Figure 4: The positioning of the new meatus has to consider the special anatomical situation of the missing os tympanicum. The meatus runs anterior partly behind the temporomandibular joint (a). If it is positioned perpenticular the middle ear space is missed with the risk of facial nerve and labyrinthine injury.
KG: temporomandibular joint, BG: lateral semicircular canal, HA: malleus-incus-conglomerat