Learning Objectives:

The protympanum is a middle ear space lying anterior to the mesotympanum. Historically, the region has often been overlooked due to its difficulty to visualize microscopically, despite optimum tissue and bone removal. Angled endoscopes with attached high definition cameras have meant that this region is now able to be fully appreciated.

This presentation will revisit the anatomical boundaries of this region, which will be demonstrated using endoscopic visualization. It will also detail and explain the newly defined classification systems for the region, including: (1) the protympanum conformation; (2) the protiniculum, a bony ridge from the promontory to the medial wall, separating the hypotympanum from protympanum; and (3) the subtensor recess, an area of pneumatisation inferomedial to the tensor tympani canal.

The presentation will utilise high definition endoscopic video and photographs taken during human cadaveric and live surgery. Normal anatomy will be demonstrated, as well as management of pathology in the area. Particular emphasis will be given to relevance of the region in both the development and surgical management of cholesteatoma.