back of the head is composed of the intersection of three bones, the superior half of the occipital bone inferiorly and the paired parietal bones superiorly. They are joined together by the lambdoidal suture lines on both sides between the parietal and occipital bones and the midline sagittal suture superiorly between the paired parietal bones.
Besides this three piece bone union on the back of the head the shape it acquires is also influenced by the open posterior fontanelle that is present after birth. The closure of the posterior fontanelle and how well it ossifies is also a major influence on the surrounding skull shape.
Combining these complex bony interfaces, sutures lines and original posterior fontanelle location it is no surprising that the back of the head is the most potentially non-smooth asymmetric skull surface. While these surface contour irregularities may be aesthetically irrelevant in a female with hair. In a shaved head male, however, every surface contour irregularity can fully be seen regardless of the thickness of the scalp. Some males so affected may desire a smoother more even back of head shape.
Case Study: This male was bothered by the bumpy irregular shape of the back of his head. There was also some noticeable asymmetry with the right upper parietal side being less round than the left.
A custom skull implant was designed that covered the entire back of his head with the objective of a smooth symmetric contour. The implant’s total volumes a mere 65ccs.
It’s thickest part over the flatter right side was 7mms. Over the bumpy filler right side the maximum implant thickness was 3mms.
Under general anesthesia and in the prone position the outline of the implant’s position and the incision location marked. Through this small scalp incision placed over the nuchal ridge the subperiosteal tissue pocket was made and the implant placed. Thin skull implants are precarious to place, as they must be folded to be inserted, they also must be unfolded once inside the sub scalp pocket. Getting all the implant edges fully unfolded so the implant lays completely flat where most of the implant is not seen can be a challenge.
Once the implant is unfolded and positioned with the right north-south and east-west orientations, a single microscrew at the bottom of the implant secures its position. A multi-layer resorbable suture closure is then done over a drain.
When seen the next day for head dressing and drain removal the improved shape of the back of his head was evident.
1) The back of the head is most affected by lack of projection and contour irregularities.
2) Recontouring the back of the head can be done by a thin custom made skull implant that covers its entire surface.
3) Placement of a thin skull implant is technically challenging because it is more prone to edge irregularities and lack of complete unfolding.
Dr. Barry Eppley
World-Renowned Plastic Surgeon