A flat back of the head is typically treated by skull augmentation, most commonly done by a custom implant design. In doing many of these back of head augmentations one quickly becomes aware that the location of the bone on the back of the head is much higher than almost anyone realizes. It does not come down as low as most think and the actual position of the visible occipital bone roughly correlates to the same position as the forehead and brow bone do on the opposite side of the skull.
While most patients have satisfactory outcomes keeping the designed implant for the back of the head on the bone, there are some patients that would benefit if the inferior bony edge of the occipital skull was lower. When considering this possibility this means that an augmentation must extend down onto the top of the muscle of the upper neck….not a typical area of ‘skull’ augmentation and uncertainty exists if that would cause issues with neck flexion and or implant bending.
Some custom skull implants for the back of the head may benefit from an extension off of the inferior end of the bone. (nuchal ridge) Alternatively other patients may just need an implant extension to add fullness into the upper neck for a better back of the head shape. This could be done by itself or, more commonly, when an occipital skull reduction is needed for too much projection up high on the bone. Extending the lower end of the skull helps balance out the needed reduction above it.
The occipital extension skull implant adds 2 to 3cms of length below the nuchal ridge. It is designed to be attached to the nuchal ridge bone. This requires dissection off of the bone on top of the muscle fascia to develop an adequate pocket. It is unknown how far an implant can extend off of the bone until it may pose a problem with neck extension. My experience so far is that no problems have arisen with this amount of implant length.
A rounder back of he head shape may in some patients require adding fullness to the bottom of the back of the head. This requires a skull implant which extends onto a soft tissue area, not that dissimilar from a forehead skull implant with an extension onto the temporal muscle fascia for an enhanced shape effect. This seems to benefit those patients who have a high occipital shape and /or a low hairline.
Dr. Barry Eppley
World Renowned Plastic Surgeon