In the case of facial feminization surgery, modifications to the frontal sinus can be made to make the face more feminine, alongside softening the orbital rims. The forehead operations for feminization were first described by Dr. Douglas Ousterhout in the 1980s. Those operations consisted of four different techniques based on the anatomy of the patient. They were named arbitrarily by number (Type 1, Type 2, Type 3 and Type 4), with no particular relevance to their level of difficulty or frequency.