Background: The shape of one’s head often takes a second place to that of the face. After all the head is but a backdrop onto which the face projects. Given that hair usually adorns most of the head’s surface, any shape issues are fairly well camouflaged. In certain skull shapes even good hair density may not be enough to hide it and may even accentuate it in some cases. Hair loss, of course, exposes any abnormality in skull shape and may tip the balance toward an interest in change.
One of the classic skull deformities is that of the sagittal crest or sagittal ridge deformity. This head shape is seen as a raised ridge or crest in the midline. It often starts behind the frontal hairline and reaches its highest near the back of the head. This creates a peaked or crestal appearance to the head shape. It is caused by some mild aberration of the sagittal suture where excess bone piles up along its course making it thicker. It is not a true sagittal craniosynostosis but probably some minor variation of it.
In the animal world, the presence of sagittal crest in the skull is common and usually indicates that the animal has very strong jaw muscles and a powerful bite force. The attachment of the temporal muscles due to their size migrates to the midline during development, creating a single midline temporal line rather than the more lateral paired temporal lines seen in humans. This is seen in a wide variety of animals from dogs, apes and even dinosaurers. Perhaps this is why the sagittal crest is undesired in humans since it is an animal feature.
Case Study: A 30 year-old male wanted to improve the shape of his head. He had a prominent ridge on the back half of his head. It was raised up in the midline creating a visible sagittal ridge. He basically shaved his head so there was no hiding this raised area of the skull.
Under general anesthesia, a curved scalp incision of 9 cms was made on the back end of the sagittal crest. A handpiece and burr was used to burr down the crestal ridge a total of 7mms, making it confluent with the rest of the parasagittal skull shape. The incision was closed with small dissolveable sutures and no drain was used.
When seen four months after the procedure, the sagittal crest had been eliminated and a smoother more convex head shape obtained. The scalp incision was extremely faint and very hard to see even on shaved head. This follow up was able to be obtained because he wanted a small revision to smooth out a few additional small raised areas.
The sagittal crest skull deformity can be safely reduced by a burring bone reduction skull reshaping method. This is often the thickest part of the skull due to the overdevelopment of bone along the suture line. The resultant scalp incision needed to do it can heal in a very discrete manner.
Case Highlights:
1) The sagittal crest skull deformity is marked by a midline ridge of varying thicknesses that is often located more to the back of the head.
2) An open burring technique can reduce a sagittal crest skull deformity up to 7mms in the midline.
3) The midline reduction must take into consideration the parasagittal bone shape to avoid a midline plateau effect.
Dr. Barry Eppley
Indianapolis, Indiana