1. Three-dimensional CT reconstruction of the left skull base showing a dehiscence of the left superior semicircular canal.
2. Poeschel and Stenver projections of the left temporal bone reveal a 3 millimeter SCD.
3. Using a left-sided middle fossa craniotomy approach and extradural dissection, the SCD is seen surrounded by a dehiscent tegmen. Copious irrigation is used around the exposed membraneous labyrinth.
4. Softened bone wax is used to gently plug the SCD and a cotton pledget is used to gently press the wax into the defect to ensure that both limbs are plugged.
5. NOT SHOWN - a split calverial bone graft, harvested from the middle fossa craniotomy bone flap, is used to resurface the tegmen. The patient had immediate improvement of aural fullness and autophony of the left ear and one month later had resolution of dizziness. Her hearing showed normal thresolds and speech understanding of the operated ear.