Background: The size and shape of the head is influenced by a variety of congenital and developmental influences on its bony framework. It is a unique bony structure of the body because it fundamentally acts as a large hollow encasement. Provided there is enough space for adequate brain development the specific dimensions and shape of the skull is otherwise an aesthetic issue. Such aesthetic head shape concerns could involve lack of (flatness) or excessive convexities (protrusions) or an overally small or large head shape.
The female who views their head shape as small, specifically in the crown area, is a common request for skull augmentation. The smallness is almost always centered around the crown area and the patient usually has a history of compensating for the lack of skull height/projection by using the hair as a camouflage technique.
With a smaller head shape comes a tighter and often thinner scalp cover. This is particularly evident in Caucasian females although there is a tendency for small head scalp tightness in all ethnicities. With a desire for skull augmentation, which usually must be significant to her worthwhile, the scalp becomes a limiting factor. This anatomic limitation can be overcome by a scalp expansion process prior to skull implant placement. While effective the capsule created and the size of the needed skull implant pose technical considersations for placement.
Case Study: This middle-aged female had long been bothered by her small head, a ‘peanut head’; as she called it. She never wore her hair down for shame of her small head. Wearing her hair up provided obvious crown of the head augmentation. Interestingly her 3D CT scan showed considerable skull flatting in the crown/parietal skull areas.
Using her scan a large custom implant was designed to augment her skull centered over the crown area. Its volume was 220ccs. To enable it to be placed through the length of the incision on the back of the head used for the scalp expander placement it was design in two pieces with a geometric midline split.
In preparation for this large custom skull implant that would exceed her scalp’s ability to accommodate it a scalp tissue expander was initially placed. The incision used to place it was on the back of her head where a scar was located from a previous hair transplant harvest for her eyebrows. She was asked to inflate at home by serial injections to over 200ccs of volume. Which she was able to achieve successfully. When seen the day of surgery, the softness of the expander could be felt and its port clearly seen above the right ear.
Under general anesthesia and in the prone position the scalp tissue expander and its port were removed. With the scalp tissue expander removal it is necessary to remove all the capsule from the skull bone’s surface (capsulectomy) as well as expand the expander pocket further forward and on each side. (capsulotomies) This is necessary as the base shape of the tissue expander (which is round) is very different from the shape of the skull implant design.
The custom skull implant was designed in two pieces so it could be passed through the original back of the head incision used for the scalp expander. The longitudinal split within a geometric locking connection is the most assured way of making sure it comes together accurately inside the scalp pocket.
Positioning such a large implant inside the scalp pocket is largely done by feel and not direct vision since most of the implant can not be seen. All that can be seen is the bottom edge of the back end of the implant as well as the alignment of the two pieces through the incision. Once what was felt to be good anterior positioning and midline alignment small screws were placed at its bottom edge. After placing Vancomycin antibiotic powder over the visible implant the scalp incision was closed in two layers over a drain on each side.
When seen the next day for head dressing and drain removals, the improvement in the projection of her head could clearly be seen.
A two stage skull augmentation offers good improvement for the small head shape. The key elements are a first stage scalp expander whose eventual inflation matches that of the implant’s design and a second expansion of the expanded scalp pocket with an an implant design that keeps a relatively small scalp incision.
Key Points:
1) Small female head shapes can be effectively augmented by a two stage skull augmentation process.
2) A first stage scalp expansion is needed whose volume must match that of the custom skull implant design.
3) The second stage scalp expander removal and implant replacement requires a multi-piece design for insertion through a limited scalp incision.
Dr. Barry Eppley
World-Renowned Plastic Surgeon