Background: Brow bone reduction is a facial contouring procedure to reduce the supraorbital rim protrusion above the eyes. While it is most commonly associated with facial feminization surgery, it is also done in men for very large brow bone protrusions that are often associated with a backward slanting forehead.
Of the two available brow bone reduction techniques the one similarity between them is that of frontal sinus preservation. Minor reductions can be done by burring alone but the amount of retrusion obtained is limited by the thickness of the anterior table of bone over the frontal sinus. More significant reductions are achieved by taking off the anterior table of the frontal sinus, reshaping it and and then setting it back more into the sinus cavity. This is easy to see why it achieves more than what can be obtained by burring alone.
But there are patients who are not satisfied with the anterior table bone flap setback technique. It could be argued in these cases that the bone flap was not set back enough initially and a further attempt should be made to set it back even further. But a patient may not have confidence in a repeat of the same procedure and there is also the potential issue that the bone flap may not heal as well the second time as the first.
Case Study: This young male to female transgender patient had two prior attempts at brow bone reduction does through a hairline incision. While he had what many would consider a good result after the bone flap setback, she desired even further reduction.
The extreme brow bone reduction technique begins with first removing the bone flap through hardware removal and recutting the original osteotomy lines. This exposes the entire frontal sinuses down into the nose. The frontal sinus may or may not have midline bony partition. The surrounding perimeter of bone as well as the forehead above it and the tail of the brow bones to the sides are reduced as needed. This also included the frontonasasl junction.
The sinus mucosa is then removed in its entirety. This is a very important step and one must search for all nooks and crannies of the frontal sinus, some of which are easy to overlook, to get all pieces of the mucosal lining. The lining is removed down into the nose. The removed bone flap is cut into small pieces where it is placed as as stacked bone graft into the frontal nasal duct. Each small piece is compacted onto each other for a tight bone graft. A layer of Surgical and antibiotic powder (Gentamicin) is placed over the bone grafts.
Using a hydroxyapatite cement formulation, the liquid and powder are mixed together to create a putty. The putty is placed into the frontal sinus cavity up to the level of the surrounding reduced bone, smoothed and allowed to set.
Unlike all other forms of this type of facial reduction, maximal brow bone reduction requires elimination of the frontal sinus to allow for its maximal effect. Given that hydroxyapatite cement was originally made for frontal sinus obliteration, this is a both a safe and effective procedure.
Highlights:
1) The two standard types of brow bone reduction are outer table burring and osteoplastic bone flap setback, both of which preserve the frontal sinus.
2) Maximal brow bone reduction is done by frontal sinus obliteration with hydroxyapatite cement
3) With the frontal sinus acting as solid bone, the brow bones can be maximally reduced.
Dr. Barry Eppley
Indianapolis, Indiana