The sinus tympani (ST) is a critical anatomic region of the temporal bone. It lies medial to the facial nerve, between the ponticulus and the subiculum, and therefore is not easily visualized by routine surgical approaches to the middle ear and mastoid.

Where is sinus tympani?

The sinus tympani is located on the medial wall of the tympanum between the subiculum and the ponticulus. It extends in a posterior direction, medial to the pyramidal eminence, stapedius muscle, and facial nerve and lateral to the posterior semicircular canal.

What is Retrotympanum?

Retrotympanic Spaces. The retrotympanum is a complex structure consisting in different spaces lying in the posterior aspect of the tympanic cavity. Different Authors studied this particularly anatomical region because microscopic view alone is inadequate to explore these posterior spaces.