ABSTRACT
A three-dimensional appreciation of the complex temporal bone anatomy is crucial for the understanding of both the pathophysiology and surgery of the ear. This chapter deals with the external ear and the adult middle ear cleft including the mastoid air cell system and Eustachian tube. It outlines the embryology of the ear and subsequent development of the temporal bone, external ear and mastoid process. The arterial supply of the tympanic membrane arises from branches supplying both the external auditory meatus and the middle ear. The bony plate separating the fundus from the middle and internal ears has a transverse crest – the crista falciformis – on its inner medial surface, which separates a small upper region from a larger lower area. The internal ear initially develops independently of the middle and external ears, although the two become interconnected by the stapes superstructure, becoming attached to the stapes footplate, thereby giving continuity to the auditory pathway.
