The external ear and the tympanic membrane. A three-dimensional study.

The study of the anatomical variations of the external ear is important for the ear surgeon who assesses the middle ear in this way. Furthermore, the design of insert earmoulds for use with either hearing aids or portable radios requires a better knowledge of the shape of the external ear. We studied the external ear structures and the drumhead in 140 cadavers with no previous history of ear pathology. A silicone resin was used, employing a dental impression technique. These permanent impressions were analysed by means of an operating microscope. Different parameters were studied, to determine the average dimensions of the structures. The clinical significance of these results is discussed.