The forehead has a variety of shapes that differ according to gender. Men tend to have flatter, fuller foreheads with more prominent brow bones (supraorbital ridges), while women’s foreheads tend to be smoother, less full, and with flatter brow bones that tend to slope toward the forehead. temporal region. Whether for a congenital deformity (such as craniosynostosis), resection of a frontal tumor (craniotomy flap), or for prior contouring purposes (FFS, facial feminization surgery), there are rare cases where one wishes to have a definition of fuller or more prominent forehead restored.
Brow bone augmentation (BBA) is one form of brow reshaping that can be performed. Using synthetic materials as a building material, the bone can be “thickened” and re-contoured to alter the appearance of the brow. Since the brow and upper eyelid are affected by their underlying bony support, such changes can produce subtle or dramatic differences.
One of the key questions of brow bone augmentation is what material to use. Currently, hydroxyapatite (HA) and acrylic (PMMA) are the only two castable materials of choice. Your own bone is usually not a good choice as you have to collect it and how it survives as an inlay is hit or miss. Both HA and PMMA have their advocates but I have had good results with both. Either one can do the job. PMMA is much cheaper from a material cost standpoint and is very hard once it sets, being harder, if not harder, than natural bone. HA is much more expensive, a bit more difficult to work with, and is more brittle on impact. But it is closer to natural bone mineral, so it has better compatibility and less risk of long-term bodily reaction problems.
There is also the option of a synthetic implant carved from llm silicone or polyethylene. (Medpor) This requires a higher degree of skill and time to get all edges flat and flush with the surrounding bone. It’s easy to see how an edge pass can feel through the skin unless it’s done perfectly. Edge fading and blending with surrounding bone is much safer with castable materials.
The other important BBA consideration is access. For the most part, an open-scalp approach provides the best vision and shape control. But this is understandably problematic for most men unless they have a pre-existing scar on their scalp to use. For most women this is not a major issue as a hairline (pretrichial) approach can be done and that scar can be quite fine and unnoticeable. I know this from extensive experience with pretrichial (hairline) brow lift procedures performed for cosmetic purposes.
An unopened (endoscopic) scalp approach may be used in selected cases of forehead augmentation. When it comes to augmenting the central or uppermost part of the forehead, the endoscopic approach can be performed using PMMA as the injectable material. PMMA can be injected and pushed like a frozen putty and shaped by external molding through the skin of the forehead. HA is quite a different material and its handling properties allow for nothing more than an open approach to the scalp. But working in the forehead area, which is a very low point for endoscopic visualization, is even difficult with PMMA. Therefore, I would recommend an open approach for any brow bone buildup.