Expanding or enlarging the forehead to a more desireable contour is most commonly considered in adults or teenagers who have had a congenital skull deformity. Most of these had some form of craniosyostosis, with or without early craniofacial surgery, and are now left with forehead irregularities, depressions, or a forehead that severely slopes to the temple area making it look too narrow. Other needs for forehead augmentation are from previous trauma cases with frontal bone fractures, neurosurgery patients with craniotomy defects, and rarely a female to male facial conversion patient.
All forehead augmentations use some form of synthetic material to add on top of the bone. The use of acrylic or PMMA, a liquid plastic that hardens after being mixed, has been around for many decades and consistently works well. The more recent uses of bone cements or HA (hydroxyapatite), which similarly harden after mixing, are of more recent use. I have used a lot of each and either PMMA or HA has its own set of advantages and disadvantages. PMMA is less expensive, sets up more reliably in surgery, and can be injected through an endoscopic technique (for small areas) if one wants to avoid a large scalp scar. It also sets up very firmly and gets as hard as any thick plastic material. Its biggest disadvantage is that it is truly a non-natural synthetic material and its long-term implantation may have higher risks of rejection or infection. HA is a more natural material that is similar to bone in structure but it sets up slower and can be more difficult to work with through small incisions. It usually is best placed through a more open scalp incision. Once set, HA is softer than PMMA and if exposed to a large impacting force, it will potentially shatter like a ceramic dinner plate. My decision as to what material to use for any particular forehead depends on the operative technique. For open forehead approaches, I will use HA. For endoscopic techniques, I will use PMMA.
Building up the forehead is similar to sculpting with clay. The forehead bone is exposed and the chosen material is applied and molded into the shape one desires. Whether it is done through an open approach when one uses the fingers to mold and shape or done through an endoscopic technique where the fingers mold it through the forehead skin, the procedure is not difficult and provides an immediate result that should not change over time. The most difficult decision for the patient is whether a larger scalp incision is acceptable or whether the endoscopic ( a few small scalp incisions) approach is preferred. Smaller or spot forehead augmentations can be done endoscopically. Larger or more complex forehead augmentations are best done with an open scalp approach.
Dr. Barry Eppley