Head and Neck Imaging

Bony dehiscence

focal interruption of a thin bony wall, presumably congenital in origin. It is seen at several sites in the skull and may be associated with an increased risk when surgery is performed in its vicinity. Examples are:

  • dehiscence of the lamina papyracea (bony separation between orbit and ethmoidal cells);

  • dehiscence of the wall of the sphenoid sinus, with possible herniation of the optic nerve or internal carotid artery into the sinus (see sinonasal cavities anatomical variations);

  • dehiscence of the facial nerve canal (usually at the tympanic portion, with possible prolapse of the facial nerve into the oval window).

    RH