Roadmap to the Mastoid Antrum
An anatomist and a surgeon shaped the landmarks that, by following the posterior canal wall at the base of the spine, one reaches the mastoid atrum. Jacob Henle (1809-1885) gave a detailed and complete description of the temporal bone and was first to describe the suprameatal spine, though he did not show the structure as a landmark to the antrum. Henle's name was attached to it later by mastoid surgeons. Sir William Macewan (1848-1924) was among the earliest surgeons to attach otitic abscesses through the ear. He identified the landmarks on the external surface of the temporal bone (Macewan's triangle) used by otologists today. The Macewan triangle is described within Chapter 1 of his book, Pyogenic infective diseases of the brain and spinal cord (1893).