Prehistoric trephination of the frontal sinus.

Two examples of prehistoric trephination of the frontal sinus are presented. Both specimens were collected in Peru during the second decade of this century and are currently preserved at the Museum of Man in San Diego. One of the skulls represents trephining by incision and the other by scraping. Both show signs of healing indicating that the operated individuals survived the procedure. No definite clues as to the indications for surgery were found in one of the specimens. Trauma involving the frontal sinus appears to have been the reason for trephination in the other.