Brow ridges are the parts covered by the entire eyebrows. Their lower margin sinks inward to form eye sockets, and the upper margin connects with the frontal bone to form part of the forehead. If looked from a side, brow ridges are the most protrusive part of the forehead. In most cases, their shape is naturally formed; however, a few reasons such as trauma or endocrinal diseases can result in their osteogenesis. Because protrusive brow ridges are prone to make people look masculine or make their eye sockets relatively deeply sunken, to improve their facial features, most patients would consider undergoing brow ridge reduction to grind off the rough surface or protrusive bones, thus softening the shape of the eyebrows and making the forehead look full and round. However, because the brow ridges and frontal bone shave thinner structures than other facial bones and are above the hollow frontal sinus and attached to the meninges of the skull, patients should undergo a skull X-ray or the more precise 3D CT scanning before surgery to accurately predict the reducible extent and range of bones and to avoid potential postoperative complications.
Because difference in thickness between the brow ridges and frontal bones varies from 2 to 5 mm, the amount of brow bone reduction needed should be determined on the basis of preoperative X-ray images. Generally, the removal of ≥3 mm of the bone is considered to be effective. Another point to be noted is the sculpture and adjustment of bone surface shapes. Commonly, two procedures are available. If the prominence is located only at the inferior or lateral margin of the brow bone, an incision of approximately 1 cm will be made at both sides of the eyebrow lower edge for shaving bone reduction; however, in case of large-area brow bone prominence or necessity of concurrent frontal bone reduction or even forehead lift, a distal incision should be created medial to the upper scalp hairline for the surgery. The surgical procedures are not complex. Dr. Chuang first dissects the subcutaneous tissues to expose the brow bone (sub-periosteum dissection) and then uses an electric high-speed titanium shaving system to flatten the unevenness or prominences at the bone surface. Because such surgery does not need any osteotomy or bone screw fixation, there is no concern of intraoperative hemorrhage and it is a highly safe osteoplasty. Nevertheless, caution should be given to bone thickness for the entire surgery duration to avoid excessive bone reduction, which can undermine the structural strength or cause a sunken appearance.