The Type I forehead describes a forehead with an absent frontal sinus or alternatively with sufficiently thick bone overlaying the frontal sinus so that burring alone is enough to correct the forehead. This type of forehead tends to occur in approximately 3% to 5% of the population. In these situations, the operation consists of using rotary instruments to shape and contour the bone to the desired level, while observing the thickness of the bone to avoid penetrating the intracranial space. The main risks associated with this operation tend to be bleeding. There are often venous lakes present throughout the frontal bone.