It depends on what context you say that and to what extent the forehead needs to be reduced. The answer is dependent on how far a forehead needs to be reduced and whether there is an underlying frontal sinus. Approximately 2-3% of the population does not have a frontal sinus, in which case you can simply “shave down a forehead.” However, the rest of that population has an underlying frontal sinus, whether it be a generally bilateral frontal sinus or a hemilateral frontal sinus, and in either scenario, an osteotomy of the forehead must be performed and the anterior sinus wall must be reconstructed in order to achieve competency of the frontal sinus as well as a good shape.