While the skull is prone to have a variety of lumps and bumps, they are more of an aesthetic concern when they occur on the forehead. Any forehead irregularity becomes a very noticeable entity as the surface area of the forehead occupies up to 1/3 of the visible face. Commonly seen as a smooth surface, with the exception of the bilateral brow break in men, any outcrop of bone becomes very apparent and is often aesthetically bothersome.
While there are numerous types of hard and soft tissue lumps that can occur on the forehead, the most common bony types are osteomas, exostoses and midline ridging. Osteomas can occur randomly anywhere on the forehead and are often the result of trauma and usually appear due to an osteoblastic response to a small subperiosteal bleed. They are like a mushroom growth on the bone. Bony exostoses, also called forehead horns, are symmetric bilateral natural growths or thickenings of the outer cranial table. (although they can be asymmetric or appear on just one side) They do not have a distinct base like that of an osteoma. Midline ridging is a raised area of bone that runs down the upper central region of the forehead. It is a variant of the neonatal metopic suture and may be considered an expression of a microform of metopic craniosynostosis.
Reduction of any of these forehead lumps and bumps can be done by a variety of surgical methods but they all share the common need for bone reduction/bony contouring. How the bony deformity is accessed will influence, favorably or unfavorably, what bony reduction can be used. Endoscopic techniques will almost exclusively limit one to using an osteome and thus is really only used for osteoma removal which can easily be severed from its more narrow base. But every other forehead bony deformity must use a more effective contouring method and needs to be done through an open hairline or scalp incision.
A handpiece and burr is the most rapid and effective method for forehead bony deformity reduction. The high speed of the rotating burr can make quick work of any projecting bony areas. But access is often a problem. Most handpieces are straight and coming from an incision above across a convex upper forehead keeps the working end (burr) of yhe instrument away from the bony surface. This is simply solved by using an angled handpiece which is also longer than the standard straight handpiece. The angle of the handpiece overcomes the curvature of the upper forehead.
The other useful tool for forehead bump reduction is a large rhinoplasty rasp. Its teeth may work a lot slower than a rotating burr but with repetitive stroking a slow and smooth reduction can be achieved. Even though it is a straight instrument and is a bone reduction manuever that is done only by feel, it is a very safe technique that creates a safe and even bone surface. It is especially good for smoothing out any areas that were initially reduced by endoscopic burring.
Various forehead lumps and bumps can be reduced through minimal incision techniques using a variety of instruments including osteotomies, burrs and rasps. By working though small scalp incisions, forehead contouring can be done without visible skin scars if desired.
Dr. Barry Eppley
Indianapolis, Indiana